Neurodevelopmental & Schizophrenia Spectrum Disorders: Key Features and Differences

Neurodevelopmental Disorders

Disorders that appear early in life due to issues in neural development.

Causes of Neurodevelopmental Disorders

Physical trauma, prenatal infections, toxins, poor nutrition, genetics, and unknown in some cases.

Impact of Neurodevelopmental Disorders

Deficits in social, academic, and/or occupational functioning.

Overlap in Neurodevelopmental Disorders

Can co-occur (e.g., ADHD + Learning Disorder).

Intellectual Developmental Disorder (IDD)

(DSM-5 term: Intellectual Disability)

Deficits in Intellectual Functioning

Measured with IQ test → 65-75 = below average.

Deficits in Adaptive Functioning

Inability to meet developmental & sociocultural standards of independence/responsibility.

Life Areas Affected by IDD

Deficits in ≥1 life area: Communication, Social participation, Independent living.

Multiple Environments Requirement for IDD

Must occur in multiple environments (e.g., home + school).

Onset during Developmental Period for IDD

Severe deficits: noticeable within first 2 years; Mild deficits: may not appear until school age.

Features of IDD

May be linked to genetic syndromes (e.g., Down Syndrome).

Course of IDD

Lifelong, but severity can shift depending on co-existing conditions.

Gender Differences in IDD

More common in males (both mild + severe).

Social Impact of IDD

Stigma and ridicule are common.

Mnemonic for IDD Criteria

IDD = I.A.D. (I = Intellectual deficits, A = Adaptive deficits, D = Developmental period onset).

IQ Cutoff Range for IDD

Know the IQ cutoff range (65-75).

Link to Down Syndrome

Down Syndrome is an example cause of IDD.

Autism Spectrum Disorder (ASD)

Spectrum Disorder: Wide range of linked conditions (DSM-5 combines Asperger's + Autism under one category).

Severity Levels of ASD

Level 1: Requiring support; Level 2: Requiring substantial support; Level 3: Requiring very substantial support.

Social Communication & Interaction Deficits in ASD

Problems with back-and-forth conversation, lack of response to social cues, abnormal eye contact, facial expressions, gestures, trouble forming/understanding relationships, limited interest in peers.

Restricted/Repetitive Behaviors in ASD

Repetitive movements (hand-flapping, rocking), insistence on sameness/routines, highly restricted, intense interests, over/under-reactivity to sensory input.

Onset in Early Childhood for ASD

Symptoms usually visible by age 2; possible developmental plateau or regression.

Significant Impairment in ASD

Symptoms interfere with daily functioning.

Intellectual Disability (ID)

Can co-occur with IDD, but IDD ≠ diagnostic feature of ASD

Early signs of ASD

Delayed language development

Course of ASD

Non-degenerative (doesn't worsen; with support, gains may occur)

Level 1 ASD

May achieve independence with support

Genetics in ASD

Twin studies → heritability 37-90%

Parental Age

Advanced age increases risk

Medication Risk Factor

Valproate use during pregnancy increases risk

Gender Risk Factor

Males 4× more likely to be diagnosed than females

Mnemonic for ASD Criteria

ASD = SRSID (S = Social deficits, R = Restricted/repetitive behaviors, S = Symptoms in early childhood, I = Impairment in functioning, D = Disturbance not better explained by IDD)

Regression or Plateau in ASD

Look for regression or plateau → red flag

Difference between ASD and IDD

ASD = social/communication + restricted behaviors; IDD = global intellectual/adaptive deficits

Definition of ADHD

Persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with development or functioning.

ADHD Subtypes

Inattentive, Hyperactive-Impulsive, Combined

Childhood ADHD Diagnosis Criteria

≥ 6 symptoms (either subtype)

Adolescents/Adults ADHD Diagnosis Criteria

≥ 5 symptoms for individuals ≥17 years

ADHD Symptoms Requirements

Symptoms must be present before adolescence, appear in multiple settings, interfere with everyday functioning, and severity can be mild, moderate, or severe.

Inattentive Subtype Symptoms

Careless mistakes, trouble sustaining attention, doesn't listen when spoken to directly, fails to follow through on instructions, disorganized tasks, avoids tasks requiring sustained attention, frequently loses necessary items, easily distracted, forgetful in daily activities.

Hyperactivity-Impulsivity Subtype Symptoms

Fidgeting, leaves seat when expected to remain seated, runs/climbs in inappropriate situations, difficulty playing quietly, restlessness, talks excessively, blurts out answers before question completed, difficulty waiting turn, interrupts/intrudes on others.

Developmental Appropriateness in ADHD

Behaviors must exceed what is typical for age.

Multiple Contexts in ADHD

Can't be explained by situation alone (e.g., only at school).

Biological Risk Factors for ADHD

Strong genetic component; having a first-degree relative increases risk.

Prenatal/Perinatal Risk Factors for ADHD

Very low birth weight = risk factor; maternal smoking during pregnancy may raise risk.

