Predictors of Cognitive Improvement Following Treatment for Late-Life Depression.

OBJECTIVE: Cognitive impairment is frequently comorbid with late-life depression (LLD) and often persists despite remission of mood symptoms with antidepressant treatment. Increasing understanding of factors that predict improvement of cognitive symptoms in LLD is useful to inform treatment recommendations. METHODS: We used data from 2 randomized clinical trials of geriatric depression to examine the relationships between sociodemographic factors (resilience, quality of life) and clinical factors (age of depression onset, severity of depression, apathy) with subsequent cognitive outcomes. One hundred sixty-five older adults with major depression who had completed one of 2 clinical trials were included: (1) methylphenidate plus placebo, citalopram plus placebo, and citalopram plus methylphenidate or (2) citalopram combined with Tai Chi or health education. A comprehensive neuropsychiatric battery was administered; 2 measures of cognitive improvement were examined, one defined as an increase in general cognitive performance score of at least 1 standard deviation and the other 0.5 standard deviation pre-post treatment. RESULTS: At posttreatment, 59% of participants had remitted, but less than a third of those who remitted showed cognitive improvement (29%). Cognitive improvement was observed in 18% of nonremitters. Lower baseline depression severity, greater social functioning, and depression onset prior to 60 years of age were significantly associated with cognitive improvement. None of the other measures, including baseline apathy, resilience, and depression remission status, were significantly associated with cognitive improvement. CONCLUSIONS: Lower severity of depression, earlier onset, and greater social functioning may predict improvement in cognitive functioning with treatment for depression in LLD.

Psychobiological factors of resilience and depression in late life.

In contrast to traditional perspectives of resilience as a stable, trait-like characteristic, resilience is now recognized as a multidimentional, dynamic capacity influenced by life-long interactions between internal and environmental resources. We review psychosocial and neurobiological factors associated with resilience to late-life depression (LLD). Recent research has identified both psychosocial characteristics associated with elevated LLD risk (e.g., insecure attachment, neuroticism) and psychosocial processes that may be useful intervention targets (e.g., self-efficacy, sense of purpose, coping behaviors, social support). Psychobiological factors include a variety of endocrine, genetic, inflammatory, metabolic, neural, and cardiovascular processes that bidirectionally interact to affect risk for LLD onset and course of illness. Several resilience-enhancing intervention modalities show promise for the prevention and treatment of LLD, including cognitive/psychological or mind-body (positive psychology; psychotherapy; heart rate variability biofeedback; meditation), movement-based (aerobic exercise; yoga; tai chi), and biological approaches (pharmacotherapy, electroconvulsive therapy). Additional research is needed to further elucidate psychosocial and biological factors that affect risk and course of LLD. In addition, research to identify psychobiological factors predicting differential treatment response to various interventions will be essential to the development of more individualized and effective approaches to the prevention and treatment of LLD.