Abstract
In this case report, we present the first 14 months of an 18-year-old adolescent male with comorbid diagnoses who exhibits extremely aggressive and self-injurious behavior and is treated with a combination of clozapine and behavioral interventions. The patient responded positively to clozapine and behavioral interventions, with decreased behavioral disturbances and improved social skills. The patient was maintained on clozapine with no significant side effects or hematologic adverse events. We would like to emphasize, through this case report, that clozapine, despite its dose-dependent effects and potential adverse effects such as increased susceptibility to infections and hematological irregularities, can be an effective treatment option for patients with severe behavioral disturbances associated with Autism.
Keywords
Introduction
The patient in the case study presented to the clinical team with comorbid diagnoses of autism spectrum disorder (ASD), schizoaffective disorder, and moderate intellectual disorder. His clinical presentation was initially intense and difficult to assess without objective testing, safety protocols, and consistent behavioral interventions. His extreme aggression and self-injurious behaviors impaired his ability to function in his home and the community. ASD is a developmental neurological disorder that exists on a spectrum. While traits often vary from individual to individual, common characteristics include deficits in communication and interaction skills, repetitive actions, and intense focus. Other factors may consist of delayed language or motor skills, delayed learning or cognitive skills, impulsivity or inattention, and hyperactive behaviors.1–4 Schizoaffective disorder is defined by The Diagnostic Statistical Manual, edition 5, as a mental health condition where a person experiences both positive symptoms of schizophrenia, such as delusions or hallucinations, and a major mood episode, such as mania or depression. The psychotic symptoms should be present for 2 weeks without the mood disturbance.1,3 The patient met diagnostic criteria for intellectual disability disorder due to his having an IQ below 70 and his having severe deficits in his adaptive behaviors that often interfered with his daily functioning.1–3
Clozapine is a second-generation antipsychotic medication used to treat mental health conditions with psychotic processes, for example, schizophrenia, that have been resistant to prior therapeutic interventions.5,6 Professionals have prescribed clozapine off-label to manage severe disruptive behaviors in some patients with ASD.7,8 Despite clozapine needing close monitoring and management, it has become an effective psychopharmacologic intervention in the treatment of severe aggressive and self-injurious behaviors seen in autistic children and adolescents.9–11
Case presentation
The patient presents as an 18-year-old adolescent Caucasian male who has a history of severe behavioral dysregulation, including physical aggression, property destruction, obsessive thoughts, and repetitive self-injury. He also struggles with poor social skills, limited expressive communication, and poor safety and body awareness. He carries a comorbid diagnosis of ASD, moderate intellectual disability, and schizoaffective disorder. The patient has a history of multiple inpatient admissions for exhibiting psychosis, mood shifts, self-injury, and extreme aggression toward family members.
The patient was transferred to a children’s residential facility for intensive applied behavior analysis (ABA) behavioral interventions and continued medication management following his discharge from an inpatient facility. Initially, the patient became very self-injurious—banging his head against walls/and windows and hard surfaces, biting himself, punching himself, and pulling his hair when limits were set with him, or he could not engage in his preferred activities. He also became physically aggressive when frustrated, exhibited perseverative speech, and was unable to communicate his needs effectively or his wants to the staff. Physical aggression was also seen during periods of mood dysregulation and impaired reality testing, or psychosis. Property destruction included the patient kicking furniture, tearing objects, and throwing objects across rooms when he became angry.
Developmental history
Because the patient was adopted, clinicians have minimal information about the patient’s birth mother, other than that the patient was born spontaneously on time via vaginal delivery. There is no information to suggest that the patient was exposed to substances in utero. Adoptive mothers stated that the patient’s birth mother had an intellectual disability and was not able to care for the patient. Early developmental milestones were all delayed, and his speech and fine and gross motor skill development occurred later than expected, consistent with his diagnosis of autism.
