Serotonin and norepinephrine reuptake inhibitors (SNRIs) work to block serotonin and norepinephrine, and increase the availability of both neurotransmitters.

Selective serotonin reuptake inhibitors (SSRIs), introduced prior to the development of SNRIs, work primarily by blocking nerve cells from reuptaking or reabsorbing serotonin, which increases the availability of this neurotransmitter in the brain. As with all medications, SNRIs and SSRIs have side effects. These may include: diarrhea, headache, nausea and/or insomnia. Talk to doctor to find out more.

Tricyclic antidepressants (TCAs) work by affecting the levels of both serotonin and norepinephrine. They are effective, but their use is limited due to unpleasant side effects.

Monoamine oxidase inhibitors (MAOIs) can be effective for some people who do not respond to their other antidepressants. They help to prevent the breakdown of norepinephrine and serotonin. MAOIs can cause dangerous reactions with certain food, beverages and medication; therefore a strict diet is critical. MAOIs should not be used in combination with any other antidepressants.