Relation of the Fliess-Swoboda Biorhythm Theory to suicide occurrence.

Data on occurrence of suicide from a population of 993 Veterans Administration hospital patients were used to test the validity of the Fliess-Swoboda Biorhythm Theory. Using a novel approach to analysis, semicritical day types were included. Sixty-four day types were generated and divided a priori into five categories which corresponded to predictions of increased or decreased suicides according to biorhythm theory. The results showed that the number of suicides observed was significantly different from the calculated number of expected suicides. The largest discrepancy between expected and observed frequencies occurred in category I for day types with all combinations of critical and semicritical days. It was concluded that biorhythm theory has some validity when the novel methods in this study are employed. The findings have heuristic value and may be useful to clinicians treating male Caucasian Veterans Administration inpatients. Suggestions for future research are also presented.