This paper reviews studies in which the effectiveness of psychological intervention against depression in informal providers of care for dementia patients was assessed by evaluating depressive symptoms with standardized quantitative instruments on at least two occasions. This criterion for inclusion in the review was met by 26 studies described in original articles, meta-analyses and previous reviews returned by a search of Current Contents, ERIC, Medline and PsycInfo. The intervention programs described differed widely in content and execution, and were not always well defined. Most participants were women. Most interventions, especially those with a psychotherapeutic emphasis, were reported to have been moderately useful in reducing depressive symptoms, at least to a limited extent. However, it is necessary to develop new interventions that pay special attention to the theoretical framework in which they are based and have adequate internal validity, that is, a design that allows testing hypothesis about the mechanism involved in the improvement of depressive symptoms.