Neurodevelopmental Disorder

Core Characteristics

  • Onset: Early developmental period (before school)

  • Domains affected: Cognitive, social, communication, motor, learning, and adaptive functioning

  • Key insight: "Present" does not always mean "visible"—some deficits may not be obvious but still impact function.

Study Pointer:
Understand that not all developmental deficits are externally observable, yet they may significantly impair functioning.

Categories of Neurodevelopmental Disorders

  1. Communication Disorders

  2. Autism Spectrum Disorder

  3. Attention-Deficit/Hyperactivity Disorder (ADHD)

  4. Specific Learning Disorder

  5. Motor Disorders

  6. Intellectual Disabilities

  7. Global Developmental Delay

Communication Disorders (4 Types)

1. Language Disorder

  • Difficulty acquiring and using language (spoken, written, sign language)

  • Symptoms: Reduced vocabulary, limited sentence structure, impaired discourse

  • Language ability is significantly below age level

2. Speech Sound Disorder

  • Difficulty with speech sound production (e.g., saying "gog" instead of "dog")

  • Impairs speech intelligibility and verbal communication

  • Phonemes (individual sounds) are not articulated properly by age 5

3. Childhood-Onset Fluency Disorder (Stuttering)

  • Interruptions in normal speech flow (e.g., sound/syllable repetition, silent blocking, prolongations)

  • Causes anxiety, especially in social speaking situations

  • Fluency often improves when reading aloud or speaking to pets

4. Social (Pragmatic) Communication Disorder

  • Difficulty using verbal and nonverbal language in social contexts

  • Struggles with conversational rules, context changes, and understanding implicit meanings

  • Impacts social participation and academic performance

Study Pointer:
Differentiate between communication form (speech/language) and function (pragmatic/social use).

Autism Spectrum Disorder (ASD)

  • Persistent deficits in social communication and interaction

  • Restricted and repetitive behaviors (e.g., flapping, lining up toys)

  • Insistence on routines; difficulty with change

  • Hypersensitivity or lack of sensitivity to sensory input

  • Varies by severity, age, cognitive level, and gender

  • Adults may "mask" difficulties using coping strategies

Study Pointer:
Understand ASD as a spectrum: symptoms vary in intensity and presentation.

Intellectual Developmental Disorder (Intellectual Disability)

  • Deficits in intellectual functioning: reasoning, problem-solving, planning

  • Deficits in adaptive functioning: social skills, conceptual understanding, and practical tasks (e.g., money, hygiene)

  • Diagnosis requires clinical and standardized testing

  • IQ typically two standard deviations below the mean (approx. <70)

Study Pointer:
Know the distinction between Criterion A (IQ) and Criterion B (adaptive skills) for diagnosis.

Global Developmental Delay

  • Used for children under 5 when full assessment is not possible

  • Delays in multiple areas (e.g., speech, motor, cognition)

Study Pointer:
Diagnosis is temporary—applied until the child is old enough for formal evaluation.

Motor Disorders

1. Developmental Coordination Disorder (DCD)

  • Poor acquisition and execution of motor skills (e.g., tying shoes, catching balls)

  • Impacts daily life activities

  • Movements may appear awkward or slow

2. Stereotypic Movement Disorder

  • Repetitive, purposeless movements (e.g., hand-flapping, rocking)

  • May result in self-injury

  • Specifiers: with or without self-injurious behavior

3. Tic Disorders

  • Tics: Sudden, rapid, non-rhythmic motor movements or vocalizations

Types of Tics:

  • Simple vocal: Grunting, throat clearing

  • Echolalia: Repeating others' words

  • Coprolalia: Involuntary swearing

  • Palilalia: Repeating one's own words

  • Echopraxia/Copropraxia: Repetitive imitation of others' movements or inappropriate gestures

Tourette’s Disorder:

  • Both motor and vocal tics for >1 year

Persistent Motor/Vocal Tic Disorder:

  • Only one type of tic present >1 year

Provisional Tic Disorder:

  • Motor and/or vocal tics <1 year duration

Study Pointer:
Differentiate tic types by duration, type, and co-occurrence.

Specific Learning Disorder (SLD)

  • Difficulty in reading, writing, or mathematics

  • Symptoms must persist >6 months despite interventions

  • Academic skills substantially below age expectations

Common Manifestations:

  • Inaccurate/slow reading

  • Poor spelling/writing

  • Trouble with calculations or mathematical reasoning

SLD vs. Intellectual Developmental Disorder:

  • SLD: Specific skill deficits, normal IQ

  • IDD: Global intellectual and adaptive deficits

Study Pointer:
Look for discrepancies between intellectual potential and academic performance.

Attention-Deficit/Hyperactivity Disorder (ADHD)

  • Inattention and/or hyperactivity-impulsivity present before age 12

  • Symptoms must occur in two or more settings

  • Affects social, academic, and work life

Inattention Symptoms (6+):

  • Careless mistakes, distractibility, disorganization, forgetfulness

Hyperactivity-Impulsivity Symptoms (6+):

  • Fidgeting, talking excessively, difficulty waiting, interrupting

Developmental Course:

  • Before age 4: High motor activity

  • Preschool: Hyperactivity dominates

  • Grade school: Inattention emerges

  • Adolescence: Hyperactivity may decline, but inattention and impulsivity persist

Study Pointer:
ADHD diagnosis requires early onset, cross-setting symptoms, and significant impairment.

Final Study Advice:

  • Master core diagnostic criteria and distinguish between overlapping symptoms (e.g., ASD vs. Social Pragmatic Disorder).

  • Understand age of onset, functional impact, and key differentiators (e.g., speech vs. language disorder).

  • Pay attention to co-occurring features and modifiers (e.g., self-injury in movement disorders).

  • Use case examples to connect diagnostic features to real-life functioning.