Reference Changed.—In the article titled, "Research Designs for the Study of Gene-Environment Interactions in Psychiatric Disorders," in the August ARCHIVES (35:925-932, 1978), the reference listing for reference 74 is incorrect. It should read as follows:
74. Matthysse S, Kidd KK: Genetic principles in defining homogeneous subgroups of the schizophrenias, in Akiskal HS, Webb WL (eds): Psychiatric Diagnosis: Exploration of Biological Predictors. New York, Spectrum Publications, 1978, pp 155-165.