Antidepressants are drugs prescribed to help treat depression. These drugs are also sometimes used to treat other mental health conditions like anxiety and obsessive-compulsive disorder (OCD). Antidepressants are commonly broken down into seven major classes: SSRIs, NARIs, SNRIs, TCAs, MAOIs, NMDA antagonists, and NaSSAs.

Each class of antidepressants works in distinct ways.

  • SSRIs, or selective serotonin reuptake inhibitors, work to prevent the reuptake of serotonin, which helps increase the amount of serotonin in the brain.
  • NARIs, or noradrenaline reuptake inhibitors, prevent the reuptake of the neurotransmitter noradrenaline at the synapses. Noradrenaline is thought to influence mood.
  • SNRIs, or serotonin and norepinephrine reuptake inhibitors, affect the neurotransmitters serotonin and norepinephrine.
  • TCAs, or tricyclic antidepressants, block the reuptake of norepinephrine and serotonin. This action helps to increase the activity of both neurotransmitters. TCAs also interact with other receptors in the brain.
  • MAOIs, or monoamine oxidase inhibitors, stop serotonin, dopamine, and norepinephrine from being removed from the brain.
  • NMDA antagonists work to limit the action of the N-Methyl-D-aspartate receptor. This class of medication is often prescribed in cases of treatment-resistant depression.
  • NaSSAs, or noradrenergic and specific serotonergic antidepressants, cause the buildup of noradrenaline and serotonin in the hopes that they become more active in the brain.

Each class of antidepressants has unique benefits and can help different people battle depression.

Research suggests that people seeking first-time treatment for depression may benefit most from sertraline and escitalopram. These two SSRIs appear to have the lowest chance of side effects compared to other choices.

Side Effects of Antidepressants

Antidepressant medications are not without side effects. Some of the most commonly reported side effects include:

  • Weight gain
  • Drowsiness
  • Sexual problems
  • Trouble sleeping
  • Gastrointestinal discomfort