GC171 Stress-related Disorders And Obsessive-compulsive Disorder (post-traumatic Stress Disorder Adjustment Disorder, Acute Stress Disorder): Rev
Stress-related disorders (including PTSD, acute stress disorder, and adjustment disorder) and obsessive-compulsive disorder are conditions characterized by maladaptive psychological and physiological responses to traumatic events, significant life stressors, or intrusive repetitive thoughts and compulsive behaviors that cause marked functional impairment.
Anxiety, Stressor-Related, and Obsessive-Compulsive Disorders
This lecture (GC 171) is a comprehensive survey covering three clusters of disorders that were historically lumped under "neuroses" but are now classified separately in both DSM-5 and ICD-11 [1][2]:
- Anxiety Disorders — Phobic disorders (agoraphobia, social phobia, specific phobia), Panic disorder, GAD, Mixed anxiety-depressive disorder
- Trauma- and Stressor-Related Disorders — Acute stress reaction/disorder, PTSD, Adjustment disorders
- Obsessive-Compulsive and Related Disorders — OCD, Body dysmorphic disorder, Hoarding disorder, Trichotillomania, Excoriation disorder
The lecture covers epidemiology, neural circuitry, diagnostic criteria, screening questions, comorbidity, and general treatment approaches (pharmacotherapy + psychotherapy). This maps directly onto the clinical encounter: recognizing pathological anxiety, differentiating between the disorders, and initiating evidence-based management.
Learning Objectives [1]:
- List prevalence of anxiety and related disorders
- Identify comorbid psychiatric diagnoses
- Perform a quick screen for anxiety and related disorders
- Apply general pharmacologic approaches to treatment
Core Concepts and Mechanisms
Normal anxiety is adaptive to stress. It is an inborn response to threat that can result in cognitive and somatic symptoms. [1]
Pathologic anxiety is anxiety that is excessive and impairs function. [1]
Why this distinction matters: Every human experiences anxiety — it is evolutionarily advantageous (the "fight-or-flight" response keeps us alive). The line between normal and pathological is crossed when anxiety becomes excessive relative to the stimulus, persistent beyond the situation, and functionally impairing (can't work, can't socialize, can't leave the house). This is the key threshold examiners test: does this patient have a disorder or a normal reaction?
Reading the Fight-or-Flight and Stress–Performance Visuals
The threat cartoon shows sympathetic redistribution rather than random symptoms:
| Organ/system | Adaptive acute response in the image |
|---|---|
| Heart/vessels | Faster heart rate and higher blood pressure |
| Eyes | Pupillary dilation and heightened vigilance |
| Lungs | Airway opening to increase ventilation |
| Skeletal muscle/metabolism | More blood flow and mobilisation of glucose/fat for energy |
| Gut | Digestion slows while resources are diverted to immediate survival |
The adjacent inverted-U curve is a teaching model: too little activation is labelled boredom/inactivity, moderate “healthy tension” is associated with better focus, and overload with fatigue, panic, anger and falling performance. It is not a diagnostic test or a universal biological law. Pathology depends on intensity, persistence, context and impairment—not simply the presence of arousal.
Amygdala — involved with processing of emotionally salient stimuli [1]
Medial prefrontal cortex (includes the anterior cingulate cortex, the subcallosal cortex, and the medial frontal gyrus) — involved in modulation of affect [1]
Hippocampus — involved in memory encoding and retrieval [1]
How to read the circuit rather than memorise three labels:
- The amygdala assigns salience and participates in threat learning.
- The medial prefrontal and anterior cingulate regions participate in appraisal, extinction learning and top-down regulation of affect.
- The hippocampus supports episodic and contextual memory, helping distinguish “then” from “now.”
Group neuroimaging studies often report altered activation or connectivity among these regions in anxiety and PTSD. “Hyperactive amygdala + hypoactive mPFC” is a useful simplified model, but it is neither universal nor diagnostic in an individual patient; a scan cannot establish PTSD or an anxiety disorder [12].
Part 1: Anxiety Disorders
Types of Anxiety Disorders [1]:
- Phobic anxiety disorders: Agoraphobia, Social phobias, Specific phobias
- Other anxiety disorders: Panic disorder, GAD, Mixed anxiety and depressive disorder
DSM-5 vs ICD Classification
In DSM-5, anxiety disorders, OCD-related disorders, and trauma/stressor-related disorders are in separate chapters. In ICD-10, they were grouped under "Neurotic, stress-related and somatoform disorders" (F40-F48). ICD-11 also separates them. Know both frameworks for exams [2].
Anxiety disorders: [1]
- Often have an early onset — teens or early twenties
- Show 2:1 female predominance
- Have a waxing and waning course over lifetime
- Similar to major depression and chronic diseases such as diabetes in functional impairment and decreased quality of life
Why this matters clinically: Anxiety disorders can cause major functional impairment and often begin early, creating prolonged disability if untreated. The slide's sex ratio is a population-level estimate, not a screening rule; assess symptoms and impairment without using sex or gender to rule a disorder in or out.
