Final answer:
The main starting mechanism for the drug addiction development process is the drug-induced release of dopamine in the nucleus accumbens, which affects cognitive processes and contributes to compulsive behavior in addiction.
Step-by-step explanation:
The main initiating/starting mechanism of conditioning processes during the development of drug addiction is b) drug-induced release of dopamine in the nucleus accumbens. This region is part of the brain's reward system and is associated with pleasure and reinforcement. Drugs like cocaine can increase dopamine levels in this area, which plays a critical role in the rewarding effects of drugs and the development of addiction. Dopamine's role in addiction is due to its ability to modulate various cognitive processes including decision-making, attention, and impulsivity. Dysfunctional interaction within neural systems, including an overactive limbic system and an underactive prefrontal cortex, contribute to the characteristic compulsive behavior and relapse in addicted individuals.