1. Introduction
This article introduces three major diagnostic categories frequently used in clinical psychology:
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Neurodevelopmental disorders
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Anxiety disorders
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Trauma- and stressor-related disorders
These groups differ in developmental timing, symptom structure, underlying neurobiology, and treatment approaches.
Students learning advanced clinical English benefit from understanding diagnostic logic, scientific explanations, and real-world case examples.
SECTION A — NEURODEVELOPMENTAL DISORDERS
Neurodevelopmental disorders begin early in life and affect cognitive, behavioural, and social functioning.
They reflect differences in brain development, neural connectivity, and information processing, not personal failings.
2. Neurodevelopmental Disorders
A. Attention-Deficit/Hyperactivity Disorder (ADHD)
Core Features
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inattention
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hyperactivity
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impulsivity
Symptoms must occur in two or more settings and cause functional impairment.
Etiology
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high heritability (~70–80%)
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frontostriatal circuit differences → difficulty with inhibition & planning
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dopamine & norepinephrine dysregulation
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delayed cortical maturation (especially prefrontal regions)
Treatment
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stimulant medication (methylphenidate, amphetamines)
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behavioural strategies
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executive-function training
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school/work accommodations
Scientific Expansion: ADHD Neurobiology
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Reduced activity in the prefrontal cortex affects sustained attention and inhibitory control.
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Slower development of connections between the PFC and basal ganglia affects planning and time management.
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Stimulants increase dopamine/norepinephrine, improving signal strength in attention circuits.
B. Autism Spectrum Disorder (ASD)
Core Features
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persistent social-communication difficulties
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restricted, repetitive behaviours or interests
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sensory sensitivity
Etiology
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strong genetic contribution
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differences in social brain networks (e.g., superior temporal sulcus)
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atypical sensory integration and prediction processing
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prenatal and early developmental factors
Treatment
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ABA or naturalistic-developmental behavioural therapies
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speech & occupational therapy
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social-skills training
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sensory accommodations
Scientific Expansion: ASD Brain Differences
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Increased local connectivity but reduced long-range connectivity → "detail-focused" processing.
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Atypical amygdala responses → altered social salience and emotional interpretation.
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Differences in predictive coding → sensory overload or difficulty with change.
SECTION B — ANXIETY DISORDERS
Anxiety disorders involve excessive fear, worry, or avoidance, leading to functional impairment.
They reflect interactions between genetic vulnerability, cognitive misinterpretation, and hyperactive threat systems.
3. Anxiety Disorders
A. Generalized Anxiety Disorder (GAD)
Core Features
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chronic, excessive worry
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restlessness or muscle tension
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irritability
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sleep disturbance
Symptoms persist 6 months or more.
Etiology
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cognitive biases toward threat
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heightened amygdala reactivity
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low GABA activity (reduced inhibition)
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genetic predisposition
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intolerance of uncertainty
Treatment
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CBT (worry exposure, reducing catastrophic thinking)
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SSRIs/SNRIs
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mindfulness & relaxation training
Scientific Expansion: Why GAD Persists
Chronic worry functions as:
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a mental avoidance strategy (“If I worry, nothing bad will happen”)
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an attempt to control uncertainty
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a reinforcement cycle (worry ↓ anxiety temporarily → worry strengthens)
B. Panic Disorder
Core Features
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recurrent, unexpected panic attacks
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persistent fear of additional attacks
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avoidance of activities or situations
Panic attack symptoms:
palpitations, shortness of breath, trembling, chest pressure, dizziness, derealization.
Etiology
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hypersensitivity to internal bodily sensations
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catastrophic misinterpretation (“I’m dying”)
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dysregulated autonomic nervous system
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increased locus coeruleus activity (noradrenaline)
Treatment
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CBT with interoceptive exposure (re-training reactions to bodily sensations)
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SSRIs/SNRIs
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controlled breathing techniques
Scientific Expansion: The Panic Feedback Loop
Interoceptive sensations → catastrophic interpretation → adrenaline surge → stronger sensations → panic attack.
