By Nestor Lopez-Duran PhD
Psychiatric disorders in children and adolescents III: Increases in psychiatric disorders during adolescence.
Today is the third of a series of brief posts about the recent results of the latest National Comorbidity Survey (NCS).
The NCS is a large nationally representative study of over 10,000 adolescents aged 13 to 18. The study aims to examine the prevalence of psychiatric disorders in youth across the United States by conducting a comprehensive face-to-face structured diagnostic assessment of every participant. Such diagnostic interview is currently the gold standard in diagnostic assessment, which arguably provides us with the most accurate picture of the true prevalence of these disorders in the population. The study included 4,945 boys and 5,170 girls. The racial/ethnicity breakdown was 65% non-Hispanic whites, 15.1% non-Hispanic black, 14.4% Hispanic, and 5% other.
Monday I discussed the overall prevalence rates of the most common psychiatric disorders in children and adolescents. Yesterday I also discussed the overall proportion of affected kids that actually experience severe functional impairment. Today, I want to comment on the age differences in life time prevalence of psychiatric disorders in early and late adolescence.
Below you can see age differences in prevalence rates for mood and anxiety disorders among kids aged 13-14, 15-16, and 17-18. The Y (vertical) axis shows the life time prevalence at each age and the X (horizontal) axis shows the age groups.
As you can see above, there is an increase in life time prevalence in most mood and anxiety disorders. The greatest increase is in depression. At age 13-14, about 8% of kids have a life time history of depression. However, this doubles to over 15% by age 17-18, which suggests that 1/2 of all cases of depression by age 18 occur between the ages of 14 to 18.
Now, the graph below shows the same information for more behavioral disorders.
Although not surprising, the drastic increases in prevalence of alcohol and drug abuse/dependence during adolescence is remarkable. For example, the prevalence of drug abuse/dependence increases from 3% at age 13-14 to over 16% by age 17-18. That is an increase of over 400%. In contrast, eating disorders remain relatively stable. This is actually very surprising as I assumed that we would see an increase in eating disorder in high school. You will also note that the prevalence of ADHD remains virtually static. This is actually not surprising at all since the diagnosis of ADHD requires that the symptoms are present during early childhood. According to current diagnostic conventions, there is no such thing as adolescence-onset ADHD.
Also in this series:
- How common are psychiatric disorders in children and adolescents?
- How many kids with psychiatric disorders experience severe impairment?
- SOON! A close look at race: Are there race biases in diagnostic practices?
The reference: Merikangas KR, He JP, Burstein M, Swanson SA, Avenevoli S, Cui L, Benjet C, Georgiades K, & Swendsen J (2010). Lifetime prevalence of mental disorders in U.S. adolescents: results from the National Comorbidity Survey ReplicationAdolescent Supplement (NCS-A). Journal of the American Academy of Child and Adolescent Psychiatry, 49 (10), 980-9 PMID: 20855043