Tardive dyskinesia prevalence rates during a ten-year follow-up

Genetic association analysis of the glutathione peroxidase (GPX1) gene polymorphism (Pro197Leu) with tardive dyskinesia

A possible involvement of oxidative stress in the pathophysiology of tardive dyskinesia (TD) has previously been proposed (reviewed in [Andreassen, O.A., Jorgensen, H.A., 2000. Neurotoxicity associated with neuroleptic-induced oral dyskinesias in rats. Implications for tardive dyskinesia? Progress in Neurobiology 61, 525-541.]). Long-term administration of neuroleptics alters dopaminergic turnover, which results in increased formation of reactive oxygen species (ROS). This is hypothesized to lead to TD through neuronal toxicity as a consequence of oxidative stress. In the present study, the relationship between TD and a possible functional polymorphism of the human glutathione peroxidase (GPX1) gene (an important antioxidant enzyme) was studied in 68 chronic treatment-refractory patients with schizophrenia. A proline (Pro) to leucine (Leu) substitution at codon 197 (Pro197Leu) in the GPX1 gene was genotyped. No significant difference in total Abnormal Involuntary Movements Scale (AIMS) scores was observed among patients in the three genotype groups. Moreover, no significant differences in genotype or allele frequencies were observed between subjects with and without TD. Our results suggest that the GPX1 gene polymorphism does not confer increased susceptibility to TD, although further studies are warranted before a conclusion can be drawn.

Quality of life in persons with schizophrenia in out-patient treatment with first- or second-generation antipsychotics

OBJECTIVE

Effects of first in comparison with second-generation antipsychotics on the subjective quality of life (QoL) of patients with schizophrenia under routine treatment conditions were examined.

METHOD

In a prospective naturalistic trial the QoL, social, clinical, and treatment-related characteristics and type of antipsychotic medication of 307 patients with schizophrenia (ICD-10 F 20) were assessed five times with 6-month intervals over 2.5 years. Longitudinal and cross-sectional effects of antipsychotic medication were assessed by hierarchical regression models. Selection bias was controlled by propensity scores.

RESULTS

While positive effects of first-generation antipsychotics on subjective QoL in comparison with no antipsychotic treatment were found, second-generation antipsychotics caused no better QoL than first-generation antipsychotics.

CONCLUSION

The hypothesis that second-generation in comparison with first-generation antipsychotics have a better effect on the improvement of subjective QoL of people with schizophrenia in routine out-patient treatment was not supported.

Association between three functional polymorphisms of dopamine D2 receptor gene and tardive dyskinesia in schizophrenia

The dopamine D2 receptor (DRD2) gene is considered one of the candidate genes contributing to the development of tardive dyskinesia (TD). In the present study, we investigated the genetic association between three functional polymorphisms (Ser311Cys, -141C Ins/Del and TaqI A) in the DRD2 gene and TD (200 patients with schizophrenia: 44 with TD and 156 without TD). No significant difference in the allelic and genotypic distribution between patients with TD and those without TD was observed. However, we found a slightly significant association between the -141C Ins/Del polymorphism and the total Abnormal Involuntary Movement Scale (AIMS) score (P = 0.037). The significant association between the -141C Ins/Del polymorphism and the total AIMS score did not remain after the regression analysis was taken into account (P = 0.14). Our results suggest that that three functional polymorphisms in DRD2 may not play a major role in the occurrence of TD.

Mitochondrial ultrastructure and density in a primate model of persistent tardive dyskinesia

The use of neuroleptic drugs to treat schizophrenia is almost invariably associated with extrapyramidal movement disorders. One of these disorders, tardive dyskinesia (TD), can persist long after neuroleptic withdrawal suggesting that permanent neurological damage is produced. However, there appears to be no convincing pathology of TD and its pathogenesis remains unknown. Findings that neuroleptics interfere with normal mitochondrial function and produce mitochondrial ultrastructural changes in the basal ganglia of patients and animals suggest that mitochondrial dysfunction plays a role in TD. We have established a model for persistent TD in baboons that appears to involve compromised mitochondrial function. In this study, we evaluated two animals treated for 41 weeks with a derivative of haloperidol and two treated with vehicle only. Treatment was then withdrawn and the animals observed for a further 17-18 weeks. Treated animals developed abnormal orofacial signs that were consistent with TD. These symptoms persisted during the drug-free period. The animals were euthanased, the brains perfused-fixed then post-fixed in 4% paraformaldehyde and the caudate and putamen prepared for electron microscopy. Regardless of whether mitochondria were located in neural soma, excitatory terminals, glia or in non-somal neuropil there was no consistent difference either in size or number between treated and control animals. Thus, even if mitochondria in striatal neurons undergo ultrastructural alterations during neuroleptic therapy, these changes do not persist after drug withdrawal.

Randomised double-blind comparison of the incidence of tardive dyskinesia in patients with schizophrenia during long-term treatment with olanzapine or haloperidol

BACKGROUND

Tardive dyskinesia is important in the side-effect profile of antipsychotic medication.

AIMS

The development of tardive dyskinesia was evaluated in patients treated with double-blind, randomly assigned olanzapine or haloperidol for up to 2.6 years.

METHODS

Tardive dyskinesia was assessed by the Abnormal Involuntary Movement Scale (AIMS) and Research Diagnostic Criteria for Tardive Dyskinesia (RD-TD), it was defined as meeting RD-TD criteria at two consecutive assessments. The risk of tardive dyskinesia, the relative risk, incidence rate, and incidence rate ratio were estimated.

RESULTS

The relative risk of tardive dyskinesia for the overall follow up period for haloperidol (n = 522) v. olanzapine (n = 1192) was 2.66 (95% CI = 1.50-4.70). Based on data following the initial six weeks of observation (during which patients underwent medication change and AIMS assessments as frequently as every three days), the one-year risk was 0.52% with olanzapine (n = 513) and 7.45% with haloperidol (n = 114). The relative risk throughout this follow-up period was 11.37 (95% CI = 2.21-58.60).

CONCLUSION

Our results indicated a significantly lower risk of tardive dyskinesia with olanzapine than with haloperidol.

Drug-induced movement disorders

Drug-induced movement disorders are often unrecognized, especially when not due to dopamine receptor blockers. This review discusses acute, subacute, and chronic syndromes. Pathophysiology relates almost always to dopaminergic transmission. Patient-dependent vulnerability and drug-dependent sensitivity are contributing factors. Young patients are more prone to acute reactions, and tardive or chronic conditions are more frequent in the elderly. Subclinical Parkinsonism can be unmasked by medication exposure. Treatment of tardive dyskinesia remains a challenging task for the clinician, but novel antipsychotics and dopamine depleting agents can be beneficial.