Conceptualizing Co-occurring Autism Spectrum Disorder,Obsessive-Compulsive Disorder,and Gender Diversity in Adolescents: A Narrative Review

Abstract

Differential diagnosis of autism spectrum disorder (ASD) and obsessive-compulsive disorder (OCD) in adolescents is difficult due to similar behavioral topography. For instance, restrictive, repetitive behavior, cognitive rigidity, anxiety, and avoidance contribute to impairment in social relationships and daily living skills in both conditions. The diagnostic picture for youth with ASD and/or OCD may be further clouded by high rates of co-occurring gender-diverse clinical concerns, attention-deficit/hyperactivity disorder, tic disorder, depression, and anxiety disorders With increased prevalence and improved identification of ASD, OCD, and gender-identity-related distress, more adolescents are seeking treatment. It is vital that providers are knowledgeable about best practices for diagnosing and treating these overlapping symptoms. This review describes the state of the literature regarding presentation and prevalence of ASD, OCD, and gender-identity concerns separately and as co-occurring phenomena. Sex differences and gender-diversity among individuals with ASD and OCD are also reviewed. We briefly describe evidence-based behavioral treatments for ASD, OCD, gender-identity-related distress as separate and co-occurring considerations. Recommendations for tailoring within these therapies and family involvement are discussed.

While early detection of autism spectrum disorder (ASD) has improved, ¹ and the evidence bases for treating both ASD and obsessive-compulsive disorder (OCD) in adolescents has grown, addressing occurrence among the two remains challenging. Practitioners competent in diagnosing and treating either OCD or ASD often struggle to integrate their skills when symptoms overlap or co-occur. As the general need for youth mental health treatment increases, ² it is vital that providers can quickly and accurately distinguish symptoms, and then select, tailor, and deliver appropriate interventions for this patient population.

Differential diagnosis between ASD and OCD is difficult due to similar behavioral topographies across conditions. For instance, restricted, repetitive behavior, cognitive rigidity, anxiety, and avoidance can contribute to impairment in social relationships and skills of daily living in both conditions. Repetitive thoughts or verbalizations may be referred to as “obsessions” by families but seem also to describe restricted interests. Avoidance of social interactions may reflect differences in social communication skills, decreased social interest, and anxiety about social interactions simultaneously. The diagnostic picture for youth with ASD and/or OCD may be further clouded by high rates of co-occurring gender-diverse clinical concerns, attention-deficit/hyperactivity disorder (ADHD), tic disorder, depression, and anxiety disorders. Given these challenges, the first goal of this paper is to provide a brief introduction to symptoms and diagnostic considerations to help providers better understand ASD, OCD, and co-occurring ASD and OCD with emphasis on how gender-identity concerns interact with ASD and OCD in adolescents.

Accurate assessment and differentiation of these symptoms is crucial not only for diagnosis but also for treatment. Tailoring treatment of OCD symptoms to the unique needs of individuals with ASD may mean significantly altering treatment duration, conceptualization of treatment mechanisms, and the specific techniques employed. As family involvement is a key component of evidence-based treatments for individuals with OCD, ³ developmental disabilities, ⁴ and gender-diversity concerns, ⁵ components of therapy incorporating family members are highlighted. Lastly, we provide a concise summary of recommendations for clinicians.

Autism Spectrum Disorder

Presentation and Prevalence of ASD

ASD is a neurodevelopmental condition about which there is still a great deal to learn. ASD is caused chiefly by genetic factors, with environmental factors contributing to a lesser degree. ⁶ While neuroimaging research on ASD is still in its infancy, some interesting findings have been replicated. For instance, researchers have found structural and functional abnormalities in the brainstem, ⁷ increased intracranial volume, and increased gray matter volume in the frontal and temporal lobes. ⁸ The Centers for Disease Control and Prevention (CDC) estimate that about 2% of children in the United States meet diagnostic criteria for ASD. ¹ Individuals with ASD exhibit significant differences across the following two primary domains: (1) social communication and (2) restricted, repetitive behaviors (RRBs). ⁹ To meet diagnostic criteria for ASD, symptoms must be present in early childhood and must cause clinically significant functional impairment across social, occupational, or educational settings.

Social communication difficulties include limited socioemotional reciprocity (e.g., atypical social approach, reduced sharing of emotions), limited nonverbal communication (e.g., eye contact, facial expressions, gestures integrated with speech), limited understanding of social relationships and setting-specific behavioral expectations, and difficulty developing and maintaining relationships. Examples of RRBs include stereotyped movements or verbalizations (e.g., motor stereotypies, echolalia, rigid routines/preference for sameness), sensory sensitivities (e.g., clothing texture or fit, loud noises, lighting), and restricted interests (e.g., unusual preoccupation specific subject matter). Based on the severity of functional impairment related to RRB symptoms and social communication symptoms, ASD diagnoses are assigned levels for each respectively. Level 1 reflects minimal support needs, while levels 2 and 3 reflect substantial and very substantial support needs. ASD diagnosis specifiers noting the presence or absence of language and/or intellectual impairment help differentiate individual presentations across the diverse autism spectrum. ⁹