The 2009 epidemiology graphic reports medians with very wide study ranges, not current universal prevalence estimates. Case definitions, populations and study methods differ [1]:
| Disorder | Approximate plotted median | Approximate range in the visual |
|---|---|---|
| Specific phobia | 9.4% | 5.4–13.3% |
| PTSD | 8.6% | 2.0–15.0% |
| GAD | 7.7% | 2.2–13.1% |
| Social anxiety disorder | 6.9% | 0.5–13.3% |
| Agoraphobia | 4.1% | 1.3–6.9% |
| OCD | 2.6% | 0.7–4.4% |
| Panic disorder | 2.1% | 0.4–3.8% |
Marked and consistently manifest fear in or avoidance of at least two of the following situations: crowds; public places; travelling alone; travelling away from home. [1]
Classification caution: Slides 9–12 reproduce an older ICD-10-style formulation. Its “at least two of four situations,” autonomic-symptom and mandatory-insight rules should not be silently mixed with DSM-5-TR. DSM describes fear/anxiety in at least two of five situation types: public transport, open spaces, enclosed spaces, crowds/queues, and being outside the home alone. The feared consequence is that escape or help may be difficult if panic-like or other incapacitating/embarrassing symptoms occur.
Symptom clusters required (at least 2 symptoms present together, at least one from autonomic arousal) [1]:
| Category | Symptoms |
|---|---|
| Autonomic arousal (≥1 required) | Palpitations, sweating, trembling/shaking, dry mouth |
| Chest and abdomen | Difficulty breathing, choking feeling, chest pain, nausea/abdominal distress |
| Brain and mind | Dizziness/faintness, derealization/depersonalization, fear of losing control/going crazy, fear of dying |
| General | Hot flushes/cold chills, numbness/tingling |
Significant emotional distress due to the avoidance or the anxiety symptoms, and a recognition that these are excessive or unreasonable. [1]
Symptoms are restricted to or predominate in the feared situations or when thinking about them. [1]
The slide's mandatory recognition that fear is excessive is also historical. Current diagnosis does not require good insight in every patient, especially children. Assess proportionality, persistence, avoidance, impairment and alternative explanations instead.
Recurrent panic attacks, that are not consistently associated with a specific situation or object, and often occurring spontaneously (i.e. the episodes are unpredictable). [1]
The panic attacks are not associated with marked exertion or with exposure to dangerous or life-threatening situations. [1]
Defining a panic attack [1]:
- Discrete episode of intense fear or discomfort
- Starts abruptly
- Reaches a crescendo within a few minutes and lasts at least some minutes
- At least four symptoms from the same four categories (autonomic, chest/abdomen, brain/mind, general)
Exam Trap: Panic Disorder vs Agoraphobia with Panic
Panic disorder requires recurrent unexpected panic attacks plus persistent concern/behaviour change; agoraphobia is fear/avoidance of situations where escape or help may be difficult. They can be diagnosed together in current DSM. If every attack is predictably cued, do not automatically call it panic disorder—consider the relevant phobia, social anxiety, PTSD or another cause [1][15].
From the 2022 MCQ: "Characteristic features of a certain disorder include unpredictable attacks, signs reminiscent of myocardial infarction, and anticipatory anxiety, in the absence of severe stress." Answer: D. Panic disorder [5]
A period of at least six months with prominent tension, worry, and feelings of apprehension, about every-day events and problems. [1]
At least four symptoms must be present from the four categories. [1]
This is the slide's ICD-10-style symptom count. Do not convert it into a universal rule: DSM-5-TR requires excessive, difficult-to-control worry plus at least 3 of 6 associated symptoms in adults (only 1 in children), whereas ICD-11 is framed differently. Both retain persistence, distress/impairment and exclusion of substances, medical causes and better-fitting disorders.
Why six months? This duration criterion separates GAD from transient worry. Everyone worries sometimes. GAD is the disorder of chronic, pervasive, free-floating worry — the patient worries about everything (health, money, family, work) and cannot control the worry. The "free-floating" nature means it is NOT attached to a specific situation (unlike phobias) or a specific trauma (unlike PTSD).
From the 2024 MCQ [6]: A 27-year-old male with 3 months of constant worry about finances, girlfriend, parents' health, trouble sleeping, restlessness, GAD-7 score of 10 → Moderate Anxiety (GAD-7 scoring: 5-9 mild, 10-14 moderate, ≥15 severe).
Fear of social situations where the person may be scrutinized, judged, or embarrassed. The key differentiator from normal shyness: it must be excessive, severe, and cause significant impairment [4].
Fear restricted to a specific object or situation (animals, heights, blood, etc.). The feared object is circumscribed and avoidable, so these patients often function well unless the phobia impacts daily life (e.g., needle phobia preventing medical care).
