P346_Neurobiology_of_Addiction_notes

Addiction

A chronically relapsing brain disorder characterized by compulsive drug seeking and taking, loss of control in limiting intake, and emergence of a negative emotional state when access is prevented.

Substance Use Disorder (SUD)

A classification that ranges from mild (2-3 criteria) to severe (≥ 6 criteria) as defined in the DSM-5, including tolerance, withdrawal, and unsuccessful efforts to control use.

Tolerance

A condition where an individual becomes less responsive to a substance, requiring more of it to achieve the same effects.

Withdrawal

Negative physical and psychological symptoms that occur when an individual stops taking a substance.

Opponent-Process Theory

A psychological theory that explains addiction through two opposing processes: an initial pleasurable response (A-process) followed by a delayed negative response (B-process) due to repeated substance use.

Incentive Sensitization Theory

Proposes that the craving or 'wanting' for drugs increases with repeated exposure, distinct from the initial pleasure ('liking'), leading to escalated drug-seeking behavior.

Allostasis Theory

A theory that explains addiction as a condition where repeated substance use disrupts the reward system, resulting in a new baseline level that requires drug use to alleviate negative states.

Ventral Tegmental Area (VTA)

A brain structure that contains neurons that release dopamine and is critical in the reward system associated with addiction.

Dopamine

A neurotransmitter that plays a key role in reward processing and is released in response to pleasurable stimuli, including drug use.

Naloxone (Narcan)

A medication that rapidly reverses opioid overdose by blocking the effects of opioids on the brain.

Opioids

A class of drugs that includes natural opiates (e.g., morphine) and synthetic opioids (e.g., fentanyl), known for their pain-relieving and euphoric effects.

Interoception

The awareness of internal bodily states, which is important in emotional processing and is linked to the insula's functioning.

Glutamate

A neurotransmitter involved in excitatory signaling in the brain; its response is altered in addiction.

ΔFosB

A transcription factor that is influenced by substance use and is associated with neuroadaptations that contribute to addiction.

CREB

A protein that regulates gene expression and is implicated in the neuroadaptations that occur with addiction.

Psychostimulants

A category of drugs, including cocaine and amphetamines, that increase brain activity and produce effects such as euphoria and increased energy.