Addiction Flashcards
A 2019 US drug survey estimated that ____% of the population were current users of illicit drugs (____% of Canadians reported using illegal drugs at least once in the last year in 2019)
20, 3
the fact that a person can develop and maintain a pattern of behaviour that is obviously destructive to his/her life
The paradox of addiction
many people take psychoactive drugs _____. Even if drug use if frequent, many ____ their intake. Heavy drug use does not necessitate ______.
recreationally, control, addict
addiction constitutes ______ drug use that persists in spite of the adverse effects on ___ and _____ life. Drug free periods or ______, even extended ones, are often followed by ____ to drug use, despite negative consequences. ____ ____ is also seen, and certain environmental ______ can prompt craving and relapse. You also see _____ _____
habitual, health, social, remissions, relapse, drug craving, trigger, physical dependence
a disproportionate amount of time spent thinking about drug use and acquiring them (drug seeking behaviour)
drug craving
suffering from withdrawal symptoms after drug use that may motivate them to return to using (taking more drug to alleviate withdrawal symptoms)
physical dependence
the body’s reaction to elimination of drug from the system after repeated exposure
withdrawal
withdrawal reactions are usually the ___ of the drug’s actions because the body / brain initiates _____ physiological changes (aka _____) to counter drug effects and try to maintain ______. When the drugs are cleared from the system, these changes can ______ for some time after, creating withdrawal symptoms. Additional drug taking can _____ withdrawal symptoms
opposite, compensatory, tolerance, homeostasis, linger, decrease
withdrawal may contribute to relapse, but may not be a ____ factor in maintaining the _____ effects of addiction. This is because withdrawal only lasts for a few ___, but addiction can last for a ______.
primary, long-lasting, days, lifetime
when cues associated with drug taking can trigger withdrawal-like symptoms even for a long period after normal drug withdrawal has ceased
conditioned withdrawal
________ injection or ______ yields the most rapid drug entry into the brain and thus the _____ onset of drug addiction. They also produce the strongest ______ effects as a result of rapid drug delivery to the _______. _____ / _____ routes result in relatively slow absorption. A _____ onset or shorter ______ of action is more likely to produce addiction. Repeated exposure to rapid delivery may produce long-term ______ changes needed for addiction to develop (learning about rewards and _____ to obtain them again)
I.V., inhalation, fastest, euphoric, brain, oral, transdermal, faster, duration, neurobiological, likeliness
many who take drugs occasionally stop before developing _____ patterns of drug taking. This is true for even highly reinforcing drugs such as ____ and _____. Thus, additional factors contribute to the development of addiction, such as life _____, ____ with anxiety / depression, and _____ as well as ____ factors.
compulsive, cocaine, heroin, stressors, comorbidity, familial, social
_____ variation may contribute to addiction vulnerability. The majority of research on genetics and addiction has focused on _______.
genetic, alcoholism
____% of MZ twins, and _____% of DZ are concordant for alcoholism. If the father is alcoholic, ______% of sons, and _____% of daughters are likely to become alcoholics.
55, 28, 25, 5-10
Variations in that change the function of the protein that the gene encodes, which may increase or decrease its activity that in turn alters how it affects neural activity or responses to the drug; can influence addiction susceptibility
polymorphisms
Those with alcohol use disorder tend to have higher _____, and metabolize ____ quicker. Other gene polymorphisms implicated in increased risk for alcohol addiction include the _____ receptor subunits, the _____ transporter, the _____ ____ receptors, and the ______ receptor
tolerance, EtOH, GABA-A, 5-HT, DA D4, opioid
For nicotine addiction, susceptibility genes include those coding for enzymes involved in nicotine ____ and _____ _____.
metabolism, nicotinic receptors
for opioid addiction, a single nucleotide polymorphism for the _____ receptor has been linked to increased vulnerability to ____ addiction
mu, heroin
Even in laboratory animals, there are _____ ______ in susceptibility to developing “addictive” like patterns of drug intake
individual differences
the idea that addiction is driven by the desire to curtail withdrawal symptoms
the physical dependence model
Problems with the physical dependence model include that _____ often occurs after withdrawal symptoms have passed, some drugs do not have ____ withdrawal symptoms such as _____, _______ users still remain addicted to drugs, and _____ used to curb withdrawal (ex. nicotine patches) are not 100% effective
relapse, severe, cocaine, detoxified, treatments
the idea that addiction is driven by the pleasurable feelings that drugs induce
positive reward model
problems with the positive reward model include that ____ use can continue even if the ____ that individuals get are not as good as in the past (tolerance to the hedonic effects). Additionally, some drugs such as _____ do not give as much of a ____ rush as other drugs like heroin, but are just as addictive.