Medical history
The patient’s medical history is significant for bilateral myringotomy for placement of tubes due to recurrent ear infections, as well as an adenoidectomy and tonsillectomy due to recurrent infection, all at the age of 3 years.
Service history
The patient was officially adopted at the age of 3. He was formally diagnosed with ASD through his county intermediate unit (IU) at the age of 3. He received early intervention services through the IU, including speech, occupational, and physical therapy. It is reported that his speech, fine and gross motor skills were delayed. He was first seen for psychiatric medication management at 3 years of age and has been followed on an outpatient basis until his admission to a residential facility. The patient also received in-home services that provided him with a comprehensive, individualized therapeutic approach to his challenges consistent with his diagnosis of autism.
Psychopharmacologic and behavioral protocol
The patient’s medical records show that clinicians had tried him on multiple psychotropic medications before admitting him to the inpatient facility. The patient had been trialed on several medications, including risperidone, aripiprazole, quetiapine, and ziprasidone as an outpatient to treat his severe irritability and behavioral dysregulation related to his diagnoses of autism, schizoaffective disorder, and moderate intellectual disability. It is reported that even when the positive symptoms of his schizoaffective disorder resolved, there was no persistent decrease in the intensity or frequency of his self-injurious or disruptive behaviors, irritability, perseverative speech, compulsive behaviors, and social/emotional skill deficits.
At the time of his inpatient admission, the patient was prescribed lithium carbonate 1200 mg daily, aripiprazole 20 mg daily, and clonidine hydrochloride 0.1 mg daily, which were ineffective. The patient became increasingly paranoid during his inpatient admission. He exhibited mood dysregulation and extreme agitation. He began believing that other patients were talking about him and planning to harm him. He had explosive outbursts and would throw furniture across the unit, often screaming while attempting to barricade himself in his room. He had difficulty falling asleep and was hyperverbal with episodes of perseveration. Due to the failed trials of other antipsychotic medications, the patient’s above clinical presentation warranted a clozapine trial.
The patient was medically cleared by the inpatient physician and tolerated the initial clozapine dose well while in the inpatient facility, with no significant decline in his absolute neutrophil count (ANC) count and no significant side effects, such as constipation. The patient was discharged to the residential facility, planning to continue titrating his clozapine dose.
Upon admission to the residential treatment facility (RTF), the patient appeared thin and slightly disheveled and continued to be easily reactive to a changing environment, exhibiting self-injurious and physically aggressive behaviors toward peers and staff. The patient was observed pacing in both the hallways and his bedroom. He was able to state his name and say hello when introduced to new people; however, he struggled to answer questions and often repeated incoherent off-topic phrases. The patient was observed mumbling to himself and frequently spoke of violent incidents, shootings, and asked repetitive questions. The patient was paranoid that he would be kidnapped, taken away, or put in a hold. Thought processes appeared to be disorganized, and there was evidence of both visual and auditory hallucinations. At times, the patient displayed hyperactive behaviors and difficulty focusing or maintaining attention on topics or people.
His clozapine dosage was increased slowly to 100 mg BID from clozapine 75 mg PO BID during his initial 4 weeks in the RTF. The patient continued to be on lithium ER 600 mg twice a day for additional mood stabilization. After 2 months on clozapine 100 mg BID, the patient’s clozapine dosage was increased to 125 mg in the AM and 100 mg in the PM due to his intermittent behavioral disturbances. The slight increase in clozapine dosage helped reduce the patient’s agitation and made it easier for him to transition throughout his daily schedule. He continued to punch himself and verbally threaten staff and peers whenever limits were set or he could not engage in a preferred activity. His clozapine dosage was again increased to 125 mg BID, which appeared to be an effective dose for the patient, as severe self-injury decreased when he was frustrated. He was better able to discuss his frustrations verbally with others. It was noted that his total ANC declined from 4.41 k/ul to 2.36 k/ul in June 2023 following an increase in his dosage. The patient did not have clinical signs of neutropenia, and his ANC rebounded at the next blood draw, increasing to 4.4 k/ul by August of 2023. It is also worth noting that the patient remained on a low dose of lithium carbonate at this time, which may have contributed to the normalization of his ANC count.
