Psychiatric comorbidities in ADHD children: an Iranian study among primary school students.

Background: This study was performed to determine the lifetime prevalence of psychiatric disorders concomitant with attention deficit/hyperactivity disorder (ADHD) among primary school students.

Methods: One thousand six hundred fifty-eight primary school students (781 females and 877 males) were selected in a cluster random manner in 2010. The first screening was performed by the Conner's teacher rating scale revised and Teacher ADHD rating scale-IV and then the students, in whom the ADHD was diagnosed by a child and adolescent psychiatrist according to DSM-IV-TR, were evaluated by K-SADS-PL semi-structured interview to detect the psychiatric comorbidities.

Results: The prevalence of psychiatric comorbidities in ADHD subjects was 62.5%. Oppositional defiant disorder (29.4%), specific phobia (21.9%), and enuresis (17.5%) were the most common comorbidities. The most common comorbidities in ADHD-IA (inattentive type) (n = 29) were specific phobia (34.5%), oppositional defiant disorder (20.7%), chronic motor tic disorder (17.2%), and enuresis (17.2%). The most common comorbidities in ADHD-HI (hyperactive/impulsive type) (n = 15) were chronic motor tic disorder (33.3%), oppositional defiant disorder (26.7%), and specific phobia (26.7%). The most common comorbidities in ADHD-C (combined type) (n = 116) were oppositional defiant (31.9%), enuresis (19%), and specific phobia (18.1%). The frequency of chronic vocal tic disorder was higher in ADHD-HI compared with ADHD-C (P = 0.01).

Conclusion: The results of this study indicated that the frequency of other psychiatric comorbidities in primary school students with ADHD is high that may affect disease course and treatment. Hence, evaluation for other comorbidities in ADHD patients should be considered.