We all enjoy the cool feeling of providing a cool drinking water on a hot summer day. Our bodies are efficiently programmed to let us know when to rehydrate. We may also be feeding our brains.
Several years ago, a team of researchers conducted a review on how hydration affects health in different ways. The results were promising.
Overall, negative emotions such as anger, hostility, confusion and agitation as well as fatigue have been found to increase with dehydration. One trial induced mild dehydration and found increased reports of agitation or anxiety and fatigue among participants.
Researchers also found that people who drank a lot of water generally felt less calm. People who drank a lot of water generally felt less calm, less satisfied and more excited when their water intake decreased. When the researchers increased the amount of water the participants drank, the people in the study generally felt happier no matter how much water they drank.
Another large study found that people who drank five cups or more of water a day had a lower risk of depression and anxiety. In comparison, drinking less than two cups a day doubles the risk. This link was less noticeable for anxiety alone (although feelings of frustration and anxiety often overlap).
More recently, researchers have found that electrolyte-containing water can withstand more anxiety than ordinary water, but it has been noted that the placebo effect may explain this connection because study participants were aware when they were given an electrolyte drink.
The link between dehydration and anxiety is also observed in children who are at risk of dehydration. Dehydration can affect how well we sleep. Bad sleep can increase feelings of anxiety.