Prevalence and treatment of 12-month DSM-IV disorders in the Northern Ireland study of health and stress

Prior to the current Northern Ireland Study of Health and Stress there have been no epidemiological studies which estimate
the prevalence and treatment of mental health disorders across Northern Ireland based on validated diagnostic criteria. This
paper provides the first nationally representative estimates of 12-month DSM-IV anxiety, mood, impulse-control and substance
disorders. Severity, demographic correlates, treatment and treatment adequacy of 12-month disorders are also examined.

Data were derived from a nationally representative face-to-face household survey of 4,340 participants (2,441 females and
1,899 males) aged 18 years and older living in Northern Ireland using the World Health Organization Composite International
Diagnostic Interview. Analyses were implemented using the SUDAAN software system.

12-month prevalence estimates were anxiety 14.6 %; mood 9.6 %; impulse control 3.4 %; substance 3.5 %; any disorder 23.1 %.
Of the 12-month cases, 28.8 % were classified as serious; 33.4 % as moderate; and 37.8 % as mild. Females were more likely
to have anxiety and mood disorders (p < 0.05) while males were more likely to have impulse-control and substance disorders. Just 40 % of individuals with any 12-month
DSM-IV disorder received treatment in the previous 12 months. 78.6 % of those with a mental disorder who sought treatment
received minimally adequate treatment.

12-month DSM-IV disorders are highly prevalent in Northern Ireland. A large proportion of those with mental health problems
did not seek treatment. Further research is required to investigate the reasons behind low levels of treatment contact.