Pharmacological Basis of Cocaine Addiction

Cocaine addiction is a chronic disease with serious consequences, both in terms of public health and economically. Clear characteristics distinguish recreational and controlled use from addiction. The first stage results from the activation of the brain’s reward circuit by the substance consumed (or the practice performed). This circuit is dependent on dopamine, in the nucleus accumbens. The repetition of this consumption will condition the person (Pavlovian learning), and dopamine discharges will gradually be released in anticipation, predicting the arrival of the reward. Thus, the reproduction of the situation (environment or mental state) associated with the consumption or the practice will promote new consumption. Thus, today, cocaine addiction includes notions of compulsive drug-seeking, associated with a loss of control over taking it, promoting the emergence of a persistent and overwhelming desire for the drug (called craving). When stopping consumption, withdrawal symptoms can emerge: a negative emotional state, cognitive problems, and physical symptoms. Relapse episodes may occur during this withdrawal period to counter the negative effects of withdrawal. Such episodes can also be seen after long periods of abstinence. They can be precipitated by re-exposure to the context, in which the drug taking took place, or by stress. Regardless of the stage at which one enters (e.g., onset of addiction, or relapse), changes in the functions and structure of the brain can be observed. Certain brain structures are therefore modified, such as the prefrontal cortex, where several neuroadaptations have been put.