Definition - At least 6 months of excessive worry about everyday issues that is disproportionate to any inherent risk, causing distress, or impairment.
- The worry is not confined to features of another mental disorder, or as a result of substance abuse or a general medical condition.
- At least 3 of the following emotional, somatic, and cognitive symptoms are present most of the time:
- restlessness or nervousness
- being easily fatigued
- poor concentration
- irritability
- muscle tension
- sleep disturbance
- Other common complaints are autonomic in nature, such as sweating, lightheadedness, palpitations, dizziness, and epigastric discomfort. [2]
- Anxiety may be 'free-floating' (i.e., not restricted to, or even strongly predominating in, any particular environmental circumstances). [2]
- Examples of worries include fears that the patient or a relative will shortly become ill or have an accident.
Risk Factors - FHx of anxiety
- Physical or emotional stress
- Hx of physical or emotional trauma
- Depression
- Other anxiety disorder
- Female gender
- Diabetes
Differential diagnosis - Panic disorder
- Characterised by recurrent episodes of sudden onset of anxiety
- Strong autonomic and physical complaints without the predominant picture of worry. [1]
- At least 4 symptoms including shortness of breath, palpitations, shakiness, nausea, hot or cold flushes, dizziness, and fear of dying.
- Panic may exist along with GAD
- Social phobia
- Anxiety or persistent fear is limited to social situations and fear of social scrutiny or embarrassment. [1]
- Obsessive-compulsive disorder
- Anxiety is directly related to compulsions or obsessions.
- Post-traumatic stress disorder
- Anxiety is directly related to exposure to reminders of past trauma.
- Somatoform disorders
- Anxiety is directly related to specific physical complaints.
- Thorough medical evaluation shows no basis for physical complaints.
- Depression
- Inability to feel pleasure with an overall sad or irritable mood. [1] [28]
- Substance- or drug-induced anxiety disorder
- Anxiety is directly related to exposure to:
- substance (e.g., caffeine, toxin, alcohol, illicit drug)
- drug (e.g., salbutamol, theophylline, corticosteroid, antidepressant)
- herbal medicine (e.g., ma huang, St. John's wort, ginseng, guarana, belladonna).
- CNS-depressant withdrawal
- Anxiety may occur during withdrawal of a substance (e.g., alcohol, opioids, sedative-hypnotics)
- Characteristic symptoms such as shakiness (i.e., rapid heart rate, fluctuating blood pressure), and, if delirium is present, mental confusion.
- Typical signs on are tachypnoea, tachycardia, and disorientation
- Anorexia nervosa
- Anxiety is directly related to a fear of gaining weight.
- Body weight <85% of ideal.
- Situational anxiety (non-pathological)
- Anxiety can be avoided and is more controllable and less pervasive.
- Situational worries are less likely to be accompanied by physical symptoms. [1]
- Restlessness, fatigue, and other physical symptoms are rarely present.
- Adjustment disorder
- Anxiety occurs temporarily in response to a life stressor and does not persist for more than 6 months after the stressor ends.
- Cardiac disease
- Anxiety symptoms are predominantly cardiac in nature
- Palpitations, sensation of rapid heartbeat or skipped heartbeat, dizziness, dyspnoea on exertion, chest pain, and numbness
- Chest pain is typically exertional.
- Pulmonary conditions
- Hyperthyroidism
- Weight loss, warm moist skin, heat intolerance, ophthalmopathy, or goitre.
- TFTs (increased T4, decreased TSH) can identify primary hyperthyroidism or use of excessive thyroid hormone.
- Infections
- Anxiety limited to the time period of the infection.
- Peptic ulcer disease
- Typically, burning epigastric pain which occurs hours after meals or with hunger, relieved by food or antacids.
- Crohn's disease
- Chronic diarrhoea, weight loss, and right lower quadrant abdominal pain mimicking acute appendicitis.
- Perianal lesions including skin tags, fistulae, abscesses, scarring or sinuses.
