Bipolar manic-depressives and unipolar depressives distinguished by tests of lateral asymmetry.
Tests of lateral asymmetry in hand preference and superiority in thumb opposition rotation (opposing the thumb's pulp surface to that of the little finger) have been applied to bipolar and unipolar affective patients in an attempt to evaluate the effectiveness of these tests in differentiating the bipolar and unipolar patient populations. Two comparison samples were also tested: nonpsychotic central nervous system (CNS) disease patients, and normal controls. The normals divided almost evenly into pure dominance (e.g., right-handed, and superior right thumb opposition) and cross-dominance (e.g., right-handed, but superior left thumb opposition). All but one of the CNS disease patients were cross-dominant; the bipolars were predominantly pure dominant; while the unipolars, in contrast to the pure dominant bipolars, were in the majority cross-dominant. This result is consistent with the view that there are two types of affective disorder, bipolar manic-depressive and unipolar depressive illness.
D001714:Bipolar Disorder / Q000175:diagnosis*; D002493:Central Nervous System Diseases / Q000175:diagnosis; D003863:Depression / Q000175:diagnosis*; D003937:Diagnosis, Differential; D004292:Dominance, Cerebral; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D013933:Thumb / Q000502:physiology