Attention Deficit Hyperactivity Disorder: What The Eyes Don’t See!!

Abstract

Attention deficit hyperactivity disorder (ADHD) is the most common neuro-behavioral disorder characterized by a classical triad of hyperactivity-impulsivity and inattention prevalent in 5% of school-going children, mostly in boys. It is a chronic disorder with persistent of symptoms in a significant proportion of children diagnosed in childhood and impairing in most domains of socio-occupational functioning. Challenges in diagnosis occur due to symptoms domains of ADHD representing extremes of developmental processes of hyperactivity and inattention. Temperament is another construct that is important while evaluating a child with ADHD to avoid misdiagnosis and/or overdiagnosis. There is literature to support that the presentation of ADHD is not just limited to the triad of symptoms described in DSM 5, but it manifests a plethora of symptoms which, in the majority of cases, often go unnoticed. These symptoms may be a result of executive function deficits, emotion dysregulation, the presence of comorbid disorders, and/or psychosocial issues. Impairments of ADHD continue into adolescence and adulthood. However, ADHD in adults is still an under-researched area. The article aims to provide a bird’s eye view of the various hidden difficulties inherent in ADHD but which often is missed in clinical practice.

Introduction

Attention deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental condition characterized by a triad of hyperactivity-impulsivity (HI) and inattention (IA). It is also one of the most common chronic health conditions affecting school going children. ¹ The prevalence rates for ADHD vary substantially for many reasons, eg, changes in diagnostic criteria over time, assessment in referred clinical samples, and varied settings for assessment. Assessments that relied on DSM IV for estimation of prevalence rates found that ~5% of school-going children have ADHD across cultures. ² However, in United States, the prevalence of ADHD increased from 6.9% in 19973 to 11% in 2011. ⁴ Since, it is a chronic condition, children with ADHD often have symptoms of ADHD during adolescence and adulthood. Although it is reported that around 50% of children who met diagnostic criteria for ADHD during childhood do not meet diagnostic criteria for a diagnosis of ADHD, symptoms of HI and IA manifest even then. Apart from behavioural problems of ADHD, it affects a multitude of areas in an individual’s life, eg, academic difficulties, academic underachievement, not getting along with peers, frequent relationship problems with parents and family members, and low self-esteem. Overall, it can be convincingly said that children and adults with ADHD often manifest much more than the classic triad of hyperactivity- impulsivity and IA but which often go unnoticed. The focus of the clinical evaluation is limited in the majority of the cases to finding the typically defined symptoms of the triad, and in the process, clinicians fail to identify and deal with the whole vista of complex problems experienced by individuals with ADHD and their families. In this article, an attempt is made to understand various issues about holistic identification of impairments due to ADHD.

Heterogeneity in ADHD Presentation

No two children with ADHD are similar in their symptomatology. As per DSM 5, ADHD is diagnosed if 6 or more criteria out of 9 in the domains of HI and IA are met. Thus, two individuals with ADHD may not necessarily have the same set of symptoms even if they have most of the symptoms from either of one domain, and they may be similar in as few as three symptoms. ⁵ Thus, to address the low level of developmental stability of ADHD types, DSM 5 has subtypes changed into presentations of ADHD-hyperactive-impulsive presentation, inattentive presentation, or combined presentation. Another problematic area is the number criteria for ADHD presentations. A child with five or fewer symptoms will not be diagnosed with ADHD despite impairments caused by the symptoms. ⁶ The heterogeneity regarding ADHD exists not only in symptom presentation but also in neuropsychological profiles, which will be discussed later.

Development and ADHD Symptoms

ADHD is a heterogeneous disorder with varying manifestations at different ages and developmental stages of an individual. The characteristic triad of ADHD includes developmentally inappropriate HI and IA. On the other hand, hyperactivity and attention span are normal developmental processes, and each infant/toddler has individual variations. These developmental processes are manifest as temperamental traits in an infant/ toddler, and these processes also change and mature as the child grows. Hyperactivity decreases, and attention span improves with age. However, diagnosing a young child with hyperactivity presents a clinical challenge. Misdiagnosis may occur if clinicians are not well-versed and trained to assess for temperamental traits. As it is, there is enough debate regarding the role of temperament and ADHD symptoms, wherein one school of thought considers ADHD symptoms to be at the extreme of a continuum of temperamental traits and the other school of thought considers temperamental traits as risk factors for the development of ADHD. There is literature supporting both schools of thought and the debate continues.

