5.6 Pharmacological therapies

Seven broad categories of medications can be used to manage the symptoms of anxiety. These are:

• Selective serotonin reuptake inhibitors (SSRIs)

• Serotonin and noradrenaline reuptake inhibitors (SNRIs)

• Monoamine oxidase inhibitors (MAOIs)

• Tricyclic antidepressants (TCAs)

• Benzodiazepines (tranquillizers)

• Anticonvulsant drugs (e.g. pregabalin)

• Beta-blockers (e.g. propranolol)

SSRIs, SNRIs, MAOIs and TCAs can be effective for treating anxiety, but are also used for treating depression and are commonly referred to as ‘antidepressant’ medications. They have varying degrees of unwanted side effects. SSRIs and SNRIs are most commonly prescribed as ‘front-line’ pharmacological treatment due to fewer side effects than MAOIs and TCAs.

Benzodiazepines may be prescribed for severe or disabling anxiety, but are less frequently used due to long-term dependence. They are instead typically used as a short-term temporary measure (for example, during crises) in cases where anxiety does not effectively respond to CBT, or to other anxiolytic medications.

An anticonvulsant drug such as pregabalin, normally used to treat epilepsy, may also be prescribed to treat certain anxiety disorders (e.g. for generalised anxiety disorder).

Beta-blockers can help to manage the physical symptoms of anxiety, such as rapid heartbeat, palpitations and tremor, and can be helpful for specific phobias (e.g. getting on an aeroplane) or situations that induce social anxiety (such as performance anxiety or public speaking), but are not thought to address psychological symptoms directly.

Table 5, based on Locke et al. (2015) provides a summary of medications that may be used in the treatment of generalised anxiety disorder and panic disorder.

SSRIS, SNRIs and MAOIs work by prolonging the activity of the neurotransmitters serotonin and noradrenaline which are involved in regulating mood, within defined pathways in the brain. SSRIs, developed in the 1980s, specifically prolong the action of serotonin at synapses (the junctions between nerve cells) by preventing its reuptake back into the nerve cells that released it (where it would normally be broken down and recycled). SNRIs, developed in the 1990s, act on noradrenaline as well as serotonin, and are sometimes used for more severe anxiety as well as for depression.

TCAs were developed in the 1950s, and their name (‘tricyclic’) reflects their chemical structure which is composed of three ‘rings’ (‘tri’ meaning three; ‘cyclic’ meaning ring-form or circular). They also prolong the action of noradrenaline and serotonin but have more severe unpleasant side effects than SSRIs or SNRIs.

MAOIs prevent the breakdown of noradrenaline and serotonin by inhibiting the action of the enzyme (called monoamine oxidase) responsible for this process, but side effects can be severe and interactions with certain foods mean that a careful diet needs to be followed if prescribed (i.e. in instances where other anxiolytic medications have not worked).