ICL 9.5: Substance Use Disorders Flashcards
what is a drug addiction?
a drug addiction is defined as a chronic, relapsing brain disease that is characterized by compulsive drug seeking behavior and use, despite harmful consequences
it is considered a disease because brain imaging shows physical changes in the areas of brain that are critical for judgement, decision making, learning, and memory as well as behavior control (other psychiatric illnesses are syndromes)
most “damage” is from drug seeking behaviors not drug itself; finding drug is the highest priority similar to drive for food or sex
what is physical dependence?
the tolerance and withdrawal from a substance
tolerance is when you have to use the same substance more and more to achieve the same effect
withdrawal is if you don’t have that substance, you have withdrawn symptoms because your body and brain are so used to that substance that it can’t live without it and there are physical manifestations like tremors, sweating, seizures, etc.
physical dependence is NOT the same as addiction!! just because you’re physically dependent and will go through withdrawal but that doesn’t mean that once you cut the substance off you will have a compulsive behavior to get that substance back; it’s the compulsive behaviors that creates addiction
what is the mechanism behind dependence?
physical dependence is a neuron-adoption with imbalance in GABA/glutamate
when you use alcohol, opioids, BZD, you are increasing the GABA role and decreasing excitatory glutamate
when you continuously suppress glutamate and then suddenly release it when you abruptly stop a drug, it will come back with a big force and cause withdrawal symptoms
withdrawal can be life threatening
which substances commonly cause physical dependence?
- alcohol
- opioids
- benzodiazepines (BZD)
what is psychological dependence?
withdrawal is unpleasant but not life threatening; withdrawal symptoms are due to the mental dependence on the substance;
withdrawal symptoms are less severe and not life threatening however, substances that cause psychological dependence can be more difficult to stop using than those that cause physical dependence
LSD, THC, Methamphetamine, cocaine
which substances commonly cause psychological dependence?
- LSD
- THC
- methamphetamine
- cocaine
what is the reward pathway in addiction?
dopamine plays a huge role in motivation and memory –> it’s part of the survival circuit because reproduction and food intake are part of the reward pathway; we need these behaviors to sustain our species
these drugs highjack the reward pathways which are extremely powerful
the dopamine is produced in the ventral tegmental area of the midbrain and then it goes to the nucleus accumbens which is responsible for motivation and goal-directed behavior that causes the compulsion behavior in addiction –> dopamine is responsible for memory so increased dopamine gives people the motivation to repeat pleasurable experiences
then you have the prefrontal cortex which is responsible for judgement; in addiction the prefrontal cortex is compromised so you don’t care that you’re going to get cirrhosis, lose your job and relationships from drinking –> without the prefrontal cortex, you don’t have the will to stop the action involved with the self destructive behaviors even though you’re aware and know it’s bad
which structures are involved in the reward pathway?
- prefrontal cortex –> command center for self control, judgement, decision making
- striatum; nucleus accumbens –> motivation, pursues goals, narrows focus*
- midbrain; ventral tegmental area –> creates dopamine surge
what causes damage to the prefrontal cortex in addiction?
this self control area is damaged by neurotoxins and high surges of dopamine coming from the ventral tegmental tracks
so now the prefrontal cortex has less communication with the striatum and therefore less control over urges
drug induced dysfunction of the dopamine reward pathway as it sends out the neurochemical message “if you don’t use, you will die”, even though higher function knows that continued use will only lead to destruction and death –> it’s not that they’re not aware, they just can’t stop it because the prefrontal cortex is damaged
how do you treat physical dependence?
- detox is first step
- if not followed up by treatment for psychological dependence-95 to 100% relapse in 1-4 weeks
- motivation to stop drugs is from “sick of the mess”. As soon as you feel better, craving and motivation from the reward pathway can easily overcome motivation to stop using
what happens to coping mechanisms with people who have physical dependence?
they lose their coping skills!
since any time that they had any stress they would just use, they lost all their coping skills
this is a problem when someone is trying to stop using because they don’t have any coping skills and when they get stressed they want to go back to using
how do you sustain recovery from addiction?
- medication assisted treatment(opioids/alcohol)+counseling+ self help groups
- anti-craving agents play key role to bolster desire to stay in treatment, providing extended window of opportunity for the behavioral treatment to be reinforced
you need a change in life style and lots of continuity in care! if patients stay in treatment, recovery can be 60% but if you don’t stay in treatment, sustained recovery is like 3%
what does MAT stand for?
medication assisted treatment
what is MAT?
(you must do MAT with counseling!!) it’s used to sustain recovery from addiction and there’s 2 types:
- agonists that bind to receptors and create a similar effect while helping lessen the physical withdrawal symptoms; use a substance similar to the original substance of dependence
buprenorphine: partial mu receptor agonist for people that abused opioids
methadone: full mu receptor agonists for people that abused opioids
acamprosate: increased GABA binding for people that abused alcohol - antagonists that bind the receptor but does not create the effect which helps weaken the mental connection between the drug and its effect; you’re using something almost exactly the opposite of the drug of choice because you’re taking away the positive reinforcement that used to come from the drug
ex. naltrexone: mu receptor antagonists for people who abuse alcohol and opioids
ex. disulfiram: inhibits full conversion of ethanol for those who abuse alcohol - agonist + antagonists prevent abuse of medication itself because when used properly it’s an agonist but when misused withdrawal symptoms will occur
how does addiction effect loneliness?
social connections are protective against addiction
a better quality of life reduces the risk of indulgence in addictive behaviors
