Classification and Diagnosis of Childhood Disorders

Developmental Psychopathology

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

• A primary principle of this field is the importance of understanding how a specific disorder may manifest differently across various age groups.

• The field considers the different expected courses of development when evaluating clinical presentations in children.

ADHD DSM-5 Diagnostic Criteria: Inattention

• Attention Deficit/Hyperactivity Disorder (ADHD) is defined by a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development.

• For a diagnosis of inattention, the following numerical thresholds must be met:   - Children up to age $16$: Six or more symptoms must be present.   - Adolescents age $17$ and older and adults: Five or more symptoms must be present.

• Symptoms of inattention must have been present for at least $6$ months, and they must be considered inappropriate for the individual's developmental level.

• Specific symptoms of inattention include:   - Often failing to give close attention to details or making careless mistakes in schoolwork, at work, or during other activities.   - Often having trouble holding attention on specific tasks or play activities.   - Often appearing as if they do not listen when spoken to directly.   - Often failing to follow through on instructions and failing to finish schoolwork, chores, or workplace duties (e.g., the individual loses focus or becomes easily side-tracked).   - Often having trouble organizing tasks and activities.   - Often avoiding, disliking, or being reluctant to engage in tasks that require sustained mental effort over a long period (such as schoolwork or homework).   - Often losing things necessary for tasks and activities (e.g., school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, or mobile telephones).   - Is often easily distracted.   - Is often forgetful in daily activities.

ADHD DSM-5 Diagnostic Criteria: Hyperactivity and Impulsivity

• For a diagnosis of hyperactivity-impulsivity, the following numerical thresholds must be met:   - Children up to age $16$: Six or more symptoms must be present.   - Adolescents age $17$ and older and adults: Five or more symptoms must be present.

• These symptoms must have been present for at least $6$ months to an extent that is both disruptive and inappropriate for the individual's developmental level.

• Specific symptoms of hyperactivity and impulsivity include:   - Often fidgeting with or tapping hands or feet, or squirming in their seat.   - Often leaving their seat in situations where remaining seated is expected.   - Often running about or climbing in situations where it is inappropriate (in adolescents or adults, this may be limited to a subjective feeling of restlessness).   - Often being unable to play or take part in leisure activities quietly.   - Is often "on the go," acting as if they are "driven by a motor."   - Often talking excessively.   - Often blurting out an answer before a question has been completed.   - Often having trouble waiting for his or her turn.   - Often interrupting or intruding on others (e.g., butting into conversations or games).

ADHD Presentations and Diagnostic Requirements

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

• Symptoms must be severe and persistent.

• Symptoms cannot be limited to the school setting; they must appear in multiple contexts.

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

• ADHD Presentations:   - Predominantly Hyperactive-Impulsive Presentation.   - Predominantly Inattentive Presentation: Characterized by distractibility and difficulty concentrating.   - Combined Presentation.

Prevalence and Course of ADHD

• The estimated prevalence rate for ADHD is $3-7\%$.

• The disorder is more common in boys than in girls.

• Peer interaction is significantly affected; children with ADHD are often extremely unpopular.

• The course of the disorder varies by individual:   - Some individuals experience no significant impairments as they reach adolescence and adulthood.   - Many individuals continue to experience the same degree of difficulty after childhood.   - The majority of individuals improve to some degree but still experience difficulties throughout adulthood.

Biological and Environmental Components of ADHD

• Genetic Factors:   - Supported by adoption and twin studies.   - Heritability estimates for ADHD are as high as $70\%$ to $80\%$.   - Two specific dopamine genes are implicated: a dopamine receptor gene and a dopamine transporter gene.

• Structural Brain Abnormalities:   - Individuals with ADHD often have smaller frontal lobes.   - Underactivity has been observed in various brain areas.

• Prenatal Factors:   - Maternal nicotine use is a significant factor, as it can interfere with the wiring of the dopaminergic system.

• Environmental Toxins:   - Research indicates that food additives and sugar are not related to ADHD.

Psychological and Social Contributors to ADHD

• Psychological and social factors seem to interact with primary genetic and neurobiological factors.

• These factors are likely to exacerbate or maintain ADHD behaviors but are usually not the entire cause.

