Subjective awareness of tardive dyskinesia and insight in schizophrenia
Background: Lack of awareness of tardive dyskinesia (TD) and poor insight into mental illness are common in schizophrenia, raising the possibility that these phenomena are manifestations of a common underlying dysfunction. Methods: We investigated relationships between low awareness of TD and poor insight into mental illness in 130 patients with schizophrenia and TD. We also examined selected demographic and clinical correlates of these two phenomena. Results: Sixty-six (51%) patients had no or low awareness of TD and 94 (72%) had at least mild impairment of insight into their mental illness. Low awareness of TD was not significantly correlated with greater impairment of insight into mental illness. Regression analyses indicated that the Positive and Negative Syndrome Scale (PANSS) disorganised factor (β=0.72, t=11.88, p<0.01) accounted for 52% of the variance in insight into mental illness (adjusted R2=0.55) (F[2, 127]=81.00, p<0.01) and the Extrapyramidal Symptom Rating Scale (ESRS) dyskinesia subscale score (β=0.47, t=6.80, p<0.01), PANSS disorganised factor (β=-0.26, t=-3.73, p<0.01), and ESRS parkinsonism subscale score (β=0.31, t=4.55, p<0.01) together accounted for 37% of the variance in awareness of TD (adjusted R2=0.37) (F[3, 126]=26.87, p<0.01). Conclusion: The two phenomena appear to be dissociated, and may be domain-specific. © 2010 Elsevier Masson SAS.