The systematic review aimed to systematize the empirical literature on the psychological impact of disability on the siblings of persons with disabilities, to inform research and provide clinical recommendations. Two research questions addressed the review: (1) What are the main psychological constructs investigated in siblings of persons with disability? (2) What is the main role of each psychological construct in siblings of persons with disability experience? The electronic search was conducted in 7 databases and the PRISMA diagram was used. The inclusion criteria were: Papers published in English and in peer-reviewed journals; papers published between January 2014 and June 2024; qualitative, quantitative, and mixed studies; and papers on the psychological impact of disabilities and/or chronic illnesses on the experience of siblings of persons with disabilities. The standardized Mixed Method Appraisal Tool protocol was used to appraise the methodological quality of the studies. To summarize the findings, a narrative approach was adopted. A total of 60 studies have been reviewed. According to the methodological quality appraisal of studies, most of them reported a high (n = 45) and medium (n = 15) quality. They involved 10,146 participants. Findings revealed that sibling relationships, sibling-focused parentification, and emotional/behavioral adjustment are the main psychological constructs investigated by existing literature. Few studies focused on siblings’ well-being. Studies exploring more than a psychological construct were included as a hybrid. Only one study examined the siblings’ psychological experience during the COVID-19 pandemic. The quality of the sibling relationship ranged from good to poor; the caregiver is the main role played by siblings of persons with disabilities; anxiety, depression, and aggressive behaviors are the main emotional/behavioral symptoms revealed. Most studies (n = 39) recruited participants with brothers or sisters with mental disorders. The findings of this systematic review may play a role in the clinical field, as they might help to design gender- and age-specific intervention programs.