Due to the patient continuing to become less self-injurious when there was a lack of structure, his clozapine was maintained at 125 mg twice a day, with a significant positive outcome. His lithium carbonate dosage was decreased to 300 mg PO BID to prevent potential side effects due to the concomitant use of lithium carbonate and clozapine.
Many behavioral interventions and ABA teaching practices were used concurrently with pharmacological treatment and consistently applied across settings. Once admitted to the RTF, the patient was given a daily structured schedule to support predictability, with built-in noncontingent reinforcement for social attention and preferred activities to reduce motivation for maladaptive behaviors. After initial admission assessments and observations were completed, weekly therapy sessions were conducted to teach appropriate replacement behaviors and social-emotional skills. ABA-based teaching strategies, including modeling, natural environment teaching, pivotal response training, social stories, and role play, were used to promote the learning and generalization of the selected replacement behaviors. Staff interacting with the patient utilized differential reinforcement of other/alternative behaviors, extinction procedures, and response blocking to promote “other”/replacement behaviors and reduce dangerous maladaptive behaviors. During February 2024, the integrity of these behavior plans decreased in the school setting, leading to an increase in the frequency and intensity of the patient’s maladaptive behaviors and a decrease in the use of his learned coping skills. The patient was also showing increased anxiety symptoms as a result of the lack of integrity of behavior plans across settings. Once the behavioral interventions were re-established with integrity across settings, the patient continued to show progress in replacement behaviors/social-emotional skills and a decrease in maladaptive behaviors.
Discussion
Following failed trials of both risperidone and aripiprazole, two FDA-approved medications to treat irritability and aggression in children and adolescents with autism, the patient’s clinical presentation while inpatient warranted a clozapine trial.12,13 According to the literature, initial monitoring and baseline work-up are crucial for maintaining safety protocols while on clozapine.5,9,14 Baseline measurements that were conducted included: basic metabolic panel, which consists of a complete blood work-up to include a white blood cell count (WBC), and an ANC baseline. Baseline ANC should be greater than or equal to 1500/µL for the general population and greater than or less than 1000/µL for patients who fall into the Benign Ethnic Neutropenia populations.8,9,14 Additional initial and ongoing lab work would include a complete metabolic panel to include Fasting blood sugar (FBS), HbA1c, and lipid profile. An electrocardiogram (ECG), should be conducted primarily for patients who have a history of cardiovascular disease.5,9,15 Although the patient did not have an initial ECG performed before starting clozapine, subsequent ECGs were within normal limits with normal sinus rhythm and a QTc less than 400 ms.
The patient was closely monitored at the RTF, with his vitals remaining within normal limits during the initial 14 months of his clozapine trial. He also had blood monitoring weekly for the first 6 months, then every 2 weeks for 1 year, per the recommended blood monitoring safety protocol for clozapine management.7–9,16,17 Some evidence suggests that lithium may be used as an adjunct to manage clozapine-induced neutropenia (low WBC), which is a profound potential side effect of clozapine monotherapy. The evidence highlights the need for a careful risk–benefit analysis by a qualified healthcare professional.5,17 At the time this case study was written, the patient was having monthly blood draws to monitor his ANC count and lithium levels, which have remained within the normal range (⩾1500/µL). He was also monitored for possible side effects, for example, leukopenia and neutropenia, and also adverse effects, such as severe constipation and seizure activity.9,14,16 Despite its many benefits, clozapine is not often prescribed widely because of its potential serious and sometimes fatal treatment risks associated with it’s use.9,18
Hematologic adverse events, such as leukopenia and agranulocytosis, are also a concern. The risk of infection increases with these blood dyscrasias. Leukopenia is defined as a low WBC, and a more severe form is called neutropenia. Hematologic adverse reactions are usually seen early in treatment with clozapine, within the first 6–18 months. Another significant potential side effect of clozapine is constipation, which can lead to gastrointestinal necrosis and, in some cases, gastric hypomotility.5,19 Seizure activity can occur in patients who are started or continued on clozapine. In some instances, a neurology evaluation is warranted. 20 The patient did not have any seizure activity when initially started on clozapine, and to date has been seizure-free. Short-term side effects that can initially be seen when starting a patient on clozapine include sedation, hypersalivation or drooling, headache, constipation, tachycardia, dizziness, and weight gain.5,7,9 The patient initially complained of some dizziness, but his vitals remained normal with no evidence of orthostatic hypotension, and the dizziness resolved within 2 weeks. To support the risk–benefit balance, patients must be educated to seek immediate medical attention if they experience symptoms such as sudden dizziness, fainting, shortness of breath, heart palpitations, or signs of neurotoxicity. This can be difficult in the autism population, due to them often having sensory impairments and communication delays.7,18,20,21 The treatment team felt it was important to discuss possible side effects with the patient, his family members, and unit staff to foster therapeutic rapport and support his ability to report them.
