Many adolescents have mental disorders at the time of transition into adulthood

A Danish nationwide birth cohort study showed that the incidence rates of any mental disorder, substance use disorders, depression and anxiety disorders increased substantially by adolescence.

By the end of adolescence, 11 in 100 individuals in the cohort had received a mental disorder diagnosis, according to the findings published in Journal of Clinical Psychiatry.

“There is converging evidence from prevalence estimation studies showing that a sizeable proportion of young people suffer from mental disorders,” Hans-Christoph Steinhausen, MD, PhD, DMSc, of Capital Region Psychiatry, Copenhagen, Denmark, and department of child and adolescent psychiatry, University of Southern Denmark, and Helle Jakobsen, MS, of Aalborg University Hospital, Denmark, wrote.

In a cohort of children born in 1995 and followed up to the end of 2013, the researchers analyzed incidence and cumulative incidence rates of diagnosed mental disorders across the entire period of childhood and adolescence using data from nationwide Danish registries.

They calculated rates for any first-time diagnosis of a mental disorder and 10 categories of mental disorders — substance use disorders, schizophrenia, depression, anxiety disorders, obsessive-compulsive disorder, eating disorders, autism spectrum disorder, ADHD, conduct disorder and tic disorder — for 68,982 individuals. They also examined whether age, sex and further child- and family-related risk factors effected mental disorders.

The results showed that in the cohort, the overall incidence rates of any mental disorder, substance use disorders, depression, and anxiety disorders increased after age 13 years; however, the rates for ASD, ADHD, conduct disorder and tic disorder increased until age 13 then decreased. The investigators found that male youth had higher risk for any mental disorders, substance use disorders, ASD, ADHD, conduct disorder and tic disorder, while female youth had higher risks for depressive, anxiety, OCD and eating disorders.

At age 18 years, the cumulative incidence rate was 11.02% for any mental disorder, with the highest rate for an individual disorder for ADHD (2.51%) followed by depression (1.84%), ASD (1.79%), conduct disorder (1.32%) and substance use disorders (1.02%).

Some risk factors for being diagnosed with a mental disorder in the cohort were perinatal risks, divorce of parents, parental mental illness prior to offspring’s diagnosis, social position as youth and paternal death, according to the results.

“These findings of the diverse developmental patterns of various mental disorders throughout childhood and adolescence and the sizable number of disorders at the time of transition into adulthood underscore the fact that childhood and adolescence are highly vulnerable periods for the development of mental disorders,” Steinhausen and Jakobsen wrote. “The findings are relevant for mental health planning activities, as the approach used in the present study provides a very solid basis for calculating the needs in youth.” – by Savannah Demko

Disclosures: Steinhausen reports speaking for Medice and receiving book royalties from Cambridge University Press, Elsevier, Hogrefe, Huber, Klett and Kohlhammer publishers. Jakobsen reports no relevant financial disclosures.