Lecture 43: Addiction Flashcards
About what portion of risk for addiction is genetic?
50%
Men are more likely to use which two drugs? What are women likely to use?
Marijuana and alcohol; nonmedical use of prescription drug
How are women vulnerable to drugs of abuse? Mediated by…
Women exhibit faster onset of SUDs and medical consequences; mediated by gonadal steroids
Three cardinal features of drug addiction (according to Dr. Nestler)
Loss of control over use, compulsive seeking/taking despite consequences, relapse even for years later
What does the DSM definition for substance use disorder include?
Physical tolerance and withdrawal
According to Dr. Nester, addiction is caused by drug-induced changes in (2)
Reward or reinforcement
Animal models of addiction have demonstrated these paradigms (4)
Conditioned place preference, drug self-administration (including overdose), relapse (cue/stress), intra-cranial self-stimulation
Most important SUD NT projection in brain
VTA –> NAc (mesolimbic)
Describe the effects of reward on VTA DA neurons: what activates them (3)? What inhibits them (1)?
Reward, expectation, and (especially) unexpected reward activates neurons; absence of expected reward inhibits neurons
T/F: Drugs of abuse activate same brain reward regions as natural rewards, only not as well
False! Drugs of abuse do it better
Three events caused by drug addiction
- Reduce response to natural rewards; 2. Sensitive response to drugs of abuse and cues; 3. Impaired cortical control over reward pathway
What is the the impaired cortical control over reward pathway called? What brain region is increased?
Hypofrontality; limbic regions
Stimulants act on what brain system via which set of proteins?
Monoamine system; monoamine transporter
Cocaine blocks…
Monoamine reuptake
Amphetamines increase…
Monoamine release
Stimulants cause (5)
Euphoria, increased arousal, suppression of fatigue, increased confidence, appetite suppression
Chronic use of stimulants cause tolerance to what and sensitization to what?
Tolerance: euphoria, tachycardia; sensitization: paranoia, irritability
Which two stimulants are toxic to neurons?
Methamphetamine and Ecstacy
Nicotine acts at…and causes (5)
nAChR; altertness, muscle relaxation, analgesia, nausea, psychomotor activation
PCP and ketamine do what to which receptor? Producing what state at high doses?
Non-competitive antagonists of NMDA glutamate receptor; a state of psychosis
What is unique about alcohol’s binding affinity?
Does not have a high affinity target in the brain
Anxiolytic effects of alcohol: NT/receptor
GABA
Dissociative, psychotogenic effects of alcohol: channel
NMDA
Coma, death effects of alcohol: channel
VG channels (and other)
Cannabinoids act how on what receptor?
Agonists at CB1 receptor
Three deleterious effects of long-term alcohol use
Apathy, addiction, schizophrenia
Drugs of abuse converge on what type of neuron where?
GABA neurons of the nucleus accumbens
T/F: Drugs of abuse can alter gene expression
True!
Replacement therapy
Long-acting drug agonist (e.g. methadone)
Classic antagonist therapy example. What’s the problem with these treatments?
Naltrexone for opiate addiction; cause negative emotional responses (feel crappy)
Most effective treatment for SUD?
Behavioral/group therapies
After about a year, relapse risk is finally…
> 50%
