The objective of this study is to explore relations between the quality of attachment relationships and control and affective interaction in families with unipolar depressed, bipolar depressed, and well mothers. As part of a large longitudinal project, attachment assessments were made, using the Strange Situation procedure, with 112 mothers and their children (aged 15–52 months). Sixty-seven percent of the children of bipolar depressed mothers were classified insecure, in comparison with 42% of children of well and unipolar mothers. Mothers of insecure children were more downcast, tended to show less tenderness/affection, were more likely to express extreme levels of anger/irritability, and were more likely to express high levels of two or more negative affects (i.e., anger, anxiousness, downcast) than were mothers of secure children. Relations were strongest in the depressed-mother groups. Insecure children expressed less tenderness/affection than did secure children (particularly in the unipolar group), and insecure girls were more likely to express high levels of anger/irritability than were secure girls. The value of studying risk and protective factors from an interactive perspective is emphasized.