Psychiatric Comorbidities in Adolescents with Attention- Deficit Hyperactivity Disorder and Their Siblings

Abstract

Objective: Despite high psychiatric comorbidities in adolescents with clinical diagnosis of attentiondeficit hyperactivity disorder (ADHD), little is known about psychiatric comorbidities in their siblings. We investigated the psychiatric comorbid conditions in adolescents with ADHD, their siblings, and healthy control subjects from their school. Method:The sample included 136 adolescent probands with ADHD according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), diagnostic criteria; 136 siblings (47 affected and 89 unaffected) and 136 age-and sex-matched healthy school control subjects. All participants and their parents received the structured psychiatric interviews for current and lifetime DSM-IV psychiatric disorders of the participants. Results:The rate of ADHD (34.6%) in the siblings of probands with ADHD was about 7 times higher than in the general population. Probands with ADHD were significantly more likely than unaffected siblings (OR 6.38; 95% CI 3.43 to 11.88) and healthy school control subjects (OR 9.60; 95% CI 5.31 to 17.34) to have a DSM-IV psychiatric disorder, including oppositional defiant disorder (ODD), conduct disorder (CD), tic disorders, major depressive disorder, specific phobia (more than control subjects only), nicotine use disorder, and sleep disorders. The affected siblings were significantly more likely than healthy school control subjects to have ODD, CD, specific phobia, and to have consumed alcohol (ORs ranging from 2.30 to 20.16). Conclusions:Our findings suggest that siblings of probands with ADHD have increased risks for ADHD and that the affected siblings have more psychiatric comorbidities than healthy school control subjects. It warrants early identification of ADHD symptoms and other psychiatric comorbid conditions as well in siblings of adolescents with ADHD.Can J Psychiatry. 2011;56(5):281-292. Clinical Implications• High sibling recurrent risk for ADHD implies the need for screening for ADHD in siblings of adolescents with ADHD.• Only affected siblings of patients with ADHD, rather than unaffected siblings, had increased psychiatric comorbidities.• It warrants early recognition of comorbid conditions to offset future adverse outcomes among adolescents with ADHD and their siblings. Limitations• There is questionable external validity for possible selection bias derived from clinic-based samples, and only probands with siblings were included.• Although we conducted structured interviews of mothers and participants to confirm the clinical diagnosis of ADHD in probands and to make ADHD diagnosis of siblings, the possible recall bias might exist to confirm the presence of ADHD symptoms in adolescents aged 7 years and younger.

Comorbid Depressive Disorders in ADHD: The Role of ADHD Severity, Subtypes and Familial Psychiatric Disorders

“…This may be considered the most original finding of this study because the findings of previous studies have shed light on other issues, such as the familial link between ADHD and depression,24 the increased likelihood of siblings of probands with ADHD of developing ADHD, and the higher prevalence of psychiatric comorbidity among affected siblings than healthy school children 25. Other studies have revealed that the co-occurrence of psychiatric disorders is more likely in children with ADHD and bipolar disorder than in those without 35…”

“…Comorbid ADHD and depression may thus be characterized by a familial component 24. Indeed, Yang et al25 found a higher proportion of individuals affected by MDD among siblings of ADHD children than among controls.…”

Sleep disturbances in adolescents with ADHD: A systematic review and framework for future research

“…Five studies examined sleep in a single sample of adolescents with ADHD, who were followed into adolescence subsequent to childhood diagnosis. Using the K-SADS diagnostic interview, researchers within this group found a higher incidence of sleep disorders in adolescents with ADHD compared to HC peers (Gau & Chiang, 2009; Gau, Lin, et al, 2010) and their unaffected siblings (Yang, Shang, & Gau, 2011). Specific sleep disorders endorsed by ADHD teens varied by subtype, such that circadian rhythm, sleep-talking, and nightmare disorders were related to ADHD-Combined (ADHD-C), while hypersomnia was associated with ADHD-Inattentive (ADHD-I).…”

Attention training for infants at familial risk of ADHD (INTERSTAARS): study protocol for a randomised controlled trial

“…The risk of ADHD is known to be familial, with elevated prevalence in individuals who have a parent or sibling with the disorder. Sibling recurrence rates have been documented to be between 12 and 35% [25–27], and similar recurrence rates have been found between parents and children [26]. …”