Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressants in many countries in the world. They can ease symptoms of moderate to severe depression, are relatively safe and typically cause fewer side effects than other types of antidepressants. They treat depression by increasing levels of serotonin in the brain.
What are SSRIs?
Serotonin is one of the chemical messengers (neurotransmitters) that carry signals between brain nerve cells (neurons); SSRIs block the reabsorption (reuptake) of serotonin into neurons, thus making more serotonin available to improve the transmission of messages between neurons. SSRIs are considered selective as they mainly affect serotonin, not other neurotransmitters.
SSRIs may also be used to treat conditions other than depression, such as anxiety disorders, post-traumatic stress disorder, obsessive-compulsive disorder, premenstrual dysphoria, impulse control disorders, rapid ejaculation, borderline personality disorder, schizo-depressive disorder, and others.
The following drugs are members of the SSRI family:
- Escitalopram
- Fluoxetine
- Paroxetine
- Sertraline
- Fluvoxamine
All SSRIs are thought to work in a similar way and generally can cause similar side effects, though some people may not experience any. Many side effects may go away after the first few weeks of treatment. The other option is to try another medicine if the side effects are severe and unbearable.
If a person cannot tolerate one SSRI, he or she may be able to tolerate a different one, as SSRIs differ in their potencies at blocking serotonin reuptake and in how quickly the body eliminates (metabolizes) the drug.
Side effects of SSRIs
Possible side effects of SSRIs may include, among others:
- Nausea, vomiting or diarrhoea
- Headache
- Drowsiness
- Dry mouth
- Insomnia
- Nervousness, agitation or restlessness
- Dizziness
- Sexual problems, such as reduced sexual desire, difficulty reaching orgasm or inability to maintain an erection (erectile dysfunction)
- Impact on appetite, leading to weight loss or weight gain
Taking the medication with food may reduce the risk of nausea. If the medicine does not keep a person alert at night, then that person can reduce the impact of nausea by taking it at bedtime.
Like many other antidepressants, the use of SSRIs has been associated with weight gain.
Weight gain caused by SSRIs may be due to fluid retention, lack of exercise, increased appetite, or other factors. It is recommended to engage in physical activity and eat fewer high-calorie foods to manage weight gain while taking SSRI or other antidepressants. Although most antidepressants potentially cause weight gain, this is more risk with some than others. Research suggests that paroxetine is linked to more weight gain than sertraline or fluoxetine. It is possible that your doctor will be able to prescribe a new SSRI that does not make you put on many kilos, or he may have you try a non-SSRI such as Wellbutrin (bupropion), an antidepressant that is a norepinephrine-dopamine reuptake inhibitor (NDRI). It works differently in the brain than SSRIs do. Some people even lose a little weight while taking Wellbutrin.
It is dangerous to just stop taking an antidepressant: With many of them, going cold turkey can lead to an array of unpleasant withdrawal side effects known collectively as discontinuation syndrome.
Studies have shown that antidepressants can increase suicidal thoughts and behaviours in children, adolescents, and younger adults who already have a major depressive disorder or other psychiatric problems. However, in those older than 24, there was no increased risk and there was actually a reduction in risk among adults 65 and older. Your doctor will decide if the risks are acceptable and will monitor you closely.