The patient made significant developmental gains while on clozapine. He tolerated transitions to school without incident and was able to be paired with peers for supportive social engagement activities. Two assessments were used to evaluate the patient’s improvement in social skills and his decrease in maladaptive behavior, specifically irritability. The Social Responsiveness Scale (SRS-2) is a questionnaire used to assess social skills and identify social impairments associated with autism. 22 The SRS was completed at the beginning of the month in February 2023 (admission), August 2023, and February 2024, and assesses 6 months before the assessment. The Aberrant Behavior Checklist (ABC-1) is an instrument used to measure behavior problems in children aged five and older through adulthood who are diagnosed with autism and intellectual disabilities. 23 The irritability subscale of the ABC is the focus of our discussion and measures irritability and related behaviors, such as tantrums, self-injury, and aggression. 23 The ABC-1 irritability subscale was completed every other month and assesses irritability for 1 month. Both scales were used to evaluate changes in clinical and behavioral presentation during the first 14 months of the patient’s clozapine trial after admission to the RTF. The patient’s total raw scores and equivalent T-scores for the SRS-2 decreased at each subsequent assessment, marking slight improvements in clinically significant reciprocal social behavior. The patient also showed decreases in total scores on the irritability subscale of the ABC-1, except in April 2023 and February 2024. The slight increases in the irritability subscale scores for these months are most likely indicative of the extinction burst across behaviors that occurred when the patient’s behavior plan was initially applied in March 2023, and of the lack of integrity of behavior plans across settings that occurred in January and February of 2024. The results of these scales are seen in Table 1. The patient’s hematologic results are also in Table 1 to display the patient’s immune response to the medication changes during the same time period. The Abnormal Involuntary Movement Scale was also administered to the patient as he continued the above medication regimen, as is recommended when the patient is prescribed neuroleptic medication.24,25 He scored zeros during the initial 14 months on clozapine and up to the time of this report.
Clinical assessment scores (SRS-2 raw and T-scores and ABC irritability subscale) and hematologic safety monitoring during the first 14 months of clozapine use.
ABA: applied behavior analysis; ABC: aberrant behavior checklist; ABC-I: aberrant behavior checklist irritability subscale; ANC: absolute neutrophil count; AIMS: abnormal involuntary movement scale; ASD: autism spectrum disorder; AST: aspartate aminotransferase; ALT: alanine aminotransferase; BID: Two times per day; PO: by mouth; RRB: restricted interest and repetitive behavior; RTF: residential treatment facility; SRS: social responsiveness scale; WBC: white blood cell count.
