According to research carried out at the Institute of Psychiatry in London and the MRC Cognition and Brain Sciences Unit in Cambridge  has found that dehydration can affect the way teenagers’ brains function.

(School pupils taking exams  could benefit from drinking a glass of water beforehand, as being dehydrated is enough to effect the neural activity in key parts of their brains which, as a result, have to work harder to achieve the same tasks. I fear I might be constantly dehydrated.)