Lecture #8 Flashcards
Definition: Addiction
a repeated behavior that has a negative impact or results in distress
What are some negative impacts of Addiction?
- financial
- relationships
- medical
Addict vs Abuser
These terms tend to refer to the severity of the behavior
- Addict implies the severity of the behavior is more serious
- But they are similar and only differ in degree
Drug vs Medicine
- Drug: addictive substance
- Medicine: curative/helpful substance
Can a substance be both a drug and a medicine?
Yes, for example painkillers like opioids.
What are the types of tolerance we discussed?
- Pharmacodynamic: regulation of receptors
- Metabolic: regulation of enzymes
- Behavioral: learned effects
What is dependence?
- Dependence is associated with physiological need:
- when drug is not taken there are physiological signs
- with addictive drugs these may be negative and thus one may continue to take the drug to avoid these symptoms
- these syptoms are called withdrawal
- combination of tolerance and dependece can lead to continued use of a drug evne after it no longer produces desired effects
What is the distinction between opioids and cocaine?
No withdrawal from cocaine. Thus, aboidance of withdrawal cannot be the sole basis of addiciton.
What does the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), replace addiction and dependence with?
DSM-5 published by the American Psychiatric Association replaces such terms with substance use disorder or sustance-induced disorder. For the reasons previously discussed in class, such as stigma of being labeled an addict.
Does the DSM-5 include other behaviors besides drug use? How does it decide which are listed?
- Gambling disorder is an example of a non drug related behavior included
- Such behavior is included because it has received scientific studies
- We can only label as addicting that which has been shown to be so in a scientiic study.
What are some of the general symptoms of addiction?
- Haven’t been able to cut back or stop
- Experience stress when trying to stop
- Lie or try to confeal behavior
- etc.
What do we know abou the Incas?
There are woddcuts from Incas of priests drinking a form of cocaine. This suggest that the effect of cocaine was associated with the Sun God.
What is laudanum?
Laudanum is opium extract in alcohol.
What effects did the temperance movement have on drug use?
Created a social stigma because it associated drug use with criminal behavior.
How have advances in drug availability changed drugs?
- advances in chemisty (morphine from opium, cocaine from coca), have been able to have drugs in more concentrated forms therefore they are more addictive.
- The developement of hypodermic syringes (1858) allowed injection into the bloodstream
How did drug laws affect drug availability?
- Lack of drug control laws resulted in these drugs being use in tonics and patent medicines.
- Heroin for examle, was synthesized by Bayer Laboratories in 1874 and was first marketed as a nonaddicitng subsitute for codeine to control coughs.
What happened in the 20th century, specifically in 1906?
- During the 20th century, the federal government increasingly controlled the commercialiation of drugs beginning with the Pure Food and Drug Act of 1906.
What act was passed in 1914 and what did it do?
The Harrison Act in 1914 controlled the use of opiates and cocaine, prohibitng non-medical use.
How did regulations affect physicians and addicts? Were clinics effective?
- Many physicians had been providing maintenance doses to addicts, but addiction was not considered a disease at the time, so addicts were cut off from this source. they turned to street dealers, and prices skyrocketed.
- Clinics to treat addicts became prevalent but were larely ineffective.
What were the consequences of alcohol prohibition (1920)?
- Speakeasis that sold alcohol illegally sprang up everywhere.
- The organized crime movement became established.
- Prohibition ended in 1933.
How has drug availability changed since the 1980s?
- Since 1980, the appearance of new drugs and increased potency of illegal drugs led to the U.S. government’s “War on Drugs” however illegal drug use continues on a massive scale.
- The current political climate is strongly agains tlegalization or decriminalization of anny currently illegal drugs.
- Marijuana legalization and opinions regarding it have changed quickly, text does reflect it.
What act was passed in 1970 and what does it do?
- The Controlled Substances Act of 1970 established a system to classify abuse potential of drugs: the Schedule of Controlled Substances.
- It excludes alcohol and tobacco which are drugs, but industry influence had an effect on the writing of this law.
- Though updated, the schedule may not accurately reflect curret understanding of some abused subtances.
How do Scheduels of addictiveness work? Are they accurate?
- The different schedules are supposed to reflect addictiveness
- But what is listed is subject to change (and liley much slower than scientific understanding)
- Other drugs can change scheduels as well
- Example: Tramadol was raised to Schedule IV drug in August (and individual states had classified it such before then)
What did government data for 2011 show?
- More than 80% of those 12 and older have used alcohol
- 8.7% of the US population were current users of illicit drugs
- Legal drugs such as tobacco and alcohol are consumed even more widely
What is one of two explantions for progression in drug use?
