The psychotherapy and cancer survival debate generated great interest in the psychoneuroimmunological and bio-behavioral mechanisms that might mediate any gain in survival. Recent methodologically-improved cognitive-existential, supportive-expressive and psycho-educational group interventions for patients with breast cancer and melanoma have not extended survival times. Shorter survival has been associated with social disparity and untreated clinical depression, potentially mediated by poorer adherence to anti-cancer treatments. Group therapy both prevents and treats depression. Future research could address these bio-behavioral mechanisms.