There are about three main types of antidepressants and they all serve a different purpose in the treatment of mood disorders. These three types of antidepressants include tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs) and monoamine oxidase inhibitors (MAOIs).

Antidepressants in and of themselves are not necessarily addicting drugs, but they can cause severe withdrawals symptoms if a person abruptly stops using them. So it’s not necessarily the drug itself that people get addicted to, but it is more the fear of the withdrawals symptoms that keeps people using antidepressants. Often if a person is unable to get their medication they will supplement it with another drug.

Antidepressants, most commonly the cyclic antidepressants, are the second leading cause of death from drug overdose in the United States, according to information published in the Prehospital Care Journal of Emergency Medicine. Cyclic antidepressants are absorbed through the intestines quickly and have a half-life (the time they remain active in the body) of more than 24 hours, which is why they often cause an overdose. The most serious symptoms of an overdose of antidepressants affect the CNS and the heart. Signs of an overdose may include drowsiness, confusion and agitation. Seizures, cardiac dysrhythmias, and apnea are the most important life threatening complications.