Among a group of young adults with ADHD at age 18, many of them did not meet diagnostic criteria for ADHD at any assessment in childhood, according to a study by Louise Arseneault, Ph.D., of King’s College London, and colleagues.
Among the 166 individuals with adult ADHD, 67.5 percent (112) did not meet the criteria for ADHD at any assessment in childhood. Analyses by the authors indicate that individuals with “late-onset” ADHD showed fewer externalizing problems and had higher IQ in childhood than those participants with persistent ADHD.
However, by young adulthood, participants with “late-onset” ADHD showed comparable ADHD symptoms and impairment, along with elevated rates of mental health disorders to those with persistent ADHD.
The authors also examined childhood predictors of ADHD persistence and remittance. They looked at functioning of participants with persistent, remitted (subsided) or late-onset ADHD to see how they compared. The study analysis included 2,040 participants from a cohort study of twins born in England and Wales.
The authors identified 247 individuals who met the diagnostic criteria for childhood ADHD; 54 (21.9 percent) also met criteria for the disorder at age 18. Persistent ADHD was associated with more childhood symptoms, lower IQ and, at age 18, those individuals had more functional impairment (school/work and home/with friends), generalized anxiety disorder, conduct disorder, and marijuana dependence compared with those whose ADHD had remitted, according to the results.
Study limitations include that diagnostic information on ADHD at age 18 was based only on self-reports. However, findings were corroborated by reports from co-informants.
“Further studies are needed to better understand the nature of the heterogeneity of the adult ADHD population. The extent to which childhood and ‘late-onset’ adult ADHD reflect different causes may have implications for research and treatment” the study concludes.
Article: Evaluation of the Persistence, Remission, and Emergence of Attention-Deficit/Hyperactivity Disorder in Young Adulthood, Arseneault et al., JAMA Psychiatry, doi:10.1001/jamapsychiatry.2016.0465, published online 18 May 2016.
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