ADHD is known to be commoner in boys, not because ADHD occurs less in girls but because literature reports that ADHD is under-identified and under-diagnosed in girls. Some of the reasons attributable to lesser identification of ADHD in girls are lower levels of externalizing symptoms in girls, higher levels of inattentiveness, internalizing symptoms and social impairment. ⁷ , ⁸ Girls are less likely to disrupt home or in class and thus less likely to be evaluated for ADHD. Also, there is referral bias wherein boys are referred/brought for evaluation more frequently than girls. additionally, gender-specific norms are not available for diagnosing ADHD and since the normative sample may have more representation of boys, the girls may not meet cut-off criteria for ADHD and thus be missed. ⁹ While a subset of girls with severe impairment was identified when gender-specific norms were used who otherwise would have been missed, the identification of boys with ADHD did not differ depending on the norms used ¹⁰ This suggests that gender-specific norms are required for accurate identification of ADHD otherwise, girls are likely to be missed out.

The inattentive subtype was introduced in the diagnostic criteria for ADHD in DSM IV. Thereafter, an increase in the prevalence rates of ADHD was also reported, which is understood to be associated with an increased diagnosis of ADHD (inattentive subtype), especially in girls. ² Biederman et al had reported that girls are 2.2 times more likely than boys to meet the criteria for inattentive ADHD. ¹¹

Executive Dysfunction in ADHD

The exact cause of ADHD is yet not known; however, ADHD is the result of the interaction of genetic and environmental factors. Most research agrees that ADHD is not a homogenous clinical disorder; rather, it represents multiple etiological pathways resulting in some of the core symptoms. Amongst the various theories, executive dysfunction theory explains quite a few symptoms of ADHD. Executive dysfunction theory posits that the basic defect is the “lack of the ability to inhibit,” a function of our pre-frontal lobes. In simpler terms, the “ability to put brakes” is lacking. Successful execution of a plan largely involves putting brakes on distracting activities. ¹² This lack of inhibition may manifest in two ways—first, the individual is unable to inhibit distractions and impulsive reactions adequately or is unable to restrain oneself to physically act upon these impulses. Secondly, individuals with ADHD cannot limit their behavior long enough for the other executive functions (EFs) to develop adequately. Apart from lack of inhibitory control, other executive dysfunction and their manifestations are reported in working memory, set-shifting, sense of time/time perception, poor foresight (planning and predicting for future) and self-control, poor hindsight, poor organization amongst many others. ¹² All these deficits lead to many impairing symptoms, eg individuals with ADHD have trouble returning to a given task, because of poor hindsight, they have difficulty in learning from past mistakes, and because of poor foresight they are not able to plan for the next moment/day activities. Overall, the EF deficits keep individuals with ADHD prisoned in the present, they cannot keep the future in mind and plan accordingly and the future catches them off guard. It is not that these individuals do not care about the future, but it is due to EF. Additionally, poor reading of social cues renders them vulnerable for poor social interaction and social rejection. Other symptoms of EF dysfunction are: trouble returning to task, thrill-seeking behavior and hyperresponsiveness. Barkley used the “hyperresponsiveness” to define excessive emotions in people with ADHD and the resultant response which according to Barkley was appropriate to the emotional charge an individual with ADHD was experiencing. ¹² All these symptoms go either unnoticed or not understood as being caused by ADHD. Understanding symptoms that result from EF deficits and are not directly measurable under the classical triad of ADHD is of utmost importance. In cases of subclinical symptoms of ADHD, the EF deficits are exacerbated in situations of increased demands and sleep deprivation, pointing towards a developmental perspective of EF in determining the way symptoms of ADHD present. ¹³