CBT breaks the loop by disconfirming catastrophic beliefs.
C. Specific Phobias
Core Features
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intense, disproportionate fear of a specific object/situation
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immediate anxiety response
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avoidance
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recognition that the fear is excessive (in adults)
Treatment
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Exposure therapy (gold standard)
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cognitive restructuring
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sometimes VR-assisted therapy
Scientific Expansion: How Exposure Works
Exposure reduces fear through:
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habituation → anxiety naturally decreases
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extinction learning → the feared stimulus becomes safe
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inhibitory learning → new memories compete with fear memories
SECTION C — TRAUMA & STRESSOR-RELATED DISORDERS
These disorders require exposure to actual or threatened trauma.
They involve dysregulation of the amygdala, hippocampus, and stress hormones.
4. Trauma- and Stressor-Related Disorders
A. Post-Traumatic Stress Disorder (PTSD)
Core Symptom Clusters
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Intrusion – flashbacks, nightmares
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Avoidance – internal or external reminders
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Negative mood/cognition changes
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Hyperarousal – irritability, startle response, sleep disturbance
Symptoms persist over 1 month.
Etiology
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amygdala overactivation
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reduced hippocampal volume → fragmented memory
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HPA axis dysregulation
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trauma severity, loss of safety, lack of support
Treatment
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trauma-focused CBT
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EMDR
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SSRIs
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grounding & stabilization (early phase)
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somatic or polyvagal approaches (in complex trauma)
Scientific Expansion: Why PTSD Memories Feel “Alive”
Trauma memories are stored as:
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sensory fragments, not narrative
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implicit emotional states
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incomplete contextual information
The hippocampus fails to fully “time-stamp” the memory → the brain re-experiences it as present.
B. Acute Stress Disorder (ASD)
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Similar symptoms to PTSD
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Duration: 3 days to 1 month
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High risk of developing PTSD if untreated
C. Adjustment Disorder
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Emotional/behavioural response to a stressor
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Symptoms begin within 3 months
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Stressor is not extreme trauma
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Often related to life transitions (e.g., divorce, job loss)
5. Differential Diagnosis Logic
ADHD vs. Anxiety
ADHD → difficulty sustaining attention
Anxiety → attention consumed by worry
ASD vs. Social Anxiety
ASD → social-communication differences present since childhood
Social Anxiety → fear of judgment; skills intact
Panic Disorder vs. Medical Conditions
Important to rule out:
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arrhythmias
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thyroid issues
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asthma
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hypoglycemia
PTSD vs. GAD
PTSD → trauma-specific intrusions
GAD → generalized worry
6. Case Studies for Clinical Reasoning
Case Study 1: ADHD or Anxiety?
A 14-year-old struggles to focus, loses items, but also worries constantly.
Questions:
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Which symptoms point to ADHD?
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Which point to anxiety?
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Why is multi-setting impairment essential?
Case Study 2: Panic Disorder
A 25-year-old has sudden episodes of choking sensations and fear of dying while driving.
Questions:
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Why does this fit Panic Disorder?
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How would interoceptive exposure help?
Case Study 3: PTSD vs Acute Stress
A paramedic develops nightmares and avoidance 2 weeks after a traumatic event.
Questions:
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Which diagnosis fits now?
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When would PTSD be diagnosed?
7. Academic Vocabulary
hyperarousal
avoidance behaviour
executive functioning
catastrophic interpretation
sensory processing
interoception
autonomic dysregulation
exposure therapy
trauma response
HPA axis
developmental onset
generalization of fear
8. Discussion Questions
How do neurodevelopmental disorders differ from anxiety disorders in onset and mechanisms?
Why do cognitive and biological factors both matter in understanding anxiety?
What distinguishes PTSD from Acute Stress Disorder?
Why is exposure therapy effective for phobias?
How do SSRIs reduce symptoms in anxiety and trauma disorders?
Why is early intervention critical for neurodevelopmental disorders?
