This preliminary study evaluated the effectiveness of psychotherapy treatment for adult clinical depression provided in a natural setting by benchmarking the clinical outcomes in a managed care environment against effect size estimates observed in published clinical trials. Overall results suggest that effect size estimates of effectiveness in a managed care context were comparable to effect size estimates of efficacy observed in clinical trials. Relative to the 1-tailed 95th-percentile critical effect size estimates, effectiveness of treatment provided in this setting was observed to be between 80% (patients with comorbidity and without antidepressants) and 112% (patients without comorbidity concurrently on antidepressants) as compared to the benchmarks. Because the nature of the treatments delivered in the managed care environment were unknown, it was not possible to make conclusions about treatments. However, while replications are warranted, concerns that psychotherapy delivered in a naturalistic setting is inferior to treatments delivered in clinical trials appear unjustified.