Psychosocial factors have been frequently suggested as important risk factors that may delay recovery in patients temporomandibular disorders. In this study, 94 subjects with chronic temporomandibular disorders were studied using IMPATH:TMJ prior to their entering an interdisciplinary treatment program to determine which factors were most predictive of outcome. Treatment outcome was determined based on significant decreases in the Craniomandibular Index and the Symptom Severity Index from pretreatment to posttreatment. The IMPATH:TMJ items were regressed on treatment outcome for a random sample of half of the subjects (n=47) to isolate the psychosocial and demographic items for these subjects (criterion group), followed by a cross-validation of the items of the remaining 47 subjects (cross-validation group). Low self-esteem, feeling worried, low energy, and sleep activity were identified as useful predictors of treatment outcome for the criterion group. Each are correlates of depression. The discriminant analyis employing these four items accounted for 49% f the variance in treatment response, was statistically significant (P<.0001), and correctly predicted treatment outcome for 41 of 47 subjects (87%) in the criterion group. The predictive utility of the identified items remained statistically significant when applied to the cross-validation group (P<.01). The discriminant function employing the items correctly predicted treatment outcome for 37 of 47 subjects (79%) and explained 28% of the variance in treatment response. Findings of this study suggest that pretreatment psychosocial information is impoortant in predicitng treatment outcome for chronic temporomandibular disorders, and that symptoms of depression mediate treatment response for chronic pain patients.