Middle age is a phase of the life cycle marked by poorly defined boundaries and declining status. Studies reveal that depression is more likely to occur during middle age than during any other phase of the life cycle. In addition, research has verified that depression occurs more commonly in women than men. A sociological analysis of factors which differentially influence men and women in middle life is presented. Factors which may account for the higher incidence of depression among middle-aged women are identified and discussed. Some suggestions are advanced for the prevention and treatment of depression in women in middle life. (Author)