Objective: Schizophrenia is a psychiatric disorder diagnosed by the presence of a number of symptoms with cognitive impairment as a core feature. Long-term antipsychotic treatment is often associated with the emergence of tardive dyskinesia (TD) and the presence of TD is linked to cognitive impairment. This study examined the relationship between TD and cognitive deficits in Chinese patients with schizophrenia.
Methods: We recruited 206 chronic patients with TD (n=102) and without TD (n=104) meeting DSM-IV criteria for schizophrenia and 104 control subjects who were matched on age, gender, and education. All the patients completed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Positive and Negative Symptom Scale (PANSS), and the Abnormal Involuntary Movement Scale (AIMS).
Results: The PANSS total score (p=0.01), N subscore (p=0.006), and AIMS total score (p<0.001) were significantly higher in patients with TD compared to patients without TD. Patients with TD scored lower for visuospatial/constructional, attention, and total index scores (all p<0.001) on the RBANS. AIMS orofacial scores were identified as an independent contributor to RBANS total scores and attention index (p<0.05), whereas AIMS limb and truncal scores were an independent determinant to the visuospatial/constructional index of RBANS (p<0.05).
Conclusion: TD was associated with greater cognitive impairment in patients with schizophrenia compared to those without TD. The orofacial and limb-trunk TD specifically appeared to be a risk factor or contributor to the different aspects of cognitive deficits in schizophrenia. The association between schizophrenia and TD may be explained in part by oxidative stress.
Keywords: AIMS; ANOVA; Abnormal Involuntary Movement Scale; Assessment of Neuropsychological Status; CLAT; Cognition; MDA; MMSE; Oxidative stress; PANSS; Positive and Negative Symptom Scale; Psychopathology; RBANS; SOD; Schizophrenia; TBARS; TD; Tardive dyskinesia; analysis of variance; conceptual analogy test; malondialdehyde; mini-mental state examination; superoxide dismutase; tardive dyskinesia; thiobarbituric acid reactive substances.
© 2013.