Antidepressant-induced tardive syndrome: A retrospective epidemiological study

Introduction: The impact of using antidepressant on the occurrence of tardive syndrome is rarely studied. Here we aimed to investigate the prevalence of various types of antidepressant-induced tardive syndrome. Methods: This study was conducted by means of a retrospective survey. Subjects receiving antidepressant(s) for over 6 months, but no other agents that may cause involuntary movements, were consecutively recruited. Tardive syndrome was evaluated in every included subject. Possible confounding medical conditions were carefully ruled out. Results: Of the 158 included subjects, 22 (14.0%) were found to have at least one tardive syndrome. The prevalence of subtypes of tardive syndromes was: tardive dystonia: 10.8%, tardive dykinesia: 3.2%, tardive tremor: 1.3%, tardive parkinsonism: 1.3%, tardive tics: 1.3%, tardive sensory syndrome: 1.3%, and tardive myoclonus: 0.6%. Using serotonin-norepinephrine reuptake inhibitors and previous marital status significantly increase the risk of tardive syndrome. Discussion: This study showed that antideÂpressants may induce various types of tardive syndrome, of which tardive dystonia is the predominant form. Clinicians should be cautious of this infrequent but distressing adverse effect when using antidepressants.