1 Vol.:(0123456789) Scientifc Reports | (2023) 13:14969 | https://doi.org/10.1038/s41598-023-41306-y www.nature.com/scientificreports Psychometric assessment of the 10‑item, revised experience of close relationship (ECR‑R‑10) in nonclinical and clinical populations of adults and older adults in Thailand Nahathai Wongpakaran 1,6 , Tinakon Wongpakaran 1,6* , Peerasak Lerttrakarnnon 2,6 , Surin Jiraniramai 2 , Nattha Saisavoey 3 , Thanita Tantrarungroj 4 , Sirina Satthapisit 5 , Justin DeMaranville 6 , Khin Moe Myint 6 & Danny Wedding 6,7,8 The experiences of close relationships‑revised (ECR‑R) is a widely used 36‑item self‑report measurement for measuring adult attachment. However, various short versions of the ECR‑R have been developed and tested psychometrically. Given the cultural impact, a short version of the Thai ECR‑R should be derived from the existing Thai version of the ECR‑R. This study aimed to develop a 10‑item version of the ECR‑R that demonstrates comparable psychometric properties to the previous Thai version and the 18‑item ECR‑R. This study included four studies with a total of 1,322 participants. In study 1, 434 adults in a nonclinical setting were used for the development of the 10‑item Thai ECR‑R and tested in an independent sample. Studies 2, 3, and 4 were conducted on 312 adults in the clinical setting, 227 older adults in the nonclinical, and 123 older adults in clinical settings. The Cronbach alphas and corrected correlations between the ECR‑R‑18 and the ECR‑R‑10 in each study were calculated. Confrmatory factor analysis of the frst‑order two‑factor solution model with ft statistics was examined with each sample. Correlations of the ECR‑R‑18 and the ECR‑R‑10 with other measurements were presented and compared. Known‑group validity and measurement invariance test were also examined. The Cronbach alphas of the ECR‑R‑10 among all samples were acceptable, ranging between .77 and .85 for avoidance subscales and between .82 and .86 for anxiety subscales. The corrected correlation between the ECR‑R‑18 and ECR‑R‑10 was between .61 (p < .001) and .82 (p < .001). The values of the comparative ft index and Tucker‑Lewis index for the model of ECR‑R‑10 were between .903 and .985, whereas the root‑mean‑square error of approximation was between .082 and .036, indicating that the model fts were acceptable. The ECR‑R‑10 was related to the measurements with a similar construct; however, no diference in the magnitude of correlation was observed between ECR‑R‑18 and ECR‑R‑10. Known group validity was established. Measurement invariance was successfully established across diferent age and gender groups, although it was only partially achieved with respect to clinical status. The ECR‑R‑10 provided equal or superior psychometric properties to the ECR‑R‑18 across age groups and settings. As it is a briefer scale, the OPEN 1 Psychotherapy Unit and Geriatric Psychiatry Unit, Department of Psychiatry, Faculty of Medicine, Chiang Mai University, 110 Intawaroros Road, T. Sriphum, A. Muang, Chiang Mai 50200, Thailand. 2 Department of Family Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand. 3 Department of Psychiatry, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. 4 Department of Psychiatry, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. 5 KhonKaen Hospital, Khon Kaen, Thailand. 6 Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand. 7 Department of Clinical and Humanistic Psychology, Saybrook University, Pasadena, CA 91103, USA. 8 Department of Psychology, University of Missouri-Saint Louis, St. Louis, MO 63121, USA. * email: tinakon.w@cmu.ac.th