Part 2: Trauma- and Stressor-Related Disorders
Trauma- and Stressor-Related Disorders: Acute Stress Reaction, Posttraumatic Stress Disorder, Adjustment Disorders [1]
| Feature | Psychosocial Stress | Traumatic Stress |
|---|---|---|
| Nature | Any life event placing strain on coping | Outside range of normal human experience |
| Severity | Subjective; depends on individual coping | Objectively severe; would be traumatic for most people |
| Physical integrity | Not necessarily threatened | Person/loved one's physical or psychological integrity seriously threatened |
| Associated diagnoses | Normal reaction, Adjustment disorder | Acute stress reaction, Acute stress disorder, PTSD |
[Source: Ryan Ho Psychiatry notes [4]]
Post-Traumatic Stress Disorder (PTSD)
Exposure to actual or threatened death, serious injury, or sexual violence in one or more of the following ways: [1]
- Direct experiencing of traumatic event(s)
- Witnessed in person the events as it occurred to others
- Learning that the traumatic events occurred to person close to them
- Experiencing repeated or extreme exposure to aversive details of trauma (e.g., first responders repeatedly collecting human remains)
Why these specific routes matter: PTSD is NOT limited to direct victims. Witnesses, bereaved relatives, and first responders can all develop PTSD. The "learning" criterion is important — a mother told her child died in an accident can develop PTSD even though she wasn't there. The "repeated exposure" criterion captures occupational trauma (paramedics, police).
Presence of 1 or more after the event: [1]
- Recurrent, involuntary and intrusive memories of event
- Recurrent trauma-related nightmares
- Dissociative reactions (flashbacks — acting/feeling as if the event is recurring)
- Intense psychological distress at cue exposure
- Marked physiological reactivity at cue exposure (e.g., heart racing when hearing a car backfire after a shooting)
Mechanistic model: Threat learning, salience and contextual-memory networks may help explain why cues trigger intrusive recollection and a sense of “nowness.” This is a useful cognitive-neuroscience model, not an established single mechanism in every patient.
Persistent avoidance by 1 or both: [1]
- Avoidance of distressing memories, thoughts, or feelings of the event(s)
- Avoidance of external reminders (people, places, activities, situations)
Why avoidance develops: This is a learned behavioral response — avoiding triggers prevents the distressing re-experiencing. But avoidance paradoxically maintains the disorder because it prevents extinction of the conditioned fear response. This is why CBT for PTSD involves graded exposure — you have to break the avoidance cycle.
Negative alterations in cognitions and mood associated with the traumatic event(s) as evidenced by 2 or more of the following: [1]
- Inability to remember an important aspect of the traumatic event(s) (dissociative amnesia)
- Persistent distorted cognitions about cause or consequence of event that lead to blame of self or others ("It was my fault")
- Persistent negative emotional state (fear, horror, anger, guilt, shame)
- Marked diminished interest in activities
- Feeling detached from others
- Persistent inability to experience positive emotions (emotional numbing)
Why this cluster is distinct from depression: While diminished interest and emotional numbing overlap with depression, in PTSD these are specifically linked to the trauma and are accompanied by the other PTSD symptom clusters. The self-blame/distorted cognitions are particularly PTSD-specific — the patient may believe they caused the event or that the world is fundamentally unsafe.
Marked alterations in arousal and reactivity with 2 or more of: [1]
- Irritable behavior and angry outbursts
- Reckless or self-destructive behavior
- Hypervigilance
- Exaggerated startle response
- Problems with concentration
- Sleep disturbance
From first principles: The arousal cluster reflects a chronically activated sympathetic nervous system. The brain is stuck in "threat mode." This explains the hypervigilance (constantly scanning for danger), exaggerated startle (primed alarm response), and sleep disturbance (the brain won't let its guard down).
Duration of disturbance is more than one month AND causes significant impairment in function [1]
Specifiers: [1]
- With dissociative symptoms (derealization or depersonalization)
- With delayed expression (don't meet criteria until > 6 months after event)
Critical Time Distinctions
This is one of the most commonly tested differentiators:
- Acute stress reaction (the slide's ICD-10 wording): A transient immediate response, typically resolving within hours to days; do not apply the old hour-by-hour rule to every current classification system
- Acute stress disorder (DSM-5): 3 days to 1 month after trauma
- PTSD: > 1 month after trauma
- PTSD with delayed expression: Full criteria not met until > 6 months
If the question says symptoms have lasted 2 weeks after a trauma → Acute Stress Disorder (not PTSD yet!). If symptoms persist > 1 month → now it's PTSD [1][4].
7-9% of general population; 60-80% of trauma victims; 30% of combat veterans; 50-80% of sexual-assault victims [1] Increased risk in women, younger people [1] Risk increases with "dose" of trauma, lack of social support, pre-existing psychiatric disorder [1]
These are historical, heterogeneous estimates, not probabilities to apply to an individual or to every trauma type. The slide's blanket “60–80% of trauma victims” is especially misleading: most trauma-exposed people do not develop PTSD. Risk varies with trauma type, severity/repetition, interpersonal violence, prior vulnerability, ongoing adversity and social support [12].
Depression; Other anxiety disorders; Substance use disorders; Somatization; Dissociative disorders [1]
Why comorbidity is the rule, not the exception: PTSD rarely exists in isolation. Depression develops because of persistent negative mood and anhedonia. Substance use develops as self-medication (alcohol to dampen hyperarousal, opioids for emotional numbing). Somatization occurs because the body is chronically hyperaroused. Always screen for these.
