Session 205 - On the Move: An Update on Tardive Dyskinesia

Abstract

Abstract: Tardive dyskinesia (TD) affects 20–50% of patients treated with antipsychotic medications. The iatrogenic nature of TD was initially unrecognized when antipsychotics were first introduced in the 1950s. However, substantial research has since been conducted to elucidate the prevalence, risk factors, possible pathophysiology, and assessment of TD. Unfortunately, TD is potentially irreversible making prevention the primary mechanism for decreasing its prevalence. Extant literature suggests differences between races and genders in rates of TD. There also appears to be a dose (mean and cumulative)-response relationship between neuroleptics and development of TD as well as an increased risk with typical versus atypical antipsychotics. Other factors potentially impacting development of TD include Major Depressive Disorder, substance use disorders, movement disorder at baseline, history of ECT, diabetes, smoking, and genetic predisposition. While there is much yet to discover, proposed underlying mechanisms for the development of TD include hypersensitivity of nigrostriatal dopamine receptors after chronic blockade by neuroleptics, impaired synaptic plasticity, neurotoxicity due to oxidative stress, and genetic mutations. Subsequently, dopamine-depleting agents, benzodiazepines, anticholinergics, and antiepileptics have been researched as possible pharmacotherapies to ameliorate TD. Thus far, the benefits of these agents have not been robust. Recently, however, the FDA has improved the first medication for treatment of TD. Valbenazine inhibits vesicular monoamine transporter type 2 (VMAT2) which decreases monoamine uptake into synaptic vesicles and depletes monoamine stores. Because of its novelty, cost can be prohibitive for some patients; however, it may provide relief for some patients for whom other treatments have thus far failed. Because of the potential long term effects of TD on patients' overall well-being, it is important for clinicians to be vigilant regarding selection of antipsychotic medication, assessment of TD and available treatments for TD.