Kaplan + Sadock's Synopsis of Psychiatry, 11e

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Chapter 31: Child Psychiatry

Intellectual disability and autism spectrum disorder (ASD) often coexist; 70 to 75 percent of those with ASD have an IQ below 70. In addition, epidemiologic data indicate that ASD occurs in approximately 19.8% of persons with intellectual dis- ability. Children with ASD have relatively more severe impair- ment in social relatedness and language than other children with the same level of intellectual disability. A child younger than the age of 18 years with significant adaptive functional impairment, with an IQ less than 70, who also meets diagnostic criteria for dementia, will receive both a diagnosis of dementia and intellectual disability. However, a child whose IQ drops below 70 after the age of 18 years with newly acquired cognitive impairment will receive only the diag- nosis of dementia. Treatment Interventions for children and adolescents with intellectual disability are based on an assessment of social, educational, psychiatric, and environmental needs. Intellectual disability is associated with a variety of comorbid psychiatric disorders that often require specific treatment, in addition to psychoso- cial support. Of course, when preventive measures are available, the optimal approach includes primary, secondary, and tertiary interventions. Primary Prevention Primary prevention comprises actions taken to eliminate or reduce the conditions that lead to development of intellectual disability, as well as associated disorders. For example, screen- ing babies for PKU, and administrating a low phenylalanine diet when PKU is present, significantly alters the emergence of intellectual disability in those affected children. Additional primary prevention steps include education of the general pub- lic about strategies to prevent intellectual disability, such as abstinence from alcohol during pregnancy; continuing efforts of health professionals to ensure and upgrade public health policies; and legislation to provide optimal maternal and child health care. Family and genetic counseling helps reduce the incidence of intellectual disability in a family with a history of a genetic disorder. Secondary and Tertiary Prevention Prompt attention to medical and psychiatric complications of intellectual disability can diminish their course (secondary prevention) and minimize the sequelae or consequent disabili- ties (tertiary prevention). Hereditary metabolic and endocrine disorders, such as PKU and hypothyroidism, can be treated effectively in an early stage by dietary control or hormone replacement therapy. Educational Interventions.  Educational settings for chil- dren with intellectual disability should include a comprehen- sive program that addresses academics and training in adaptive skills, social skills, and vocational skills. Particular attention should focus on communication and efforts to improve the qual- ity of life.

and concurrent attentional deficits are also more likely to show aberrant frontal-striatal pathways on MRI than those patients without attentional problems. MRI is also useful to elucidate myelination patterns. MRI studies can also provide a baseline for comparison of a later, potentially degenerative process in the brain. Hearing and Speech Evaluations Hearing and speech should be evaluated routinely. Speech development may be the most reliable criterion in investigating intellectual disability. Various hearing impairments often occur in persons who are intellectually disabled, but in some instances hearing impairments can simulate intellectual disability. The commonly used methods of hearing and speech evaluation, however, require the patient’s cooperation and, thus, are often unreliable in severely disabled persons. Course and Prognosis Although the underlying intellectual impairment does not improve, in most cases of intellectual disability, level of adap- tation increases with age and can be influenced positively by an enriched and supportive environment. In general, persons with mild and moderate mental intellectual disabilities have the most flexibility in adapting to various environmental conditions. Comorbid psychiatric disorders negatively impact overall prog- nosis. When psychiatric disorders are superimposed on intel- lectual disability, standard treatments for the comorbid mental disorders are often beneficial; however, less robust responses and increased vulnerability to side effects of psychopharmaco- logic agents are often the case. Differential Diagnosis By definition, intellectual disability must begin before the age of 18. In some cases, severe child maltreatment in the form of neglect or abuse may contribute to delays in development, which can appear to be intellectual disability. However these damages are partially reversible when a corrective, enriched, and stimulating environment is provided in early childhood. Sensory disabilities, especially deafness and blindness, can be mistaken for intellectual disability when a lack of awareness of the sensory deficit leads to inappropriate testing. Expressive and receptive speech disorders may give the impression of intel- lectual disability in a child of average intelligence, and cere- bral palsy may be mistaken for intellectual disability. Chronic, debilitating medical diseases may depress and delay a child’s functioning and achievement, despite normal intelligence. Sei- zure disorders, especially those that are poorly controlled, may contribute to persisting intellectual disability. Specific organic syndromes leading to isolated handicaps such as failure to read (alexia), failure to write (agraphia), or failure to communicate (aphasia), may occur in a child of normal and even superior intelligence. Children with learning disorders (which can coex- ist with intellectual disability) experience a delay or failure of development in a specific area, such as reading or mathematics, but they develop normally in other areas. In contrast, children with intellectual disability show general delays in most areas of development.