Conditioned fear; Genetic/familial vulnerability; Stress-induced release — Norepinephrine, CRF, Cortisol; Autonomic arousal immediately after trauma predicts PTSD [1]
Breaking this down:
- Conditioned fear: Classical conditioning — the traumatic event (unconditioned stimulus) becomes associated with neutral cues present during the trauma (conditioned stimuli). These cues later trigger the fear response.
- Genetic vulnerability: ~1/3 of variance in PTSD susceptibility is heritable [4]
- Neuroendocrine: Noradrenergic and HPA-axis findings are group-level associations, not a clinical biomarker. The simplistic claim that PTSD means “low cortisol from HPA exhaustion” is not established.
- Immediate autonomic arousal: Higher early arousal is associated with later symptoms in some cohorts, but it does not deterministically predict PTSD and is not itself an indication for preventive medication.
Increased amygdala activation is seen in PTSD pts compared to controls [1]
Hypoactivation of the medial prefrontal cortex including the orbitofrontal cortex and anterior cingulate cortex (area implicated in affect regulation) [1]
How to interpret the slide: Increased amygdala and reduced medial prefrontal/ACC responses are recurring group averages during particular tasks. They support a network model of threat salience and regulation but are not present in every patient and cannot diagnose PTSD [12].
Debriefing immediately following trauma is NOT necessarily effective [1]
High Yield — Debriefing Myth
Do not offer psychologically focused debriefing to prevent or treat PTSD. Early care should prioritise safety, practical and social support, information about common reactions, active monitoring and access to assessment if symptoms persist or risk emerges [12].
Cognitive-behavioral therapy [1]
Trauma-focused CBT is a core first-line psychological treatment. It includes:
- Cognitive restructuring: Challenging distorted beliefs about the trauma ("It was all my fault")
- Prolonged exposure: Graded, systematic re-exposure to trauma memories and avoided situations to extinguish the conditioned fear response
- Psychoeducation: Normalizing symptoms, explaining the disorder
Eye Movement Desensitization and Reprocessing (EMDR) [1]
EMDR uses structured trauma-memory processing with repeated bilateral stimulation, delivered by a trained practitioner within a validated protocol. NICE offers it to adults presenting more than 3 months after non-combat trauma and considers it at 1–3 months when preferred [12].
The slide lists antidepressants, beta-blockers, mood stabilisers, clonidine, prazosin and gabapentin. [1] The list mixes established therapy with off-label or weak-evidence adjuncts.
| Medication | Role in PTSD |
|---|---|
| SSRIs/SNRIs | For adults who prefer medication, NICE suggests an SSRI such as sertraline or venlafaxine; trauma-focused psychotherapy remains central and medicines should not be used to prevent PTSD |
| Prazosin (α1-blocker) | Not a routine NICE core treatment; some other guidelines use it selectively for nightmares, with mixed evidence and blood-pressure monitoring |
| Clonidine, beta-blockers, mood stabilisers, gabapentin | Not routine core PTSD treatments; any off-label use requires a specific target, comorbidity and specialist judgement |
| SGAs (antipsychotics) | Not routine; selected specialist augmentation or treatment of a separate psychotic/mood indication |
| Benzodiazepines | Generally avoid as PTSD treatment because benefit is poor and dependence, disinhibition and interference with trauma therapy are concerns |
Similar exposure as in PTSD [1]
Presence of ≥9 symptoms across the 5 categories of intrusion, negative mood, dissociation, avoidance, and arousal related to the trauma. [1]
Slide correction: the slide says “≥9 of 5 categories.” DSM-5-TR actually requires 9 or more of 14 individual symptoms, drawn from those five categories; no fixed number is required from each category.
Duration of disturbance is 3 days to 1 month after trauma [1]
Causes significant impairment [1]
Key discriminator from PTSD: Time plus the diagnostic symptom structure. Acute stress disorder covers 3 days to 1 month; if clinically important trauma symptoms continue beyond 1 month, reassess for PTSD. Unlike DSM-IV acute stress disorder, DSM-5-TR does not require a special dissociative cluster.
| Feature | Acute Stress Reaction (ICD-10) | Acute Stress Disorder (DSM-5) | PTSD |
|---|---|---|---|
| Onset | Within 1 hour of stressor | During/shortly after stressor | Anytime, usually within 6 months |
| Duration | Hours to ~2-3 days | 3 days to 1 month | > 1 month |
| Key emphasis | Transient immediate response in the older slide framework | ≥9 of 14 symptoms drawn from 5 categories; dissociation is not mandatory | 4 symptom clusters (intrusion, avoidance, cognition/mood, arousal) |
| Significance | Often short-lived; still assess safety and function | Risk marker, but many patients do not progress to PTSD | Can be severe or persistent; assess risk, comorbidity and impairment |
While not given a dedicated slide, adjustment disorder is listed under trauma- and stressor-related disorders [1] and is an important differential:
- Stressor: Any psychosocial stressor (NOT necessarily traumatic) — job loss, divorce, moving, illness
- Symptoms: Anxiety and/or depressive symptoms that are clearly arising from the stressor and out of proportion to the stressor, but do NOT meet criteria for a full mood or anxiety disorder
- Onset: Within 3 months of the stressor (DSM-5) / within 1 month (ICD-10)
- Duration: Resolves within 6 months after the stressor or its consequences have ended
- Subtypes: With depressed mood, with anxiety, with mixed anxiety and depressed mood, with disturbance of conduct, with mixed disturbance of emotions and conduct [4]
Adjustment Disorder = Diagnosis of Exclusion
Adjustment disorder is diagnosed only when symptoms don't meet criteria for any other specific disorder (e.g., MDD, GAD, PTSD). If the stressor was traumatic AND the patient has intrusion/avoidance/arousal symptoms → consider PTSD or acute stress disorder, not adjustment disorder [4].