- Starts with a legal drug, progresses to marijuana and then to other illegal drugs. The **Gateway Theory **is one explanation.
- An individual who first experiments with an abused drug may or may not progress to regular, nonproblematic use or beyond.
What factors influence addiction?
- route of administration
- genetic variation (may contribute to vulnerability to addiction)
Expain how the route of administration has an influence over addiciton?
- IV or inhalation results in very fast action but not long lasting
- increased addiciton potential compared to oral or transdermal (slower action but longer lasting
How does genetic variation influence addiction?
- There appear to be many genes that potentialy influence susceptibility to addiction
- Individuals who carry specific alleles of genes are at increased risk of developing substance abuse disorders.
What is CYP2A6? How does it work?
- CYP2A6 is an enzyme works on nicotine (inactivaitng it)
- Some genes for this enzyme result in individuals being more susceptible to smoking addiction
What are Alcohol degydrogenase (ADH) and aldehyde dehydrogenase (ALDH)?
- Alcohol degydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are enzymes for alcohol
- genetic variants can result in negative association (flushed face, feeling sick)
Can abused drugs act as positive reinforcers?
- Abused drugs can act as positive reinforcers: the drug effect is associatied with the preceding behavior and streghtens desire to perform behavior.
Waht is known as Drug Reward?
the positive experience associated with drug effect is known as drug reward
What is one method we use to study reinforcement?
Animal self-administration is one of the most common methods for studying reinforcement.
What does FR stand for, and what does it show?
FR stands for fixed-ration schedule, we typically see the dose-response function as a U-shaped curve. It is a way of studying self-administration, and how varying the administered dose affects animals.
In an FR schedule why go we see a down curve with higher doese?
- Reinforcing properties may decline due to station, aversive reactions/side effects.
How does plotting FR scedules help us?
Plotting allows us to compare drugs and dose.
How does progressive-ratio procedure work?
- Progressive-ration procedure begins iwth training animal to press lever on continuous reinforcement (CR) shedule
- Following this, swith for a Fr schedule
- Usually start low, like FR-5
- Then progressively increase the ration in an orederly fashion and see when animal stops pressing the lever
- BP
What is the Breaking Point?
- Breaking point (or breakpoint) is the ration where responding stops
- Generally increases with higher doses
How can relapse be modeled in self-administration studies?
- Relapse can be modeled in self-administration studies by removing the drug (forced abstinence) for a period of time (extinction), then introducing stimuli that has been shown to cause animal to readminister drug (relapse).
- These stimuli include:
- Drug priming: giving a small dose of the drug
- Creating a stressful situation/subject animal to stress
- Introduce environmental cues that were paried with the initial administration of the drug
Relapse stimuli include:
These stimuli include:
- Drug priming: giving a small dose of the drug
- Creating a stressful situation/subject animal to stress
- Introduce environmental cues that were paried with the initial administration of the drug
Can self-administration experiments be tested in humans?
- Self-administration experiments have been done with humans
- Generally experienced drug users
- One example is testing medications (example administration of heroin combined with methadone)
What is the Hart (2000) et al experiment?
- Looked at human self-administration and alternative reinforcement
- participants were in a hospital
- participants had the option to smoke cocaine 90, 12, 25, 50mg doses) or receive $5 voucher after the study
- 6 trials a day, the first a ‘sample’ trial then 5 ‘choice trials’
- sample trial given both voucher and FR-200 for dose available that day
- on choice trails they select option and perform FR-200 to receive it
- according to stereotype and addict will always choose the drug. What happened here?
What were the results of the Hart (2000) et al experiment?
- choice for cocaine increased with dose, but participants did make choices (evidence that alternative reinforcers can be beneficial for treatment)
- even if cash was a means to obtain drug later, demonstrates ability to delay gratificaiton
If an addict encounters the negative aspects of drug addiction, why does that not counter the positive reinforcement pf drug use?
- Drug-induced high occurs very quickly after consumption; negative consequences are after a time delar, usually linked to a long pattern of use, may be less directly associated.
What is the reward circuit?
- The reward circuit: **neural circuit responsible for the acute rewarding and reinforcing effects of abused drugs.
- Neuroimaging confirms human brais have a reward circuit siilar to that identified in animals, and it is activated by both drug and non-drug rewards
What pathway is the reward circuit?
The mesolimbic pathway is the reward circuit.
What is the primary neurotransmitter involved in the reward circuit?
Dopamine is a primary neurotransmitter involved.
