More than 20 percent of U.S. teenagers experience a mental disorder with severe distress or impairment, but only 36 percent of them receive mental health services, according to a study of more than 10,000 young people by the National Institute of Mental Health (NIMH).
"This is the first nationally representative sample of American adolescents and covers a full range of psychiatric disorders," study leader Kathleen Merikangas, Ph.D., told Psychiatric News. Merikangas is chief of the Genetic Epidemiology Research Branch in the intramural research program at NIMH.
"There is an increasing gap between what mental health professionals see and what's out there, and this study shows many people could use good mental health treatment," said Merikangas. "Substantial unmet needs for care persist."
She and her colleagues used data from the National Comorbidity Survey–Adolescent Supplement (NCS-A). They published the first two articles on prevalence and treatment in the Journal of the American Academy of Child and Adolescent Psychiatry in October 2010 and January 2011. Analyses covering anxiety, depression, substance abuse, and medication use data drawn from the same survey are in preparation.
The survey consisted of face-to-face interviews with 10,123 adolescents aged 13 to 18 and questionnaires completed by 6,491 of their parents. The team at NIMH worked closely with psychiatrists who have extensive clinical experience to develop the questions used in the NCS-A, said Merikangas.
The results were striking.
"The prevalence of severe emotional and behavioral disorders is even higher than [that of] the most frequent major physical conditions in adolescence, including asthma or diabetes, which have received widespread public attention," wrote the authors.
Lifetime prevalence rates varied among disorder categories, they found.
Most common were anxiety disorders, for which 31.9 percent of the adolescents met diagnostic criteria. About 14.3 percent met DSM-IV criteria for mood disorders, 8.7 percent for attention-deficit/hyperactivity disorder (ADHD), and 11.4 percent for substance use disorders.
Overall, 49.5 percent of the sample met criteria at some time in their young lives for a mental disorder. About 40 percent of those met criteria for at least one additional psychiatric diagnosis.
Prevalence varied by sex, age, and some demographic factors. Girls had double the rate of unipolar mood disorders, while boys were three times as likely to have ADHD.
The median age of onset was 6 for anxiety disorders, 11 for behavior disorders, 13 for mood disorders, and 15 for substance use disorders.
Parental divorce or separation was associated with higher rates of anxiety, behavior, and substance use disorders compared with adolescents who had married or cohabiting parents. Rates of all categories of disorders were higher among youth whose parents were not college graduates.
Non-Hispanic black respondents showed lower rates of substance use disorders and higher rates of anxiety disorders than their white counterparts. Hispanic youth had higher rates of mood disorders than did whites.
"The prevalence rates reported here closely approximate those of our nationally representative sample of adults using nearly identical methods, suggesting that the majority of mental disorders in adults emerge before adulthood," wrote the authors.
A study about eating disorders based on the NCS-A appeared online in the March Archives of General Psychiatry. The prevalence of anorexia nervosa was 0.3 percent, bulimia nervosa 0.9 percent, and binge-eating disorder 1.6 percent. Rates were higher for subthreshold anorexia and binge eating.
Those rates may seem low, but the adolescents with eating disorders also reported high levels of impairment and worrisome levels of lifetime suicidality. Half of those with bulimia and about one-third of those with anorexia or binge-eating disorder reported suicidal ideation.
Service use among those with eating disorders followed an unusual pattern. Between 76 percent and 88 percent of these youth said they had sought some form of general mental health treatment. However, many fewer (3 percent to 27 percent) had addressed eating or weight problems with a professional.
"For some reason, eating disorders are not well recognized," said Merikangas. Denial, shame, and stigma may keep adolescents from talking about eating problems. Families get blamed but may not be aware of what their child is doing.
"And clinicians complain that with perhaps 30 minutes available for an intake interview, they can't ask about everything," she said.
Despite this demonstrated need for care, wrote Merikangas and colleagues in their article on service utilization, "... most youth with mental disorders do not receive mental health treatment for their symptoms."
Half of those with comorbid and severely impairing disorders had never gotten treatment. Members of racial or ethnic minorities were less likely to be treated than whites, particularly in regard to internalizing disorders.
Youth with externalizing disorders got the most attention.
"This suggests that aggressive, impulsive, and disruptive behaviors tend to drive or attract mental health care treatment seeking of adolescents," they wrote.
Highest service rates were found for youth with ADHD (59.8 percent) and behavioral disorders (45.2 percent), while youth with mood disorders (37.7 percent), anxiety disorders (17.8 percent), or substance use disorders (15.4 percent) were less likely to receive treatment.
"[T]hese findings underscore the key public health importance of mental health in American youth," the researchers said. Their conclusions can help facilitate getting young people into treatment, direct future prospective research, and guide health policymakers in trying to alleviate the economic and personal burden of mental disorders among adolescents, they said.
The studies by Merikangas and colleagues were funded by the Intramural Research Program at NIMH. Funding for the NCS-A came from NIMH, the National Institute on Drug Abuse, the Substance Abuse and Mental Health Services Administration, Robert Wood Johnson Foundation, and John W. Alden Trust.
An abstract of "Service Utilization for Lifetime Mental Disorders in U.S. Adolescents: Results of the National Comorbidity Survey–Adolescent Supplement (NCS-A)" is posted at <www.jaacap.com/search/quick#>. An abstract of "Lifetime Prevalence of Mental Disorders in U.S. Adolescents: Results from the National Comorbidity Survey Replication–Adolescent Supplement (NCS-A)" is posted at <www.jaacap.com/search/quick#>.