Epidemiology of psychiatric comorbidity in Thailand: a national study 2008

Objective To determine the prevalence of psychiatric comorbidity, the co-occurrence of two or more psychiatric diagnoses, in Thai people. Materials and methods Target population of the 2008 National Mental Health Survey (Thai-NMH Survey) was civilian non-institutionalized people aged between 15 and 59 years residing in households. Stratified three-stage random sampling was applied. A random sample of 17,140 Thai people was interviewed by using the Mini International Neuropsychiatric Interview (M.I.N.I.) version 5.0. To be a nationally representative data, design, gender and response weights were applied. Results The prevalence of psychiatric comorbidity was 1.4 %. Of these, 0.3 % was homotypic comorbidity (all psychiatric diagnoses being in the same category), and 1.1% was heterotypic comorbi- dity (the psychiatric diagnoses being in two or more categories). For the homotypic comorbidity, mixed bipolar disorder was found in 34.7 % of the respondents with bipolar disorder. Compared with men, the heterotypic comorbidity was more common in women. While the most common disorders in women were the comorbidity of affective and anxiety disorders (14.7 %), those in men were the comorbidity of alcohol use disorders and affective disorders (3.4 %). Individuals with psychiatric comorbidity, especially women, had an increased risk of suicide. Two-third of the respondents with comorbid affective and anxiety disorder and almost a half of those with comorbid alcohol use and affective disorders were at risk for suicide. Conclusion Although the psychiatric comorbidity is uncommon. The individuals with psychiatric disorder increased risk of comorbidity especially in women. The heterotypic comorbidity was marked increased in suicidal risk. The mental health service system should consider the special services for psychiatric comorbidity.