The selective serotonin re-uptake inhibitors (SSRIs) are a group of antidepressant medicines which have only been available for the last few years. They include citalopram (Cipramil), fluoxetine (Prozac), fluvoxamine (Faverin), paroxetine (Seroxat), and sertraline (Lustral). SSRIs are the most commonly prescribed antidepressants in the UK. They are also used to treat other mental and physical illnesses, such as anxiety, panic, bulimia nervosa, and chronic pain.
How they work
Our brains contain chemicals called neurotransmitters. In depression, the levels of certain neurotransmitters can be disturbed. SSRIs help to return the levels of one of these chemicals, serotonin, towards normal, by reducing its uptake into brain cells.
How well they work
Research shows that each group of antidepressants works as well as the others (50-60% improvement rate) in the treatment of depression. The main difference between the groups is in the side effects that they may produce. However, a form of psychological treatment, cognitive behaviour therapy (CBT), may be more effective than SSRIs. People who are depressed and have physical illness also benefit from the use of SSRIs, as do people with dysthymia.
It normally takes a week or two before SSRIs start working. They should be taken as prescribed, on a regular basis, to work properly. Drinking alcohol may prevent recovery from depression. If, after 6 weeks of taking an SSRI regularly, there has been no improvement, it may be worth changing to a different antidepressant (perhaps a tricyclic antidepressant (TCA)).
If the depression improves, treatment should be continued for 4-6 months after return to normal. Research shows that this can often reduce the chance of depression returning. People who have had more than one episode of depression may benefit from taking SSRIs long-term, for years rather than for months, as a preventive measure.
SSRIs are a useful treatment for depression. This includes people:
- with depression
- with dysthymia
- with depression and a physical illness
- who have experienced side effects on TCAs and wish to try an alternative treatment
- who have had more than one episode of depression.
There are several treatments available for depression, with different side-effects. Therefore, people may prefer other antidepressants (TCAs or monoamine oxidase inhibitors (MAOIs)), herbal remedies such as St John's Wort, or a psychological treatment such as cognitive behaviour therapy (CBT).
Side-effects
Some people suffer from side-effects when they take SSRIs. Common side-effects include agitation, dry mouth, headache, nausea, and nervousness. Other side-effects include interference with sexual function, such as delayed orgasm. These often settle over a few days. Therefore, if the side-effects are tolerable, it is worth continuing to take the medicine. Overall, SSRIs may be better tolerated than TCAs.
Side effect Dry mouth Constipation Dizziness Nausea Diarrhoea Anxiety Agitation Insomnia Nervousness Headache SSRIs generally do not cause drowsiness, and may increase alertness and energy. This is why they are usually taken in the morning. Occasionally, SSRIs, particularly paroxetine, can cause drowsiness. If affected, do not drive or operate machinery. It may then be worth taking the SSRI at bedtime. Poor sleep often improves on SSRIs as mood lifts. However, because SSRIs generally do not cause drowsiness, the prescription of another medicine to help sleep may be needed in the short term.
SSRIs (particularly paroxetine) may cause weight gain.
Some people suffer from side-effects if they suddenly stop taking SSRIs. This can be a problem especially with short-acting SSRIs like paroxetine. People should consult there doctor before they stop taking their SSRIs.
SSRIs are not addictive and they do not increase the risk of suicide in people who take them.
Who should avoid taking them
SSRIs should not be taken by:
- people with mania
- people with poorly controlled epilepsy
- people who are taking MAOIs (or have stopped taking MAOIs within the last 2 weeks).
SSRIs should be used carefully in:
- people with epilepsy, heart disease, liver or kidney disease, or bleeding disorders
- people who drink excessive alcohol
- people taking TCAs, warfarin, phenytoin, and some other medicines.
There is no evidence that SSRIs are harmful in women who are pregnant or breast-feeding, and there is some evidence that they are safe. However, SSRIs should be used carefully in these circumstances.