Intellectual Disability, Developmental Delay, Learning or Communication Disorders, and Attachment Disorders

Intellectual disability, also called intellectual developmental disorder and formerly mental retardation, requires an IQ below 70, significantly reduced intellectual function, and concurrent difficulty adapting to demands at school, work, socially, or in other environments. Onset is before age 18. It affects about 1% of the population and is more common in school-age boys.

Global developmental delay usually appears in children younger than 5 as below-average intellectual functioning plus significant limitations in at least two other developmental areas. Clues include delayed sitting, crawling, or walking; limited reasoning or conceptual ability; poor social skills and judgment; communication difficulty; and aggressive behavior used as a coping skill.

Specific learning disorder means achievement in a particular area is substantially below expectations for the patient’s age, intelligence, sensory abilities, and educational experience. Types affect reading, mathematics, or written expression; reading disorder is the most common.

Communication disorders include language disorder, speech sound disorder, childhood-onset fluency disorder, and social (pragmatic) communication disorder, which impairs social verbal and nonverbal communication. Phonological disorder and stuttering fall within this group. Speech therapists provide treatment tailored to the individual’s needs.

Reactive attachment disorder is uncommon and involves markedly disturbed, developmentally inappropriate social relating in most contexts. Its inhibited form shows persistent failure to initiate or respond to social interaction appropriately, including extreme reluctance to initiate or accept comfort and affection, even from familiar adults, especially when distressed. Disinhibited social engagement instead involves active approaches to and interaction with unfamiliar adults.

Family involvement is crucial in child and adolescent treatment. Parents are often the primary agents of change, especially for younger children. Family therapy can address family dynamics that contribute to or maintain a child’s symptoms.

The three most common inborn causes are Down syndrome, velocardiofacial syndrome, and fetal alcohol syndrome. Other genetic or chromosomal causes include lipidoses, aminoacidurias, glycogen storage diseases, cri du chat syndrome, and fragile X syndrome. Additional causes include intrauterine or postnatal rubella or CMV infection, toxins, alcohol, hypoxia, malnutrition such as iodine deficiency, heavy metals, physical trauma, and social deprivation.

Causes and risk factors may be genetic, such as fragile X syndrome; metabolic, such as phenylketonuria; prenatal, such as rubella or birth trauma; or perinatal, such as prematurity, injury, or infection. Sometimes no cause is identified. Treatment targets the underlying cause.

Specific learning disorder affects about 5% of school-age children. Associations include male sex, genetic factors, low socioeconomic status, cerebral palsy, lead poisoning, and fetal alcohol syndrome. Many cases have no obvious cause.

Disinhibited behavior may include indiscriminate, excessive attempts to obtain comfort and affection from any available adult, even a relative stranger. Examples include sitting on a stranger’s or peer’s lap or leaving with a stranger. The pattern significantly impairs relationships with adults and peers.

Consider the child’s environment beyond the family and coordinate with the school when support is needed. Child and adolescent psychiatrists must recognize child-protection concerns; as mandated reporters, they must know when and how to report suspected abuse or neglect.

Mild intellectual disability: IQ 50–69. Academic skills may reach the sixth-grade level, and the person may live independently or with minimal supervision. Impulse control and self-esteem problems may occur, with associated conduct disorders, drug abuse, and ADHD.

Onset is usually during elementary school, with difficulty in reading, mathematics, or written expression. School failure, low self-esteem, poor social maturity, and behavioral disturbance may follow, and the disorder may persist into adulthood. Perceptual-motor problems, conduct disorder, oppositional defiant disorder, and ADHD may coexist.

Disinhibited social engagement disorder, also called disinhibited attachment disorder of childhood, is not diagnosed before 9 months of age or after age 5. Inconsistent or insufficient care from a primary caregiver is a risk factor.

Moderate intellectual disability: IQ 35–49. Academic skills may reach the second-grade level. The person may manage activities of daily living and work with serious supervision but have significant difficulty conforming to social norms. A patient with Down syndrome has increased risk of early Alzheimer disease.

Use IQ and academic achievement testing as the major diagnostic tools. Rule out hearing impairment, vision impairment, environmental deprivation, and intellectual disability.

Reactive attachment management may combine psychosocial support for the family, including financial or domestic aid, psychotherapy, education in basic parenting skills and child development, and monitoring the child’s safety. For disinhibited social engagement, two effective approaches are play therapy and expressive therapy; both help form attachment through multisensory means.

Severe: IQ 20–34. Profound: IQ below 20. Speech is limited or absent, self-care ability is very limited, and intensive support in a continuously highly supervised environment is required.

The main treatment is special education, such as remedial or individual classes and high-quality instruction, to improve general learning and skills in deficient areas. Counseling for the patient and family can support self-esteem, social behavior, and family functioning.