Sex Differences in the Presentation and Prevalence of ASD. Previous research has estimated that individuals assigned male at birth (AMAB) are 4 times as likely to be diagnosed with ASD than are individuals assigned female at birth (AFAB).^10–12 Newer research indicates that this is related not only to sex differences in symptom presentation but to those AFAB being under-identified ¹³ even when they demonstrate the same degree of ASD symptoms as those AMAB. ¹⁴ When a concurrent intellectual disability is present, the AMAB to AFAB ratio falls below 2 to 1. ¹⁵ Therefore, individuals AFAB with greater cognitive abilities and language skills are most likely to be missed for ASD diagnosis. In AFAB individuals, symptoms of ASD are also more likely to be misdiagnosed as another a mood or anxiety disorder, OCD, ADHD, or a personality disorder.^{16, 17} Further, AFAB individuals are older on average at the time of ASD diagnosis than individuals AMAB ¹⁸ and subsequently have less access to early interventions and their cascading developmental effects.

Despite growing awareness of the sex gap in ASD diagnostics, research on sex differences in the presentation of ASD is limited. Historically, clinical samples have not been particularly useful in identifying sex differences in presentation because they contain the same bias toward those AMAB. ¹⁹ Likewise, the under-identification of ASD in those AFAB is perpetuated by diagnostic measures normed on samples containing an AMAB majority. ²⁰ Most notably, the Autism Diagnostic Observation Schedule – Second Edition (ADOS-2), which is often considered the “gold standard” of ASD assessments, typically under-represents ASD in those AFAB, particularly those with high verbal abilities. ¹⁷

Some differences in ASD presentation by sex have been identified. AFAB participants have demonstrated fewer RRBs and appeared to be more socially motivated to interact with peers compared to AMAB participants.^{21, 22} Researchers have also highlighted a greater presence of “masking” behavior (i.e., behavior that conceals differences associated with ASD in social situations) in those AFAB with ASD.^{14, 23} To illustrate, an AFAB student may study her yearbook to learn everyone’s name. This knowledge can contribute to the impression of having many friends, when no associated friendships exist. Since one’s abilities to mask symptoms of ASD likely improve with practice over time, diagnosis early in development is important to capitalize on more conspicuous symptom presentations for those AFAB.

Evidence-Based Treatments (EBTs) for Adolescents with ASD

The most widely recognized EBTs for youth with ASD take a comprehensive, early intervention approach (e.g., The Lovaas Model). ²⁴ Comprehensive treatment models aim to address core differences in ASD and how they impact learning and socialization on a broad scale. They require a high number of treatment hours per week, ideally 40 face-to-face hours. ²⁵ These approaches are typically delivered by specialists in applied behavior analysis (ABA). There are many barriers to accessing these services, such as the limited number of providers, long waitlists, and substantial associated costs. ²⁶ While comprehensive interventions are often important for younger children and individuals with greater impairment (e.g., ASD levels 2 and 3, lower cognitive and language abilities), focused interventions may be more appropriate for older individuals and those with less impairment.

Focused interventions are defined as short-term and goal-oriented with narrower behavioral targets selected for clinical relevance and applicability to more specific treatment goals. ²⁷ These goals may relate to communication, social skills, problem behavior, play, school and academics, self-help, joint attention, motor, cognitive, vocational, and/or coping skills. Focused interventions have the advantage of being easier to access for many families, given the smaller amount of time, lower cost, and fewer number of staff required to deliver them. In line with standards for EBTs as detailed by the American Psychology Association’s Division 12,^{28, 29} 27 such focused EBTs pertinent to adolescents with autism emerged in a recent comprehensive review. ²⁷

Given the well-supported efficacy of comprehensive ABA in the treatment of ASD, many focused EBTs for ASD have distinctly behavioral underpinnings. These include prompting, reinforcement, response interruption/redirection, extinction, discrete trial training, functional behavior assessment, antecedent-based intervention, differential reinforcement of alternative, incompatible, or other behavior, functional communication training, picture exchange communication systems, exercise, self-management, task-analysis, and time-delay. Social learning and traditional instruction underlie several other EBTs for ASD adolescents, including social skills training, scripting, modeling and video modeling, peer-mediated instruction and intervention, structured socialization groups, technology-aided instruction and intervention, and visual supports. Three EBTs extend social and behavioral approaches for use specifically within naturalistic settings; they are naturalistic intervention, parent-implemented intervention, and pivotal response training. Finally, given cognitive differences among many individuals with ASD (e.g., rigidity, concrete thinking, language abilities), only 2 EBTs take a decidedly cognitive approach: cognitive behavioral intervention and social narratives.

