Web-based interventions for comorbid depression and chronic illness: a systematic review. 
Web-based interventions offer potential benefits for managing and treating depression in the context of chronic physical illness, however their use with this population has yet to be quantitatively assessed.  The present systematic review examined the biopsychosocial data from 11 independent studies (N = 1348 participants), including randomised controlled and quasi-experimental designs most commonly performed with diabetes and multiple sclerosis.  Study quality was evaluated using the Downs and Black (1998) index, with most studies being statistically underpowered although internal validity was demonstrated.  Treatment outcomes were quantified using Cohen's d effect sizes.  Results indicated significant short-term improvements in depression severity (d w = 0.36, CI = 0.20-0.52, p < 0.01), in addition to quality of life, problem-solving skills, functional ability, anxiety and pain-related cognitions (d range = 0.23 to 1.10).  Longer-term outcomes could not be determined based on the limited data.  Further robust studies are required before wider adoption of web techniques takes place.