Borderline Intellectual Functioning: A Scoping Review

Borderline intellectual functioning (BIF) is a condition that involves limitations in cognitive skills that affect the daily functioning of people who present it. BIF has lost visibility in diagnostic manuals such as the DSM-5-TR and ICD-11, which relegate it to complementary categories of aspects requiring attention, rather than recognising it as a category of its own. This lack of recognition as well as unclear criteria for diagnosis underscores the need for a deeper understanding of BIF.

The study conducted a scoping review to map the available evidence in the field of BIF. Following the PRISMA-ScR framework, ProQuest, WoS, SCOPUS and EBSCOhost databases were searched. Documents were selected based on inclusion criteria: date of publication (since 2012), study of BIF as a specific group and language (English or Spanish). A total of 138 documents were included, both academic and grey literature.

The review mapped the literature into key categories: intellectual functioning, adaptive functioning and additions for a comprehensive evaluation. Most research focused on comorbid psychiatric, emotional and behavioural disorders associated with BIF, as well as cognitive aspects. Very few addressed adaptive functioning explicitly, a crucial area for diagnosing and supporting individuals with BIF, though many covered its domains (conceptual, social and practical). Studies predominantly used quantitative methodologies, with only a few incorporating qualitative methods and directly involving people with BIF.

The review emphasises the need for a clearer definition of BIF. Future studies should incorporate the perspectives of individuals with BIF to fully understand their needs and challenges across various life domains.