RT Journal Article SR Electronic T1 Cognitive behavioural group therapy is moderately effective for depression, with continued effect for up to 6 months but not beyond JF Evidence Based Nursing JO Evid Based Nurs FD BMJ Publishing Group Ltd and RCN Publishing Company Ltd SP ebnurs-2012-100767 DO 10.1136/eb-2012-100767 A1 Thomas J Currid YR 2012 UL http://ebn.bmj.com/content/early/2012/08/20/eb-2012-100767.abstract AB