Anxiety, OCD, and Trauma Disorders

Anxiety, OCD, and Trauma Disorders

6 min read Updated Apr 19, 2026

Anxiety is a normal response to threat. Anxiety disorders involve anxiety that is excessive, persistent, and disruptive, far out of proportion to actual danger. This group and the closely related OCD and PTSD make up the most common psychiatric conditions - the lifetime prevalence of any anxiety disorder is around 30%.

Black-and-white anatomical engraving of a coronal section of the human cerebrum (Henry Vandyke Carter for Gray's Anatomy, 1918) with labels along the top for thalamus, caudate nucleus, internal capsule, globus pallidus, putamen, claustrum, and insula, and labels along the left for corpus callosum, lateral ventricle, choroid plexus, fornix, third ventricle, optic tract, and corpora mamillaria. The amygdaloid nucleus is highlighted in purple at lower right with a red arrow pointing to it
The amygdala (highlighted in purple), the brain's threat-detection hub. It is hyperactive in anxiety disorders, panic disorder, and PTSD - and treatments that work (SSRIs, exposure-based CBT) tend to dampen its reactivity over time. Credit: Henry Vandyke Carter (Gray's Anatomy, 1918) via Wikimedia Commons (Public Domain).

Generalized Anxiety Disorder (GAD)

Persistent, excessive worry about a range of life situations, lasting at least 6 months, with at least three of:

  • Restlessness, feeling “on edge.”
  • Easily fatigued.
  • Difficulty concentrating.
  • Irritability.
  • Muscle tension.
  • Sleep disturbance.

The worry is hard to control and is about everyday things (money, family, work) rather than specific triggers.

Panic Disorder

Recurrent, unexpected panic attacks plus persistent worry about future attacks or maladaptive behavior changes to avoid them.

A panic attack is a discrete episode of intense fear that peaks within minutes, with at least 4 of:

  • Pounding heart, palpitations.
  • Sweating, shaking, trembling.
  • Shortness of breath.
  • Choking sensation.
  • Chest pain.
  • Nausea.
  • Dizziness or faintness.
  • Chills or hot flashes.
  • Numbness or tingling.
  • Derealization (feeling unreal) or depersonalization (detachment from self).
  • Fear of losing control or “going crazy.”
  • Fear of dying.

The physical symptoms are so intense that first panic attacks are often mistaken for heart attacks. The fear of having another attack - and avoiding situations where one might happen - drives the disorder’s course.

A surreal, distorted self-portrait conveying the subjective experience of a panic attack. The face is stretched, mouth wide open as if mid-scream, with checkerboard fragments dissolving on one side and red droplets and blurred light scattered around the head, evoking derealization and overwhelming sensory chaos
An artist's rendering of the subjective experience of a panic attack: derealization, sensory distortion, and the overwhelming "I'm dying" terror that defines the moment. The first attack is so visceral that patients often present to the ER convinced they are having a heart attack. Credit: Yitzilitt via Wikimedia Commons (CC BY-SA 4.0).

Agoraphobia

Intense fear of being in places or situations from which escape would be difficult or embarrassing if panic or incapacitation struck. Classic examples: crowded markets, open spaces, enclosed spaces, public transportation, being far from home alone.

Often co-occurs with panic disorder - once someone has had a panic attack in a supermarket, they may avoid supermarkets.

Specific Phobias

Marked, persistent fear of a specific object or situation that is disproportionate to actual danger. Exposure almost always provokes anxiety. Common phobias include:

  • Animals - spiders (arachnophobia), snakes (ophidiophobia), dogs.
  • Natural environment - heights (acrophobia), water, storms.
  • Blood-injection-injury - medical procedures.
  • Situational - flying, elevators, driving, enclosed spaces (claustrophobia).

Recall from Chapter 3 that preparedness theory explains why ancestrally dangerous stimuli (snakes, heights) produce phobias more readily than modern dangers (electrical outlets, cars).

Close-up macro photograph of a brown garden spider hanging upside down at the center of its web, surrounded by blurred green foliage in the background
Spiders are one of the most common targets of specific phobia (arachnophobia) - and a textbook example of preparedness theory: humans acquire phobias of ancestrally dangerous stimuli (spiders, snakes, heights) much more readily than of modern dangers like cars or electrical outlets, even though the modern dangers actually kill far more people. Credit: Karin Schmitt via Wikimedia Commons (Public Domain).

Social Anxiety Disorder

Intense fear of social situations in which one might be scrutinized or judged. Public speaking is the most common trigger, but broader social anxiety disorder extends to most social interactions. Causes significant avoidance of social, occupational, and academic opportunities.

Obsessive-Compulsive Disorder (OCD)

OCD was reclassified out of the anxiety disorder group in DSM-5 but is still conceptually related.