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

Pharmacological Treatment of ADHD

• Stimulant medications are the most common pharmacological treatment.

• Specific medications include Ritalin and Adderall.

• Mechanism: These medications increase dopamine levels.

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

• Possible Side Effects:   - Loss of appetite.   - Sleep problems.

Psychological and Behavioral Treatment of ADHD

• Behavioral Treatment:   - Utilizes operant conditioning principles.   - Includes parent training.   - Includes classroom management and teacher training.

• Classroom Structure Recommendations:   - Use of brief assignments.   - Provision of immediate feedback.   - Maintaining a task-focused style.   - Allowing breaks for exercise.

• Effectiveness:   - Often very successful while being actively implemented.   - Benefits do not always last after treatment ends, and the skills do not always generalize to other settings.

Autism Spectrum Disorder (ASD): Overview and Classification

• ASD previously belonged to a category called Pervasive Developmental Disorders (PDD).

• This older category included "Autistic Disorder," "Asperger Syndrome," and other similar disorders.

• Research suggested these conditions were similar enough to be merged, differing mostly in terms of severity.

DSM-5 Diagnostic Criteria for Autism Spectrum Disorder

• Category 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.

• Category B: Restricted, repetitive patterns of behavior, interests, or activities, as manifested by at least two of the following:   1. Stereotyped or repetitive movements, use of objects, or speech (e.g., simple motor stereotypies, lining up toys, flipping objects, or 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 interest in sensory aspects of the environment.

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

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

Characteristics of Classic Autistic Disorder

• Impairments in Social Interactions:   - Lack of normal social attachment development.   - Infants may not engage in joint attention.   - Infants may look at faces less frequently.   - Physical play is often unpleasant; children typically do not enjoy hugging or being touched.

• Repetitious or Rigid Behaviors:   - Individuals are extremely upset by changes in routine.   - Abnormal preoccupation with objects (e.g., staring at or examining parts of objects).   - Ritualized behaviors such as body rocking and hand flapping.

• Impairments in Communication:   - Abnormalities in pre-verbal processes during infancy, such as delayed babbling.   - Echolalia: The repetition of things heard.   - Pronoun reversal: For example, saying "you" instead of "me."

Asperger Syndrome (High-Functioning Autism)

• Asperger Syndrome is no longer an official distinct disorder; it is now included within Autism Spectrum Disorder.

• It is often referred to as high-functioning autism.

• Cognitive and language skills are typically unimpaired.

• Social Abnormalities:   - Unlike "classic" autistic disorder where people appear withdrawn, individuals with Asperger Syndrome typically have as much interest in social interaction and relationships as typically-developing people.   - Their difficulty lies in not knowing what is appropriate and failing to understand social cues.

Prognosis and Demographics of Autism Spectrum Disorders

• ASD is more common in boys, with a ratio of approximately $4:1$.

• Prognosis Indicators:   - Children who have higher IQs and are able to speak before age $6$ have the best outcomes.

• Adult outcomes:   - Many can function fairly independently in adulthood.   - Even those who function well occupationally often continue to have extreme social impairments.

Etiological Factors and Biological Explanations for Autism

• Genetic Factors:   - Siblings of individuals with ASD are much more likely to have the disorder.   - Twin studies show a strong genetic influence:     - Concordance rates for identical twins range from $60\%$ to $91\%$.     - Concordance rates for fraternal twins range from $0\%$ to $21\%$.   - Risk may increase with an older father.

• Neuroanatomical Factors:   - Brain Size: Though brain size is normal at birth, the brains of autistic children and adults are larger than normal.   - Pruning: The process of pruning neurons, where the nervous system trims away extra neurons and connections during the first $1-2$ years of life for efficiency, may not occur properly.   - Cerebellum abnormalities are noted.   - Communication: The most significant abnormalities are in the pathways between brain structures rather than the structures themselves, leading to abnormal communication among brain parts.

Behavioral and Biological Interventions for Autism

• Biological Intervention:   - Drugs are sometimes used to control self-injurious behaviors or uncontrollable harmful behavior.

• Behavioral Interventions:   - Recognized as the most effective and widely used approach.   - Based on operant conditioning principles.   - Includes parent training and education.   - Some programs are very time-intensive but highly effective.   - Early intervention is considered particularly important for success.