Conclusion
This case highlights the successful use of clozapine in an adolescent with ASD, moderate intellectual disability, and schizoaffective disorder, who exhibited extreme aggression, self-injurious behavior, and limited social functioning. After failing multiple antipsychotic regimens, the patient responded positively to clozapine with a significant reduction in aggressive and self-injurious behaviors, improved emotional regulation, and enhanced social engagement. The data collected from February 2023 through April 2024 showed a substantial decrease in the frequency of property destruction, aggression, self-injury, and repetitive violent language. His score on the ABC, irritability subscale, changed significantly after the patient began clozapine. During this time frame, the patient had increased his use of coping skills in all settings. Importantly, the patient has tolerated the medication well, with no serious side effects during treatment.
Although clozapine is generally reserved for treatment-resistant psychotic disorders due to its side effect profile, this case demonstrates that it can help manage severe behavioral dysregulation in complex ASD presentations. Because the patient was able to remain on a relatively low dosage of clozapine, he did not develop significant side effects or adverse reactions that would have warranted discontinuing the medication.
The clinical team’s behavioral intervention and psychopharmacological approach for this patient was patient-specific, closely monitored, and resulted in positive clinical outcomes, as evidenced in Table 1. The multidisciplinary team observed the patient and delivered interventions across community, school, and residential settings, resulting in a comprehensive and holistic treatment plan. The case involves a highly complex presentation (ASD, schizoaffective disorder, and intellectual disorder), which is rare and clinically significant. Real-world challenges were demonstrated in the context of treatment-resistant behavioral dysregulation, periodic lack of treatment integrity across settings, limited data accumulation, and overlapping symptomology of comorbid diagnoses.
At the time of this report, the patient continues to make significant strides in his psychiatric and behavioral stability. The patient participates in weekly ABA sessions, during which he maintains focus and earns reinforcement. He successfully transitions to and from school with significantly fewer disruptive behaviors and spends more time with peers, thereby improving his communication and social skills. The patient is also able to participate in community outings to small petting zoos and farms, as well as accompany staff on local shopping trips. The patient engages in multiple extended home visits per month and has completed overnight home visits with no staff support. The patient verbalizes his understanding and is excited about the improvement in his behavior due to the above interventions, which allows him to do his very favorite thing: spend more time at home with his family. The patient continues to demonstrate the successful use of coping strategies, both prompted and unprompted, across multiple staff members, and displays extended periods with organized thought and maintained attention.
Clinicians should consider clozapine as a therapeutic option in similar situations where conventional treatments have proven ineffective, while keeping in mind the need for close monitoring and individualized care. Clozapine has a potential role in managing severe behavioral dysregulation in complex ASD cases when other treatments are ineffective. Further research is needed to evaluate its broader applicability in the autism population who exhibit severe behavioral disturbances to ensure its safe and effective use.
Supplemental Material
sj-docx-1-sco-10.1177_2050313X261419571 – Supplemental material for Clozapine use in an adolescent with comorbid diagnoses of autism spectrum disorder, schizoaffective disorder, moderate intellectual disability, and severe behavioral dysregulation: A case report
Supplemental material, sj-docx-1-sco-10.1177_2050313X261419571 for Clozapine use in an adolescent with comorbid diagnoses of autism spectrum disorder, schizoaffective disorder, moderate intellectual disability, and severe behavioral dysregulation: A case report by Pamela Ralph, Shannon See and Allison Faust in SAGE Open Medical Case Reports
Footnotes
Acknowledgements
The authors express their gratitude to the patient, residential facility, and his parents for their informed consent and assent to the publication of this report.
Ethical considerations
As an anonymized retrospective review, the authors determined that the study did not require approval from an ethics committee or institutional review board; consent from the legal guardians, assent from the patient, and consent from the residential treatment facility were obtained.
Consent to participate
The patient’s legal guardians provided written informed consent, and the patient provided written informed assent for their anonymous information to be published in the article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Data availability statement
Data and materials are not available to be accessed due to patient confidentiality and privacy.
Declaration of use of AI software
During the preparation of this manuscript, Grammarly was used to refine language and edit for flow. All content was reviewed, edited, and verified by the authors, who take full responsibility for the final publication.
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References
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