Self-Regulation and Emotional Dysregulation in ADHD

ADHD was, for the very first time, understood as being caused by some kind of brain dysfunction and hence was known as “minimal brain dysfunction.” Emotional symptoms as a part of the presentation were considered even in diagnosing minimal brain dysfunction. Over the years and evolving nosological systems, emotional symptoms became an associated symptom in DSM IV and it lost its significance until recently when again self-regulation, emotional regulation, and emotional dysregulation are being researched in individuals with ADHD given the frequent complaints of inability to delay gratification, affective instability, emotional lability seen in ADHD. ¹⁴ There have been an increasing number of studies highlighting that more the severity of emotional dysregulation, more is the risk of disruptive behavior disorders and substance use disorders in individuals with ADHD. Barkley’s “hyperresponsiveness” seems to echo with emotional regulation difficulties where individuals with ADHD have problem in emotion generation, emotion expression, or both that predispose to behavior problems. ¹⁵ Both top-down regulatory processes (associated with nonemotional stimuli) and bottom-up regulatory processes (associated with emotional stimuli) are impaired in individuals with ADHD. The top-down regulatory processes are also associated with development of Theory of Mind (ToM) and EFs most closely associated with ToM are inhibitory control, working memory, cognitive flexibility, and attention. ¹⁶ The hyperactivity and impulsivity of ADHD is explained in part by the dysfunction in top-down regulatory processes; however, if dysfunction in both top-down and bottom-up regulatory processes is taken together, it explains a major part of the phenotypic variance in individuals with ADHD. ¹⁷ DSM 5 and ICD 10/ ICD 11 do not include emotional problems as a core feature of ADHD. However, research indicates that emotional dysregulation is a significant feature to understand ADHD for reasons, namely, emotion dysregulation persists throughout the lifespan and is a significant contributor to impairment, deficits contributing to orienting, recognizing and/or allocating attention to emotional stimuli are affected, and there is some improvement in emotion dysregulation while on the pharmacological treatment of ADHD. ¹⁸

Comorbid Disorders

Females not diagnosed as having ADHD during their childhood were more likely to report stress, anxiety symptoms, depressive symptoms, eating disorders, substance use disorders, sleep problems, low self-esteem among many other impairments. ¹⁹ Mental health problems are reported at an increased frequency in women not diagnosed on time, but negative impact on everyday life-low self-image, interpersonal problems, disorganization, poor planning and execution, and emotional outbursts are significant concerns. All these issues additively culminate in poor work adjustment, poor work competency, and underachieved career goals, among many others. In addition to a more significant burden of comorbid psychiatric condition in females with undiagnosed ADHD, ADHD has many comorbid conditions like learning disability, depressive disorder, anxiety disorder, oppositional defiant disorder, obsessive-compulsive disorder, tics, and Tourette’s syndrome, etc. ¹² These disorders may coexist with ADHD or can also be the differential diagnosis for symptoms presenting as hyperactivity and/or impulsivity. While 20% to 30% of individuals with ADHD have learning disabilities (LD), LD can also mimic ADHD especially inattentive ADHD and at the same time exacerbate symptoms of ADHD. Hence, a careful history, examination, and psychoeducational assessment is required.

Around half of the children diagnosed with ADHD have oppositional defiant symptoms/disorder/conduct symptoms/disorder. Even if a full diagnostic criterion of oppositional defiant disorder or conduct disorder is not fulfilled, irritability, anger, lying, and stealing are commonly seen in children with ADHD. Much of this can be explained by the EF deficits in ADHD. Despite a prevalence of around 30% of anxiety disorders in ADHD, the majority of the children never disclose the symptoms (such as, being stressed out, sleep problems, panic-like symptoms, and worries not due to any overt stressor) to anyone. Like anxiety disorders, obsessive-compulsive disorder/symptoms may be present in one-third of individuals with ADHD. Although a difficult situation, it is reported that the future goal-directed behaviors of OCD might help mitigate the disorganizational problems of ADHD. As with anxiety disorders, 10% to 30% of individuals with ADHD may experience depressive symptoms briefly. ¹² 20% of individuals with ADHD have bipolar disorder. A family history of bipolar disorders and/or substance use disorder, history of prolonged temper tantrums, mood swings, risk taking behavior, separation anxiety, gory dreams, and worsening irritability with stimulant medications should be a warning sign to look and monitor for bipolar disorder in individuals with ADHD. ¹² ADHD is comorbid with tics and Tourette’s disorder. Whereas 7% of children with ADHD have tics, around 60% of those having Tourette’s syndrome have ADHD. ¹² Social cues misinterpretation can be present in ADHD and Asperger’s syndrome. All these disorders can be comorbid and have differential diagnoses while evaluating for ADHD. Some children with ADHD may also present with sensory issues like oversensitive or under-sensitivity to stimuli. If these symptoms are not assessed, the child with ADHD will continue to suffer a cumulative load of impairing symptoms.

