Study designs of evaluations included in the review
Placebo-controlled RCTs were eligible for inclusion in the review. All of the included studies were randomised crossover trials.
Specific interventions included in the review
Studies investigating the effect of bright light therapy on depressive symptoms were eligible for inclusion in the review. No further information was reported for the included studies.
Participants included in the review
Studies of participants with PMDD were eligible for inclusion. Not all included studies specified the American Psychiatric Association's DSM diagnostic criteria for establishing PMDD among participants.
Outcomes assessed in the review
The studies had to report on depression, using validated instruments, to be eligible for inclusion. The included studies used the Hamilton Depression Rating Scale or the Beck Depression Inventory. One study also reported adverse effects.
How were decisions on the relevance of primary studies made?
Two reviewers independently assessed the studies for eligibility; no disagreements occurred.