When selecting an intervention, Odom and colleagues ³⁰ advocate using a technical eclectic model, in which treatment for ASD youth draws on components of EBTs, individualized treatment goals, theoretical grounding, and professional judgment. As more than half of adults diagnosed with autism are unemployed, ³¹ and 55% live dependently with caregivers, ³² working to increase daily living skills in adolescence is vital. Therefore, treatment goals should be highly functional and focused on building independent living skills. Finally, it is critical to involve caregivers in the delivery of such treatments, as they play an integral role in providing intensive intervention. ³³

Obsessive-Compulsive Disorder (OCD)

Presentation and Prevalence of OCD

OCD is defined by the presence of obsessions, compulsions, or both. Obsessions are defined as unwanted, intrusive, recurring thoughts or impulses that cause marked anxiety or distress. Attempts to suppress, ignore, or neutralize these thoughts or impulses by performing a ritual or action indicates the presence of compulsions. Compulsions are defined as repetitive behaviors or mental acts that occur in response to an obsession or rigid rule. Compulsions are aimed at reducing anxiety and distress or preventing some dreaded event. They are clearly excessive and/or not realistic in relation to what they are designed to prevent. ⁹ When distinguishing obsessions and compulsions from other symptoms like RRBs, obsessions are ego-dystonic, meaning that they are inconsistent with someone’s self-image, values, and beliefs. Conversely, RRBs that are ego-syntonic and do not create this internal conflict are not attributable to OCD. ³⁴

The lifetime prevalence of OCD has been estimated at 2.3%, ³⁵ with about 50% of cases having begun by age 14. ³⁶ There is still much work to be done to understand the neural correlates of OCD, particularly across development. However, a meta-analysis of pediatric OCD studies has indicated altered functional activation of the affective and cognitive corticostriatal-thalamic (CST) circuits. ³⁶ In adults, dysregulation in the cortico-striato-thalamo-cortical (CSTC) circuits, particularly regions found in the prefrontal cortex, striatum, and mediodorsal thalamus, has been found in individuals with OCD; dysregulation also appears to normalize following treatment with medications, cognitive-behavior therapy (CBT), or deep brain stimulation. ³⁷

The World Health Organization has rated OCD as one of the top ten most disabling psychological or physical disorders. ³⁸ By late adolescence, the lifetime prevalence of OCD in the United States is 1 to 3%. ³⁹ Children and adolescents with OCD report poorer quality of life, ⁴⁰ impaired academic performance, ⁴¹ stunted social development, ⁴² and high rates of peer victimization. ⁴³ Pediatric OCD also affects the child’s family. Caregivers report a greater burden of care and decreased quality of life compared to those of typical controls. ⁴⁴ If left untreated, symptoms of pediatric OCD rarely remit throughout development. ³⁹ Untreated OCD in adulthood has been linked to higher unemployment rates, impaired romantic relationships, and worse health outcomes. ⁴⁵ Given the prevalence and severity of the disorder, developing effective and efficient treatments for OCD is a public health concern.

Evidence-based Treatment of OCD in Adolescents

CBT with exposure and response prevention (ERP) is widely considered the first-line treatment for OCD in adolescents.^46–49 Specifically, a meta-analysis of 34 randomized controlled trials for pediatric OCD treatment found that CBT had a significantly larger treatment response rate (70%) when compared with medication, placebo, and waitlist control. ⁴⁹ While this section will focus primarily on this modality of treatment, it is important to mention that there has been empirical support for other modalities of treatment as well, including serotonergic medications, family-focused group CBT, and technology-based CBT.^{47, 50}

The theoretical underpinnings of ERP are pertinent to family psychoeducation and treatment fidelity. There are several theoretical models. The habituation model, initially proposed by Mathews, ⁵¹ is an extension of systematic desensitization. In this model, exposure is conducted gradually. Exposures with higher Subjective Units of Distress Scale (SUDS) ratings gradually follow exposures with lower SUDS ratings only after habituation (i.e., reduction of SUDS ratings by at least 50%) occurs. This model uses emotional processing theory ⁵² to explain that habituation to the feared situation creates information that is incompatible with the previous fear structure and therefore forces corrective learning. According to this model, habituation that occurs within session, as well as habituation that occurs between sessions, are both essential to overall symptom improvement.

However, research has demonstrated that habituation is not essential for overall symptom improvement.^{53, 54} The inhibitory learning model explains situation-specific anxiety as a result of the situation’s real or perceived connection to a negative outcome.^{53, 55} In this model, the goal of exposure is to create inhibitory associations (i.e., associations between the anxiety-producing situation and the nonoccurrence of the feared outcome), not habituation. With repetition, this process extinguishes the negative connections by violating expectancies. ⁵⁶ As such, the exposures used in treatment are ranked in a hierarchy based on ratings of their associated feared outcomes rather than ratings of associated distress. According to the inhibitory model, exposures teach patients that they continue to function while experiencing anxiety. ⁵⁷

Exposure with Response Prevention (ERP) for Obsessive Compulsive Disorder (OCD). Both habituation and inhibitory learning inform EBTs for OCD. Edna Foa and colleagues’ manual, Exposure and Response (Ritual) Prevention for OCD: A Therapist’s Guide, ⁵⁸ outlines one such gold-standard EBT. The following is a summary of a typical course of treatment for OCD in adolescents. ERP for OCD involves 12, 90-minute sessions, but due to practical limitations, outpatient settings often deliver treatment in 60-minute appointments for greater than 12 sessions. Individuals with severe symptoms benefit from participating in multiple sessions per week, intensive outpatient services, or partial hospitalization programs. A comprehensive list of higher levels of care that specialize in the treatment of OCD can be found through the International OCD Foundation at https://iocdf.org/.

