“The feeling of power has been found to have a similar effect on the brain to cocaine. It increases the levels of testosterone and its by-product 3-androstanediol in both men and women. This in turn leads to raised levels of dopamine, the brain’s reward system called the nucleus accumbens, which can be very addictive.

Like cocaine, scientists now believe power can lead to too much dopamine causing more negative effects such as arrogance and impatience.”

http://www.dailymail.co.uk/sciencetech/article-2778336/Power-REALLY-does-head-Giving-people-taste-authority-corrupt-honest-members-group.html