Offer an explanation of the physiological basis of drug addiction.

While taking the drug, a special combination of psychophysiological sensations activates certain centers of emotional pleasure in the hypothalamus and stimulates the formation of new connections between neurons; in the future, a person needs to take this drug again to resume sensations, but since the excitability of neurons has limits, the dose of the drug must be increased to enhance the effect, and in the absence of a chemical stimulant, psychosomatic stress is observed.