Final answer:
Antidepressant medications like MAO inhibitors and SSRIs increase levels of neurotransmitters in the brain, which can help alleviate symptoms of depression.
Step-by-step explanation:
Certain antidepressant medications are thought to work by increasing the levels of neurotransmitters in the brain, which are chemicals that help transmit signals between nerve cells. These medications include monoamine oxidase inhibitors (MAOIs) and selective serotonin reuptake inhibitors (SSRIs). MAOIs work by blocking the enzyme monoamine oxidase, which breaks down neurotransmitters such as dopamine, serotonin, and norepinephrine, leading to increased levels of these chemicals in the synaptic cleft. SSRIs, on the other hand, block the reuptake of serotonin into the presynaptic neuron, which results in an increase in serotonin availability in the synaptic cleft. This increased presence of neurotransmitters can help improve mood and alleviate symptoms of depression.