People with depression also tend to “visit primary care physicians more often than others,” explains Prof. Lorenzo-Luaces. “They have more medical problems, and their depression sometimes gets in the way of their taking their medication for other medical problems.”

So, for the new review, the team examined 21 existing studies using meta-regression analysis. The analysis concluded that CBT apps were effective for treating mild, moderate, and severe depression.

Some of the trials included in the review compared a CBT app with a sham app. In these studies, the real apps were also significantly more effective at treating depression.