Better safe than sorry. A systematic review of monitoring for negative effects in preregistrations of psychological interventions.

Although negative effects of psychological interventions are common, they are rarely investigated. Experts and international guidelines agree that monitoring for negative effects in clinical studies is needed to make psychological interventions safer and to empower patients before they consent. The aim of this systematic review was to find out how often studies on psychological interventions monitor their negative effects and to investigate reasons why monitoring is not carried out. Preregistrations of psychological interventions on Clinicaltrials.gov were scrutinized for information on monitoring of negative effects and other study characteristics. Researchers of studies in which no monitoring was reported were asked for reasons in a survey.