Background: The purpose of this study was to investigate the prevalence of extrapyramidal symptoms (EPS) and tardive dyskinesia (TD) in affective disordered patients treated with lithium and to study the association of these symptoms with medication and other factors.
Methods: This cross-sectional study was carried out in all consenting outpatients attending an affective disorders clinic in a psychiatric hospital. The study sample consisted of 130 stable outpatients: 110 with bipolar disorder, 18 with unipolar (major) depression, and 2 with atypical affective disorder. At the time of evaluation, 110 patients were receiving lithium, 37 in combination with antidepressants and 19 with neuroleptics, and 40 had a history of neuroleptic treatment during the previous 6 months. The patients were assessed with the Extrapyramidal Symptom Rating Scale (ESRS) for parkinsonism, akathisia, dystonia, and TD. The prevalence of these symptoms was calculated for all patients and by current lithium and neuroleptic intake. Multiple linear regression analysis was used to investigate the relationship between the ESRS subscale scores and gender, age, diagnosis, and medication type.
Results: The prevalence of tremor was 20.8%; hypokinetic parkinsonism, 7.7%; akathisia, 4.6%; dystonia, 3.8%; and TD, 9.2%. Tremor was associated with lithium and neuroleptic intake; hypokinesia was associated with neuroleptic treatment and age; and TD was associated with neuroleptic, lithium, and tricyclic intake and age. Seven of 51 patients taking lithium but without a history of neuroleptic treatment during the previous 6 months presented symptoms of TD.
Conclusion: The combination of lithium and neuroleptics was associated with a high prevalence of EPS. The presence of TD in lithium-treated patients not treated with neuroleptics for at least 6 months is consistent with the hypothesis that lithium may exacerbate the vulnerability of affective disordered patients to dyskinesias.