Historically, depression was explained and treated intrapsychically and/or biochemically. In the 1970s theoretical propositions and treatment applications began to appear that offered that depression should be viewed cognitively (Beck 1963, 1974; Beck et al. 1979) or interpersonally (Coyne 1976a, 1976b; Klerman et al. 1984). Simultaneously, though more sporadically, marital interventions started to attract interest (Feldman 1976; Friedman 1975). The cognitive and interpersonal trends of thinking stimulated researchers to investigate the efficacy of these therapeutic modalities and to compare them with each other. Interest in these two treatments peaked with the publication of the study that emerged from the National Institute of Mental Health (NIMH) Treatment of Depression Collaborative Research Program (Elkin et al. 1989). This well-known research found that the two psychotherapies were similarly effective, but that the interpersonal approach was slightly more successful with more severely depressed patients.