<p>The purpose of this narrative review was to examine the efficacy and effectiveness of psychotherapy for older adults with depressive disorders or clinically significant depressive symptoms; describe extensions of psychotherapy across populations, settings, providers, and modalities; review mechanisms and predictors of treatment response; and consider future directions. Numerous systematic reviews and meta-analyses demonstrate that psychotherapy benefits many depressed older adults, with the strongest evidence for a variety of cognitive-behavioral therapy (CBT) approaches, including problem-solving therapy (PST) and behavioral activation (BA), and consistent evidence for interpersonal, reminiscence, and life review therapies as well. Great advances have been made extending these interventions, particularly CBT-based interventions, such as adaptations for older adults with psychiatric, physical, or cognitive comorbidities; in primary care, aging services, and residential settings; and low-intensity, often technology-based interventions. Several neurobiological, psychological, behavioral, social, and treatment-related mechanisms and predictors of psychotherapy response have been identified, which may explain heterogeneity of treatment effects and may lead towards more personalized, tailored interventions to achieve better outcomes for more older adults. More research is needed in all areas, including expanding from traditional psychotherapy models to novel technology-based, neuroscience-informed interventions, and implementation research to continue expanding the reach, feasibility, and acceptability of evidence-based psychotherapy.</p>