Anxiety

Definition

Anxiety is a mental health condition characterized by excessive fear, worry, or nervousness that is disproportionate to actual threats and interferes with daily functioning. It can manifest as generalized anxiety disorder, panic disorder, phobias, or social anxiety.

Epidemiology

• Among the most common psychiatric disorders worldwide
• Lifetime prevalence approximately 10–30%
• Onset often occurs in childhood, adolescence, or early adulthood
• Women are more frequently affected than men
• Comorbidities include depression, substance use, and other psychiatric conditions

Etiology

• Genetic predisposition and family history of anxiety or mood disorders
• Neurobiological factors: dysregulation of amygdala, prefrontal cortex, and neurotransmitters (serotonin, GABA, norepinephrine)
• Environmental stressors: trauma, abuse, chronic stress
• Personality traits: high neuroticism, perfectionism
• Medical conditions: thyroid disorders, cardiac arrhythmias, chronic illness
• Substance use: caffeine, alcohol, stimulants, or withdrawal

Pathophysiology

• Hyperactivation of the amygdala leading to heightened fear response
• Altered prefrontal cortex function impairing regulation of emotions
• Imbalance in neurotransmitters (serotonin, GABA, norepinephrine)
• Hypothalamic-pituitary-adrenal (HPA) axis dysregulation with elevated cortisol
• Autonomic nervous system hyperactivity causing physical symptoms
• Genetic factors affecting stress response pathways
• Chronic stress leading to structural and functional brain changes