Mental Disorders: Prevalence

Psychotherapy Resources

13 October 2008 77 views No Comment

Mental disorders have been found to be relatively common, with more than one in three people in most countries reporting sufficient criteria for at least one diagnosis at some point in their life up to the time they were assessed. A new WHO global survey currently underway indicates that anxiety disorders are the most common in all but 1 country, followed by mood disorders in all but 2 countries, while substance disorders and impulse-control disorders were consistently less prevalent. Rates varied by region. Such statistics are widely believed to be underestimates, due to poor diagnosis (especially in countries without affordable access to mental health services) and low reporting rates, in part because of the predominant use of self-report data rather than semi-structured instruments.[citation needed] Actual lifetime prevalence rates for mental disorders are estimated to be between 65% and 85%.
A review of anxiety disorder surveys in different countries found average lifetime prevalence estimates of 16.6%, with women having higher rates on average. A review of mood disorder surveys in different countries found lifetime rates of 6.7% for major depressive disorder (higher in some studies, and in women) and 0.8% for bipolar 1 disorder.
The updated US National Comorbidity Survey (NCS) reported that nearly half of Americans (46.4%) meet criteria at some point in their life for either an anxiety disorder (28.8%), mood disorder (20.8%), impulse-control disorder (24.8%) or substance use disorder (14.6%).
A 2004 cross-Europe study found that approximately one in four people reported meeting criteria at some point in their life for at least one of the DSM-IV disorders assessed, which included mood disorders (13.9%), anxiety disorders (13.6%) or alcohol disorder (5.2%). Approximately one in ten met criteria within a 12-month period. Women and younger people of either gender showed more cases of disorder. A 2005 review of surveys in 16 European countries found that 27% of adult Europeans are affected by at least one mental disorder in a 12 month period.
An international review of studies on the prevalence of schizophrenia found an average (median) figure of 0.4% for lifetime prevalence; it was consistently lower in poorer countries.
Studies of the prevalence of personality disorders (PDs) have been fewer and smaller-scale, but one broad Norwegian survey found a five-year prevalence of almost 1 in 7 (13.4%). Rates for specific disorders ranged from 0.8% to 2.8%, differing across countries, and by gender, educational level and other factors. A US survey that incidentally screened for personality disorder found a rate of 14.79%.
Approximately 7% of a preschool pediatric sample were given a psychiatric diagnosis in one clinical study, and approximately 10% of 1- and 2-year-olds receiving developmental screening have been assessed as having significant emotional/behavioral problems based on parent and pediatrician reports.