habitual, rush, nicotine, euphoric
Studies using animal models have identified a group of interconnected brain regions known as the ____ circuit that is responsible for the ____ rewarding / reinforcing effects of ____ drugs. This is similar in humans, and the circuit is activated by both ____ and ______ rewards.
reward, acute, abused, drug, nondrug
____ within the numerous nodes of the reward circuitry are thought to underlie addiction. The PFC is responsible for ____ functions, ____, ____ regulation, response to ____, and behavioural _______. It is ______ by drugs of abuse. The ____ _____ of the amygdala regulates learning about reward ____ cues, while the ___ _____ mediates _____ aspects of reward and _____ toward reward-related stimuli.
neuroadaptations, executive, flexibility, emotional, stress, inhibition, cued, basolateral nucleus, predictive, central nucleus, motivating, approach
all drugs of abuse with a high addictive potential either directly or indirectly activate the _____ DA system (VTA –> ______). This causes a ___% increase of DA from baseline. Natural rewards such as food, and / or cues associated with rewards also increase DA release, especially during ______ about cues associated with rewards, but they only increases it _____% from baseline. The magnitude of DA release by drugs of abuse can be ____x greater than that induced by natural rewards. Thus, drugs of abuse activate the brain’s natural reward pathways, but to a much greater _____ degree. This may trick the brain into thinking that this is ______ and starts to form ____ with cues linked with drug taking
mesolimbic, NAcc, 500, learning, 50, 10, pathological, important, associations
most abused drugs act as positive _____, that is consuming the drug strengthens whatever ____ behaviour was performed.
reinforcers, preceding
positive drug-associated experiences (subjective high, euphoria, etc.)
drug reward
changes in drug ____ may not necessarily relate to reward and vice versa. Reward has two components: _____, which is the pleasurable, hedonic effects of the rewarding substance, and ___ which is the craving and willingness to work for the reward
reinforcement, liking, wanting
DA is not involved in the ____ effects of drugs of abuse (or natural rewards). DA mediates _______. Using acute _____ depletion in cocaine does not affect the cocaine-induced ______. Similarly, acute dopamine ________ do not affect the reported amphetamine induced euphoria
pleasurable, wanting, catecholamine, euphoria, antagonists
The firing of DA neurons is sensitive to the cies associated with the rewards and ____ of expected rewards (aka: reward ____ ____). DA cells increase in firing in response to ______ rewards, and _____ cues signalling rewards (when something important is happening). DA neurons shut off when expected rewards ____ received. This facilitates learning about reward-related cues and may increase likelihood of doing those actions / _____ stimuli that led to rewards again
absence, prediction errors, unexpected, conditioned, aren’t, approaching
If an animal will press a lever to receive an injection of drug, then by definition the drug must have ____ properties
reinforcing
when the drug is delivered after a fixed number of lever presses
fixed ratio schedule
with FR schedules, the typical dose-response function is an ____ _____ shaped curve. At higher doses, the number of reinforcers ___ due to ____, _____ reactions, or disruptive ____ _____.
inverted U, decrease, satiation, adverse, side effects
Experimentally induced ______/_____ in drug taking (e.g, treatment with another drug or brain lesion) can sometimes be difficult to interpret. For example, if a manipulation increases pressing for a drug, does that reflect an increased ____/____ of the drug or a ___ increase in drug intake because the manipulation reduced the rewarding effects of the drug?
