Mental fatigue: we know why overthinking exhausts your brain

According to the results of this study, thinking intensely and for several hours releases glutamate, one of the most important neurotransmitters in the nervous system. Accumulated in too large quantities, it can become harmful and make it difficult to use the prefrontal cortex, which pushes us to make more impulsive choices. This toxin reduces the control of the decisions taken by the person, which will favor the actions of least effort as the fatigue progresses.