Childhood Disorders: ADHD and Autism

Developmental Psychopathology: Classification and Diagnosis

• Developmental psychopathology is the study of childhood disorders within the context of normal child development.

• It is critical to understand how the same disorder manifests differently across various age groups.

• The study takes into account the different expected courses of development for children as they mature.

Attention Deficit/Hyperactivity Disorder (ADHD): DSM-5 Diagnostic Criteria

• ADHD is defined as a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development.

• Criteria for Inattention:

  • Children (up to age $16$): Require six or more symptoms.

  • Adolescents ($17$ and older) and Adults: Require five or more symptoms.

  • Duration: Symptoms must have been present for at least $6\,\text{months}$.

  • Qualifiers: Symptoms must be inappropriate for the individual's developmental level.

  • Specific Inattention Symptoms:

    • Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or during other activities.

    • Often has trouble holding attention on tasks or play activities.

    • Often does not seem to listen when spoken to directly.

    • Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., loses focus, gets side-tracked).

    • Often has trouble organizing tasks and activities.

    • Often avoids, dislikes, or is reluctant to do tasks requiring mental effort over a long period (such as schoolwork or homework).

    • Often loses things necessary for tasks and activities (e.g., school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).

    • Is often easily distracted.

    • Is often forgetful in daily activities.

• Criteria for Hyperactivity and Impulsivity:

  • Children (up to age $16$): Require six or more symptoms.

  • Adolescents ($17$ and older) and Adults: Require five or more symptoms.

  • Duration: Symptoms must have been present for at least $6\,\text{months}$ to an extent that is disruptive and inappropriate for the person's developmental level.

  • Specific Hyperactivity-Impulsivity Symptoms:

    • Often fidgets with or taps hands or feet, or squirms in seat.

    • Often leaves seat in situations when remaining seated is expected.

    • Often runs about or climbs in situations where it is not appropriate (Note: In adolescents or adults, this may be limited to feeling restless).

    • Often unable to play or take part in leisure activities quietly.

    • Is often "on the go," acting as if "driven by a motor."

    • Often talks excessively.

    • Often blurts out an answer before a question has been completed.

    • Often has trouble waiting his/her turn.

    • Often interrupts or intrudes on others (e.g., butts into conversations or games).

ADHD Subtypes and General Diagnostic Requirements

• General Requirements:

  • Symptoms must be severe and persistent.

  • Several symptoms must be present before age $12$.

  • Symptoms must occur in more than just a school setting.

  • There must be clear evidence that symptoms interfere with or reduce the quality of social, school, or work functioning.

• Presentations (Subtypes):

  • Predominantly Hyperactive-Impulsive Presentation: Primary symptoms fall under hyperactivity and impulsivity.

  • Predominantly Inattentive Presentation: Characterized by distractibility and difficulty concentrating.

  • Combined Presentation: Meets criteria for both inattention and hyperactivity-impulsivity categories.

Prevalence, Course, and Biological Components of ADHD

• Rate and Course:

  • Prevalence rate is estimated to be between $3\,\%$ and $7\,\%$.

  • The disorder is more common in boys.

  • Peer Interactions: Children with ADHD are often extremely unpopular due to their symptoms.

  • Developmental Path:

    • Some individuals have no significant impairments upon reaching adolescence and adulthood.

    • Many continue to experience the same degree of difficulty after childhood.

    • The majority improve to some degree but continue to have difficulties throughout adulthood.

• Biological Components:

  • Genetic Factors:

    • Supported by adoption and twin studies.

    • Heritability estimates are as high as $70\,\%$ to $80\,\%$.

    • Two dopamine genes are specifically implicated: a dopamine receptor gene and a dopamine transporter gene.

  • Neuroanatomical Factors:

    • Structural abnormalities include smaller frontal lobes.

    • Underactivity is observed in various areas of the brain.

  • Prenatal Factors:

    • Maternal nicotine use can interfere with the wiring of the dopaminergic system.

  • Environmental Toxins:

    • Food additives and sugar are specifically noted as not being related to ADHD.

Other Contributors and Treatments for ADHD

• Psychological and Social Factors:

  • These factors interact with primary genetic and neurobiological foundations.

  • They are likely to exacerbate or maintain ADHD behaviors rather than being the sole cause.

  • Examples include ineffective parenting, allowing over-stimulation, or ignoring the child.

• Pharmacological Treatment:

  • Stimulant medications are most common, specifically Ritalin and Adderall.

