Copyright © 2019 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Original article 1 0342-5282 Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/MRR.0000000000000383 International classification of diseases/disorders diagnosis and International Classification of Functioning, Disability and Health activity/participation limitation among psychiatric patients: a cross-sectional and exploratory study Jacek Wciórka, Marta Anczewska, Piotr Jaholkowski and Piotr Świtaj To explore the relationships between international classification of diseases/disorders (ICD)-10 diagnoses and International Classification of Functioning, Disability and Health (ICF) disability dimensions – activity and participation restriction among mental health service users. Three hundred sixty patients from different health services diagnosed with diverse mental disorders (ICD- 10) participated in the study. Functioning restrictions were evaluated by use of the Mini-ICF-APP. Selected sociodemographic and clinical variables were also analysed. The Mini-ICF-APP scores correlated positively with the clinical impression of disease severity and negatively with general functioning. As independent factors determining the Mini-ICF-APP score, regression analysis suggests diagnosis and severity of disorder but also contextual factors such as general functioning and active occupation. Percentage and percentile distributions of activity and participation restrictions in diagnostic sections and categories revealed noticeable variability regardless of diagnosis-related differences. The diagnosis determines them neither in an ambiguous nor an absolute manner. There is a need to further explore the covariability between clinical diagnosis and ICF activity and participation restriction, particularly in regard the rationalization of social welfare benefits. International Journal of Rehabilitation Research XXX: 000–000 Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved. International Journal of Rehabilitation Research 2019, XXX:000–000 Keywords: diagnosis, functioning, mental disorders Department of Psychiatry I, Institute of Psychiatry and Neurology, Warsaw, Poland Correspondence to Jacek Wciórka, MD, PhD, Department of Psychiatry I, Institute of Psychiatry and Neurology, ul, Sobieskiego 9, 02-957 Warsaw, Poland Tel: +48 224582773; fax: +48 224582818; e-mail: wciorka@ipin.edu.pl Received 26 June 2019 Accepted 30 September 2019 Introduction The WHO International Classifcation of Functioning, Disability and Health, known at the ICF (WHO, 2001), provides a unifed and standard language for the descrip- tion of health, functioning and disability. For a better understanding of and action on health-related issues, the simultaneous usage of the ICF and the international classifcation of diseases/disorders (ICD; WHO, 1992) has been proposed, linking disease and functioning (Baron and Linden, 2008; Kostanjsek et al., 2011; Kohler et al., 2012; Escorpizo et al., 2013; Selb et al., 2015). ICF appli- cations may shed light on the interrelationship between pathogenic and salutogenic processes (Amering and Schmolke, 2007; Jonas et al., 2014; Nowak et al., 2016), and thereby contribute to effective prevention, care and rehabilitation as well as to the rationalization of social welfare benefts (Wilmowska-Pietruszyńska and Bilski, 2012). Particularly, in the feld of mental health, these expec- tations refer to the continued debate as to whether and to what extent personal (distress), clinical (disorder) and social (disability) aspects of crises may be separated from each other. In the feld of mental healthcare, these aspects inevitably overlap to a greater or lesser extent and codefne real tasks (Ustün and Kennedy, 2009, along with comments). Studies indicate that functioning and disability are much more strongly and extensively infu- enced by mental disorders than somatic diseases (Reed et al., 2009; Cabello et al., 2012; Świtaj et al., 2012; Linden et al., 2015b). Opinions and studies indicate that in the case of mental disorders, and not only the chronic and recurrent ones, these associations are not as obvious as it is assumed in the traditional medical model, giving the decisive importance to pathogenetic determinism and leaving aside salutogenic determinants (Amering and Schmolke, 2007; Jonas et al., 2014; Nowak et al., 2016). The ICF may compensate for these shortcomings in the focus on diseases and disorders. It supplements a descrip- tion and clinical evaluation with variables independent of nosological categories. It enables the identifcation of the quantitative and qualitative characteristics of health of a person who is healthy, ill or recovering. The disability level assesses not only the violated body structures and functions but also available social capacity (activity), the fulflment of social roles (participation) and the impor- tance of the context in which a person lives. Only a small number of attempts to use the ICF in mental health have been undertaken in Poland to date