Generalised Anxiety Disorder

Synonyms: GAD, Anxiety Neurosis

The term anxiety neurosis was coined by Freud, but now it is superseded by the ICD 10 diagnosis of Generalised Anxiety Disorder. (Patients may be offended by the label 'neurotic').
Generalised anxiety disorder 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.
In 2000 the Office of National Statistics (ONS) presented a survey called Psychiatric Morbidity among Adults living in Private Households¹ and found that:

• The incidence of neurotic disorder in the week before interview was 164 per 1,000 or about 1 adult in 6.
• Of these the diagnosis of GAD was 44 per 1,000 or 4.4%.
• Figures were higher for women than for men.

Risk Factors were found to be:

• Aged between 35 and 54
• Divorced or separated
• Living alone or as a lone parent

Protective factors include being aged between 16 and 24 and married or co-habiting.²

Exclusions

The criteria for panic disorder, phobic anxiety disorder, obsessive-compulsive disorder, 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, generalised anxiety disorder 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 (PTSD)
• Obsessive compulsive disorder (OCD)
• Phobias eg arachnophobia
• Social phobia, sometimes called social anxiety disorder or SAD that 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 can present with anxiety. Ask what the patient thinks caused the symptoms. An irrational answer may show unexpressed delusional ideas.
• Dementia is often associated with anxiety and often 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 frequently co-exist.⁴ 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 is much less likely to present as simply GAD:
  • Thyrotoxicosis may produce irritability, restlessness, tremor and tachycardia.
  • Phaeochromocytoma is usually part of multiple endocrine neoplasia, usually MEN2.
  • Hypoglycaemia 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 and the Hospital Anxiety and Depression Scale. However, the value of routine questionnaires in diagnosis and evaluation of treatment is dubious.⁵

Evidence based guidelines are laid down by NICE.⁶ 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,⁷ 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.⁸
If treating a child or adolescent, be much more reluctant and cautious about prescribing.⁹

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 weekly session of 1 or 2 hours and completed within 4 months.
• If offering briefer CBT, it should be about 8-10 hours, 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 behaviour 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.

Drug 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 4 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.¹⁰ They take longer to work than benzodiazepines but they can be continued for longer.

• NICE recommends an 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 Hamilton anxiety scale).¹¹ However, there have been some reports of severe hepatic compromise in patients receiving kava.¹²
NB. Beta blockers, MAOIs and antipsychotic medication are not effective.

Self-Help

• Self help is best in the form of bibliotherapy based on CBT principles.¹³
• Exercise as an adjunct to a healthy lifestyle may be of value.¹⁴
• If one form of therapy does not work another may be tried. More than one style may be used simultaneously.
• If 2 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 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.¹⁵Those 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 generalised anxiety disorder is a condition that worsens the prognosis for any other condition, and that people who have only generalised anxiety disorder are likely to develop further conditions.