The efficacy of exercise in reducing depressive symptoms among cancer survivors: a meta-analysis.
BACKGROUND
The purpose of this meta-analysis was to examine the efficacy of exercise to reduce depressive symptoms among cancer survivors. In addition, we examined the extent to which exercise dose and clinical characteristics of cancer survivors influence the relationship between exercise and reductions in depressive symptoms.


METHODS
We conducted a systematic search identifying randomized controlled trials of exercise interventions among adult cancer survivors, examining depressive symptoms as an outcome. We calculated effect sizes for each study and performed weighted multiple regression moderator analysis.


RESULTS
We identified 40 exercise interventions including 2,929 cancer survivors. Diverse groups of cancer survivors were examined in seven exercise interventions; breast cancer survivors were examined in 26; prostate cancer, leukemia, and lymphoma were examined in two; and colorectal cancer in one. Cancer survivors who completed an exercise intervention reduced depression more than controls, d(+) = -0.13 (95% CI: -0.26, -0.01). Increases in weekly volume of aerobic exercise reduced depressive symptoms in dose-response fashion (β = -0.24, p = 0.03), a pattern evident only in higher quality trials. Exercise reduced depressive symptoms most when exercise sessions were supervised (β = -0.26, p = 0.01) and when cancer survivors were between 47-62 yr (β = 0.27, p = 0.01).


CONCLUSIONS
Exercise training provides a small overall reduction in depressive symptoms among cancer survivors but one that increased in dose-response fashion with weekly volume of aerobic exercise in high quality trials. Depressive symptoms were reduced to the greatest degree among breast cancer survivors, among cancer survivors aged between 47-62 yr, or when exercise sessions were supervised.
Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America. brownjus@mail.med.upenn.edu
Justin C
JC
Brown
Tania B
TB
Huedo-Medina
Linda S
LS
Pescatello
Stacey M
SM
Ryan
Shannon M
SM
Pescatello
Emily
E
Moker
Jessica M
JM
LaCroix
Rebecca A
RA
Ferrer
Blair T
BT
Johnson
D000328:Adult; D000368:Aged; D003863:Depression / Q000628:therapy*; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000523:psychology* / Q000628:therapy*; D017741:Survivors / Q000523:psychology*; D016896:Treatment Outcome