Addiction Flashcards
Addictions
-Clinically-impairing pattern of inflexible reward pursuit and consumption
-Patient must participate actively in “getting” this disorder
o Similar to type 2 diabetes, cardiovascular disease, etc.
o Genetic and environmental factors influence susceptibility
-Best understood as a clinical brain disorder with observable physiological manifestations that underlie pathological aspects of behavior
Progression of relapse
Use (abstinence then relapse) then heavy use (abstinence then relapse) then early dependence (abstinence then relapse) then late dependence neuroadaptation
First time use of a drug
euphoria, feel good, reduces stress
After many times of using the drug…
I need this drug to get by - depression, agitation, anxiety
Progression of drug addicition
-motivation increases
-negative reinforcement increases
-positive reinforcement decreases
Substance Use Disorder
describes a problematic pattern of using alcohol or another substance that results in impairment in daily life or noticeable distress
Symptoms of Substance Use Disorder
-11 symptoms total
-physical dependence symptoms
-loss of control symptoms
-clinical impairment symptoms
-2 to 3 symptoms = mild
-4 to 5 symptoms = moderate
-6+ symptoms = severe
Physical dependence symptoms
-“Craving” the substance (alcohol or drug)
-Building up a tolerance to the alcohol or drug
o needing to use noticeably larger amounts over time to get the desired effect
OR
o noticing less of an effect over time after repeated use of the same amount
-Experiencing withdrawal symptoms after stopping use
Loss of control symptoms
-Consuming more alcohol or other substance than originally planned
-Worrying about stopping or consistently failed efforts to control one’s use
-Spending a large amount of time using drugs/alcohol, or doing whatever is needed to obtain them
-Continuing the use of a substance despite health problems caused or worsened by it
Clinical Impairment Symptoms
-Use of the substance results in failure to “fulfill major role obligations” (home, work, or school)
-Continuing the use of a substance despite its having negative effects in relationships with others
-Repeated use of the substance in a dangerous situation
-Giving up/reducing activities in a person’s life because of the drug/alcohol use
Manifestations
-illicit
-licit
-non chemical
illicit manifestations
Cannabis (in most states), stimulants, narcotics, hallucinogens
licit manifestations
Cigarettes, alcohol, cannabis (legal in over 20 states + DC)
non chemical manifestations
-Gambling disorder (in DSM5)
-Internet gaming disorder (possible)
-Food, pornography, sex, shopping, exercise (under study)
Marijuana is most misused by who?
ages 12-17
Prescribed drugs are most misused by who?
ages 18-25
alcohol is most misused by who?
ages 26+
Alcohol Use Disorder
-loss of control over drinking
-negative emotions when not drinking
-have to drink more for the same effects
Risk Factors
-men > women
-adolescents > adults
-co-morbidity with other psychiatric illnesses
-pain disorders, other “somatic” diseases
-genetics
-environment
Environmental risk factors
-exposure to adverse events during early-life and adolescence leads to affective disorders and increases the risk of developing alcohol and substance use disorder
What are drugs?
Drugs are chemical ligands that interact with brain neurotransmitter systems and that can change the way people “feel” by altering neural signaling
When consumed, drugs produce…
-internal feeling states/stimulus effects
o Positive, negative, mixture
o E.g., cocaine produces euphoria, energy, sympathomimetic activation and anxiety
What causes drugs to produce stimulus effects?
These stimulus effects are due to the pharmacological actions of the drug (what receptors the drug interacts with)
What system does the stimulus effects of drugs involve?
mesolimbic dopamine system
Are the effects of drugs learned?
-No, liking the positive reinforcing stimulus effects of the drug, or disliking the aversive effects, is not “learned”
-These effects mean that drugs can act as unconditioned stimuli
Dopamine
a neurotransmitter that is released during a happy event or in the presence of a rewarding stimulus
Mesolimbic Dopamine System brain regions
- Ventral tegmental area (VTA)
- Nucleus Accumbens (NAc)
Ventral tegmental area (VTA)
Dopamine is produced here and flows outward along neurons distributed throughout the brain’s reward system
Nucleus Accumbens (NAc)
amplifies the response to pleasure and is involved in stress processing
Where is the presynaptic terminal in the mesolimbic dopamine system?
-Nucleus Accumbens (NAc)
-Presynaptic terminals from the Ventral tegmental area release dopamine in the Nucleus Accumbens
Fewer dopamine receptors means…
-less response
-in addicts, less receptor availability, overstimulation of dopamine terminals (Post-synaptic side, there’s neural activation where D2 receptors are becoming deactivated, less binding)
Dopamine as causal influence
-6-OHDA = neurotoxin that kills catecholaminergic neurons and/or their terminals
-Dopamine depletions within the ventral striatum (aka Nucleus Accumbens) reduce cocaine taking, but similar lesions of other parts of the brain are ineffective
Is addiction learning?
Because drugs have unconditioned stimulus properties,
they support learning (Action-outcome)
Drug Associated Cues
Pavlovian (stimulus-stimulus) association learning
Drug Paired Cues
-Drugs can be the unconditioned stimulus in an stimulus-stimulus association
-Drug associated cues can gain “incentive value” and elicit craving
o Sight of drug and paraphernalia, people with whom drugs are used, places where drugs are used, smell and/or taste of drug
Other brain areas involved in addiction
- Basal Ganglia - learning & memory
- Prefrontal Cortex - control over behavior
- Extended Amygdala - reward & motivation
Drug paired cues cocaine example
Showing cocaine addiction patients pictures of things that remind them of cocaine (syringes, white powder, etc) dramatically increases blood flow in the amygdala and the anterior cingulate cortex
Instrumental Learning
-Because drugs are rewards, they support instrumental learning
-Actions associated with drug intake are reinforced, occurring with increasingly higher probability
Non-associative learning
-Tolerance
-Certain aspects of the drug’s effect diminish with repeated intake
-Tolerance to the rewarding effects is a common phenomena (re: DSM diagnosis)
Compulsive Habit Formation brain regions
- Ventromedial Striatum (Nucleus Accumbens)
-Greater dopamine response in week 1, which then reduces in week 2 and then reduces more in week 3 - Dorsolateral Striatum (Caudate)
-No dopamine response in week 1, but we start to see a dopamine response in week 2 and 3 – when drug seeking is becoming habitual