  • Obsessions. Unwanted, intrusive, recurrent thoughts that cause anxiety (fear of contamination, fear of harming someone, unwanted taboo thoughts, need for symmetry).
  • Compulsions. Repetitive behaviors or mental acts the person feels driven to perform in response to obsessions (washing, checking, counting, arranging, silent prayers).

The compulsions temporarily relieve the anxiety caused by the obsessions but reinforce the cycle. Compulsions become time-consuming (at least 1 hour/day for diagnosis) and often severely impair functioning.

Close-up photograph of a pair of hands lathered in soap suds being scrubbed together repeatedly under running water from a metal faucet over a white sink with a chrome drain
Compulsive handwashing in response to contamination obsessions is one of the most recognizable OCD presentations. The act briefly reduces anxiety, which negatively reinforces the behavior - creating the loop that keeps the disorder going. Exposure and response prevention (ERP) breaks the loop by exposing the patient to the obsession trigger while preventing the compulsion. Credit: Lars Klintwall Malmqvist via Wikimedia Commons (Public Domain).

Biology:

  • Abnormalities in the cortico-striatal-thalamic loop.
  • Genetic component - about 25% of first-degree relatives have OCD or related conditions.
  • Serotonin dysfunction - SSRIs at high doses are first-line medical treatment.
Sagittal cross-section of the human brain with three regions implicated in OCD highlighted and labeled: the orbitofrontal cortex (purple oval at the front), the cingulate cortex (green band arching over the corpus callosum), and the amygdala (yellow oval in the medial temporal lobe)
Brain regions implicated in OCD - the orbitofrontal cortex, anterior cingulate cortex, and amygdala - which together form part of the cortico-striato-thalamo-cortical (CSTC) loop. Hyperactivity in this circuit is hypothesized to drive the intrusive thoughts and the urge to neutralize them. Credit: Created with BioRender via Wikimedia Commons (Public Domain).

Cognitive-behavioral therapy with exposure and response prevention (ERP) - deliberately exposing the patient to triggers while preventing the compulsive response - is the most effective psychological treatment.

Post-Traumatic Stress Disorder (PTSD)

Also reclassified in DSM-5 into “trauma- and stressor-related disorders.”

Requires:

  • Exposure to actual or threatened death, serious injury, or sexual violence (direct, witnessed, or learned about in a close other).
  • Intrusion symptoms - distressing memories, nightmares, flashbacks, intense distress at reminders.
  • Avoidance - of memories, thoughts, feelings, or external reminders of the trauma.
  • Negative alterations in cognition/mood - inability to remember aspects of the trauma, persistent negative beliefs, persistent negative emotions, detachment from others.
  • Alterations in arousal/reactivity - irritable outbursts, hypervigilance, exaggerated startle, sleep disturbance, concentration problems.
  • Duration at least 1 month.

Partial PTSD is common - not everyone exposed to trauma develops PTSD, and prior trauma plus inadequate social support raise risk.

Treatments include trauma-focused CBT, prolonged exposure therapy, eye movement desensitization and reprocessing (EMDR), and SSRIs.

Treatment of Anxiety Disorders

Medications

  • SSRIs - first-line for most anxiety disorders, OCD, and PTSD. Also treat depression (common comorbidity).
  • SNRIs - also effective.
  • Benzodiazepines - rapid anxiety relief but risk of dependence. Used short-term or acutely (pre-flight, during a panic attack). Not first-line for chronic treatment.
  • Beta blockers - reduce physical symptoms of anxiety (racing heart, trembling). Used for performance anxiety.

Psychotherapy

  • Cognitive-behavioral therapy (CBT) - gold standard. Challenges catastrophic thoughts and gradually exposes patients to feared situations.
  • Exposure therapy - repeated, safe exposure to feared stimuli extinguishes conditioned anxiety.
  • Systematic desensitization (Wolpe) - relaxation paired with a graded fear hierarchy.
  • Flooding/implosive therapy - full-intensity exposure in a safe context.
What distinguishes obsessions from compulsions in OCD?
Click to reveal answer
Obsessions are unwanted intrusive THOUGHTS that cause anxiety (fear of contamination, need for symmetry). Compulsions are repetitive BEHAVIORS or mental acts performed to reduce the anxiety (washing, checking, counting). Compulsions temporarily relieve but reinforce the cycle.
What is the gold-standard psychological treatment for OCD, and how does it work?
Click to reveal answer
Exposure and response prevention (ERP), a form of CBT. The patient is exposed to obsession-triggering stimuli but prevented from performing compulsions. Over time, the anxiety extinguishes without reinforcement, and the OCD loop breaks.
A patient experiences recurrent nightmares, intrusive memories, and hyperarousal 3 months after a car accident. Which diagnosis?
Click to reveal answer
Post-traumatic stress disorder (PTSD). Requires exposure to trauma, plus intrusion symptoms (nightmares, flashbacks), avoidance, negative cognitions/mood changes, and arousal/reactivity alterations, lasting at least 1 month.