Psychosocial Issues in ADHD

Psychosocial issues in any illness play a significant role in exacerbating or ameliorating the symptoms. On one hand a child is subjected to a genetic vulnerability in cases where family members have neuropsychiatric conditions, including ADHD, OCD, depressive illness, anxiety disorder, etc, in parents. ADHD has a strong genetic component and is a heritable condition, and parents of children with ADHD may likely have ADHD, which may not be diagnosed and may be living with the impairments caused by ADHD symptoms, adding to the already existing difficulties of a child with ADHD. ¹² The second scenario arises due to the vicious cycle created due to a misfit between ADHD symptoms and negative parenting behaviors. The family atmosphere becomes chaotic, siblings are affected by the special (positive/negative) attention being given to child with ADHD. The child’s academic demands take a toll on the mental health of the parent involved more in caregiving; which can have ramifications in the marital life of parents, disagreeing/arguing with each other on the best handling strategy for the child with ADHD. All this is a source of additional stress for the already stressed child with ADHD.

Hidden Problems in ADHD

It is said that if the clinicians just evaluate for the triad of symptoms (hyperactivity-impulsivity and IA) of ADHD, they are just assessing the tip of the iceberg known as the “ADHD iceberg. The symptoms/issues mentioned earlier arising from EF deficits, emotional dysregulation, comorbid disorders, psychosocial issues, represent the plethora of symptoms that can coexist with ADHD, but which is never assessed. These symptoms include impaired efficiency on thinking tasks, problem identifying, regulating and modifying emotions and emotional responses, losing track of time, forgetful in daily activities, avoiding homework and if does homework, then it is never finished, sleep disturbances, morning battle with family members, less mature, does not learn from past experiences/rewards/punishments, cannot delay gratification, socially immature, etc. Thus, these hidden symptoms must be understood and evaluated in their own right to provide holistic support to individuals with ADHD.

ADHD in Adults

ADHD is a neurodevelopmental condition and it continues through life. There is enough evidence that reports that although hyperactive-impulsive symptoms decline by adolescence and adulthood, inattentive symptoms continue to cause socio-occupational and interpersonal relationship impairments. The remission rates are reported to be 70% for hyperactive-impulsive symptoms versus 40% for inattentive symptoms. ²⁰ Although DSM 5 states that the criterion requirement for diagnosing ADHD in adults is five out of 9 in either of the hyperactive-impulsive domain and inattentive domain, the symptom description seems inappropriate to capture age and development-specific clinical manifestations, especially for the hyperactive-impulsive symptoms alongside difficulties in retrospectively assessing for the presence of ADHD symptoms in childhood. ²¹ In adults, symptoms may be due to executive dysfunction or emotional dysregulation which are not tapped effectively using the diagnostic criteria, and they may also have more impairments even with a lower symptom load. ADHD in adults is still an under-researched area; however, given the impairments of ADHD and the persistence of ADHD symptoms in a significant proportion of individuals diagnosed with ADHD in childhood, it becomes prudent to evaluate adults for ADHD.

Not everything is bad about ADHD!! Some individuals have done wonders despite having ADHD—Michael Phelps, an American swimmer; Justin Timberlake, a multifaceted singer and actor; Simone Biles, U.S. Olympic champion, are some of the international celebrities who have lived with ADHD and fought its impairments and come out victorious. The crux lies in early diagnosis, effective treatment, recognition, and management of all symptoms—evident and hidden—of ADHD.