women who drink coffee cut their risk of depression by 15 percent compared to those who don’t. Caffeine7 has also been found to promote production of the neurotransmitters serotonin, dopamine and noradrenaline. As explained by World of Caffeine:8“Many of caffeine’s powers depend on its power to pass into the central nervous system (CNS). To enter the CNS, caffeine must cross the blood-brain barrier… Even when injected into the bloodstream, many drugs fail to penetrate this barrier… However, caffeine passes through the blood-brain barrier as if it did not exist. All psychoactive drugs, including caffeine, achieve their effects by imitating or altering the release or uptake of neurotransmitters, the chemical messengers that direct how the neurons of the CNS interact with each other.Caffeine achieves many of its effects by blocking the activity of adenosine… Because one of the primary actions of adenosine is to make us tired or sleepy, caffeine, by blocking the uptake of adenosine, keeps us from feeling the effects of fatigue. But scientists have learned that, largely as a consequence of its blockade of adenosine receptors, caffeine also has profound effects on most of the other major neurotransmitters, including dopamine, acetylcholine, serotonin, and, in high doses, on norepinephrine.”Increasing your dopamine levels may have a beneficial impact on mood, while increasing acetylcholine may help improve long-term memory. Meanwhile, it is commonly thought that adjusting your serotonin levels upward may play a role in relieving depression. This is primarily how antidepressants work.That said, it’s worth noting that the low serotonin theory, which antidepressant drugs attempt to address, has been thoroughly debunked. Investigations have been done to see whether or not depressed people actually have lower serotonin levels in their brains, and in 1983 the National Institute of Mental Health (NIMH) concluded that:
“There is no evidence that there is anything wrong in the serotonergic system of depressed patients.”
Still, coffee appears to affect a number of neurotransmitters related to mood control, so it’s certainly plausible that this could have an effect on your general sense of wellbeing.
Research has also shown that coffee triggers a mechanism in your brain that releases a growth factor called Brain-Derived Neurotrophic Factor (BDNF), which activates your brain stem cells to convert into new neurons, thereby improving your brain health. Interestingly enough, recent research9 also suggests that low BDNF levels may play a significant role in depression, and that increasing neurogenesis has an antidepressant effect! This may be yet another piece of the puzzle explaining whyexercise tends to have a higher success rate in treating depression than antidepressant drugs do, as exercise naturally increases BDNF levels10 in your body.