Generalised Anxiety Disorder

Synonyms: GAD, anxiety neurosis

See our calculator Generalised Anxiety Disorder Assessment (GAD 7)

The term anxiety neurosis was coined by Freud, but now it is superseded by the International Statistical Classification of Disease and Related Health Problems (known as ICD) 'ICD-10' diagnosis of Generalised Anxiety Disorder (GAD). (Patients may be offended by the label 'neurotic').
GAD is a syndrome of ongoing anxiety and worry about many events or thoughts that the patient generally recognises as excessive and inappropriate. The condition can be chronic and debilitating.

Prevalence is difficult to ascertain without precise diagnostic criteria.

• The incidence of neurotic disorder is thought to be around 1 adult in 6.
• Of these, the diagnosis of GAD was between 1.5-3.6%.¹
• Figures are higher for women than for men.

Risk factors are:

• Being aged between 35 and 54
• Being divorced or separated
• Living alone or as a lone parent

Protective factors include being aged between 16 and 24 and married or cohabiting.

Exclusions

The criteria for panic disorder, phobic anxiety disorder, obsessive-compulsive disorder (OCD), or hypochondriacal disorder must not be met. If the symptoms are due to a physical disorder or organic mental condition or a substance-related disorder, GAD is excluded.

There are a number of related conditions 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
• Obsessive-compulsive disorder
• Phobias, e.g. 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 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 coexist.³ Ask about depressive symptoms. Those symptoms that appear first or are most severe determine the diagnosis.
• Alcoholism. 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. However, the value of routine questionnaires in diagnosis and evaluation of treatment is dubious.⁴

Evidence-based guidelines are laid down by the National Institute for Clinical Excellence (NICE).⁵ This includes:

• The patient's preference for method of treatment.
• 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 groups.
• In terms of long-term effectiveness, the best results are from psychotherapy,⁶ followed by medication, followed by self-help.
• Placebo response can vary from 20% to over 50%.
• Treatment should be available in primary care with only the most difficult cases requiring referral.

There are frequently comorbid conditions, especially depression, that may need treating too.⁷
If treating a child or adolescent, be much more reluctant and cautious about prescribing.⁸

Psychological therapy

Cognitive-behavioural 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 to 20 hours, delivered in a weekly session of 1 or 2 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 cognitive-behavioural therapy. 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.

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.⁹ 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
• At the start of 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.
• There is no evidence to guide duration of therapy.
• Any form of medication should be reviewed at 2, 4, 6 and 12 weeks after starting.

One systematic review found that kava extract significantly reduced symptoms compared with placebo (according to scores on the HAS).¹⁰ However, there have been some reports of severe hepatic compromise in patients receiving kava.¹¹

NB: beta blockers, monoamine oxidase inhibitors, and antipsychotic medication are not effective.

Self-help

• Self-help is best in the form of bibliotherapy based on CBT principles.¹²
• Exercise as an adjunct to a healthy lifestyle may be of value.¹³
• If one form of 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.

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

It is usually a chronic disease that is controlled rather than cured but the ambience of the doctor should be positive towards a favourable result.¹⁴Those with the condition tend to be more frequent attenders in surgeries, and users of NHS resources.
They tend to have more absence from work, greater turnover of jobs, and reduced productivity. This has financial impact on the individual who may also believe that there is serious underlying disease.
Long-term follow-up studies suggest that GAD is a condition that worsens the prognosis for any other condition, and that people who have only GAD are likely to develop further conditions.

1. Carter RM, Wittchen HU, Pfister H, et al; One-year prevalence of subthreshold and threshold DSM-IV generalized anxiety disorder in a nationally representative sample. Depress Anxiety. 2001;13(2):78-88. [abstract]
2. Slade T, Andrews G; DSM-IV and ICD-10 generalized anxiety disorder: discrepant diagnoses and associated disability. Soc Psychiatry Psychiatr Epidemiol. 2001 Jan;36(1):45-51. [abstract]
3. Alonso J, Angermeyer MC, Bernert S, et al; 12-Month comorbidity patterns and associated factors in Europe: results from the European Study of the Epidemiology of Mental Disorders (ESEMeD) project. Acta Psychiatr Scand Suppl. 2004;(420):28-37. [abstract]
4. Gilbody SM, House AO, Sheldon TA; Routinely administered questionnaires for depression and anxiety: systematic review. BMJ. 2001 Feb 17;322(7283):406-9. [abstract]
5. NICE; Algorithm Management of generalised anxiety disorder in primary care, April 2007
6. Durham RC, Chambers JA, MacDonald RR, et al; Does cognitive-behavioural therapy influence the long-term outcome of generalized anxiety disorder? An 8-14 year follow-up of two clinical trials. Psychol Med. 2003 Apr;33(3):499-509. [abstract]
7. Ballenger JC, Davidson JR, Lecrubier Y, et al; Consensus statement on generalized anxiety disorder from the International Consensus Group on Depression and Anxiety. J Clin Psychiatry. 2001;62 Suppl 11:53-8. [abstract]
8. Hawkridge SM, Stein DJ; A risk-benefit assessment of pharmacotherapy for anxiety disorders in children and adolescents. Drug Saf. 1998 Oct;19(4):283-97. [abstract]
9. Schmitt R, Gazalle FK, Lima MS, et al; The efficacy of antidepressants for generalized anxiety disorder: a systematic review and meta-analysis. Rev Bras Psiquiatr. 2005 Mar;27(1):18-24. Epub 2005 Apr 18. [abstract]
10. Pittler MH, Ernst E; Efficacy of kava extract for treating anxiety: systematic review and meta-analysis. J Clin Psychopharmacol. 2000 Feb;20(1):84-9. [abstract]
11. Kapczinski F, Lima MS, Souza JS, Cunha A, Schmitt R. Antidepressants for generalized anxiety disorder. Cochrane Database Syst Rev 2003;(2):CD003592.
12. Bower P, Richards D, Lovell K; The clinical and cost-effectiveness of self-help treatments for anxiety and depressive disorders in primary care: a systematic review. Br J Gen Pract. 2001 Oct;51(471):838-45. [abstract]
13. Jorm AF, Christensen H, Griffiths KM, et al; Effectiveness of complementary and self-help treatments for anxiety disorders. Med J Aust. 2004 Oct 4;181(7 Suppl):S29-46. [abstract]
14. Gale C, Davidson O; Generalised anxiety disorder. BMJ. 2007 Mar 17;334(7593):579-81.

• Anxiety, NICE Clinical Guideline (2004); (management of anxiety (panic disorder, with or without agoraphobia, and generalised anxiety disorder) in adults in primary, secondary and community care)
• Talking therapies. Dr Stephen Pilling, a consultant clinical psychologist, describes the different talking therapies that can help people overcome a range of problems, from depression to stress. Short video from NHS Choices. (June 2009)