increases, decreases, liking, wanting, compensatory
schedule where the number of presses to get a drug infusion increases after delivery of each dose
progressive ratio schedule
the number of presses when rats “give up” pressing because its too much work
breakpoint
PR schedules are a classic measure of relative strength of drug _____, in other words, how ___ animals are to obtain drug
reinforcement, motivated
DA depletion in the _____ abolishes the ____ learning to self-administer many drugs. (exception is _______). In rats already trained to self administer drugs, DA ______ increase the ________ of most drugs of abuse on ___ _____ FR schedules. This is thought to represent a reduction in the ____ properties of increased DA release induced by these drugs. (ie. need more drug to ____ reduced DA receptor activation). DA antagonism reduces self administration on ___ schedules. This is interpreted as reduced ______ for the drug. Thus, DA is critical for motivation self administration for many but not all drugs
NAcc, initial, opioids, antagonists, self-administration, low cost, reinforcing, offset, PR, motivation
relies on learned association between the drug effect and environment, a classic measure of drug reward
conditioned place preference
conditioned place preference does not measure drug ______ because the animal gets the drug no matter what it does. This is a measure of the ____ of drug-associated _____, or cues associated with the reinforcing properties of drug _____ approach behaviour. If the drug is rewarding, rats tend to spend ______ time where they were under the influence of the drug
reinforcement, attractiveness, environments, bias, more
drugs of abuse can establish a place preference when given ____ or directly in the ____ and or the ______. Blockade of DA receptors ____ place preference for all drugs of abuse including _____. This type of reward learning is also dependent on the ____ which is connected with the NAcc. Lesions to it can also _____ place preference. Thus, pairing certain drugs of abuse with cues can cause ____ and induce approach behaviour. This appears to be linked to the drugs’ effects on DA transmission in the NAcc and interactions with the _____
systemically, NAcc, VTA, abolish, opiates, amygdala, abolish, learning, amygdala
Conditioned place preference was tested in humans using a ___ ____, in which they had to find the red ball, and not the black ball. Finding the red ball led to a pleasant tone, with distinct pattered background and a ____ reward. Finding the black ball led to a ___, no reward, and another pattern. When subjects were shown different patterns, including the ones linked to the red ball reward responses, they preferred the pattern associated with the ______. Parkinson’s patients (who have lower ____), did not show this preference. However, controls had no ____ association between the pattern and the reward. This shows that reward associated cues can control our behaviour, sometimes without us being _____ of them. These reward-related associated are mediated by _____
memory task, food, buzzer, reward, DA, conscious, aware, DA
Repeated exposure to all addictive drugs can sensitize ____ ____ in animals and humans, and put the system into a ______ state. This can lead to increased _____ to seek drugs in response to cues associated with it. This was shown with both ____ and ______ for DA in the ____ in animals and humans
DA transmission, hyperdopminergic, motivation, microdialysis, PET, NAcc
when relapse is triggered either by a small dose of the drug, cues associated with drug taking, or by stress
reinstatement paradigm
reinstatement is tested through 3 phases
- train rats to administer drugs (cues can be presented with drug infusion), 2. take the rat through extinction (ie. lever presses no longer deliver drugs or cues and rats stop responding), 3. no drug is provided but reinstatement is induced by a drug prime, a stressor, or a cue
All 3 methods of reinstatement evokes DA release in the _____. It can also increase ____ ____ in the absence of drug administration. This increase in responding is thought to model ____ of drug seeking behaviour.
NAcc, lever pressing, relapse
Blocking DA receptors, particularly in the NAcc, abolishes / reduces ____ of drug seeking for all drugs of abuse, including opiates.
