The factor structure of extrapyramidal symptoms evaluated using the Drug‐Induced Extrapyramidal Symptoms Scale in patients with schizophrenia: Results from the 2016 REAP AP‐4 study

• Published in: Human psychopharmacology Vol. 38; no. 2; pp. e2861 - n/a
• Main Authors: Kubota, Chika, Inada, Toshiya, Lin, Shih‐Ku, Avasthi, Ajit, Chee, Kok Yoon, Tanra, Andi Jayalangkara, Yang, Shu‐Yu, Chen, Lian‐Yu, Chong, Mian‐Yoon, Tripathi, Adarsh, Kallivayalil, Roy Abraham, Grover, Sandeep, Park, Seon‐Cheol, Kato, Takahiro A., Xiang, Yu‐Tao, Sim, Kang, Maramis, Margarita M., Noor, Isa Multazam, Tan, Chay‐Hoon, Sartorius, Norman, Shinfuku, Naotaka
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.03.2023
• Subjects: Antipsychotic Agents - adverse effects; Antipsychotics; Basal ganglia; Basal Ganglia Diseases - chemically induced; Basal Ganglia Diseases - diagnosis; Basal Ganglia Diseases - epidemiology; Central nervous system diseases; DIEPSS; Dopamine receptors; Dyskinesia; Dystonia; extrapyramidal symptoms; Extrapyramidal system; Factor analysis; Gait; Humans; Japan; Mental disorders; Movement disorders; Parkinsonian Disorders - chemically induced; Parkinsonian Disorders - drug therapy; Saliva; Schizophrenia; Schizophrenia - drug therapy; Tremor; Japan; antipsychotics; schizophrenia; extrapyramidal symptoms; DIEPSS
• ISSN: 0885-6222; 1099-1077
• DOI: 10.1002/hup.2861

Introduction Drug‐induced extrapyramidal syndrome (EPS) remains a major problem in clinical psychiatry. This study aimed to examine the factor structure of drug‐induced extrapyramidal symptoms observed in patients with schizophrenia and assessed using the Drug‐Induced Extrapyramidal Symptoms Scale (DIEPSS). Methods The participants were 1478 patients with a diagnosis of schizophrenia whose EPS was assessed using the DIEPSS in India, Indonesia, Japan, Malaysia, and Taiwan in the 2016 REAP AP‐4 study. The records of the participants were randomly divided into two subgroups: the first for exploratory factor analysis of the eight DIEPSS items, and the second for confirmatory factor analysis. Results The factor analysis identified three factors: F1 (gait and bradykinesia), F2 (muscle rigidity and tremor), and F3 (sialorrhea, akathisia, dystonia, and dyskinesia). Conclusion The results suggest that the eight individual items of the DIEPSS could be composed of three different mechanisms: acute parkinsonism observed during action (F1), acute parkinsonism observed at rest (F2), and central dopaminergic mechanisms with pathophysiology other than acute parkinsonism (F3).