ADHD and Autism

Attention-Deficit/Hyperactivity Disorder (ADHD)

• Definition: A neurodevelopmental disorder involving age-inappropriate levels of hyperactivity, impulsivity, and inattention.
• Presentations:
  • Predominantly inattentive: difficulty with attention to detail, following instructions, organization, tasks requiring effort, and managing timetables. Frequently misplaces items. Easily distracted.
  • Predominantly hyperactive-impulsive: fidgeting, difficulty remaining still, excessive running/climbing (in childhood), excessive talking, blurting out answers, difficulty waiting turns, interrupting others.
  • Combined presentations: exhibit symptoms of both inattentive and hyperactive-impulsive types.
• Clinical Presentation Across Different Developmental Stages: Characteristic behaviors (inattention, distractibility, impulsivity) are observed across childhood, adolescence and adulthood.
• Adults: Symptoms manifest as inattention, distractibility, disorganization, and inefficient task completion negatively impacting academics and employment.
• Prevalence: Common in childhood and adolescence, persisting in about 50% of individuals into adulthood. Affects approximately 10% of children and 4.5% of adults; males are affected more commonly (2:1 ratio).
• Etiology: Multifactorial; genetic predisposition (increased incidence in first-degree relatives) and environmental factors (prenatal exposure to neurotoxins, low birth weight, potential abuse/neglect) are involved.
• Diagnosis (DSM-5): Onset before age 12; symptoms for at least 6 months observed in two or more settings (e.g., home, school).
• Differential Diagnosis: Conditions such as oppositional defiant disorder, conduct disorder, mood disorders, substance use disorder, and anxiety must be ruled out.
• Treatment: Medications combined with education and behavioral interventions.
  • First-line: Stimulants (methylphenidate, dextroamphetamine).
  • Second-line: Alpha-2 agonists (e.g., clonidine) for those who do not respond to or have side effects from stimulants.
  • Mechanism of Action: Catecholamines play a role in attention within the cerebral cortex; methylphenidate is a common intervention.
  • Dosage and Administration: Typically begins with a low dose (e.g., 5mg), gradually increasing over weeks depending on the response and side effects. Multiple daily doses are often needed.
  • Potential Adverse Effects: Insomnia, anorexia, weight loss, and growth suppression (in children).

Autism Spectrum Disorder (ASD)

• Definition: A neurodevelopmental disorder characterized by persistent difficulties with social communication and repetitive, restricted patterns of behavior, interests, or activities.
• Onset: Typically in developmental period, often before school entry.
• Diagnosis (DSM-5): Criteria are focused on:
  • A. Persistent Deficits in Social Communication and Social Interaction:
    • Difficulties in social-emotional reciprocity, nonverbal communication, developing and maintaining relationships.
  • B. Restricted, Repetitive Patterns of Behavior, Interests, or Activities:
    • Stereotyped motor movements, use of objects, or speech; insistence on sameness, inflexible adherence to routines; highly restricted interests.
    • Includes sensory sensitivities: unusual interests in sensory aspects of the environment.
  • C-E: Symptoms must be present in early developmental period; significantly impact functioning in various areas; and not better explained by another condition.
• Severity Specifiers: Very substantial, substantial, support (based on social communication and restricted behaviors.)
• Specifiers: With or without intellectual impairment, language impairment; associated with a known genetic or medical condition or environmental factor, or associated with a neurodevelopmental, mental, or behavioral problem.
• Specifiers with catatonia: also be specified
• General Characteristics: May present with language deficits (absence of speech, delays, or unusual speech patterns), social deficits that may manifest differently in older children and adults.
• Social Interactions and Preferences: Solitary activities might be preferred; interactions with individuals younger or older could be preferred. Approaches that seem aggressive or disruptive may occur.
• Diagnostic Features: Restricted/repetitive patterns of behaviors (hand flapping, repetitive use of objects, stereotyped words/phrases).
• Development and Course: Typically recognized during the second year of life (12-24 months). Severe cases may be recognized earlier.
• Prognosis: Dependent on presence of comorbid conditions.
• Differential Diagnosis: Comorbidities must be considered, including epilepsy (associated with greater intellectual disability); ADHD (distinguishing features: absence of restricted behaviors or unusual interests).
• Psychiatric Comorbidities: High prevalence (70%) of comorbid mental disorders (including anxiety, depression, ADHD) and frequent presentation of avoidant/restrictive food intake disorder (ARFID).