What is imvolved with the limbic system?
emotion and memory are involved with the limbic system
What is the amygdala?
The amygdala is part of this circuit and is a part of the limbic system.
What is the prefrontal cortex involved with?
- The prefrontal cortex is implicated in the decision making and planning process
- Important to self-control and judgment making (part of planning: the anticipation of negative outcomes)
How is the PFC related to drug use?
- Drug use has been shown to influence PFC
- Alcoholics show lower PFC volume (comparable to level seen in schizophrenics)
How do genetic factors further influence addiction?
- Genetic factors go further than different coding for enzymes we discussed
- There are genetic differences in receptors themselves
- Different alleles for particular dopamine receptors affect alcoholism rates
- Differet acetylcholine receptors affect smoking (nicotine) rates
- There are genetic differences in receptors themselves
What is the heriability ratio?
The heritability ratio is a comparison of the genetic make-up and the actual behavior
Can psychosocial variables also contribute to addiction risk?
- Psychosocial variables also contribute to addiction risk:
- Stress and the ability of the person to cope with stress; treatment often includes learning new coping skills
- Anxiety, mood, or personality disorders; co-occurence with addiction is called comorbidity
What is comorbidity?
- Comorbidity is the co-occurance of addiction and anxiety, mood or personality disorders.
- possible to have deficient reward mechanism in brain leading to both personality disorder and likelihood to abuse for reward
What are the two possible explanations for the chicken and egg situation of Comorbidity and Risk Factors?
- Self-medication hypothesis
- Shared etiology gypothesis
- Current evidence does not rule out either
What is the self-medication hypothesis?
Self-medication hypothesis: stressful life event can trigger anxiety and mood disorders (like depression), which in turn can lead to substance use in an attempt at self-medication
What is the shared etiology hypothesis?
Shared etiology hypothesis: certain factors (genetic and/or environmental) contribute to elevated risk of both addiction and other psychiatric disorders
What is the opposite of most risk factors?
Protective factor
What are some risk factors?
- Certain personality traits: risk taking, sensation seeking and impulsive behavior
- This can be related to judgement (remember PFC)
- Environment with peers who tried or use the drug and will offer the drug/acceptance of use by friends
- Community attitudes towards substance use
- Parental attitudes
- Perceived prevalence
What are some protective factors?
- An intact and positive home environment
- Parent/child bond
- Positive educational experience
- Exercise
- Conventional peer relationships
- Positive attitudes and believes
- 2+ extracurricular activities
- Important: compensation for risk factors
- Dealing with health problems in non-problematic ways
How does stress affect a person?
- Stress alters biological functions including immune response and development
- Stress at a young age may be particularly destructive and age of drug use is a predictor of future addiction
- Adolescent rats seek more reward than adutls, may administer more drug, may reflect similar tendency in humans
How did the Modeling Stress experiment work on rats?
- Rat experiment: 2 weeks of once daily separation of mother from pups
- Group 1 15 minutes, Group 2 180 minutes
- Group 2 self-administerers more than twice as much (for both alcohol and cocaine)
How has the study of monkeys given us knowledge on evironmental interactiosn?
- Monkeys in groups establish hierachies
- One experiment measure d2 receptors and drug self-administration with monkeys in group
- At start there was no structure to group
- After several months a hierarchy was established
- The dominant monkeys in the group had increased D2 receptor levels by 20 to 25%
- Subordinates had no change
- The dominant monkeys were less vulnerable to drug use
How were dominant monkeys affected?
- The dominant monkeys were less vulnerable to drug use
- Because of more receptors, they did not need as much drug to have a rewarding effect
- Implicaitosn that social situations can change drug vulnerability
- For good or bad depending on the situation
- Relates back to risk and protective factors
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What are some Heroin counter claims to popular beliefs?
- The large majority of people exposed to these drugs do not become addicted
- Clinical research
- 19th century many were taking opioids the resulting addiciton <1% of the pupulation
- In UK heroin has been used in medical practve and there is a virtual absence of addicts created by this practice
- PCA (patient controlled analgesia) does not results in addictions
the Hart et al. experiment was repeated with crystal meth, what were the results?
- Repeated same expriment with crystal meth and found similar results
- Even at low alternative reinforcer levels 9around $5) participatns only picked the drug around half the time (averaged across all doses)
- At higher levels (around $20) that number drops significantly
What do animals studies find?
- Animals will self-administer most of drugs of abuse
- Psychological dependence
- Physical dependence
- Maybe the animals feel isolated and stressed out?
- Rat park experiment
- The rats had space
- Males/ females
- Rats did not choose to administer morphine