Mnemonic for Inattentive Symptoms

"FAILS FOCUS" → (Forgetful, Attention lapses, Items lost, Listening poor, Sustained focus avoided)

Mnemonic for Hyperactive/Impulsive Symptoms

"HYPER TALKS" → (Hyper, Yells, Plays rough, Excessive talking, Restless, Turn-taking poor, Answers blurted, Leaves seat, Kinetic climbing, Squirming)

ADHD Diagnosis Requirements

Diagnosis requires: Early onset + multiple environments + impairment.

Differentiating ADHD from Normal Behaviors

Be ready to differentiate ADHD from normal childhood behaviors.

Schizophrenia Spectrum Disorders

Psychotic disorders marked by loss of contact with reality.

Core domains of disturbance

Delusions, Hallucinations, Disorganized thinking/speech, Grossly disorganized/abnormal behavior, Negative symptoms.

Delusions

False beliefs.

Hallucinations

False sensory experiences, especially auditory.

Disorganized thinking/speech

Incoherent or illogical thought processes and speech.

Grossly disorganized/abnormal behavior

Includes catatonia and socially inappropriate actions.

Negative symptoms

Absence of normal behaviors/emotions.

Schizophrenia

Distortions in thought, perception, and emotions.

Positive Symptoms

Symptoms that are 'added' such as delusions and hallucinations.

Disorganized Symptoms

Symptoms that include disorganized speech and behavior.

Clang associations

Word choice by sound rather than meaning, such as rhyming.

Catatonia

Rigid posture, no response, purposeless movement, repetitive grimacing.

Diagnosis (DSM-5 Criteria)

Requires ≥2 symptoms, one must be delusions, hallucinations, or disorganized speech.

Disturbance duration

Lasts ≥6 months, with ≥1 month of active symptoms.

Impaired functioning

Must cause impaired functioning in work, relationships, or self-care.

Substance exclusion

Symptoms cannot be explained by substances or medical conditions.

Genetics

Strong hereditary component; 14× higher risk if a parent has schizophrenia.

Neurobiology

Dopamine abnormalities; reduced brain volume; poor eye-tracking ability.

Diathesis-Stress Hypothesis

Biological predisposition + environmental stress = onset.

Onset for Men

Early to mid-20s, worse prognosis, more negative symptoms.

Onset for Women

Late 20s, better prognosis.

Suicide risk

~20% attempt at least once.

Life expectancy

Lower due to lifestyle, poor health care, substance abuse.

Comorbidities

Commonly associated with depression and substance use disorders.

Developmental Onset

Symptoms begin in childhood (severe = early, mild = later)

Lifelong condition

Severity may change over time.

Associated with genetic syndromes

Examples include Down Syndrome.

Males > females

Indicates a higher prevalence in males.

Social stigma

Commonly associated with developmental disorders.

IDD

Mnemonic for Intellectual, Adaptive, Developmental.

Severity Level 1

Requiring support.

Severity Level 2

Requiring substantial support.

Severity Level 3

Requiring very substantial support.

Criteria SRSID

Social deficits, restricted/repetitive behaviors, symptoms in early childhood, impairment in daily life, not explained by IDD.

Non-degenerative

Symptoms may improve with support.

Causes of ASD

Genetics (37-90% heritability), advanced parental age, prenatal valproate.

Males 4× more likely

Indicates a higher prevalence of ASD in males.

ADHD

Persistent pattern of inattention and/or hyperactivity-impulsivity that impairs development.

Inattentive subtype

Characterized by ≥6 symptoms in children or ≥5 in adolescents.

Hyperactive-Impulsive subtype

Characterized by ≥6 symptoms in children or ≥5 in adolescents.

Combined subtype

Includes symptoms of both inattentive and hyperactive-impulsive types.

Inattentive Symptoms (FAILS FOCUS)

Forgetful, Attention lapses, Items lost, Listening poor, Sustained tasks avoided, Focus difficult, Organization poor, Careless mistakes, Unfinished tasks, Stimuli distractible.

Hyperactive/Impulsive Symptoms (HYPER TALKS)

Hyperactive, Yells, Plays rough, Excessive talking, Restless, Turn-taking poor, Answers blurted, Leaves seat, Kinetic climbing, Squirming.

Schizophrenia Spectrum & Other Psychotic Disorders

Psychotic disorders characterized by distortions in thought, perception, and emotions.

Core Symptom Categories (P.N.D.)

Positive (delusions, hallucinations), Negative (flat affect, anhedonia, poverty of speech), Disorganized (speech, bizarre behavior, catatonia).

Diagnosis of Schizophrenia

≥2 symptoms (one must be delusions, hallucinations, or disorganized speech), duration ≥6 months (≥1 month active), impaired functioning, not due to substances or other conditions.

Causes of Schizophrenia

Genetics (14× higher risk if parent has it), dopamine dysfunction, reduced brain volume, poor eye-tracking.

Onset of Schizophrenia

Males (early-mid 20s), females (late 20s).

Males = worse prognosis

More cognitive & negative symptoms observed in males.

20% attempt suicide

Indicates a significant risk factor in schizophrenia.

Life expectancy reduced

Individuals with schizophrenia may have a lower life expectancy.