It can be very easy for us to become trapped in our modern whirlwind days and forget to take on board enough fluids to prevent slipping into a state of mild dehydration. It seems like this simple common error can affect our mental function.
One possible mechanism, proposed by researchers in this field for cognitive deficits during dehydration could be increased levels of cortisol, often released during a stress response. It has been shown that higher levels of cortisol can lower memory function and processing speed and consequently cause memory-related cognitive deficits.
Other neurotransmitter systems have been shown to act differently as a consequence of dehydration, potentially mediating the cognitive deficits reported. Serotonergic and dopaminergic systems modify blood–brain barrier permeability, which, if sustained, causes central nervous system dysfunction.
The evidence for reported mood state changes associated with mild dehydration is even more consistent across studies.
Dr Chris Harper