Objective: This paper will summarize the authors' research that disproved the accepted lifetime suicide risk in major depression. It will then explore the pivotal issue of gender in understanding suicide risk in depression and raise questions as to whether this is adequately reflected in the current diagnostic construct of this condition.

Method: The methods of two recent papers published by the authors are briefly recounted. In the first of these papers, an age-specific algorithm was developed to reflect the necessary mathematical relationship between the prevalence of major depression, total population suicide rates and suicide risk in depression. It allowed for deaths in each age group from other causes, corrected for official underreporting, and was calculated on the entire population of the USA. In the second paper this methodology was further refined and applied to gender and age data.

Results: The suicide risk in major depression as it is currently defined diagnostically is of the order of 3.4% rather than the previously accepted figure of 15%. However, a single figure is misleading as it averages two highly disparate figures of almost 7% for men and only 1% for women. In youths (< age 25) the male: female ratio is even higher (10:1).

Conclusions: Among sufferers of major depression, men and those who have been hospitalized have a much greater risk of suicide. These findings are sensitive to diagnostic inclusivity (the algorithm's denominator) which raises the question as to whether women with a depressive illness are more likely to be correctly identified than male sufferers? An argument is made for a gender-based nosological revision of the diagnostic criteria. In the interim, given the treatable morbidity of depression and the availability of safe, well-tolerated antidepressants, there is a prima facie case for lowering our threshold of treatment in men and youths presenting with a history of anger dyscontrol, or substance abuse, who have decompensated from previous levels of functioning and who show features of either typical or atypical depression.