Following a thorough clinical interview and assessment of symptoms, ERP for OCD begins with psychoeducation and cognitive training to help adolescents and their families understand OCD as a neurobehavioral disorder that is responsible for the difficulties the adolescent is experiencing. This involves giving the symptoms a “nickname.” This helps adolescents separate their sense of self from OCD-related thoughts and lays a foundation for resisting those thoughts. Adolescents learn that the treatment team and involved family members are joining their fight against OCD, rather than teaming up against the adolescent to make them upset.

Next, the process of ERP is explained, so adolescents better understand their symptom patterns based on behavior. Specifically, compulsions and/or family accommodation temporarily reduce distress, which strengthens the likelihood of compulsions occurring in the future. Despite temporary relief, compulsive behavior leads to increases in symptom severity over time. The concept of habituation is also introduced as an alternative method for reducing distress. Adolescents are taught that by staying in the situation, the body acclimates to stress, and distress decreases. Adolescents are warned that initial levels of distress may rise higher than they are accustomed to, but distress will peak and fall. It is explained that, through the course of treatment, the adolescent will learn to resist compulsions and immediate symptom reduction, so they can acclimate to feeling distress and its noncontingent dissipation over time.

Subjective Units of Distress (SUDS). In ERP for OCD, adolescents must identify their obsessions and compulsions and rate them using subjective units of distress: termed “SUDS.” In this case, distress refers to the amount of distress the adolescent experiences while having an identified obsessive thought or avoiding engagement in a specific compulsion. Much like pain, distress cannot be objectively measured and can only be subjectively reported. SUDS are an attempt to provide measurement to this experience. SUDS scales vary by therapist or agency, though generally range from 0 to 10 or 0 to 100, with ratings of 0 indicating no distress (e.g., so calm you are about to fall asleep) and ratings of 10 or 100 indicating severe distress (e.g., panic attack).

SUDS ratings are used to develop exposure hierarchies (i.e., fear ladders). A hierarchy serves as a list of exposures that the adolescent works through in therapy from least to most distressing. SUDS ratings also help to classify areas of the adolescent’s daily functional impairment related to OCD. Elements of functioning that are impacted by OCD but over which the adolescent still has some control are classified as being in the “transition zone.” Other areas may be completely under the control of OCD symptoms. As exposures are completed, the number of areas controlled by OCD symptoms decrease and those controlled by the adolescent increase.

Exposures. The next phase of treatment, generally sessions 3 to 12, focuses on implementing exposures with response prevention. Exposure is defined as the act of approaching a feared object, action, or thought. Response prevention is the act of resisting or blocking rituals or compulsions, behavior that has been used to reduce distress. ⁵⁸ For example, touching a door handle for a specified length of time is an exposure for adolescents with contamination obsessions. Subsequent refraining from handwashing for a specified amount of time constitutes response prevention. The roles of the therapist during exposures are to model approaching of the feared situation, to monitor the patient’s SUDS ratings, and to encourage the individual to remain in the feared situation until SUDS ratings decrease, ideally to 0 or 1. The therapist also ensures that the individual avoids compulsions during exposures, which include mental rituals. Mental rituals can be prevented by discussing or repeating the obsessions out loud, singing a song about the obsessions, completing challenging math problems, or another distraction activity.

Reinforcement as a motivator for successful completion of an exposure task or session should be discussed prior to beginning the exposure work. Positive reinforcement may be provided in the form of tangibles (e.g., candy, stickers, sensory-focused objects, tokens in a token economy), preferred activities (e.g., watching tablet, building with Legos), self-stimulation (e.g., running in the hall), or social interaction (e.g., specific praise, playing UNO with a parent, talking about a restricted interest in Star Wars with the clinician). Negative reinforcement through escape or avoidance may also be used. For instance, if a child completes a number of exposures on the session to-do list, they take a break, leave the session early, or have an assigned chore removed (e.g., picking up toys). Using rewards during treatment can increase engagement in the tasks, build a sense of accomplishment even if distress is high, and strengthen the therapeutic alliance.

Finally, daily homework is a major component of treatment. The adolescent must engage in daily agreed upon exposures at home, between sessions. These repeated exposures maximize learning and generalization to other environments. Reinforcement may be offered at home to motivate consistent homework completion.

Involvement of Family. Inclusion of support people improves the efficacy of OCD treatment, especially when (1) adolescent or young adult patients are not motivated to engage directly in therapy; (2) there is limited capability for patient introspection; and/or (3) there are high levels of distress related to treatment.^59–63 Family and caregivers can provide the consistent structure that many individuals with OCD need for generalizing treatments between the clinic and the home setting. Family members act as therapy coaches to the patient, so they must understand the rationale for specific therapeutic interventions. Throughout treatment, family members receive psychoeducation and observe therapist coaching during exposures. They are also taught to model the exposures, provide encouragement (e.g., “You’re being so brave right now.”), and avoid providing reassurance (e.g., “Don’t worry. This won’t make you sick.”). These family members then take on the coaching role with the adolescent at home.

