精神疾患は何歳頃に発症する？

こころの病気は、何歳ごろに発症するものなのですか？
子どもより、大人がなるものですかね？

細川院長

精神疾患は半数が14歳までに、3分の2が24歳までに発症すると言われています。

Context: Little is known about lifetime prevalence or age of onset of DSM-IV disorders. Objective: To estimate lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the recently completed National Comorbidity Survey Replication. Design and Setting: Nationally representative face-to-face household survey conducted between February 2001 and April 2003 using the fully structured World Health Organization World Mental Health Survey version of the Composite International Diagnostic Interview. Participants: Nine thousand two hundred eighty-two English-speaking respondents aged 18 years and older. Main Outcome Measures: Lifetime DSM-IV anxiety, mood, impulse-control, and substance use disorders. Results: Lifetime prevalence estimates are as follows: anxiety disorders, 28.8%; mood disorders, 20.8%; impulse-control disorders, 24.8%; substance use disorders, 14.6%; any disorder, 46.4%. Median age of onset is much earlier for anxiety (11 years) and impulse-control (11 years) disorders than for substance use (20 years) and mood (30 years) disorders. Half of all lifetime cases start by age 14 years and three fourths by age 24 years. Later onsets are mostly of comorbid conditions, with estimated lifetime risk of any disorder at age 75 years (50.8%) only slightly higher than observed lifetime prevalence (46.4%). Lifetime prevalence estimates are higher in recent cohorts than in earlier cohorts and have fairly stable intercohort differences across the life course that vary in substantively plausible ways among sociodemographic subgroups. Conclusions: About half of Americans will meet the criteria for a DSM-IV disorder sometime in their life, with first onset usually in childhood or adolescence. Interventions aimed at prevention or early treatment need to focus on youth. The purpose of the current report is to present nationally representative estimates of lifetime prevalence and age-of-onset distributions of the DSM-IV disorders assessed in the recently completed National Comorbidity Survey Replication (NCS-R).1 While the Epidemiological Catchment Area Study2 and the baseline National Comorbidity Survey (NCS)3 both reported high lifetime prevalence and generally early age-of-onset distributions of most DSM-III (NCS) and DSM-III-R (NCS-R) disorders, it is not clear whether similar results will hold for DSM-IV disorders because of the greater emphasis on clinically significant distress and impairment in DSM-IV than in earlier editions. In addition to examining prevalence and age-of-onset distributions, we distinguish between lifetime prevalence, the proportion of those in the population who had a disorder at some time in their life up to their age at interview, and projected lifetime risk, the estimated proportion of those in the population who will have the disorder by the end of their life. Lifetime risk cannot be estimated directly from community surveys because respondents in such surveys differ in age and, therefore, in number of years of expected future risk. Projections of estimated future risk can be made from survey data, though, using either the Kaplan-Meier method4 or the slightly more precise actuarial method5 to estimate survival distributions. Although lifetime risk estimates are useful in assessing societal burden, we are aware of no previous published report that has presented such estimates for a wide range of mental disorders.

Kessler RC, Berglund P, Demler O, Jin R, Merikangas KR, Walters EE. Lifetime Prevalence and Age-of-Onset Distributions of DSM-IV Disorders in the National Comorbidity Survey Replication. Arch Gen Psychiatry. 2005;62(6):593–602.

子どものうちに発症する人が多い、ということなのですね。

細川院長

そうですね。
ただし、子どもを診てくれる場所は少なく、子どものうちに精神科にかかる人は少ないですから、発症後何年もたち、大人になってから診断を受ける人も多いと思われます。

大人になって受診したときに、「実は子どもの頃から困っていて～」という話はよくあります。

早めに受診できるよう、子どもも受診できる医療機関が増えると良いですね。

細川院長

では、この知見を臨床ではどう活かせば良いでしょうか？