Maternity blues research: a critical review.

Maternity blues research from 1962, when the first study was published, to the present is critically evaluated. Each study that met the sample criteria was judged against the following categories: measurement, research designs, sampling, and clinical description. Two major weaknesses in blues research were identified: (1) lack of standardized instruments for the measurement of the incidence, severity, and duration of the blues and (2) inconsistencies in research design.