Defining and operationalizing personalized psychological treatment - a systematic literature review

This systematic literature review aimed to propose a definition of personalized psychological treatment and to suggest how the definition can be operationalized. PsycINFO, Cochrane Library, MEDLINE and EMBASE were searched up to 11 December 2023 for studies in which a definition of personalized psychological treatment was included or a systematic operationalization of personalized psychological treatment was described. Based on a narrative synthesis of the collected definitions, summary categories were developed that informed the proposed definition. Operationalizations were described according to what aspect of treatment, how and when treatment was personalized. The extent to which the operationalizations deviated from the proposed definition was assessed. Thirty-four studies with definitions and 200 with operationalizations were included. The following definition was proposed: personalized psychological treatment aims to optimize treatment outcome for the individual patient by tailoring treatment to unique or specific needs, preferences or other characteristics and includes a systematic adaptation of treatment or a differentiation between treatment strategies. Based on the operationalizations, timing of personalization, specification of the systematic approach and treatment elements that could be personalized were added to the proposed definition. Evidence-based personalization of psychological treatments can be enhanced by clear operationalization based on a comprehensive definition of personalization.