Generalised anxiety disorder. Guidelines for diagnosis and treatment

Generalised anxiety disorder (GAD) is the most common anxiety disorder. It is usually a chronic condition, but the severity of symptoms may depend greatly on the degree of stress the patient is under at any one time. According to DSM-IV, the symptoms of GAD consist of excessive anxiety and worry, hyperarousal, increased muscular tension, difficulties concentrating, irritability and sleep disturbances. While autonomic symptoms are not required for the diagnosis, subgroups of patients with GAD do manifest a considerable degree of cardiac or gastrointestinal symptoms. GAD is frequently associated with affective and other anxiety disorders. The treatment of GAD includes psychological and pharmacological interventions. Psychological interventions consist of explanations, reassurance, support and, in more persistent conditions, cognitive and behavioural therapy. In pharmacotherapy, benzodiazepines, antidepressants, antihistamines and, less frequently, antipsychotics and β-adrenergic blockers are used. The choice of medication depends on the severity of symptoms, the degree to which psychic and somatic symptoms contribute to the overall picture, and whether symptoms are episodic or continual. Benzodiazepines have anxiolytic, sedating and muscle relaxing properties. Since their onset of effect is rapid, they are useful whenever rapid anxiolysis is indicated. Benzodiazepines with a long elimination half-life are preferable if long term treatment is required, but may accumulate in elderly patients or in patients with liver disease. Benzodiazepines do not seem to lose their effectiveness during long term treatment. However, because of their addictive potential, in most cases, benzodiazepines should only be given for a short time. Frequently, patients with GAD use benzodiazepines intermittently, i.e. only in situations that they perceive as stressful. Benzodiazepines should only be prescribed on a long term basis in severely anxious patients who have responded poorly to other treatments. In such patients, the improvement in functioning that can be induced by the drugs outweighs the risk of addiction. Antidepressants, and particularly those with serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibiting properties, reduce worries and obsessions, and so are useful in patients in whom excessive worrying predominates. However, they have to be taken on a long term basis to provide adequate control of symptoms and often have unpleasant adverse effects. Anxiolytics that affect specific serotonin receptors also have anxiolytic properties by lowering psychic anxiety, but also have to be taken long term to be effective. Antihistamines and antipsychotics have some anxiolytic effect and are not habit forming. They can be prescribed on an 'as needed' basis or as a regular prescription. Antihistamines should be given to patients in whom addiction to benzodiazepines is a possibility. However, antipsychotics should be avoided in all but the exceptional case because they may induce tardive dyskinesia. β-Adrenergic blockers have no direct anxiolytic properties, but are useful as adjunctive therapy in patients with prominent cardiac symptoms or tremor.