SSRI antidepressants, often known simply as SSRIs, are a class of commonly prescribed antidepressants. They are designed to raise levels of a brain chemical called serotonin, which can have a positive effect on mood over time. They are usually considered to be safer and have fewer side effects than older antidepressants. Some of the more common SSRI antidepressants include fluoxetine, sertraline, and citalopram, which are marketed as Prozac®, Zoloft®, and Celexa®, respectively.
The primary effect of SSRIs is to increase the amount of available serotonin in the brain. This is accomplished by partially preventing brain cells from reabsorbing serotonin. The increased amount of serotonin is thought to be partially responsible for the better mood that often results. This action is reflected in the drugs' full name, selective serotonin re-uptake inhibitors.
SSRI antidepressants begin to affect serotonin levels in the brain within a few hours of taking a dose. They don't, however, have an immediate effect on mood. It usually takes between four and eight weeks for SSRIs to have an effect on mood. It's not exactly known why this is this case, but it can have a discouraging effect for some people taking SSRI antidepressants. It's recommended that they allow one to two months to see an improvement in mood before trying a different medication.
Although SSRIs are chemically similar drugs, they have different effects. If one SSRI doesn't have a mood-enhancing effect for an individual, another still could. In the United States, certain SSRIs are also approved to treat anxiety disorders that occur alone or along with depression. If SSRIs are not helpful, the so-called atypical antidepressants may be more useful for some people. These drugs affect other brain chemicals in addition to serotonin.
SSRIs are usually well tolerated, but can cause some unpleasant side effects. Some more common side effects include dizziness or faintness, drowsiness, and changes in weight. SSRIs have been linked to worsening depression and suicidal thoughts in teenagers and also young adults less than the age of 25. In the United States, they have been required to carry a warning explaining this risk. Rarer side effects are more likely to occur in people taking more than one medication, especially more than one antidepressant.
People who are taking SSRI antidepressants shouldn't stop taking them without their doctor's knowledge or advice. Suddenly stopping SSRI use can cause antidepressant withdrawal. This condition can cause headaches and nausea, anxiety, and worsening symptoms of depression. Gradually reducing SSRI use with a doctor's supervision makes withdrawal less likely.