Anxiety Disorders and OCD

Anxiety disorders are the most prevalent mental health conditions worldwide, characterised by excessive fear and anxiety and related behavioural disturbances. In New Zealand, anxiety disorders affect approximately 15% of the population at any one time and represent a major burden on primary care and emergency services.

Generalised Anxiety Disorder (GAD) is characterised by persistent, uncontrollable worry about multiple domains (work, health, finances, relationships) accompanied by physical symptoms including fatigue, muscle tension, irritability, sleep disturbance, and difficulty concentrating. The cognitive model of GAD emphasises intolerance of uncertainty — individuals interpret ambiguous situations as threatening. Treatment includes CBT targeting worry and intolerance of uncertainty, and SSRIs (first-line pharmacotherapy). Buspirone is an effective non-benzodiazepine anxiolytic for GAD with no dependence risk, though its onset is slower (2-4 weeks).

Panic disorder is defined by recurrent unexpected panic attacks followed by at least one month of anticipatory anxiety or avoidance. The cognitive model (Clark, 1986) proposes that panic results from catastrophic misinterpretation of benign physical sensations (e.g., interpreting palpitations as an imminent heart attack, causing further anxiety and physical arousal — a vicious cycle). Agoraphobia — avoidance of situations where escape is difficult — frequently complicates panic disorder. Treatment: CBT with interoceptive exposure; SSRIs are pharmacotherapy of choice.

Social anxiety disorder (social phobia) involves marked fear of scrutiny in social or performance situations, leading to avoidance. It is common, underdiagnosed, and associated with significant functional impairment. OCD (obsessive-compulsive disorder) involves intrusive, ego-dystonic obsessions (the person recognises the thoughts as irrational) and compulsions performed to reduce distress. Compulsions provide short-term relief but maintain the cycle long-term. Exposure and Response Prevention (ERP) is the gold-standard psychological treatment; SSRIs at higher doses than for depression are effective pharmacotherapy.

PTSD (Post-Traumatic Stress Disorder) requires exposure to actual or threatened death, serious injury, or sexual violence, followed by intrusive symptoms (flashbacks, nightmares), avoidance, negative cognitions/mood, and hyperarousal persisting beyond one month (DSM-5). In NZ, ACC provides cover for psychological injuries arising from mental injury caused by a work-related or criminal event — PTSD following a qualifying event may entitle patients to funded psychological treatment. Evidence-based treatments include Trauma-Focused CBT (TF-CBT) and Eye Movement Desensitisation and Reprocessing (EMDR). SSRIs (particularly sertraline) are used pharmacologically; benzodiazepines should be avoided in PTSD.