Study designs of evaluations included in the review
There were no inclusion criteria relating to the study design.
Specific interventions included in the review
Studies describing the use of specific doses of HD for at least 6 months were eligible for inclusion. The included studies used doses ranging from 15 to 1,800 mg every 4 weeks.
Participants included in the review
Studies of people with schizophrenia were eligible for inclusion. The studies included in- and out-patients.
Outcomes assessed in the review
Studies reporting on relapse of schizophrenia were eligible for inclusion.
How were decisions on the relevance of primary studies made?
The author did not state how the studies were selected for the review, or how many reviewers performed the selection.