Family involvement in adolescent OCD treatment is crucial for replacing unhelpful patterns of family interaction which previously maintained symptoms: termed “family accommodation.” With the best of intentions, families often accommodate OCD by participating in rituals, providing excessive reassurance about obsessive thoughts, and modeling anxious or avoidance responses. Clinicians can have family members rate their level of accommodation using the Family Accommodation Scale for OCD: Self-Rated Version (FAS-SR). ⁶⁴ Systematic reduction of family accommodation can be folded into hierarchy or to-do lists as in-vivo exposure challenges and homework assignments. For instance, parents may be instructed to answer reassurance seeking questions with “maybe, maybe not” or only buy one bottle of soap per week. Token economies can also be utilized in the home environment to encourage reduced reliance on accommodation, build adaptive skills, and ultimately increase independence.

Caregiver Coaching. In addition to family accommodation, parental psychopathology, parenting style, and caregiver engagement patterns may also contribute to the maintenance of OCD symptoms.^{63, 65, 66} Luckily, several useful caregiver coaching techniques for the treatment of OCD have been derived from parent-child interaction therapy (PCIT). ⁶⁷ PCIT is an evidence-based, dyadic treatment for child behavior change. Its adaptation for the treatment of childhood anxiety disorders, coaching approach behavior and leading by modeling (CALM) protocol,^{68, 69} is particularly appropriate. Although this model was originally developed for use with younger children, a few core principles are useful for adolescents, namely the describe, approach, direct command, and selective attention (DADS) skills. Prior to exposure sessions, psychoeducation for encouraging approach-oriented behavior and limiting avoidance is provided. During exposure sessions, caregivers can be coached in-room or through a bug in the ear. They are coached to describe in-the-moment events without commenting on fear or giving reassurance. For instance, in a sticky substance exposure, a caregiver might say, “That maple syrup makes it smell like breakfast in here.” Next, caregivers are coached to increase the likelihood of approach behavior by modeling (e.g., calmly applying syrup to the caregiver’s own hands) and reinforcing approximations of approach. Social reinforcement in the forms of praising, reflecting, imitating, describing, and showing enthusiasm/enjoyment (PRIDE skills) for desirable behavior is particularly effective. ⁶⁷ For younger or less developmentally advanced patients, caregivers are coached to help the adolescent initiate the exposure task by giving a direct command (e.g., “Please, dip your finger in the syrup.”). Adolescents may benefit to tailoring the use of a direct command to a question or invitation (e.g., “Are you ready to join us?”). Caregivers are then coached to use selective attention to continue reinforcing approach behavior and actively ignoring avoidance. Successful completion of an exposure is always following with a specific or “labeled” praise (e.g., “I am proud of you for facing your fears.”).

Parent-led exposure therapy (PLET) ⁶³ is another family-based treatment for childhood anxiety that was developed for use with younger children. PLET lasts for 10 sessions. Caregivers observe therapist-led exposures for the first half of treatment and lead the child through exposures with therapist coaching for the second half of treatment. An initial randomized controlled trial demonstrated greater anxiety symptom improvement for PLET participants than those receiving treatment as usual. ⁶³ Regardless of age and developmental level, families greatly impact the maintenance of OCD symptoms in a variety of ways.

The Autism Spectrum Disorder and Obsessive-Compulsive Disorder Overlap

Prevalence and Presentation of OCD in Individuals with ASD

Though there is little agreement in the literature on the prevalence of co-occurring OCD and ASD, some level of correlation has been demonstrated consistently. Prevalence estimates of OCD in autistic individuals range from 4% to 9% on the lower end^70–72 to 37% on the higher end.^73–75 Higher estimates may be skewed due to reliance on clinical samples. Meta-analytic data have indicated that 17.4% of young individuals with ASD met criteria for OCD. ⁷⁶ A longitudinal study also found that individuals with ASD were more than twice as likely to be diagnosed with OCD later in their life compared with the population base rate. ⁷⁰

Conversely, when evaluating the co-occurrence of ASD in individuals with OCD, individuals diagnosed with OCD were nearly four times as likely to be subsequently diagnosed with ASD. ⁷⁰ Another study found that 25% of youth with a diagnosis of OCD also met diagnostic criteria for ASD. ⁷¹

Overall, individuals with ASD are more likely to exhibit OC symptoms or meet criteria for OCD, while individuals diagnosed with OCD are also at a higher risk of exhibiting autistic traits or also being diagnosed with ASD. This implicates a potentially shared etiology.^{71, 74, 77–82} While a comprehensive understanding of the etiology of ASD and OCD is likely decades away, clinicians must rely on current literature to make important diagnostic and treatment decisions.

