Prevalence of Attention-Deficit/Hyperactivity Disorder (ADHD) Symptomatology and Psychiatric Co-Morbidity Among Adolescents Diagnosed with ADHD in Childhood (Clinical Report‪)‬

It was once thought that attention-deficit/hyperactivity disorder (ADHD) did not persist into adolescence, but results from two prospective studies suggest otherwise. (1-3) The results of a meta-analysis suggest a 15% persistence rate of ADHD into adolescence when the full Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) diagnostic criteria are used. (3) However, it has been postulated that persistence rates of ADHD into adolescence would be much higher if adolescents meeting the partial remission criteria were also included. (4) With this in mind, a recent study of 157 individuals who had been diagnosed with ADHD between the ages of 6 and 15 years found that on the basis of parents' reports, 60% of these individuals still met the DSM-IV criteria for ADHD 5 years after diagnosis. (5) There would therefore appear to be convincing evidence of noteworthy persistence rates into adolescence for both full DSM-IV criteria and partial-remission ADHD. Longitudinal studies of children with ADHD indicate that the majority of individuals diagnosed with the disorder during childhood continue to exhibit clinically significant symptom levels during adolescence. A recent study found that in a sample of 296 individuals diagnosed with DSM-IV ADHD at a mean age of 6 years, 68.8% still had persistent ADHD between the ages of 11 and 17 years. (6) Most adolescents suffering from ADHD report higher levels of emotional, social and scholastic impairment than their non-ADHD peers. (7) Moreover, psychiatric co-morbidities appear to be the norm rather than the exception among adolescents diagnosed with ADHD. (8) The most commonly occurring co-morbid conditions are reported to be oppositional defiant disorder (ODD), conduct disorder (CD), mood disorders, anxiety disorders, learning disorders and substance abuse disorders. Co-morbid ODD and/or CD have been reported in 30-45% of children diagnosed with ADHD by the time they reached 15 years of age. (9) Anxiety was evident in 30% of the same sample, while rates of depression and bipolar mood disorder were reported to be 45% and 23%, respectively. Youth with persistent ADHD have been found to be at higher risk for anxiety disorders than controls and more likely to meet the DSM-IV diagnostic criteria for ODD than youth with partially remitted ADHD. (6) However, both individuals suffering from persistent ADHD and those with partially remitted ADHD have been found to be significantly more likely than controls to be diagnosed with ODD, CD, tics, mood disorders, past and regular use of substances, and sleep disorders. (5) It would therefore appear that while persistent ADHD places adolescents at increased risk for a variety of psychopathologies, reduced ADHD symptoms in adolescents previously diagnosed with the disorder do not necessarily imply reduced risk for psychiatric co-morbidities.