There are 3 major chemicals in the human brain that must be active in sufficient amounts in the right places of our brain in order for us to feel good.
1) Serotonin: This molecule is responsible for happiness, and can also decrease pain levels in the brain.
2) Norepinephrine: This molecule is responsible for mood, as well as focus and concentration.
3) Dopamine: This molecule is responsible for mood, and allows the “pleasure center” in the brain.
At present, there are no reliable lab tests that can tell doctors which of these three molecules you need more of. That is part of why you may have to try several medications prescribed by your doctor before you feel better.
Major Classes of Antidepressants:
SSRIs: This class of medications increase Serotonin levels. Examples of these include Celexa, Lexapro, Prozac, Luvox, Paxil, Zoloft, Viibryd, and Brintellix.
SNRIs: This class of medications increase Serotonin and Norepinephrine levels. Examples of these include Cymbalta, Effexor, Pristiq, and Fetzima.
NDRIs: This class of medications increase Norepinephrine and Dopamine levels. Examples of this class include Wellbutrin.
By Dr. Terra Caudill, MD, MS