Scales for Antipsychotic-Associated Movement Disorders: Systematic Review, Critique, and Recommendations

Background: Antipsychotic-associated movement disorders remain common and disabling. Their screening and assessment are challenging due to clinical heterogeneity and different use of nomenclature between psychiatrists and neurologists.

Objective: An International Parkinson and Movement Disorder Society subcommittee aimed to rate psychometric quality of severity and screening instruments for antipsychotic-associated movement disorders.

Methods: Following the methodology adopted by previous International Parkinson and Movement Disorders Society subcommittee papers, instruments for antipsychotic-associated movement disorders were reviewed, applying a classification as "recommended," "recommended with caveats," "suggested," or "listed."

Results: Our review identified 23 instruments. The highest grade of recommendation reached is "recommended with caveats," assigned to seven severity rating instruments (Extrapyramidal Symptoms Rating Scale, Barnes Akathisia Rating Scale, Abnormal Involuntary Movements Scale, Drug-Induced Extra-Pyramidal Symptoms Scale, Maryland Psychiatric Research Centre involuntary movements scale, Simpson Angus Scale, and Matson Evaluation of Drug Side effects). Only three of these seven (Drug-Induced Extra-Pyramidal Symptoms Scale, Maryland Psychiatric Research Centre, Matson Evaluation of Drug Side effects) were also screening instruments. Their main caveats are insufficient demonstration of psychometric properties (internal consistency, skewing, responsiveness to change) and long duration of administration. Eight "suggested" instruments did not meet requirements for the "recommended" grade also because of insufficient psychometric validation. Other limitations shared by several instruments are lack of comprehensiveness in assessing the spectrum of antipsychotic-associated movement disorders and ambiguous nomenclature.

Conclusions: The high number of instruments "recommended with caveats" does not support the need for developing new instruments for antipsychotic-associated movement disorders. However, addressing the caveats with new psychometric studies and revising existing instruments to improve the clarity of their nomenclature are recommended next steps. © 2023 International Parkinson and Movement Disorder Society.