Generalised anxiety disorder

Synonym: anxiety neurosis

See also the Generalised Anxiety Disorder Assessment (GAD-7) calculator.

What is generalised anxiety disorder?

The International Statistical Classification of Disease and Related Health Problems (ICD-11) defines generalised anxiety disorder (GAD) as follows:¹

Generalised anxiety disorder is characterised by marked symptoms of anxiety that persist for at least several months, for more days than not, manifested by either general apprehension (ie ‘free-floating anxiety') or excessive worry focused on multiple everyday events, most often concerning family, health, finances, and school or work, together with additional symptoms such as muscular tension or motor restlessness, sympathetic autonomic over-activity, subjective experience of nervousness, difficulty maintaining concentration, irritability, or sleep disturbance. The symptoms result in significant distress or significant impairment in personal, family, social, educational, occupational, or other important areas of functioning. The symptoms are not a manifestation of another health condition and are not due to the effects of a substance or medication on the central nervous system.

Generalised anxiety disorder (GAD) in a child or adolescent is excessive worry and tension about everyday events that the child or adolescent cannot control and that is expressed on most days for at least six months, to the extent that there is distress or difficulty in performing day-to-day tasks.²

Epidemiology³

Prevalence of generalised anxiety disorder is difficult to ascertain without precise diagnostic criteria. Anxiety disorders are often under-recognised and undertreated in primary care.⁴

• Anxiety disorders are the most common psychiatric disorders. A survey in 2007 estimated the prevalence of generalized anxiety disorder (GAD) among adults in England to be 4.4%. In primary care settings, GAD has been estimated to occur in 7 to 8% of patients.

• GAD is most common in people aged between 35 and 55 years of age, and is more common in women than in men.

• Differences in rates across cultural groups are evident. This may be due to variation in symptom presentation and the interpretation of symptoms as much as true differences in prevalence.⁵

• Generalised anxiety disorder is more prevalent in elderly populations than was once thought.⁶

Risk factors

• Some factors associated with GAD include female sex, lower education level, poor health, and presence of life stressors.

• Other factors include being divorced or separated, and living alone or as a lone parent.

GAD diagnosis⁷

Patients with GAD typically present with excessive anxiety about ordinary, day-to-day situations. The anxiety is intrusive, causes distress or functional impairment, and often encompasses multiple domains (eg, finances, work, health). The anxiety is often associated with physical symptoms, such as sleep disturbance, restlessness, muscle tension, gastrointestinal symptoms, and chronic headaches.

Diagnosing GAD requires caution to identify confounding variables and comorbid conditions. Screening and monitoring tools, such as GAD-7, can be used to help make the diagnosis and monitor response to therapy.

GAD differential diagnosis

There are a number of related conditions to GAD that need to be differentiated at an early stage. There may be confusion and overlap:

• Panic disorder, with or without agoraphobia.

• Post-traumatic stress disorder.

• OCD.

• Phobias - eg, arachnophobia.

• Social phobia, sometimes called social anxiety disorder, or 'SAD'. (This gets it confused with 'seasonal affective disorder' which is totally different.)

• Acute stress disorder.

Anxiety is commonly a feature of other disorders.

Other conditions to consider include:

• Schizophrenia. This can present with anxiety. Ask what the patient thinks caused the symptoms. An irrational answer may show unexpressed delusional ideas.

• Dementia. This is often associated with anxiety and often with depression. Check the memory of any middle-aged or older patient presenting for the first time with anxiety. Screening for dementia gives some quick but validated tests.

• Anxiety and depression. These frequently co-exist.⁸ Ask about depressive symptoms. Those symptoms that appear first or are most severe determine the diagnosis.

• Alcohol dependency. Can cause anxiety as a symptom of withdrawal and may be worse in the morning. Abuse of many other drugs can also produce anxiety.

• Physical illness. This is much less likely to present as simply GAD:
  

  • Thyrotoxicosis. May produce irritability, restlessness, tremor and tachycardia.

  • Phaeochromocytoma. Normally is part of multiple endocrine neoplasia - usually MEN2.

  • Hypoglycaemia. This is usually part of failure of control of diabetes but insulinoma can be part of MEN.

There are a number of validated screening tests that can be used, including the Beck's Anxiety Inventory, General Health Questionnaire, Hamilton Anxiety Scale (HAS) and the Hospital Anxiety and Depression Scale (HADS). There are limitations in the use of routine questionnaires but providing these limitations are recognised, the general consensus is that they are worth employing in evaluation and treatment.^{9 10}

GAD management

Evidence-based guidelines are laid down by the National Institute for Health and Care Excellence (NICE).¹¹ Relevant issues are as follows:

• Identify the diagnosis and inform the patient as soon as possible so treatment can be commenced.

• The patient's preference for method of GAD treatment.

• Make independent interpreters available if necessary.

• Emphasise to the patient that the disease can be managed and give as much information as possible, including written information and access to self-help and psycho-educational groups.

• Make an assessment of the patient's functional disability and distress.

• Assess past experience and response to previous treatment.

• In terms of long-term effectiveness, the best results are from psychotherapy, followed by medication, followed by self-help.