reinstatement
the ability of triggers to reinstate drug seeking is mediated by neural circuits linked to the DA system, including the _____, the ____ or the ____. Inactivating or disrupting DA transmission in these brain regions in animals _____ reinstatement. _______ drug exposure can make these regions more responsive to triggers. Showing human addicts drug related ____/______ can activate networks of _____ ____ involved in reinstatement. This activation is associated with increased ___ _____
PFC, NAcc, amygdala, decreases, repeated, videos, cues, brain regions, drug craving
the hypothesis that cues associated with drug taking take control over behaviour
incentive-sensitization hypothesis
the incentive sensitization hypothesis says that initial drug taking is driven by the ____ drug effects. Over time, tolerance develops to the _____ effects, making you like the drug less. However, effects on the dopamine system and the learning about drug-related cues become ______. Multiple cues (internal, external, _____, ____, or stress), activate neural networks, including the ____ system, that trigger ______ responses that collectively may be viewed as ______. These conditioned responses make you think you want the drug. The associative memories between the drug’s effects and their related cues become amplified by the _______ state, making drug cues trigger more ___ and more drug _____, even if the effects of the drug are not as pleasurable
pleasurable, hedonic, sensitized, contextual, temporal, DA, conditioned, craving, hyperdopaminergic, craving, taking
repeated exposure to drugs causes many types of long-term _____ changes, such as _____ _____, ______ of reward circuitry, and recruitment of the _______ system
neuroadaptive, DA sensitization, downregulation, anti-reward
repeated drug makes the DA system more responsive to drug related cues and stress; also changes in neural networks that include the VTA, PFC and NAcc
DA sensitization n
________ adaptations resulting in down-regulation of reward circuitry mediates tolerance to _____ effects of drugs. ________ adaptions, are those such as gradual recruitment of the anti-reward system
within-system, pleasurable, between-systems
Stress and aversion related circuits that include NE, peptide transmitters (CRF and dynorphin), the central nucleus of the amygdala and the NAcc
anti-reward system
Koob and LeMoal produced the hypothesis that drug taking behaviour progresses initially from an ______ stage. The primary motivation is the drug’s positive reinforcing effects, and with repeated use it transitions to ________. In other words, the primary motivation is relief from ________. While physical withdrawal can contribute to drug carvings and maintenance of addiction is cannot explain all aspects, as they last only for _____ _____. However, other aspects of withdrawal such as ____ ____ may persist for longer periods, get worse over repeated withdrawal experiences and contribute to addiction
impulsive, compulsive, withdrawal, 1 week, dysphoric mood
Initially, all drugs activate reward circuitry (_____ and ____ in the VTA, NAcc, etc.), promoting the drugs’ positive reinforcing effects. After repeated use, drugs become less ____ at activating the reward circuitry. At the same time, activation of the anti-reward system increases, releasing ___, ____ and _____, in the ___ and _____. This leads to ____ ____, and mediates some of the aversive effects of _____, as well as puts a _____ on reward functions. The anti-reward system is activated during _____ and plays a major role in its aversive effects and negative ______ states (ie. depressed mood) that can promote ____ drug taking.
DA, GABA, effective, NE, CRF, dynorphin, amygdala, brainstem, negative reinforcement, stress, limit, withdrawal, emotional, renewed
opioid that acts on kappa receptors
dynorphin
the reward / anti-reward circuitry model is an update of the classical ______ model of motivation. Neural mechanisms mediating mood and emotions provoke a strong _______ reaction, but also triggers an opposing response occurring after the initial stimulus ______.
opponent, initial, ends
subjects that smoked coca-paste initially report a _____, but then a _____, even though coke was still in their system.
high, crash
____ or ____ ___ hedonic states (mood) gradually changes over repeated drug exposure, so that without the drug, the user feels worse over time (______ in baseline state). Over repeated use, positive effects of drugs get _____/_______ and compensatory negative effects get ______/________
baseline, set point, down shift, shorter, weaker, longer, larger
Structural and ____ abnormalities in the ____ have been discovered in drug addicted subjects. For example there is reduced volume in _____ abusers. Different regions regulate _____ _____, and _____/____ processes. MRI studies show reduced ___ ___ volume in many drug addicts, sometimes even after long-term abstinence. Behavioural and imaging studies suggest that PFC function such as decreased ____ and increased ______ (reduced response inhibition) are impaired in drug abusers. PFC dysfunction may also contribute to _____ ____ and _____.
functional, PFC, methamphetamine, executive function, emotional, motivational, grey matter, flexibility, impulsivity, intrusive thoughts, craving
pre-existing ______ conditions may also be a risk factor for addiction
behavioural
Chronic drug users have fewer ____ receptors in the striatum as measured by _____. These receptors have been proposed to serve as a _____ function on certain actions
D2, PET, brake
The PFC regulates many functions via interactions with the ______, which are modulated by _____. Reduced prefrontal functioning and striatal abnormalities may contribute to the lack of ____ ___ and _____, as well as poor ____ ____ and increased ___ _____
striatum, DA, impulse control, planning, emotional regulation, drug salience
_____ transmission may mediate liking of a drug
opioid