Mental health inequalities in Wales, UK: multi-level investigation of the effect of area deprivation.

BACKGROUND Geographical variation in the prevalence of common mental disorders has not been explained adequately. AIMS To investigate whether regional mental health differences in Wales would persist after having taken into account the characteristics of individuals and regional social deprivation. METHOD Data from the 1998 Welsh Health Survey were used. Common mental disorders were assessed with the mental health index included in the Short-Form 36 health survey (SF-36). The data were analysed using a multi-level linear regression model. RESULTS Of the total variance in the mental health index, 1.47% occurred at regional level (95% CI 0.56-2.38). Adjustment for individual characteristics did not explain the between-region variation. A higher area deprivation score was associated with a higher score on the mental health index. CONCLUSIONS Mental health differences in Wales are partly explained by the level of regional social deprivation.