15.10 - disorders in childhood

Attention Deficit/Hyperactivity Disorder (ADHD)

Definition:

  • A neurodevelopmental disorder characterized by patterns of inattention, hyperactivity, and impulsivity that interfere with normal functioning.

Symptoms:

  • Inattention: difficulty sustaining attention, avoidance of tasks requiring prolonged focus, failure to follow instructions, disorganization, forgetfulness, easily distracted.

  • Hyperactivity: excessive movement, fidgeting, trouble sitting still, running or climbing inappropriately.

  • Impulsivity: blurting out answers, difficulty waiting one’s turn, interrupting others.

  • Behavior is often hasty and impulsive, leading to academic and social challenges.

Prevalence:

  • Affects about 8% of children.

  • Boys are diagnosed about three times more often than girls.

  • For approximately 60% of individuals, ADHD persists into adulthood.

Life Impact:

  • Children with ADHD often have lower academic achievement, higher rates of expulsion, grade retention, and school dropout.

  • Social challenges include peer rejection and social functioning difficulties.

  • Adults with untreated ADHD show poorer educational attainment, occupational status, social functioning, and are more likely to have substance abuse issues.

  • Higher risk of substance abuse and traffic accidents in adolescence and adulthood.

Causes:

  • Strong genetic component: higher concordance in identical twins (.66-.90) than fraternal twins (.20).

  • Involves dopamine regulation deficits and abnormalities in the frontal lobes of the brain.

  • Environmental factors: prenatal exposure to nicotine linked with more severe symptoms.

  • Not caused by poor parenting or sugar consumption (contrary to common misconceptions).

Diagnosis and Trends:

  • Increased awareness and better diagnostics have contributed to rising reported prevalence.

  • Increase in ADHD diagnosis may relate to greater recognition, changes in diagnostic criteria, and technological factors influencing attention spans.

Autism Spectrum Disorder (ASD)

Definition:

  • A neurodevelopmental disorder involving significant deficits in social interaction, communication, and the presence of repetitive patterns of behavior or interests.

  • The "spectrum" indicates a range of symptom severity from mild to severe.

Symptoms:

  • Social deficits: avoidance of conversation, poor eye contact, preference for solitary play.

  • Communication difficulties: lack of speech or limited speech, echolalia (repeating others’ words), trouble maintaining reciprocal conversation.

  • Repetitive behaviors: stereotyped movements (rocking, hand-flapping), insistence on routines, highly fixated interests.

  • Not caused by intellectual disability, although they may co-occur.

Prevalence:

  • About 1 in 59 children in the U.S. diagnosed with ASD.

  • Boys are about four times more likely to be diagnosed than girls.

  • Rates of diagnosis have increased markedly since the 1980s.

Life Impact:

  • Varies widely; some individuals with higher functioning can live independently.

  • Many experience substantial impairments in social, academic, and occupational areas.

Causes:

  • Strong genetic influence: high concordance in identical twins (60%-90%).

  • Multiple genes involved, particularly those affecting brain connectivity and synaptic circuits.

  • Environmental factors such as pollutants, prenatal conditions, and vitamin D deficiency may increase risk.

  • No credible scientific evidence linking vaccines to ASD; an early study proposing this was discredited and retracted.

Additional Notes:

  • Both disorders involve complex interactions of genetics and environment.

  • Increased public awareness and diagnostic sophistication have led to higher reported prevalence.

  • Treatments and research continue to evolve to better address these lifelong conditions.