Preventing the onset of depressive disorders: a meta-analytic review of psychological interventions.
OBJECTIVE
A growing number of studies have tested the efficacy of preventive interventions in reducing the incidence of depressive disorders. Until now, no meta-analysis has integrated the results of these studies.


METHODS
The authors conducted a meta-analysis. After a comprehensive literature search, 19 studies were identified that met inclusion criteria. The studies had to be randomized controlled studies in which the incidence of depressive disorders (based on diagnostic criteria) in an experimental group could be compared with that of a control group.


RESULTS
The mean incidence rate ratio was 0.78, indicating a reduction of the incidence of depressive disorders by 22% in experimental compared with control groups. Heterogeneity was low to moderate (I(2)=33%). The number needed to treat to prevent one case of depressive disorder was 22. Moderator analyses revealed no systematic differences between target populations or types of prevention (universal, selective, or indicated). The data included indications that prevention based on interpersonal psychotherapy may be more effective than prevention based on cognitive-behavioral therapy.


CONCLUSIONS
Prevention of new cases of depressive disorders does seem to be possible. Prevention may become an important way, in addition to treatment, to reduce the enormous public health burden of depression in the coming years.
Cuijpers
Pim
P
Department of Clinical Psychology, Vrije Universiteit Amsterdam, Van der Boechorststraat 1, 1081BT Amsterdam, The Netherlands. p.cuijpers@psy.vu.nl
van Straten
Annemieke
A
Smit
Filip
F
Mihalopoulos
Cathrine
C
Beekman
Aartjan
A