The main use for antidepressants is treating depression. They are also used for other mental health conditions and treatment of long-term pain.

In most cases, people with moderate to severe depression are given antidepressants as a first form of treatment. They are often prescribed along with a talking therapy such as cognitive behavioural therapy (CBT). CBT is a type of therapy that uses a problem-solving approach to help improve thought, mood and behaviour.

Antidepressants are not always recommended for treating mild depression because research has found limited effectiveness.

However, antidepressants are sometimes prescribed for a few months for mild depression to see if you experience any improvement in your symptoms. If you don’t see any benefits in this time, the medication will be slowly withdrawn.

Initially, a type of antidepressant called a selective serotonin reuptake inhibitor (SSRI) will usually be prescribed. If your symptoms have not improved after about four weeks, an alternative antidepressant may be recommended or your dose may be increased.

Many antidepressants can be prescribed by your GP, but there are some types that can only be used under the supervision of a mental health professional. If the depression does not respond to simple antidepressant medication, specialists often use other treatments (such as CBT) along with the medication to help achieve better results. They may also give higher doses of the medication.

Other mental health conditions

Antidepressants can also be used to help treat other mental health conditions, including:

• anxiety disorder
• obsessive compulsive disorder (OCD)
• panic disorder
• serious phobias, such as agoraphobia and social phobia
• bulimia
• post-traumatic stress disorder (PTSD)

As with depression, SSRIs are usually the first choice of treatment for these conditions. If SSRIs prove ineffective, an alternative type of antidepressant can be used.

Long-term pain

Even though a type of antidepressant called tricyclic antidepressants (TCAs) were not originally designed to be painkillers, there is evidence to suggest they are effective in treating chronic (long-term) nerve pain in some people.

Chronic nerve pain, also known as neuropathic pain, is caused by nerve damage or other problems with the nerves, and is often unresponsive to traditional painkillers, such as paracetamol.

Amitriptyline is a TCA that is usually used to treat neuropathic pain. Conditions that may benefit from treatment with amitriptyline include:

• complex regional pain syndrome
• peripheral neuropathy
• multiple sclerosis
• conditions where a nerve becomes trapped, such as sciatica

Antidepressants have also been used to treat cases of chronic pain that do not involve nerves (non-neuropathic pain). However, they are thought to be less effective for this purpose. As well as TCAs, SSRIs and serotonin-noradrenaline reuptake inhibitors (SNRIs) can also be used to treat chronic non-neuropathic pain.

Conditions that cause non-neuropathic pain which may benefit from treatment with antidepressants include fibromyalgia, chronic back pain and chronic neck pain.

Bedwetting in children

TCAs are sometimes used to treat bedwetting in children as they can help relax the muscles of the bladder. This increases bladder capacity and reduces the urge to urinate.