Passive smoking is associated with psychological distress and the risk of developing severe psychiatric illness, a cross-sectional and longitudinal study has found. A total of 8,155 adults, of whom 2,595 were smokers, with no previous history of admission to psychiatric hospital were recruited from the Scottish Health Survey. 'It is unlikely to be helpful if we suggest to patients that their depression has been caused by their partner's smoking habit. Nevertheless, this study provides a useful reminder that we should consider depression within the context of relationships: depression is often preceded by marital problems, and the effects of the depression on the other partner and his/her reaction to it are likely to have an important influence on the future course of both the depression and the relationship.'