Part 3: Obsessive-Compulsive and Related Disorders
OCD and Related Disorders: [1]
- Obsessive-Compulsive Disorder
- Body Dysmorphic Disorder
- Hoarding Disorder
- Trichotillomania
- Excoriation Disorder
Why these are grouped together: They all share a core feature of repetitive thoughts and/or behaviors that the person feels driven to perform, causing distress or impairment. They share overlapping neurobiology (frontal-striatal circuitry) and treatment response (serotonergic medications, CBT).
The percentages on slides 32 and 37 are lecture-era estimates from different settings. They are useful for recognising that these disorders are not rare, but should not be treated as one current population survey or used as diagnostic priors for an individual.
Body Dysmorphic Disorder — 2.4% [1]
- 9-15% of dermatologic patients
- 7% of cosmetic surgery patients
- 10% of patients presenting for oral or maxillofacial surgery
Hoarding Disorder — est. 2-6%, F < M [1]
Trichotillomania — 1-2%, F:M 10:1 [1]
Excoriation Disorder — 1.4%, F > M [1]
Clinical Pearl — BDD in Surgical Settings
Body dysmorphic disorder is overrepresented in dermatology and cosmetic settings. A request for repeated procedures for a slight or unobservable defect should prompt sensitive assessment of preoccupation, repetitive behaviours, impairment, depression and suicide risk. Cosmetic intervention is not a treatment for BDD; coordinate mental-health assessment rather than promising that a procedure will resolve the distress [13].
Obsessive-Compulsive Disorder (OCD)
Obsessions defined by: recurrent and persistent thoughts, impulses or images that are intrusive and unwanted that cause marked anxiety or distress. [1]
The person attempts to ignore or suppress such thoughts, urges or images, or to neutralize them with some other thought or action (i.e. compulsion). [1]
Key features: Obsessions are ego-dystonic — the patient recognizes them as their own thoughts but finds them distressing, unwanted, and alien to their personality. A patient with violent obsessional thoughts is horrified by them, not entertained. This distinguishes obsessions from delusions (which are held with conviction) and from normal worries (which are about realistic concerns).
Compulsions defined by: Repetitive behaviors or mental acts that the person feels driven to perform in response to an obsession or according to rigidly applied rules. [1]
The behaviors or acts are aimed at reducing distress or preventing some dreaded situation however these acts or behaviors are not connected in a realistic way with what they are designed to neutralize or prevent. [1]
Why "not connected in a realistic way" matters: Washing hands after touching something dirty is normal. Washing hands 50 times because you fear contaminating your family with an unspecified toxin, while feeling unable to stop, is a compulsion. The excessive or unrealistic link is a key diagnostic feature, interpreted alongside distress, time cost and impairment.
Common obsession-compulsion pairings:
| Obsession Theme | Common Compulsion |
|---|---|
| Contamination | Washing, cleaning |
| Doubt ("Did I lock the door?") | Checking |
| Need for symmetry/order | Arranging, counting |
| Forbidden thoughts (aggression, sexual, religious) | Mental rituals, reassurance seeking |
| Fear of harm to self/others | Checking, avoidance |
The obsessions or compulsions cause marked distress, take > 1 hour/day or cause clinically significant distress or impairment in function [1]
Specify if: [1]
- With good or fair insight — recognizes beliefs are definitely or most likely not true
- With poor insight — thinks are probably true
- With absent insight — is completely convinced the OCD beliefs are true
- Tic-related
Why insight specifiers matter: Most OCD patients have good insight ("I know this is ridiculous, but I can't stop"). However, some patients have poor or absent insight, making them difficult to distinguish from psychotic disorders. Absent insight OCD can be mistaken for delusional disorder. The tic-related specifier is important because OCD with comorbid tics may respond differently to treatment (may need augmentation with antipsychotics).
> 70% have lifetime dx of an anxiety disorder (PD, SAD, GAD, phobia) [1] > 60% have lifetime dx of a mood disorder, MDD being the most common [1] Up to 30% have a lifetime Tic disorder [1] 12% of persons with schizophrenia/schizoaffective disorder [1]
Key clinical implication: Always screen for depression in OCD patients. The relentless nature of obsessions and the time consumed by compulsions makes OCD patients profoundly miserable. Suicide risk exists.
