Left turning (swivel) in medicated chronic schizophrenic patients

34 medicated schizophrenic inpatients, 34 normal control subjects, 18 affective disorder patients (four in manic phase), nine schizoid personality disorder subjects, and nine anxiety/histrionic disorder patients were tested on a two-button task which required turning 180 degrees to collect coin reinforcers. Schizophrenic patients turned consistently left (16 times) significantly more (nine of 34) than normal controls, all of whom turned consistently right (chi 2 = 10.37, P = 0.005). Schizophrenic patients also turned left significantly more than the 18 affective disorder subjects, all of whom turned consistently right (chi 2 = 5.76, P = 0.02). All schizoid personality disorder subjects turned consistently right, and eight of nine anxiety histrionic disorder subjects turned consistently right. Left turning was not correlated with any other variables measured, including handedness, demographic, diagnostic and symptom variables. Left rotation has been previously measured during free ambulation in acute, non-medicated patients (Bracha, Biol. Psychiatry 22 (1987), 995-1003). Left turning bias in a subset of medicated, chronic schizophrenic inpatients may be linked to an underlying asymmetric striatal dopaminergic activity, specifically, an ipsilateral hypoactivity or contralateral hyperactivity, which would lead to left turning and right hemi-spatial neglect.