A large proportion of psychotherapy patients remain untreated, mostly because they drop out. This study compares the short- and long-term outcomes of patients who dropped out of psychotherapy to those of therapy completers. The sample included 63 patients (23 dropouts and 40 completers) from a controlled clinical trial, which compared narrative therapy vs. cognitive-behavioral therapy for major depressive disorder. Patients were assessed at the eighth session, post-treatment, and at 31-month follow-up. Dropouts improved less than completers by the last session attended, but continued to improve significantly more than completers during the follow-up period. Some dropout patients improved with a small dose of therapy (17% achieved a clinically significant change before abandoning treatment), while others only achieved clinically significant change after a longer period (62% at 31-month follow-up). These results emphasize the importance of dealing effectively with patients at risk of dropping out of therapy.Patients who dropped out also reported improvement of depressive symptoms without therapy, but took much longer to improve than did patients who completed therapy. This might be attributable to natural remission of depression. Further research should use a larger patient database, ideally gathered by meta-analysis.