Substance Use Disorders

What is tolerance of drugs?

requiring increasing amount of the drug for the same effect

What is dependence of drugs?

where you have acquired tolerance to a drug, and you will have withdrawal if removed

What is abuse of drugs?

continuing to use the drug such that it offers a central place in the person’s life, and they continue to use despite aversive consequences, such as loss of job, relationships, etc.

What are the key areas of the brain involved in addiction circuitry?

frontal cortex - the decision to take the drug

brainstem - endogenous opioid systems in PG/raphe

mesolimbic pathway - dopaminergic neurons in the midbrain project to nucleus accumbent, frontal cortex, and limbic systems

dorsal striatum - caudate/putamen initiate a “learned” response “habit”