Intellectual disability: definition, etiological factors, classification, diagnosis, treatment and prognosis

Salud Publica Mex. 2008:50 Suppl 2:s132-41. doi: 10.1590/s0036-36342008000800005.


ETIOLOGY AND CLASSIFICATION: Causal factors related with cognitive disability are multiples and can be classified as follows: Genetic, acquired (congenital and developmental), environmental and sociocultural. Likewise, in relation to the classification, cognitive disability has as a common denominator a subnormal intellectual functioning level; nevertheless, the extent to which an individual is unable to face the demands established by society for the individuals age group has brought about four degrees of severity: Mild, moderate, severe and profound.

Diagnostic: The clinical history must put an emphasis on healthcare during the prenatal, perinatal and postnatal period and include the results of all previous studies, including a genealogical tree for at least three generations and an intentional search for family antecedents of mental delay, psychiatric illnesses and congenital abnormalities. The physical exam should focus on secondary abnormalities and congenital malformations, somatometric measurements and neurological and behavioral phenotype evaluations. If it is not feasible to establish a clinical diagnosis, it is necessary to conduct high-resolution cytogenetic studies in addition to metabolic clinical evaluations. In the next step, if no abnormal data are identified, submicroscopic chromosomal disorders are evaluated.

Prognosis: Intellectual disability is not curable; and yet, the prognostic in general terms is good when using the emotional wellbeing of the individual as a parameter.

Conclusions: Intellectual disability should be treated in a comprehensive manner. Nevertheless, currently, the fundamental task and perhaps the only one that applies is the detection of the limitation and abilities as a function of subjects age and expectations for the future, with the only goal being to provide the support necessary for each one of the dimensions or areas in which the persons life is expressed and exposed.

Publication types

  • Review

MeSH terms

  • Algorithms
  • Humans
  • Intellectual Disability* / classification
  • Intellectual Disability* / diagnosis
  • Intellectual Disability* / etiology
  • Intellectual Disability* / therapy
  • Prognosis