Many people who have problems with depression have been prescribed antidepressant medication at some point. Whether the medication worked for you or not, you may have noticed that when you ran out inadvertently or stopped taking the medication intentionally, you had some unpleasant symptoms. This is known as antidepressant discontinuation syndrome.
This syndrome is known to occur in approximately 20 percent of patients who take antidepressants for a minimum of about six weeks and suddenly discontinue for any reason. Though there have been no clinical trials yet, the common consensus is that slowly tapering or weaning off of the medication over a period of weeks will prevent or lessen the discontinuation symptoms.
Some of the symptoms associated with this syndrome are as follows:
Flu-like symptoms
Insomnia
Nightmares
Dizziness
Vertigo
Difficulties with balance
Gastrointestinal disturbances
Anxiety
Sensory disturbances such as electrical shock sensations
Depressed mood
Irritability
Agitation
Antidepressant discontinuation syndrome seems to be an issue with nearly every type of antidepressant, although specific symptoms are more commonly seen with specific medication classes. For instance, symptoms of psychosis are mainly associated with abrupt discontinuation of MAOI inhibitors, while the sensory disturbance symptoms seem to be more common with SSRI discontinuation.
At this time it is unknown exactly what causes discontinuation symptoms. There are several theories and it seems as though drugs with a shorter half-life cause more symptoms than those with a longer half-life, because the body clears them faster. Antidepressants are not thought to be addictive because they are not really drugs that people abuse for the effects. However, it is important to know about the discontinuation syndrome, because if you suddenly stop taking your antidepressants for any reason then see a physician because of these symptoms without thinking to mention your medication cessation, you could be incorrectly diagnosed with a medical or psychiatric problem.
Not every provider is aware of this syndrome. If you are taking antidepressants and decide you want to stop, just be sure you discuss it with your health care provider so that you can work together on a tapering schedule. While antidepressant discontinuation syndrome is not thought to be dangerous or life threatening, it can be very unpleasant and worth avoiding with a slow drug taper.
Sources:
American Family Physician: Antidepressant Discontinuation Syndrome
http://www.aafp.org/afp/2006/0801/p449.html
Primary Psychiatry: Antidepressant Discontinuation Syndrome
http://www.primarypsychiatry.com/aspx/articledetail.aspx?articleid=625