In this article, we review empirical research on the role of individuals' parenting and maltreatment histories as developmental antecedents for symptoms and diagnosable episodes of unipolar and bipolar spectrum disorders. Our review is focused on the following three overarching questions: (1) Do negative parenting and a history of maltreatment contribute risk to symptoms or diagnosable episodes of unipolar and bipolar disorders? (2) Are the associations of negative parenting and maltreatment histories with bipolar disorders similar to those for unipolar depression? and (3) Are the associations between negative parenting and maltreatment histories and unipolar and bipolar symptoms or disorders mediated by cognitive vulnerability to depression? We begin by discussing the methodological requirements for demonstrating a psychosocial risk factor and the methodological issues that plague the parenting and maltreatment literatures. Next, we review the extant studies on the role of parenting histories in unipolar and bipolar disorders. We consider the specificity and possible moderators of the parenting-mood disorder relationship, as well as cognitive vulnerability to depression as a mediator of this relationship. Then, we review studies on the association of maltreatment histories with unipolar and bipolar disorders and the role of cognitive vulnerability to depression as a mediator of this association. We conclude with an assessment of the state of the parenting and maltreatment literatures in unipolar and bipolar disorder with regard to our guiding questions.