Frequency and correlates of tardive dyskinesia in Indian patients with type I bipolar disorder.

BACKGROUND: Patients with Bipolar Disorder (BD) may have higher risk of Tardive Dyskinesia (TD). Theories for TD include inflammatory or oxidative stress and altered iron metabolism. The current frequency and clinical and biochemical correlates of TD in BD needs exploration.

OBJECTIVES: To assess: (1) the frequency of TD in BD; (2) clinical correlates of TD in BD; (3) oxidative stress markers, inflammatory markers and hepcidin in TD in BD.

MATERIALS & METHODS: In this cross-sectional study, 170 patients with BD were assessed for clinical characteristics using structured assessments. Inflammatory and oxidative markers like Interleukin-6 (IL-6), high sensitivity C-Reactive Protein (hsCRP), malondialdehyde (MDA), Total Antioxidant Status (TAS) and hepcidin were assessed by ELISA.

RESULTS: Frequency of TD was 10.6% (95%C.I.=6.4%-16.2%). Compared to patients without TD, patients with TD were older (F=0.340;p=0.000), had more episodes of illness (U=962.5;p=0.044) higher rates of medical comorbidity (X 2=6.924; p=0.009*), antipsychotic exposure (U=592.5;p=0.000), typical antipsychotic exposure (U=756.5;p=0.001) and cognitive deficits (F=1.129;p=0.001). The biomarkers levels did not differ between the groups. Hepcidin levels correlated with Abnormal involuntary Movements scale (AIMS) score (r=0.213;p=0.006). Patients treated with lithium were more likely to have TD, but also had greater exposure to antipsychotics than patients on valproate.

CONCLUSION: About one-tenth of patients with BD-I have TD. The presence of TD is associated several clinical characteristics such as age, exposure to typical antipsychotics and chronicity of illness. Hepcidin was associated with greater severity of dyskinetic movements and needs further exploration.