Despite the fact that clinical researchers have turned increasingly to media advertisements in recent years to obtain sufficiently large and homogeneous samples for psychotherapy and psychopharmacological treatment outcome studies, it has not been clear to what extent it is possible to generalize from solicited to traditionally referred patient populations. To shed light on this topic, 14 studies that compared solicited and nonsoliticed patient groups treated or studied in clinical settings were reviewed.Findings suggest that it may be possible to generate relatively comparable samples of solicited and nonsolicited patients, in terms of pretreatment symptomatology, provided there is adequate screening.Although the existing data suggest that treatment response may also be similar across these groups, these data are too limited to permit conclusions regarding generalizability of treatment efficacy findings based on solicited patient samples. Possible implications for treatment outcome of differences found on two variables (presence of precipitants and duration of illness) are discussed.Clinical researchers have turned increasingly to media advertisements in recent years to obtain subjects for psychopharmacology and psychotherapy outcome studies. The recruited subjects, called solicited patients in psychotherapy studies and symptomatic volunteers (SVs) in drug trials, display psychiatric symptomatology, but technically they are not psychiatric patients. Like traditionally referred outpatients (i.e., those who seek treatment on their own because of psychological distress or who are referred by physicians, mental health professionals, or workers in social service agencies), solicited patients receive treatment because of clinical disorders such as depression and anxiety. Unlike traditionally referred outpatients, however, they initially present for help as subjects in a research study. Thus, their experience of psychological distress may be the same as or similar to that of psychiatric patients, but the external trigger to which they respond is different.Use of a solicited patient population to test the efficacy of psychiatric treatments is controversial. Some researchers consider advertising for subjects an acceptable practice. Others, however, worry about the appropriateness of this sample given that study patients should ideally be drawn from the population to which findings are to be generalized. In their outline of methodological criteria for outcome research, Luborsky, Singer, and Luborsky (1975) maintained that "real" patients are preferable to volunteers. Weissman (1979), too, gave less weight to depression treatment outcome studies that use symptomatic volunteers and dismissed research findings that are not conducted on real patients. This article is an expansion of a paper entitled "Similarities and Differences Between Solicited and Traditionally Referred Patients," presented at the June 1984 annual meeting of the Society for Psychotherapy Research,