The purpose of the present review is to evaluate the effects of common risk factors for suicide by meta-analyses using data extracted from studies based on the psychological autopsy method. We focused on five common risk factors of suicide: substance-related disorders, mood disorders, adverse marital status, adverse employment status, and self-harm behaviors. A total of 24 articles were identified from MEDLINE in which the crude odds ratio (OR) could be calculated for the above five risk factors through 30 April 2007, using such search keywords as "suicide," "psychological autopsy," and "case-control study." Overall, both substance-related disorders [OR = 5.24; 95% confidence interval (CI) = 3.30-8.31] and mood disorders [OR = 13.42; 95% CI = 8.05-22.37] were strongly associated with suicidal risk. Suicidal attempt and deliberate self-harm, which can directly lead to completed suicide, have been shown to be very strongly associated with suicidal risk [OR = 16.33; 95% CI = 7.51-35.52]. Effects of social factors such as adverse marital and employment status were relatively small. As substance-related disorders and mood disorders were strongly associated with an increased risk of completed suicide, the comorbidity of these two disorders should be paid a maximum attention. The effective prevention of suicide depends on whether we can successfully incorporate these personal factors as well as social factors into an adequate multi-factorial model.