Substance Abuse Flashcards
Drugs are primarily used for their rewarding and euphorigenic effects (positive reinforcement)
Dopamine theory
Drugs produce their desired effects by increasing the activity of the reward pathway which consists of dopamine neurons in the ventral tegmental area (VTA) that connect to the nucleus accumbens, frontal cortex, and other areas of the limbic system
dopamine theory
dopamine theory
Drugs produce their desired effects by increasing the activity of the reward pathway which consists of dopamine neurons in the ventral tegmental area (VTA) that connect to the nucleus accumbens, frontal cortex, and other areas of the limbic system
dopamine theory
Drugs are primarily used for their rewarding and euphorigenic effects (positive reinforcement)
Drugs are primarily used for self-medication purposes, such as relief from negative emotional states (stress, anxiety, etc.)
Self-medication theory
Over time, tolerance to these effects develops, resulting in increased drug intake to produce desired effects, which leads to dependence and withdrawal which further perpetuates the cycle of addiction
Self-medication theory
__________ is the process of maintaining stability through adaptation
allostatis
initial drug use is primarily controlled by the drug’s rewarding effects, but chronic drug use produces tolerance to the rewarding effects and behavior that is largely controlled by negative reinforcement
allostatis theory
states that all pleasant or unpleasant processes are followed by an opposite “opponent process”. Over time, the primary process becomes weaker while the opponent process is strengthened.
opponent-process theory of motivation
addiction develops from a sensitization of the mesolimbic dopamine system
Incentive sensitization theory
this dopamine system normally functions to attribute incentive salience
(attention-getting and desirable qualities, or “wanting”) to reward stimuli such as
food and sex
Incentive sensitization theory
• Wanting is different than liking (the positive experience of euphoria)
• Drugs hijack this “wanting” system, and chronic use causes the dopamine system
becomes hyper-responsive and drug cues to become hyper-salient
Incentive sensitization theory
In other words, drug cues are nearly impossible for addicts to ignore, and when
they are encountered they can lead to intense cravings and/or relapse, even years after an addict quits drugs and drug biological withdrawal has ceased.
Incentive sensitization theory
Abused drugs promote neuroplasticity, which is the long-term alteration of the function of neurons and synapses that underlies normal learning and memory processes
abberant learning and memory theory
The end result is over-strengthening of the neural circuits that
produce habits, memories of prior drug use, and associations between drugs/drug effects and environmental contexts and cues (similar to incentive sensitization theory)
Aberrant learning and memory theory
The prefrontal cortex exerts “top-down” executive control over behavior, impulse control, planning, decision-making, and responsiveness to external cues and punishment
Hypofrontalism theory
Addictive drugs cause deficits in prefrontal cortex structure and function that lead to loss of impulse control, impaired planning and decision-making, exaggerated responsiveness to drug-associated cues, and compulsive drug use despite adverse consequences
Hypofrontalism theory
Major dopamine systems of the brain: reward, motivation, pleasure, attention, located in VTA –> frontal lobe
mesocorticolimbic pathway/reward
Major dopamine systems of the brain: motor control, habitual behaviors, located in substantia nigra –> striatum
nigrostriatal pathway
regulates mood, pleasure, appetite, sleep, learning, memory, sexual function
serotonin
Regulates energy, arousal, alertness, attention, learning, memory, autonomic function
Neocortex
Where is the neocortex located in the brain?
locus coerulus
Regulates arousal, attention, learning, memory, autonomic function
Acetylcholine
As the major _____ and ______ neurotransmitters in the brain (~50-70% of all synapses), neurons containing glutamate and GABA (respectively) are widely distributed throughout the brain
excitatory, inhibitory
