TARDIVE-DYSKINESIA - WHO IS AT RISK

Tardive dyskinesia (TD) has been associated with female gender, affect ive symptoms and good outcome, but also with negative symptoms, cognit ive deterioration and deteriorating illness course. Furthermore, antip sychotic medication is thought to be an important risk factor, yet abn ormal movements also occur in patients who have never received such me dication. We followed 166 subjects with recent onset of psychotic illn ess and brief previous exposure to antipsychotic medication. Informati on on 17 previously reported risk factors was available for 125 patien ts at baseline and, for factors that vary over time, again at follow-u p 4 years later (median, 50 months; interquartile range, 29-70). Movem ent disorder was assessed at follow-up using the Abnormal Involuntary Movement Scale (AIMS). Six non-interacting variables were independentl y associated with the 4-year risk of TD: male sex (OR, 2.5; 95% CI, 1. 1-5.0), age (OR over quartiles at baseline, 1.6; 95% CI, 1.1-2.2), lac k of insight at baseline (OR over four categories, 2.0: 95% CI, 1.2-3. 2), time on antipsychotics during the follow-up period (OR over quarti les, 2.3; 95% CI, 1.5-3.4), an increase in negative symptoms during th e follow-up period (OR over quartiles, 1.7; 95% CI, 1.2-2.5), and alco hol/drug misuse at follow-up (OR, 3.0; 95% CI, 1.3-7.4). The presence of individual risk factors was found to be of little use as a screenin g test for subsequent clinically relevant TD. Given the absence of a r isk factor, however, the probability that an individual would not deve lop TD was high. These results suggest that two discrete effects may o perate to increase the risk of TD, namely an exogenous factor (medicat ion, drugs), and an illness-related factor, the highest risk being con ferred by deteriorating illness course in male patients.