The study of depression in women in the perinatal period has led to increased understanding about the course, causes and potential points of intervention and screening. The importance of, for example, post-natal depression in women is now well recognised, both in terms of its effect on maternal health and on children's development. There is growing evidence that the perinatal period is also a point of increased risk for men, and constitutes a public health concern. For example, research to date suggests that men are also affected by the birth of their child, and previous work by this team has shown that depression in men is associated with an increased risk of behavioural and emotional problems in their children. A novel feature of this research is that it examines an under-appreciated health concern in men, depression and anxiety, in a transition period of increased strain. There is ample evidence, for instance, that the transition to parenthood is associated with a marked decrease in marital quality, but little of that work incorporates the findings from perinatal psychiatry. An improved understanding of mood and anxiety changes in men in the perinatal period is important in its own right and will increase our understanding of the dynamics of mental disorder between partners in a period of increased normative stress. This will enable us to improve our prediction and assessment targeting of families at risk for individual, couple, and family disturbance.