Differentiating OCD and ASD Symptoms

As with all mental health concerns, an accurate differential diagnostic assessment is imperative for case conceptualization, selection of appropriate evidence-based interventions, and treatment planning. Due to the overlapping presenting concerns for ASD and OCD, this difficult differential often results in over- or under-diagnosis and inappropriate treatment selection. ³⁴ ASD and OCD can both include perseveration around one topic, social functioning impairment, sensory sensitivities or not feeling “just right,” adherence to strict routines, and repetitive behavior. While Lewin and colleagues found that OC symptoms in youth with ASD and OCD did not exclusively manifest as autism-like repetitive behaviors (e.g., stereotypies, fixed interests, hoarding), ⁸³ other studies have found that individuals with co-occurring ASD and OCD are more likely to present with hoarding, repeating, ordering, touching/tapping/rubbing, and self-harm rituals. Comparatively, youth with OCD-only reported more frequent and complex obsessions compared to youth with ASD and OCD.^84–86 Unfortunately, current assessment measures are limited in their abilities to distinguish ASD and OCD symptomatology and often capture symptoms of ASD as OCD-related compulsive symptoms. ⁸⁷

When an individual with concurrent ASD and OCD seeks treatment, the clinician must determine whether each relevant presenting behavioral concern is better classified as a symptom of ASD or OCD by assessing its behavioral function.^{88, 89} If a behavior occurs in response to a specific stimulus that meets criteria for an obsession, functions as escape or avoidance of anxiety or distress, and causes clinical impairment (e.g., takes significant time, uses significant resources, or impairs daily functioning), it should be identified as a compulsion. For example, insisting on following detailed and impractical driving routes in response to unrealistic fears of having an accident (e.g., obsession) may coincide with decreases in distress (i.e., escape) and frequently make an adolescent and their family late. Conversely, if the behavior does not function as escape or avoidance from anxiety or distress, represents a simple preference, and does not cause impairment it is likely related to ASD. For instance, insisting on leaving personal decorative items organized by size in an adolescent’s bedroom is unlikely to be related to OCD if it functions as a preferred activity or tangible, is not associated with fear or distress, and does not take significant time or impinge upon the lives of others. The adolescent may describe a strong preference for this method of organization but is more likely to remain calm if circumstances disrupt it. Still, organization preferences may also meet criteria for OCD symptoms if they must be exact or “just right,” the adolescent feels “off” or fears that something bad will happen (i.e., magical thinking), or if this preference interferes with other activities or others’ needs. Further, if a ritual associated with ASD is reinforced by escape from anxiety, it may become a compulsion over time. Distinguishing ASD from OCD symptoms is important for treatment target selection, as the former may not necessarily require treatment, while the latter likely will.

Evidence-Based Treatment for ASD and OCD

Treatment for individuals with concurrent ASD and OCD is most successful when evidence-based protocols for OCD are implemented with tailoring or adaptations with respect to ASD.^90–94 After appropriate assessment of symptoms and determination of dual ASD and OCD diagnosis, psychoeducation about both diagnoses and their treatments should be provided to the adolescent and their family members. Psychoeducation should include the relevant best practices for ASD and OCD, summarized above. Additionally, several key differences in treatment for individuals with co-occurring ASD and OCD should be highlighted.

Longer Treatment Duration. Adolescents with ASD and their families should expect treatment for OCD to require a greater number of sessions. ⁷¹ The episode of care for OCD-only generally lasts for 12 sessions. ⁵⁸ While autistic individuals with OCD also show symptom improvement during the first 12 sessions, their greater levels of initial impairment and more gradual rates of symptom improvement may necessitate additional sessions to meet remission criteria.^{71, 92, 95} In their CBT-ERP for OCD intensive outpatient and partial hospitalization programs, Iniesta-Sepúlveda and colleagues ⁹⁰ reported an episode of care lengths of 24 to 80 daily sessions (M = 46.5 ± 20.9) for adolescents with ASD. These sessions lasted for 3 hours or up to 4 to 5 hours each, respectively. In this study, family dynamics, financial considerations, geographic locale, and symptom severity contributed to treatment duration.

Distress Tolerance Versus Habituation. Another key distinction in tailoring treatment for autistic adolescents relates to differences in habituation. Individuals with autism may experience exposures as more challenging and are less likely to experience large decrements in distress by the end of the session. With these individuals, the goals for exposure are to improve distress tolerance rather than achieve habituation. Distress tolerance refers to the ability to function without becoming overwhelmed despite physiological and psychological activation. ⁹⁶ Historically, CBT-ERP protocols have used measures of in-session habituation to guide treatment pace and gauge progress; however, recent recommendations have emphasized the goal of distress tolerance over habituation.^{58, 97} Because many individuals with ASD often have differences in sensory sensitivities and self-regulation abilities, in-session habituation may not be realistic. Nevertheless, continued exposure homework completion may contribute to between-session habituation, resulting in lower SUDS ratings and increased approach behavior during subsequent exposure sessions. ⁹⁸ When prioritizing distress tolerance and forgoing habituation as an indicator that an exposure is complete, parameters of exposure exercises must be operationally defined. Predetermined frequencies, durations, and quotas work well (e.g., touch 10 door handles for 1 minute each; make eye contact with 10 people in 2 minutes). Adolescents should receive reinforcement following completion of each exposure task or session even is distress remains high.