Genetics; Serotonergic dysfunction; Cortico-striato-thalamo-cortical loop; Autoimmune — PANDAS (Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal infection) [1]
How to interpret the mechanisms:
- Serotonin: Response to SSRIs and clomipramine supports a therapeutic serotonergic target; it does not prove that OCD is caused by a simple serotonin deficiency.
- Cortico-striato-thalamo-cortical (CSTC) networks: Orbitofrontal/anterior-cingulate, striatal, pallidal/subthalamic and thalamic nodes participate in salience, habit, action selection and inhibitory control. “A hyperactive loop” is a model, not a complete causal explanation.
- PANS/PANDAS: Consider this only with abrupt, severe childhood onset of OCD/restrictive eating plus the relevant associated features. There is no confirmatory laboratory test; assess for competing neurological, infectious, medication and primary psychiatric causes. Treat documented streptococcal infection conventionally; long-term prophylactic antibiotics lack sufficient evidence, and IVIG is reserved for severe specialist-selected cases [14].
The direct pathway reduces GPi/SNr inhibition of the thalamus, increasing thalamocortical drive; the indirect pathway increases GPi/SNr output and suppresses that drive. OCD models propose excessive activity or impaired gating within orbitofrontal/anterior-cingulate–striatal–thalamic loops, so intrusive salience and action urges keep recycling. The diagram is a circuit model, not a diagnostic scan for an individual patient.
Increased activity in the right caudate is found in pts with OCD and Cognitive behavior therapy reduces resting state glucose metabolism or blood flow in the right caudate in treatment responders. [1]
Similar results have been obtained with drug treatment. [1]
Interpretation: The images show group-level regional activity before and after successful treatment. They support treatment-related network plasticity, but “right caudate hyperactivity” is neither specific enough nor validated as an individual diagnostic or response biomarker. The figure does not prove that one caudate abnormality causes OCD or that CBT works through a single pathway.
40-60% treatment response [1] Serotonergic antidepressants [1] Behavior therapy [1] Adjunctive antipsychotics [1] Psychosurgery (rarely) [1]
Current staged treatment [13]:
| Modality | Details |
|---|---|
| ERP-based CBT | Offer low-intensity ERP for mild impairment; offer more intensive ERP-based CBT or an SSRI for moderate impairment/patient preference; combine ERP-based CBT and an SSRI for severe impairment. |
| SSRIs | Use an adequate, monitored trial; response may take up to 12 weeks. Do not prescribe a memorised “high dose” without considering the product limit, adverse effects, interactions, age and suicide risk. |
| Clomipramine | Consider after an adequate SSRI trial is ineffective or poorly tolerated, or when previously effective/preferred; account for anticholinergic, cardiac and overdose toxicity. |
| Persistent symptoms | Check diagnosis, adherence, dose/duration, comorbidity and whether ERP was actually delivered. Then consider combined treatment, a different SSRI or clomipramine and specialist multidisciplinary review. |
| Antipsychotic augmentation | A specialist option after adequate SSRI, ERP-combination and clomipramine pathways; not monotherapy and not an automatic next step. |
| Neurosurgery/neuromodulation | Only for exceptionally severe, chronic, refractory illness in highly specialised services with rigorous governance—not a routine algorithm item. |
Exam Point — OCD Has a Specific Evidence-Based Pathway
ERP-based CBT and SSRIs are the core initial treatments. Clomipramine has evidence but greater toxicity. The lecture's “serotonergic drugs work, noradrenergic drugs do not” is a useful historical pharmacology clue, not proof of a single-neurotransmitter cause and not permission to skip ERP, measurement-based follow-up or specialist review [13].
Screening Questions: [1]
- "When you are in a situation where people can observe you, do you feel nervous and worry that they will judge you?" → Social Anxiety Disorder
- "Do you consider yourself a worrier?" → GAD
- "Have you ever experienced a panic attack?" → Panic Disorder
- "Have you ever had anything happen that still haunts you?" → PTSD
- "Do you get thoughts stuck in your head that really bother you, or need to do things over and over like washing your hands, checking things, or counting?" → OCD
High Yield — Memorize These 5 Screening Questions
These one-liners are practical conversation starters, not validated stand-alone rule-in/rule-out tests. A “yes” needs a full assessment of duration, impairment, differential diagnoses, substances/medical causes and risk; a “no” does not exclude the disorder. [1]
The slide's broad treatment menu: [1]
- Pharmacotherapy: Antidepressants, Anxiolytics, Antipsychotics, Mood stabilizers
- Psychotherapy: Cognitive Behavior Therapy (CBT), Mindfulness-based Therapy
That list is not a one-size-fits-all algorithm. “Anxiolytics, antipsychotics and mood stabilisers” are not interchangeable treatments for all diagnoses, and generic mindfulness/supportive therapy should not displace a disorder-specific intervention.
