Clinical characteristics of patients with tardive dyskinesia

Although there is a great number of studies on the relationship between tar dive dyskinesia and patient characteristics, too often their validity is im paired by the lack of operationalized criteria for the description of patie nts and signs. Reliable phenotyping is of utmost importance for linking cli nical data with data from methods in neurobiology or molecular genetics. 24 1 patients with the DSM IV diagnosis "schizophrenia" or "schizoaffective di sorder" were examined with the instruments SADS-L, OPCRIT, BPRS and PANSS. Motor phenomena were analyzed on 2 separate days within 3 months with the s cales TDRS, AIMS, SAS, BAS. Tardive dyskinesia was diagnosed following the research criteria of Schooler and Kane. Lifetime medication with neurolepti cs and anticholinergic drugs was assessed quantitatively. Results: 97 out o f 233 patients (= 41,6%) displayed persistent tardive dyskinesia. In univar iate analysis, signifikant associations were found between tardive dyskines ia and the following independent variables (higher values means greater ris k): Age (p = 0,0001), years from onset of the disorder (p = 0,001), total l ength of stay in hospital (p = 0,001), PANSS (single scales and sum score) (p = 0,0001), total amount of neuroleptics expressed as CPZ equivalents (p = 0,004). Logistic regression analysis showed that only the variables "age" and "negative symptoms" expressed as score on the PANSS negative subscale showed an association with tardive dyskinesia that could not be explained b y covariation with other variables. The same results were found when, inste ad of the dichotomous variable "tardive dyskinesia yes/no" the associations with the TDRS score were analyzed. Future research should aim to approach the neurobiological correlates of "age" and "negative symptoms" in relation ship to tardive dyskinesia.