Dermatoglyphic analysis in bipolar affective disorder and schizophrenia--"continuum of psychosis" hypothesis corroborated?

Dermatoglyphic features are thought to be indicators of events in the early embryonal stages. They might also be associated with the developmental disorders of the central nervous system (CNS) including schizophrenia. Dermatoglyphic features of 92 male patients with bipolar affective disorder (BPAD) (unipolar depression and schizoaffective psychosis were excluded from the study) were compared with those of 195 males with schizophrenia (SCH) and both with those of 200 male controls (control group-CG). DSM-III-R criteria were used for the diagnostic evaluation. Quantitative analysis showed only one statistically significant difference between BPAD and SCH patients groups, regarding the c-d ridge count of the left hand. The canonical discriminant analysis did not permit correct classification (only 59.23% of cases were correctly classified) between BPAD and SCH. Numerous quantitative dermatoglyphic features of both BPAD and SCH differed significantly from those of the control subjects. Finger ridge counts as well as palmar ridge counts were markedly lower in BPAD and SCH as compared to the controls. These findings are not in contradiction with the hypothesis claiming that psychoses are a set of diverse expressions (due also to noninherited factors) of a single underlying entity.