| Presentation | Evidence-based starting pathway | Important cautions |
|---|---|---|
| GAD | Stepped care: education/active monitoring for milder illness, then CBT or applied relaxation, or an SSRI according to impairment and preference [15] | Benzodiazepines only as a brief crisis measure, not routine treatment; antipsychotics are not routine primary-care treatment |
| Panic disorder | Panic-focused CBT or an antidepressant; an SSRI licensed for panic is usual first pharmacological choice [15] | Benzodiazepines are associated with poorer long-term outcome and should not be prescribed as treatment; exclude urgent medical mimics when clinically indicated |
| Social anxiety disorder | Individual disorder-specific CBT is preferred; if declined and medication is preferred, offer an SSRI such as sertraline or escitalopram [16] | Do not routinely substitute group CBT, mindfulness, benzodiazepines, anticonvulsants or antipsychotics for the recommended pathway |
| Specific phobia/agoraphobia | Exposure-based CBT matched to the feared situation and safety behaviours | Medication does not replace exposure learning; assess panic, medical causes and functional restriction |
| PTSD | Trauma-focused CBT or EMDR; medication is an adult preference/indication pathway, not prevention [12] | No routine debriefing; do not use benzodiazepines or a broad adjunct list as default PTSD treatment |
| OCD/BDD | ERP-based CBT and/or an SSRI, intensity matched to impairment [13] | Clomipramine and antipsychotic augmentation sit later in a staged, monitored specialist pathway |
| Adjustment disorder/early post-trauma distress | Safety/risk assessment, practical support, address the stressor and functioning, then targeted psychotherapy if symptoms persist | Avoid reflex sedative prescribing; reassess if a depressive, anxiety, substance-related or trauma-specific disorder becomes clearer |
For any antidepressant: discuss early activation, adverse effects, interactions, withdrawal/discontinuation, overdose risk, reproductive context and the delayed onset of benefit; monitor suicide/self-harm risk, particularly after starting or changing treatment.
| Feature | GAD | Panic Disorder | Agoraphobia | Social Phobia | Specific Phobia | PTSD | OCD | Adjustment Disorder |
|---|---|---|---|---|---|---|---|---|
| Core feature | Chronic free-floating worry | Recurrent unpredictable panic attacks | Fear of crowds/public/travel | Fear of social scrutiny | Fear of specific object/situation | Re-experiencing + avoidance + arousal after trauma | Intrusive thoughts + compulsions | Emotional/behavioral response to identifiable stressor |
| Duration | ≥6 months | Recurrent | Persistent | Persistent | Persistent | > 1 month | Persistent | ≤6 months after stressor ends |
| Trigger | Non-specific ("everything") | Spontaneous, unpredictable | Specific situations | Social situations | Specific stimulus | Trauma cues | Obsessional triggers | Identifiable stressor |
| Insight | Variable | Variable | Variable; no mandatory good-insight rule | Variable | Variable | Variable | Good/fair, poor or absent | Variable |
| Epidemiology | Varies by population | Varies by population | Varies by population | Varies by population | Varies by population | Trauma- and population-dependent | Sex ratio varies by age/sample | — |
| Key treatment | Stepped CBT/applied relaxation or SSRI | CBT or antidepressant | Exposure-based CBT | Individual disorder-specific CBT; SSRI if preferred | Exposure therapy | Trauma-focused CBT or EMDR; medication if preferred/indicated | ERP-based CBT and/or SSRI | Address stressor, safety and functioning; targeted psychotherapy |
From the 2023 MCQ [7]:
"It is not uncommon to have difficulties during interview with patients with anxiety disorder. Which of the following techniques would have a negative impact during interviewing anxious patients?"
A. Address the anxious feeling
B. Ask specific questions
C. Clarification and explanation
D. Give a diagnostic label ✓
Rationale for the exam answer: Giving a premature or unexplained label can increase anxiety and shut down communication. In real care, do not withhold a diagnosis indefinitely: after collaborative assessment, explain the formulation and diagnosis in plain language, check the patient's understanding and discuss uncertainty and options. Addressing emotion and asking specific clarifying questions remain useful [7].
| Trap | How to Avoid |
|---|---|
| Confusing acute stress disorder with PTSD | Time: ASD = 3 days to 1 month; PTSD = > 1 month |
| Confusing adjustment disorder with PTSD | Stressor type: Adjustment = any stressor (non-traumatic OK); PTSD = traumatic event. Symptoms: Adjustment = non-specific anxiety/depression; PTSD = specific intrusion/avoidance/arousal |
| Confusing GAD with adjustment disorder | Stressor: Adjustment has identifiable stressor; GAD = free-floating worry without specific trigger |
| Confusing panic disorder with agoraphobia | Setting: Panic = unpredictable, spontaneous; Agoraphobia = situational (crowds, public, travel) |
| Treating the monoamine clue as a complete OCD algorithm | Start with ERP-based CBT and/or an SSRI; use clomipramine and augmentation only within the staged pathway |
| Recommending debriefing for trauma prevention | Do not offer psychologically focused debriefing; provide safety, practical/social support, information and monitoring |
| Forgetting duration criteria | GAD ≥6 months; ASD 3 days–1 month; PTSD > 1 month; Adjustment ≤6 months after stressor resolution |
| Thinking OCD patients enjoy their rituals | Compulsions are ego-dystonic — performed to reduce distress, not for pleasure |
| Assuming OCD always has good insight | OCD insight ranges from good to absent; absent insight mimics psychosis |
- CFB PSY02 [2]: DSM-5 classifies Anxiety disorders, OCD and related disorders, and Trauma/stressor-related disorders as separate chapters — this reclassification from DSM-IV (where they were grouped) is exam-relevant.
