Our brains are 75% water. That water is essential for delivering nutrients to and removing toxins from the brain. Dehydration, then, can cause your brain to function inefficiently or even shut down. Your brain functions optimally when it has a full reserve of water.
Because mental health is driven primarily by your brain's activity, social stresses such as anxiety, fear, and insecurity — and ongoing emotional problems including depression — can be tied to not consuming enough water, says Solara Mental Health.
Dehydration impedes your brain's production of serotonin, a neurotransmitter that affects mood. Serotonin is created from the amino acid tryptophan; the brain requires sufficient water for that production. Dehydration can also negatively impact other amino acids the brain requires to produce functions that impact mood. The result may be feelings of dejection, inadequacy, anxiety, and irritability.
"Dehydration appears to be associated with mood, including depression, and with anxiety. Dehydration might, therefore, make these conditions worse," says Joshua Thurman, M.D.
Drinking sufficient water can help reduce both the negative psychological and physiological impacts of stress. Stress can result in many of the same responses as dehydration, including increased heart rate, nausea, fatigue, and headache. If you can remain hydrated you can reduce the magnitude of those responses, says WebMD.
When you're under stress your heart rate goes up and you breathe more heavily: You're losing fluid. When stressed, you're also more likely to forget to follow healthy habits. Ensuring you are properly hydrated daily can help to reduce the impact of daily stress factors in your life.
"Dehydration is not generally the cause of mood or anxiety-related conditions, though, so drinking water should not be thought of as a cure-all for these conditions. For all of us, eating well, exercising, sleeping well and staying hydrated are important for managing our moods."
ABOUT OUR EXPERT
Dr. Joshua Thurman, MD is a board-certified nephrologist and Professor of Medicine specializing in renal medical diseases and hypertension at the University of Colorado School of Medicine. He received his medical degree from the University of Chicago Pritzker School of Medicine and his undergraduate degree from Harvard University. He has been in practice for more than 22 years.