Do the mentally retarded suffer from affective illness?

Area of Science:

• Psychiatry
• Developmental Psychology
• Clinical Psychology

Background:

• Affective illnesses, including depression and mania, are prevalent psychiatric conditions.
• Mental retardation (MR) is a developmental disability characterized by significant limitations in intellectual functioning and adaptive behavior.
• The co-occurrence of affective disorders in individuals with MR has been a subject of clinical and research interest.

Purpose of the Study:

• To review published reports on the occurrence of affective illness in individuals with mental retardation.
• To assess the validity of diagnosing depression and mania in this population using DSM-III criteria.
• To provide guidance on diagnosing and treating affective disorders in individuals with varying degrees of mental retardation.

Main Methods:

• A systematic review of twenty-five published reports was conducted.
• Diagnostic validity was assessed using the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III) criteria.
• Clinical presentation, behavioral changes, vegetative functioning, and family history were considered for diagnosis.

Main Results:

• Individuals with mental retardation manifest the full range of affective disorders.
• Social functioning and intelligence levels influence clinical presentation but not the development of affective symptoms.
• Affective disorder diagnoses are possible for all levels of MR severity, with adapted criteria for severe and profound cases.

Conclusions:

• Affective disorders are diagnosable in individuals with all levels of mental retardation.
• Standard DSM-III criteria are applicable for mild to moderate MR; modified approaches are useful for severe/profound MR.
• Individuals with MR and psychiatric symptoms warrant evaluation for affective disorders and consideration for comprehensive treatment, including psychotherapy and pharmacotherapy.