- GC 167 (Anxiety Disorders) [11]: Provides the broader anxiety disorders overview including the "Major Anxiety Related Disorders" map showing how panic, GAD, phobias, OCD, and PTSD relate to each other via the common pathway of psychological and somatic anxiety manifestations.
- AOS Psych [3]: Notes that exam MCQs often test medication management — "BZD and sleeping pills will NOT be used in long-term management; long-term management includes antidepressants, antipsychotics, mood stabilizers." Also notes common exam diagnoses include anxiety, PTSD, OCD, adjustment disorder.
- Ryan Ho Psychiatry [4]: Provides the detailed differential diagnosis table (PTSD vs adjustment disorder vs acute stress disorder vs TBI) and treatment algorithms that complement the lecture slides.
High Yield Summary
-
Anxiety vs pathological anxiety
- Normal = adaptive; Pathological = excessive + impairs function.
-
Neural circuit visual
- Amygdala, medial prefrontal/ACC and hippocampal networks support salience, regulation/extinction and contextual memory. Group differences are mechanistic clues, not diagnostic scans.
-
PTSD requires
- (A) Traumatic exposure + (B) ≥1 intrusion symptom + (C) ≥1 avoidance symptom + (D) ≥2 negative cognition/mood changes + (E) ≥2 arousal symptoms + duration > 1 month + functional impairment.
-
Time discriminators
- The slide's acute stress reaction concept covers the immediate transient response; DSM acute stress disorder = 3 days–1 month; PTSD = > 1 month. Adjustment disorder follows an identifiable stressor but lacks the specific PTSD syndrome.
-
OCD
- Intrusive obsessions and/or compulsions consume time or impair function; insight can be good/fair, poor or absent. ERP-based CBT and SSRIs are the treatment core. CSTC and caudate figures are group-level network models, not biomarkers.
-
Debriefing after trauma is NOT effective
- do not recommend routine psychological debriefing.
-
PTSD treatment
- Trauma-focused CBT or EMDR are core treatments. If an adult prefers medication, an SSRI such as sertraline or venlafaxine may be considered. Prazosin is not a universal first-line PTSD treatment.
-
Screening questions
- (5 one-liners for SAD, GAD, Panic, PTSD, OCD) are high-yield for clinical exams.
-
Always assess comorbidity and risk
- Depression, suicide/self-harm risk, substance use, other anxiety disorders, dissociation and tics can change both formulation and treatment.
-
BDD in procedural settings
- Repeated requests about a slight/unobservable defect should prompt BDD, depression and suicide-risk assessment; a cosmetic procedure is not BDD treatment.
Active Recall - Lecture Notes
[1] Lecture slides: GC 171. Stress-related disorders and obsessive-compulsive disorder (Post-traumatic stress disorder adjustment disorder, acute stress disorder)_rev.pdf (slides 1-44) [2] Lecture slides: CFB (PSY02) Classification and Diagnosis of Psychiatric Illness.pdf (p4, p29, p53) [3] AOS material: AOS - Psych.md [4] Senior notes: Ryan Ho Psychiatry.pdf (p170-171, p191-192, p196-197) [5] Past papers: 2022 Fourth Summative MCQ.pdf (Q24, p9) [6] Past papers: 2024 Fourth Summative MCQ.pdf (Q77, p28) [7] Past papers: 2023 Fourth Summative MCQ.pdf (Q95, p36) [11] Lecture slides: GC 167. I feel very nervous Anxiety disorders.pdf (p12) [12] NICE. Post-traumatic stress disorder (NG116): recommendations. https://www.nice.org.uk/guidance/ng116/chapter/recommendations [13] NICE. Obsessive-compulsive disorder and body dysmorphic disorder: treatment (CG31): recommendations. https://www.nice.org.uk/guidance/cg31/chapter/Recommendations [14] National Institute of Mental Health. PANS and PANDAS: Questions and Answers (revised 2025). https://www.nimh.nih.gov/health/publications/pandas [15] NICE. Generalised anxiety disorder and panic disorder in adults: management (CG113): recommendations. https://www.nice.org.uk/guidance/cg113/chapter/Recommendations [16] NICE. Social anxiety disorder: recognition, assessment and treatment (CG159): recommendations. https://www.nice.org.uk/guidance/cg159/chapter/recommendations
GC170 Schizophrenia And Related Psychoses
Schizophrenia and related psychoses are a group of severe mental disorders characterized by disturbances in thought, perception, emotion, and behavior, including hallucinations, delusions, and disorganized thinking, often with impaired social and occupational functioning.
GC173 Why Should I Be Locked Up Ethics In Psychiatry, Consent And Refusal In Treatment
This topic explores the ethical principles governing involuntary psychiatric detention, patient autonomy, informed consent, and the legal and moral frameworks for treating individuals who refuse psychiatric care against clinical recommendations.