Borderline intellectual functioning

Borderline intellectual functioning, previously called borderline mental retardation (in the ICD-8),¹ is a categorization of intelligence wherein a person has below average cognitive ability (generally an IQ of 70–85),² but the deficit is not as severe as intellectual disability (below 70). It is sometimes called below average IQ (BAIQ). This is technically a cognitive impairment; however, this group may not be sufficiently mentally disabled to be eligible for specialized services.³

The DSM-IV-TR code of borderline intellectual functioning is V62.89.⁴ DSM-5 diagnosis codes are V62.89 and R41.83.⁵

During school years, individuals with borderline intellectual functioning are often "slow learners".³ Although a large percentage of this group fails to complete high school and can often achieve only a low socioeconomic status, most adults in this group blend in with the rest of the population.³

According to the DSM-5, differentiating borderline intellectual functioning and mild intellectual disability requires careful assessment of adaptive and intellectual functions and their variations, especially in the presence of co-morbid psychiatric disorders that may affect patient compliance with standardized test (for example, attention deficit hyperactivity disorder (ADHD) with severe impulsivity or schizophrenia).⁵