Time‐Limited Counseling Outcome in a Nationwide College Counseling Center Sample

This study examined the dose-effect relationship between the number of sessions and therapeutic outcome in a large, nationwide counseling center research consortium. A positive relationship was found between the outcome of counseling and the number of sessions attended. The results of this study support the effectiveness of brief psychotherapy. ********** Several studies in the 1950s and 1960s examined the relationship between the number of sessions attended and the amount of gain achieved, indicating that the greater number of sessions a client attended, the greater the client gain (R. W. Johnson, 1965; Seeman, 1954; Standal & Van Der Veen, 1957). More recent studies have verified these early findings, concluding that length of treatment is positively and reliably associated with improvement and therapeutic benefit (Kadera, Lambert, & Andrews, 1996; Orlinsky, Grawe, & Parks, 1994). In recent years, the dose-response metaphor borrowed from pharmacology research has gained prominence in psychotherapy outcome research, as well (see Jones, Bigelow, & Preston, 1999, for example). One of the major contributions to this type of research is the influential meta-analysis performed by Howard, Kopta, Krause, and Orlinsky (1986), who proposed a dose- effect model linking the dosage of therapy sessions attended to the improvement clients experienced by attending each session. The log of the number of sessions became the dose, and the normalized probability of improvement was defined as the effect, using probits as the unit of analysis. The researchers constructed their dosage model by probit analysis of 15 previous outcome studies, some dating as far back as 1950, and computed the predicted improvement session by session. The results verified that the longer patients remained in therapy, the greater the gain. Results also revealed that 15% of patients improve between intake and the first session (pr esumably due to spontaneous remission and the ameliorative effects of having sought treatment), 50% improve after 8 sessions, and 75% improve after 26 sessions. Inspired by these results, other researchers began to analyze the dose effect for different diagnoses and levels of acute or chronic distress (Barkham, Rees, Stiles, & Shapiro, 1996; Kopta, Howard, Lowry, & Beutler, 1994). Criticism of the meta-analysis by Howard, Kopta, et al. (1986) surfaced soon after the articles were published. Phillips (1988) contended that earlier research failed to provide a sufficient database for determining a valid dose--effect relationship due to vague definitions of reliable improvement. Other critics questioned the previous research that grouped clients by diagnosis because patients with a specific diagnosis and similar symptoms respond differently to treatment (Kadera et al., 1996; Kopta et al., 1994). Other researchers pointed out that some researchers controlled the number of sessions clients could attend, rather than simply observing what naturally occurred in various treatment settings (Kadera et al., 1996). Observation of naturally occurring improvement in the session-by-session process of counseling has become much easier with the development of brief outcome measures such as the Outcome Questionnaire 45 (OQ45; Lambert, Lunnen, Umphress, Hansen, & Burlingame, 1994), which was designed for use not just at the beginning and end of therapy but throughout the course of treatment. By using measures such as the OQ45 to track the progress of groups of clients session-by-session naturally, researchers can begin to examine questions not only about efficacy but also about the effectiveness of treatment in these natural settings (Howard, Moras, Brill, Martinovich, & Lutz, 1996). Researchers may also begin to examine the effectiveness of counseling under a managed-care model, a model used by some college counseling centers and not yet thoroughly researched from a dose--effect paradigm (L. …