Dopamine is a neurotransmitter that plays a crucial role in the brain's reward system. When addictive substances are consumed, they cause a surge in dopamine levels in the brain, leading to feelings of pleasure and reinforcement.

The basal ganglia, particularly the ventral striatum, is a brain region involved in reward processing and habit formation. It plays a significant role in the development and maintenance of addictive behaviors.

Neuroadaptation refers to the changes that occur in the brain in response to repeated exposure to addictive substances. These changes can include alterations in synaptic plasticity, long-term potentiation, and other neurochemical processes, leading to compulsive behaviors.

The prefrontal cortex, particularly the ventromedial prefrontal cortex, is involved in executive function, decision-making, and impulse control. Impairments in this region are commonly observed in individuals with addiction.

Compulsion refers to the irresistible urge to engage in addictive behaviors, even when an individual recognizes the negative consequences. This is a common characteristic of addiction.

GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter that plays a crucial role in regulating brain activity. Deficiencies in GABA signaling have been linked to impaired inhibitory control and increased risk of addiction.

Tolerance refers to the decreased response to a substance over time, requiring higher doses to achieve the same level of effect. This is a common phenomenon in addiction, where individuals may need to consume increasing amounts of the addictive substance to experience the desired effects.

The amygdala is a brain region involved in processing emotional responses, including fear, anxiety, and pleasure. Dysregulation of the amygdala is commonly observed in addiction, contributing to emotional dysregulation and relapse.

Withdrawal refers to the physical and psychological symptoms that occur when an individual stops using an addictive substance. These symptoms can range from mild to severe and can include anxiety, insomnia, sweating, nausea, and cravings.

Serotonin is a neurotransmitter that plays a crucial role in regulating mood, sleep, and appetite. Dysregulation of serotonin signaling has been linked to depression, anxiety, and increased risk of addiction.

Relapse refers to the return to using addictive substances after a period of abstinence. This can be triggered by various factors, including stress, environmental cues, and social influences.

The hippocampus is a brain region involved in the formation of memories and spatial navigation. Impairments in the hippocampus have been linked to memory deficits and difficulty in learning from past experiences, which can contribute to addiction.

Craving refers to the intense desire or urge to use an addictive substance. This is a common symptom of addiction and can be triggered by various factors, including stress, environmental cues, and social influences.

Cortisol is a hormone that is released in response to stress. Dysregulation of the cortisol stress response system has been linked to increased risk of addiction and difficulty in coping with stress.

Sensitization refers to the increased response to the rewarding effects of addictive substances over time. This can lead to a cycle of escalating substance use in an attempt to achieve the same level of pleasure or relief.