- Irritable bowel syndrome
- Alteration of bowel habits associated with pain, and abdominal discomfort, bloating, or distention.
Epidemiology - Generalised anxiety disorder (GAD) usually occurs along with other mental disorders. [5] [6] [7]
- One study in Europe showed that 76% of people who had more than 1 mental disorder for 12 months had GAD.
- In the US, GAD has an estimated lifetime prevalence of 5% and a 12-month prevalence of 3%
- About two thirds of patients diagnosed are female, and more women (55% to 60%) than men are diagnosed in clinical settings. [1]
- Over half of the people seeking help have an onset in childhood or adolescence.
- Diagnosis is less common in people over 65 years of age. [9] [10]
- A large US epidemiological study found that almost half of people retained the diagnosis over 2 years after diagnosis. [5]
Aetiology - No single aetiology exists
- An increase in minor life stressors, [13] [14] presence of physical or emotional trauma, [15] and genetic factors seem to contribute.
- A systematic review found that bullying or peer victimisation among youths was associated with an increased incidence. [16]
- A review of 35 twin and family studies found a significant association with other anxiety disorders and depression, suggesting a common underlying genetic factor. [18]
- Abnormality of chromosome 15 has been associated with panic, agoraphobia, social phobia, and joint laxity in families, and with panic disorder in non-familial cases.
- However, this data is preliminary only
- Further investigations, including more sophisticated studies of genetic markers, are warranted to substantiate this and identify other genetic factors associated with anxiety disorders. [19]
Clinical features - Presence of risk factors
- Excessive worry for at least 6 months
- Anxiety not confined to another mental disorder
- Anxiety not due to medication or substance
- Muscle tension
- Sleep disturbance
- Fatigue
- Restlessness
- Irritability
- Poor concentration
- Headache
- Sweating
- Dizziness
- GI symptoms
- Muscle aches
- Increased heart rate
- Shortness of breath
- Trembling
- Exaggerated startle response
- Chest pain
Pathophysiology - Not clearly understood
- Studies have identified changes in cerebral blood flow in response to stress
- Hypervigilance and increased metabolic activity suggest hyperactive brain circuitry. [20]
- Multiple neurotransmitters involving wide areas of the brain have been implicated in anxiety and other disorders [21]
- Including receptors for benzodiazepines, N-methyl-D-aspartate/glutamate, serotonin, and cholecystokinin.
- Abnormalities in brain corticotrophin-releasing factor secretion in the hypothalamic-pituitary-adrenal axis appear to co-occur with anxiety episodes
- May adversely affect neurotransmitters and arousal. [22]
- The associated heightened vigilance and arousal are associated with insomnia and diurnal fatigue. [23]
Investigations- DSM-IV-TR criteria for GAD:
- At least 6 months of excessive worry about everyday issues that is disproportionate to any inherent risk, causing distress, or impairment.
- The worry is not confined to features of another mental disorder or as a result of substance abuse or a general medical condition.
- At least 3 of the following symptoms are present most of the time:
- restlessness or nervousness, being easily fatigued, poor concentration, irritability, muscle tension, or sleep disturbance. [1]
- Tests to rule out other conditions:
- TFTs
- urine drug screen
- 24-hour urine for vanillylmandelic and metanephrines
- pulmonary function tests
- ECG
- echocardiogram
- EEG
Managementa) conservative- CBT
- Psychotherapy
- Applied relaxation
b) medical - Hydroxyzine
- Benzodiazepines
- Antidepressants if depression coexists
- SSRIs, SNRIs, or buspirone are considered the drugs of choice
c) surgicalPrognosis- Pharmacotherapy should be given for at least 6 to 8 weeks to determine efficacy, and continued for up to 6 to 12 months if effective. [27]
- The physician may attempt to taper the medication after this period, monitoring the patient for recurrence of symptoms.
- With proper treatment, a decrease in symptoms, improved psychosocial functioning, and a reduction in over-utilisation of medical care can be achieved.
- Generalised anxiety disorder may recur under physical or emotional stress.
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