Tardive dyskinesia in schizophrenic patients: correlation with negative symptoms.

The relationship between severity of tardive dyskinesia (TD) and the prominence of negative symptoms was assessed in 25 right-handed, medicated schizophrenic patients. TD was quantified using ultrasound detectors and frequency measurement techniques as well as with observer rating scales. Electromechanical studies revealed a systematic relationship between TD severity and negative symptoms; TD was more severe in patients with fewer negative symptoms. The correlation was small in magnitude.