What does the reward system do?
The basal ganglia and associated reward circuits help us stay motivated by food, social interaction, and other natural rewards. Addictive substances can strongly stimulate this system, and with repeated use, the balance of the reward response may change.
Why are stress circuits important?
During withdrawal, restlessness, anxiety, and irritability can increase. Over time, an individual may turn to the substance not only to “feel good,” but also to avoid feeling bad.
The role of impulse control
The prefrontal cortex is associated with planning, decision-making, and impulse control. In addiction, the balance between these control systems and the reward/stress circuits can be disrupted. This biology does not eliminate personal responsibility; however, it explains why it is important not to view addiction as a moral failing.
What does treatment target?
Depending on the substance, behavioral therapies, medications, social support, treatment of co-occurring mental disorders, and a relapse prevention plan can be used together. A single “brain exercise” or device does not replace evidence-based addiction treatment.
Source
NIDA – Drugs, Brains, and Behavior: The Science of Addiction