ADHD: Current Concepts and Treatments in Children and Adolescents

Abstract

Attention deficit hyperactivity disorder (ADHD) is among the most frequent disorders within child and adolescent psychiatry, with a prevalence of over 5%. Nosological systems, such as the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) and the International Classification of Diseases, editions 10 and 11 (ICD-10/11) continue to define ADHD according to behavioral criteria, based on observation and on informant reports. Despite an overwhelming body of research on ADHD over the last 10 to 20 years, valid neurobiological markers or other objective criteria that may lead to unequivocal diagnostic classification are still lacking. On the contrary, the concept of ADHD seems to have become broader and more heterogeneous. Thus, the diagnosis and treatment of ADHD are still challenging for clinicians, necessitating increased reliance on their expertise and experience. The first part of this review presents an overview of the current definitions of the disorder (DSM-5, ICD-10/11). Furthermore, it discusses more controversial aspects of the construct of ADHD, including the dimensional versus categorical approach, alternative ADHD constructs, and aspects pertaining to epidemiology and prevalence. The second part focuses on comorbidities, on the difficulty of distinguishing between “primary” and “secondary” ADHD for purposes of differential diagnosis, and on clinical diagnostic procedures. In the third and most prominent part, an overview of current neurobiological concepts of ADHD is given, including neuropsychological and neurophysiological researches and summaries of current neuroimaging and genetic studies. Finally, treatment options are reviewed, including a discussion of multimodal, pharmacological, and nonpharmacological interventions and their evidence base.

Arousal and Executive Alterations in Attention Deficit Hyperactivity Disorder (ADHD)

“…Although the first case description of ADHD was reported in 1902 (Still, 1902), the etiology, diagnosis, and treatment of ADHD are still unclear. Concerning diagnosis, the symptoms of ADHD lack significant specificity, making it difficult to detect the disease at an early stage, and the diagnosis is still mainly based on observation and informant reports (Drechsler et al, 2020). A lack of specificity in the diagnosis increases the possibility that patients may not be correctly diagnosed (Levelink et al, 2020).…”

“…A lack of specificity in the diagnosis increases the possibility that patients may not be correctly diagnosed ( Levelink et al, 2020 ). In addition, manifestations of ADHD seem to be very heterogeneous, and it is difficult to understand both the neurological and cognitive mechanisms underlying ADHD-related deficits ( Drechsler et al, 2020 ; Sutcubasi et al, 2020 ). In a recent systematic review, Bellato et al (2020) suggest a possible link between a dysregulation of arousal (related to the autonomic nervous system) and a deficit in attentional and executive functions as the core problem associated with ADHD.…”

Traditional Scales Diagnosis and Endophenotypes in Attentional Deficits Disorders: Are We on the Right Track?

“…In addition, they are not only present in this disorder but also in other conditions. Furthermore, the neuropsychological deficits profiles identified are also present in the general population, but in children with ADHD the values are utmost [132].…”

Comorbidity in Children and Adolescents with ADHD

“…It is estimated that about 66% of ADHD patients have at least one comorbid disorder, and the most common are learning disorders, sleep disorders, oppositional defiant disorder and anxiety disorders [42]. Treating children and adolescents with ADHD who have comorbid conditions is a challenge for clinicians [43].…”

“…Psychopharmacology is the primary treatment for ADHD, and behavioral treatment is used in combination with medication or in children with minimal impairment or when medication is not possible due to contraindications or parents 'refusal to accept medication. Most guidelines recommend a stepwise approach to treatment, beginning with non-drug interventions and then moving to pharmacological treatment in those most severely affected [47]. In large birth cohort study, where a great majority of children with ADHD used medication, only child characteristics were significantly associated with the use of medication [48].…”