SAN DIEGO (FRONTLINE MEDICAL NEWS) – Cognitive-behavioral therapy (CPT) interventions delivered online are effective in reducing symptoms of mild to moderate depression in adults, according to results presented at the annual meeting of the American Psychiatric Association.

The findings, presented by Charles Koransky, MD , of the University of Maryland, Baltimore, derive from a meta-analysis of 14 randomized studies, conducted between 2005 and 2015, that enrolled more than 1,600 patients aged 18 years and older in Europe and Australia.

Patients in the studies were not receiving any other form of therapy, though some studies allowed concurrent use of antidepressant medications.

Results from patients assigned to the web-based interventions, which lasted 1 month or more, were compared with those who remained on waiting lists for treatment. Most of the interventions included brief clinician contact as part of their designs. Others were entirely self-guided.

Dr. Koransky and his colleagues found that completion rates were high, with between 55% and 93% of patients finishing the assigned interventions. The intervention groups saw significant improvement in symptoms after the online CBT interventions, with a standard mean difference of 0.74 (95% confidence interval, 0.63-0.86; P less than 0.001), compared with patients randomized to wait lists.

For the 11 studies that included between 3- and 6-months’ follow-up, improvement in depressive symptoms was seen to be durable, with a large SMD of 0.85 (95% CI, 0.79-0.90; P less than 0.001). “This shows that the effects last,” Dr. Koransky told conference attendees.

Dr. Koransky noted that statistically significant difference was seen between the studies with interventions that included clinician contact and those that did not. “This is probably because the clinician contact in the studies was brief, 10-minute chats or emails,” he said.

“Internet-based CBT leads to immediate and sustained reduction of depressive symptoms, which is consistent with analyses in the past,” Dr. Koransky said. “We also found that iCBT may be a good option for patients not able to access traditional face-to-face therapy,” he said, noting that several of the interventions in the study were designed to help address access issues in rural Australia.

Dr. Koransky noted that the results might not be generalizable because of the large portion of female patients across studies – more than 75% – and the fact that all patients were recruited through advertisements, suggesting that these were “highly motivated participants seeking some alleviation of their symptoms.” Another limitation of the study was a lack of uniformity across iCBT interfaces.

Nonetheless, he said, the findings have implications for U.S. practitioners, particularly primary care doctors in regions with poor access to mental health specialists.

Internet-delivered CBT may be “great for people in rural settings, especially if prescribed by primary care providers who don’t have the training to provide CBT,” he said.

Dr. Koransky said his group aimed to study these interventions in a U.S. population and among patients referred to iCBT by their primary care doctors. The researchers disclosed no conflicts of interest related to their findings.