Domains of Functional Impairment. As with CBT-ERP for OCD with typically developing adolescents, realistic exposures applicable to the individual’s real-life challenges are highly effective. When working with autistic individuals, exposure tasks relevant to sensory sensitives, delays in social skills, and activities of daily living skills may be particularly useful. These tasks may include cooking, tolerating certain clothing textures, brushing teeth, or having conversations with peers. Realistic and functional tasks have the added benefit of improving adaptive functioning, fostering a sense of accomplishment, and increasing buy-in from family members through reduced family conflict and improved functioning. ⁹⁹

Limiting Abstraction. Youth with ASD often have greater difficulty engaging in and benefiting from traditional CBT and CBT-ERP due to differences in communication, abstract thinking, and emotion identification skills, as well as cognitive and behavioral rigidity. ⁹² As such, therapy skills may be more easily acquired in the moment or “in-vivo” rather than through abstract or cognitive exercises. To illustrate, autistic adolescents may better learn to identify emotions by practicing as the emotions are experienced in session rather than by recalling a past moment of distress. Similarly, reliance on imaginative or narrative exposures should be limited with many autistic adolescents. Cognitive techniques like challenging or reframing irrational thoughts are also less likely to be effective. Fortunately, exposure can be effective, even for typically developing children, without preparatory cognitive work (e.g., identifying emotions) altogether. ¹⁰⁰

Because the creation of fear hierarchies and the overall treatment plan in CBT-ERP relies heavily on the understanding and communication of inner experiences (e.g., obsessions, distress), modified procedures for adolescents with ASD and OCD are often used. Family members can be employed to help the adolescent communicate and recognize their internal experiences (e.g., patterns of physiological activation, details about obsessions) in relation to OCD. Family members may also be able to provide insights to inform the use of appropriate distress tolerance skills. ⁹⁰ Additional psychoeducation about bodily sensations, feelings, and OCD may help increase treatment efficiency. Relatedly, the use of SUDS ratings may be too abstract for individuals with ASD and OCD. Simplified rating scales may be more appropriate and have demonstrated effectiveness in the treatment of OCD with younger children. ¹⁰¹ Simpler scales may use “easy, medium, hard,” “thumbs up, down, or in the middle,” or “green light, yellow light, red light” ratings. The therapist may ask for a simplified rating, a report of the patient’s physiological activation, and a family member input to determine the next step in treatment.

Gender Identity

Gender Identity Presentation and Prevalence

The term gender identity refers to an individual’s personal experience of themselves as male, female, some degree of both, or neither. ¹⁰² Individuals whose gender does not fully align with the sex they were assigned at birth are referred to as transgender; whereas individuals whose identities align with their sex assigned at birth are referred to as cisgender.^{103, 104} Approximately 0.5% of adults and 1.4% of teens in the U.S. identify as transgender, representing an increase in prevalence of gender identity differences across the population. ¹⁰⁵

Evidence-Based Treatment for Gender Identity-Related Distress

Transgender individuals experience varying degrees of distress related to incongruence between their bodies, their identities, and the way they are treated by others. Only individuals who experience significant, unremitting distress in this domain, may be diagnosed with gender dysphoria. ¹⁰⁴ Therefore, the prevalence of gender dysphoria is much lower than the number of individuals who identify as transgender overall. ¹⁰⁷ The most empirically supported treatment for gender dysphoria is gender-affirming care, which collectively refers to a variety of practices (e.g., behavioral, medical, social) that recognize, support, and validate the patient’s gender identity regardless of sex assigned at birth. ¹⁰⁸ The specific components and course of gender-affirming care vary with the goals of individual patients.^{109, 110} Many transgender individuals wish to “socially transition” only, by ensuring their names, pronouns, and outward characteristics (e.g., clothes, hair) accurately reflect their gender identities. Another subset of transgender individuals seeks to transition medically by undergoing hormone therapies and/or surgeries to more closely align their bodies and identities. ¹¹¹ Many academic medical centers have opened multidisciplinary gender clinics to support the needs of transgender youth. The number of these clinics across the United States and Canada has nearly doubled from 36 to 68 over the past 8 years.^{112, 113}

Family support is essential in mitigating serious risks to health and well-being among transgender youth. Transgender individuals who have experienced family rejection are at greater risk for experiencing homelessness, engaging in sex work, reporting serious psychological distress, and attempting suicide than those with more supportive families. ¹¹⁴ On the other hand, transgender youth with supportive families have lower risk levels for depression, suicide attempts, homelessness, and human immunodeficiency virus (HIV) infection.^115–118

Because positive family relationships play such a critical role in reducing negative outcomes for transgender individuals, support for their families is also important. Clinical recommendations for work with these families include (1) providing psychoeducation about gender identity among transgender youth with emphasis on the importance of family support, (2) allowing space for families to process their reactions to their child’s identity, and (3) connecting the family with the broader transgender community, opportunities for advocacy and allyship, and other sources of community support. ⁴

