Antidepressant medications are also used to treat bipolar disorder. An important thing to remember about antidepressants is that if they are not taken along with a drug that combats mania/hypomania, antidepressants can actually cause these conditions to appear. Many people who seem to be suffering only from clinical depression are diagnosed with bipolar disorder after taking an antidepressant and experiencing mania or hypomania as a result.

There are several antidepressant classes. The names of these classes reflect either their chemical structure or, more commonly, their effect on brain chemistry. The best known at present are the SSRIs and SNRIs which are, respectively, selective serotonin reuptake inhibitors and serotonin norepinephrine reuptake inhibitors.

Serotonin and norepinephrine are neurotransmitters – chemicals in the body that help the nerves pass along messages, and these medications help make more of these chemicals available.

Other classes of antidepressants include the MAOIs – monoamine oxydase inhibitors – and tricyclics, which are named for their chemical structure. There are also a few that do not fit into any of these classes and are thus called “atypical” antidepressants.