  • Mechanisms: Increases dopamine levels.

  • Benefits: Reduces disruptive behavior, increases goal-directed behavior, and improves attention, concentration, and social functioning.

  • Side Effects: Loss of appetite and sleep problems.

• Psychological Treatment:

  • Behavioral Treatment: Based on operant conditioning principles.

  • Parent and Teacher Training: Focuses on classroom management and home environments.

  • Classroom Structure Recommendations:

    • Brief assignments.

    • Immediate feedback.

    • Task-focused style.

    • Breaks for exercise.

  • Effectiveness: Often very successful while actively being used; however, effects do not always generalize to other settings or persist after the treatment ends.

Autism Spectrum Disorder (ASD): Overview and DSM-5 Criteria

• Classification History:

  • Previously categorized under Pervasive Developmental Disorders (PDD), which included "Autistic Disorder" and "Asperger Syndrome."

  • Research suggested these were similar enough to be grouped, differing primarily in severity.

• DSM-5 Diagnostic Criteria:

  • Criterion A: Deficits in social communication and social interaction across multiple contexts, manifested by:

    1. Deficits in social-emotional reciprocity.

    2. Deficits in nonverbal communicative behaviors used for social interaction.

    3. Deficits in developing, maintaining, and understanding relationships.

  • Criterion B: Restricted, repetitive patterns of behavior, interests, or activities, manifested by at least two of the following:

    1. Stereotyped or repetitive movements, use of objects, or speech (e.g., motor stereotypies, lining up toys, flipping objects, echolalia).

    2. Insistence on sameness, inflexible adherence to routines, or ritualized patterns of behavior.

    3. Highly restricted, fixated interests that are abnormal in intensity or focus.

    4. Hyperreactivity or hyporeactivity to sensory input or unusual interests in sensory aspects of the environment.

  • Criterion C: Signs must be present in the early developmental period.

  • Criterion D: Symptoms cause clinically significant impairment in social, occupational, or other important areas of functioning.

Manifestations of Autism and Asperger Syndrome

• "Classic" Autistic Disorder:

  • Social Impairments: Lack of normal social attachment development. Infants may not engage in joint attention and often look at faces less. Physical play (hugging, touching) is often perceived as unpleasant.

  • Rigid Behaviors: Extreme distress over changes in routine. Abnormal preoccupation with objects or parts of objects. Ritualized behaviors such as body rocking and hand flapping.

  • Communication Impairments: Abnormal pre-verbal processes (e.g., delayed babbling). Characterized by Echolalia (repeating heard words) and Pronoun Reversal (e.g., saying "you" instead of "me").

• Asperger Syndrome:

  • Now subsumed under Autism Spectrum Disorder.

  • Often referred to as "high-functioning autism."

  • Language and cognitive skills remain unimpaired.

  • Social differences: Unlike "classic" autism where individuals appear withdrawn, those with Asperger Syndrome typically have a high interest in social interaction but struggle with social cues and knowing what is appropriate.

Etiology and Prognosis of Autism Spectrum Disorder

• Demographics and Prognosis:

  • More common in boys with a ratio of approximately $4:1$.

  • Best outcomes are associated with children who have higher IQs and are able to speak before age $6$.

  • Many can function fairly independently in adulthood, though extreme social impairments often persist even in those who are occupationally successful.

• Genetic Factors:

  • Siblings are much more likely to have the disorder.

  • Twin studies:

    • Concordance rates for identical twins: $60\,\%$ to $91\,\%$.

    • Concordance rates for fraternal twins: $0\,\%$ to $21\,\%$.

    • This disparity highlights a strong genetic influence.

  • Risk may increase with an older father.

• Neuroanatomical Factors:

  • Brain Size: Normal at birth, but brains of autistic adults and children become larger than normal.

  • Neural Pruning: There is a suggestion that the pruning of neurons (trimming extra neurons/connections in the first $1-2\,\text{years}$ of life) may not occur properly.

  • Structure and Communication: Cerebellum abnormalities are noted. The most significant abnormalities involve the pathways between structures, leading to abnormal communication among brain regions.

• Interventions:

  • Biological: Drugs may be used to control self-injurious or uncontrollable harmful behavior.

  • Behavioral: The most effective and widely used approach.

    • Utilizes operant conditioning principles.

    • Includes parent training and education.

    • Early intervention is particularly critical for better outcomes.

    • Programs can be time-intensive but very effective.