Psychopathological Severity Across the Cognitive Continuum: A Comparative Study of Adolescents with Average Intelligence, Borderline Intellectual Functioning, and Intellectual Disability

OBJECTIVE: Borderline intellectual functioning (BIF), defined by intelligence quotient (IQ) scores between 71 and 84, is associated with increased psychiatric vulnerability but remains poorly characterized in terms of clinical severity and treatment complexity. This study aimed to compare psychopathological burden, adaptive functioning, suicidality, and psychopharmacological treatment patterns among hospitalized adolescents with BIF, average intellectual functioning, and intellectual disability. METHODS: A retrospective chart review was conducted on adolescents aged 12-18 years admitted to a tertiary child and adolescent neuropsychiatry inpatient unit. Participants were classified into three groups based on full-scale IQ. Standardized assessments of cognitive functioning, psychiatric diagnoses, symptom severity, adaptive behavior, global functioning, and suicidality were integrated with clinical indicators derived from medical records, including emergency service utilization and psychotropic medication at discharge. Group differences were examined using nonparametric statistical analyses. RESULTS: The sample included 194 adolescents. Adolescents with BIF showed significantly poorer adaptive functioning across conceptual and practical domains compared with peers with average intellectual functioning, despite comparable global functioning. Overall psychiatric symptom severity at admission and discharge did not differ across groups; however, the BIF group displayed a mixed clinical profile with both internalizing and externalizing symptoms and persistent behavioral dysregulation. Compared with adolescents with average intellectual functioning, those with BIF demonstrated more frequent emergency psychiatric admissions and a higher likelihood of antipsychotic prescription at discharge. Suicidality differed qualitatively across cognitive groups: adolescents with cognitive impairment showed lower rates of suicide attempts, characterized by precipitation (i.e., falling from height) or defenestration (i.e., jumping from a window) as the only suicidal modality observed in this group. CONCLUSIONS: BIF in adolescence is associated with a distinct pattern of functional impairment and clinical complexity, characterized by adaptive difficulties and increased reliance on psychopharmacological treatment. These findings highlight the importance of considering cognitive functioning when planning treatment strategies in inpatient child and adolescent psychiatry.