Those are antidepressant drugs that
increase the level of neurotransmitters. Selective serotonin reuptake inhibitors (SSRIs) affect the process of neurotransmitters’ reabsorption back into nerve cells. This inhibitor prevents reuptake of serotonin and instead of that, the serotonin stays in the gap between the nerves-synapse.
Tricyclics are antidepressants that block the reabsorption of neurotransmitters, in this case, serotonin, and epinephrine. As a result, these chemicals are released into a synapse.
Monoamine oxidase inhibitors (MAOIs) block the enzyme monoamine oxidase which breaks down serotonin, epinephrine, and dopamine. As a result, the levels of those neurotransmitters are increased.