• Patients with mild learning disability or mild acquired cognitive impairment should be offered the same services as other people with GAD, making appropriate adjustment for the disability.

• People with GAD and a moderate-to-severe learning disability or moderate-to-severe acquired cognitive impairment should be offered specialist referral.

• Placebo response can vary from 20% to over 50%.

• Treatment should be available in primary care with only the most difficult cases requiring referral.

• Make the patient aware of the hazards of over-the-counter medications.

• Provide contact details in the event of a crisis.

The stepped-care model

Psychological therapy

CBT is the technique of choice for an effective and lasting response:

• It must be delivered by appropriately trained professionals.

• The optimum duration of therapy would seem to be about 16-20 hours, delivered in a weekly session of one or two hours and completed within four months.

• If offering briefer CBT, it should be about 8-10 hours and should be designed to integrate with structured self-help materials.

Anxiety management treatment is also better than no treatment and its efficacy may equal that of CBT. It is a structured therapy involving education, relaxation training, and exposure. Relaxation involves practising techniques that lead to muscular or bodily relaxation. Exposure entails (over a period of time) graded, repeated confrontation (through visualisation, image, or the stimulus) with a stimulus that causes anxiety.

Recently a simplified protocol for the treatment of a wide range of psychological conditions - transdiagnostic CBT - has been used to good effect in the management of GAD.¹³

Pharmacological treatment

Before prescribing, consider:

• Age of patient.

• Previous treatment response.

• Risks of deliberate self-harm or accidental overdose.

• Tolerability.

• Possible interactions with existing medications.

• The patient's preference.

• Cost, where equal effectiveness.

Where a rapid response is required:

• The sedative antihistamines may be effective or the benzodiazepines. The latter should not be used beyond four weeks. Apparent dependence may be because the disease has returned as the drug is withdrawn or there may be a physical dependence.

• It has been suggested that buspirone is less sedative and less addictive than benzodiazepines but it should be used with similar caution.

Antidepressants are often good at alleviating anxiety, even if there is no true depression.¹⁴ They take longer to work than benzodiazepines but they can be continued for longer.

• NICE recommends a selective serotonin reuptake inhibitor (SSRI) or venlafaxine as the first choice. If one SSRI is not suitable or there is no improvement after a 12-week course and if a further medication is appropriate, another SSRI should be offered. Long-term treatment and doses at the upper end of the indicated dose range may be necessary. NICE recommends sertraline first-line but acknowledges that this is an unlicensed use. SSRIs licensed for the treatment of GAD in the UK are escitalopram and paroxetine.

• At the start of GAD treatment, patients should be informed about:
  

  • Potential side-effects (including transient increase in anxiety at the start of treatment).

  • Possible discontinuation/withdrawal symptoms.

  • Delay in onset of effect.

  • Time course of treatment.

  • Need to take medication as prescribed.

• If there is no benefit in 12 weeks an antidepressant from a different class may be tried.

• SSRIs and venlafaxine should be tailed off, as sudden discontinuation can produce withdrawal.

• If sertraline is ineffective, offer an alternative SSRI or a serotonin-noradrenaline reuptake inhibitor (SNRI), such as duloxetine or venlafaxine.

• Pregabalin may be considered in patients who cannot tolerate SSRIs or SNRIs.

• Duloxetine, although not mentioned by NICE, is licensed for the treatment of GAD and has been found effective.

NB: beta-blockers and monoamine-oxidase inhibitors are not usually considered appropriate options for GAD.¹⁵

Self-help

• Self-help interventions are effective but are best used as part of a stepped-care approach.¹⁷

• NICE advocates instructing the person to work through the materials systematically over a period of six weeks. Occasional contact with a therapist is advocated (eg, a five-minute telephone call).¹¹

• Internet-based self-help CBT has proved effective but the evidence base is currently small.¹⁸

• Interventions such as exercise, yoga, mindfulness-based meditation, t'ai chi, or qi gong may have benefits as adjunctive therapy for patients with depression, anxiety disorders, or both.¹⁹

• If one form of GAD therapy does not work, another may be tried. More than one style may be used simultaneously.

• If two interventions have been tried without success then referral to mental health services is required.

Monitoring

• Primary healthcare professionals should monitor progress. Review interval should be determined on a case-by-case basis but is likely to be every 4-8 weeks.

• For patients on medication, NICE recommends a review every 2-4 weeks for the first three months and three-monthly thereafter.

• Medication should be continued for a minimum of one year.

• A short, self-complete questionnaire should be used to monitor outcomes wherever possible.

GAD prognosis

Generalised anxiety disorder is usually a chronic disease that is controlled rather than cured but the ambience of the doctor should be positive towards a favourable result.²⁰

Generalised anxiety disorder often pursues a waxing and waning course and long-term support and education are required.¹²

Studies of older individuals with GAD report a duration of 20 years or more. Significant quality of life impairment and increased burden of healthcare cost have been noted in older adults. Chronic anxiety conditions are associated with increased morbidity, possibly due to cardiovascular complications and insulin resistance linked to an acceleration of the ageing process.⁶