Gender Diversity in ASD

In recent years, research has begun to examine the co-occurrence of ASD and transgender identities. This research suggests that transgender individuals are up to 6 times as likely to be autistic than are cisgender individuals. ¹¹⁹ A variety of mechanisms have been proposed to account for this overlap. Heightened in utero exposure to certain sex hormones has been linked to vulnerability for ASD, but the role that these hormones may play in gender identity development is less clear. ¹¹⁹ Elevated rates of gender diversity among autistic individuals may also be attributable to broader differences in socialization. Some autistic people have suggested that this association is attributable to their different experiences of gender as a construct and their willingness to behave in ways that others may find unusual. ¹²⁰

OCD and Gender Diversity

Research suggests that transgender individuals are up to 3.5 times as likely as cisgender persons to be diagnosed with OCD. ¹²¹ It is important for clinicians to accurately differentiate symptoms of gender identity-focused OCD from those of gender dysphoria and healthy gender identity concerns among transgender patients with OCD. To make these distinctions, clinicians must determine whether the individual’s thoughts and experiences about living as another gender are ego-syntonic or ego-dystonic. ¹²² To meet criteria for OCD symptoms, these thoughts and impulses must be ego-dystonic and be followed by compulsive behavior to neutralize them. ¹²² To aid in accurate diagnostics, providers should assess for a history of OCD symptoms in other domains like contamination, harm, symmetry/exactness, and taboo thoughts, prior to assessing for gender identity concerns. ¹²³

Many transgender persons with OCD do not have gender-related OC symptoms. Nevertheless, those who do may seek treatment to decrease their associated distress and impairment. While there is limited research on gender identity-related themes in OCD, sexual orientation themes in OCD have been studied. For these individuals, ego-dystonic obsessions about uncertainty with their sexual orientation are followed by a variety of compulsions intended to prove their identity to themselves and/or others. ¹²⁴ Researchers from this parallel symptom domain have recommended a variety of exposure exercises including engaging with LGBTQ+-friendly media, holding Pride flags, attending Pride events, and completing imaginal exposures about coming out or telling their romantic partner they are not attracted to them. ¹²⁴ Increasing distress tolerance for uncertainty about “never knowing the right answer” or “being a liar to everyone” has also been recommended. ¹²⁴ To treat gender-related obsessions and compulsions, clinicians may first monitor the patient’s degree of observable distress during conversations about gender and later use exposure exercises to target that distress. After the patient can discuss issues of gender with minimal distress, they may arrive at their own conclusion about their gender identity or benefit from additional psychoeducation and exploration with the therapist.

Collaboration with Prescribers

In many health systems, the individuals providing behavioral interventions and those prescribing medications are separate entities. The focus of this article was on behavioral interventions as these require the most modification when both ASD and OCD are present. The information above regarding differential diagnosis between ASD rigidity and OC symptoms is also relevant when determining if medication is appropriate. Importantly, serotonergic medications are the first-line medical intervention for OCD and can be appropriate for individuals with ASD when OCD is present as well. ⁴⁸ ADHD is also commonly co-occurring in individuals with ASD or OCD; therefore, patients may be using stimulant medication. ⁷⁹ Collaboration and data sharing between providers is essential. Moreover, it is advised to time interventions strategically so it is clear where any benefit for side-effect is originating.

Conclusion

The literature supporting diagnosis and evidence-based care for youth with co-occurring ASD, OCD, and/or gender-identity concerns is in its infancy. While researchers and providers have successfully adapted and tailored techniques from each domain to create more intersectional approaches, there is much work to be done. Research gaps exist for autistic individuals AFAB, treatments applicable to those with level 2 and 3 ASD, and gender-related OC themes. Based on current best practices for the treatment of OCD symptoms in adolescents with level one ASD, a few key considerations are summarized:

In-session and at-home caregiver involvement in exposures is likely even more important with this population.

A greater number of sessions may be required.

Providers should prioritize improving distress tolerance over habituation during exposures. Between-sessions habituation is more likely than in-session habituation.

Domains of functional impairment, including sensory sensitives, delays in social skills, and activities of daily living skills are particularly relevant for exposure exercises.

The use of abstract and cognitive treatment components should be minimized. The use of simpler rating scales, concrete language, in-vivo practice, and behavioral strategies may be more effective.

In addition, the vast majority of medical and behavioral health providers require further training to increase competence with this population. Although not covered in this paper, a nuanced approach is also required to further distinguish other commonly co-occurring symptoms related to attention, anxiety, mood, and other repetitive behavior disorders in ASD-OCD youth. For further reading of a detailed case study describing the differential diagnosis of an adolescent with ASD, OCD, gender-identity concerns, and several comorbid disorders ¹²⁵

Contribution to the Field Statement

This manuscript provides a brief introduction and overview of state-of-the-art best practices for diagnosing and treating concurrent ASD, OCD, and gender-identity concerns in adolescents. Medical and psychological professionals, even those familiar with one or more of these domains, are likely unfamiliar with the nuanced skills and conceptual background required to accurately assess and treat this population. As awareness, early detection, and research around these co-occurring phenomena expands, more providers will need access to this information. This article contributes to the current literature by summarizing recent developments in the scientific literature in this emerging topic. It is the goal of these authors that familiarization with concepts presented will increase providers’ confidence and increase access to care for individuals with ASD, OCD, and gender-identity concerns as well as spark further research.