In the past years, the development and use of e-health applications (e.g., video games; but also computerized therapies, smartphone apps etc.) have grown rapidly, with the aim to disrupt more traditional forms of therapy, to make therapy more effective and to increase accessibility of mental health services. In the development of e-mental health applications the focus is almost exclusively on specific factors or techniques; these factors are drawn from theories about the specific working mechanisms responsible for the development and maintenance of the specific mental health disorder. Because traditional evidence-based programs in the field of developmental psychopathology are based on Cognitive Behavioural Therapy (CBT), the majority of e-mental health applications are based on CBT principles. That is, therapeutic techniques from CBT are translated into an app or video game to reduce mental health problems (see for example MindLight).
The underlying assumption in the aforementioned approach is that these specific CBT techniques are (mainly) responsible for the observed improvements in mental health outcomes. However, in the therapy literature there is a consistent and large body of evidence showing that nonspecific factors - factors not specific to any theory of psychotherapy - play an important role in positive intervention outcomes as well. These nonspecific factors include client variables (e.g., beliefs about the malleability of symptoms; motivation to change), extra-therapeutic events (e.g., trauma), therapeutic relationship factors (e.g., therapeutic alliance), and expectancy and placebo effects (e.g., expectations for improvement or side-effects). Given the central role of nonspecific factors in nearly all psychological interventions, I think it is not unlikely that also in well-designed e-mental health applications nonspecific factors (partly) drive mental health improvements. Instead of controlling for nonspecific factors, I think it is crucial to harness these effects in order to optimize the effecitveness of e-health applications.