[Clinical characteristics of patients with tardive dyskinesias]

Although there is a great number of studies on the relationship between tardive dyskinesia and patient characteristics, too often their validity is impaired by the lack of operationalized criteria for the description of patients and signs. Reliable phenotyping is of utmost importance for linking clinical data with data from methods in neurobiology or molecular genetics. 241 patients with the DSM IV diagnosis "schizophrenia" or "schizoaffective disorder" were examined with the instruments SADS-L, OPCRIT, BPRS and PANSS. Motor phenomena were analyzed on 2 separate days within 3 months with the scales TDRS, AIMS, SAS, BAS. Tardive dyskinesia was diagnosed following the research criteria of Schooler and Kane. Lifetime medication with neuroleptics and anticholinergic drugs was assessed quantitatively.

97 out of 233 patients (= 41.6%) displayed persistent tardive dyskinesia. In univariate analysis, significant associations were found between tardive dyskinesia and the following independent variables (higher values means greater risk): Age (p = 0.0001), years from onset of the disorder (p = 0.001), total length 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 by covariation with other variables. The same results were found when, instead 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 relationship to tardive dyskinesia.