Basic Psychopharmacology Exam PDF

Basic Psychopharmacology/Learning (Associative/Non-Associative) Psychopharmacology ​ Study of psychoactive substances ​ Drug- substance that alters physiology of the body but is not a food or nutrient ○​ Psychoactive- pharmaceutical or non-pharmaceutical ○​ Non-psychoac...

Basic Psychopharmacology/Learning (Associative/Non-Associative) Psychopharmacology ​ Study of psychoactive substances ​ Drug- substance that alters physiology of the body but is not a food or nutrient ○​ Psychoactive- pharmaceutical or non-pharmaceutical ○​ Non-psychoactive- pharmaceutical or non-pharmaceutical ○​ Psychoactive drugs- substance that impact the nervous system to alter a person’s mood, perception, or level of consciousness ​ Supplement- a product intended for ingestion that, among other requirement, contains a “dietary ingredient” intended to supplement the diet ○​ Cannot make structure/function claims ○​ Firms do not have to provide FDA with the evidence it relies on to substantiate safety Classification of Drugs ​ Therapeutic- similar/same outcome within class; may differ in terms of biological mechanism of action ○​ ie) anxiolytics ​ Pharmacologic- similar/same biological mechanisms of action within class ○​ ie) stimulants ​ Legal- DEA schedules Pharmacological Classes of Psychoactive Drugs ​ Sedative-hypnotics- slow down (depress) CNS activity via several mechanisms ​ Stimulants- CNS excitation via several mechanisms ​ Cannabinoids- mimic endocannabinoids or interacts with endocannabinoids ​ Hallucinogens- distort perception and cause hallucinations via effects on serotonin and glutamate (primarily) ​ Opiates- depress CNS activity; exogenous endorphins Therapeutic Classes of Psychoactive Drugs ​ Anti-psychotics ​ Anti-depressants ​ Anti-anxiety ​ Pain relievers Drug Scheduling- DEA Schedule of Controlled Substances ​ Schedule 1- high abuse potential (++++), no accepted medical use ​ Schedule 2- high abuse potential (++++), accepted medical use ​ Schedule 3- moderate abuse potential (+++), accepted medical use ​ Schedule 4- low abuse potential (++), accepted medical use ​ Schedule 5- low abuse potential (+), accepted medical use How Do We Know What Drugs Do? Research. ​ Differences- between groups  ○​ Knowing theres is a difference- means/average of data; effect size within context ​ Change- within groups ○​ Knowing there is a change- compare means to baseline ​ Associations- correlational ​ Frequency- descriptive Types of Variables ​ Experimental studies ○​ Independent variable- true or quasi ○​ Dependent variable- measured ○​ Error variable- extraneous, random ​ Descriptive studies ○​ Measured variables ○​ Frequency variable ○​ Qualitative studies- non-numerical data Types of Drug Studies ​ Epidemiological studies- population level studies ​ Human studies- basic, translational, clinical ​ Pre-clinical- animal studies, pre-clinical other (petri dish) Conceptualizing Drugs and Drug Effects ​ Molar → molecular → interactions ○​ Social systems ○​ Social interactions ○​ Individual ○​ Systems within individuals ○​ Organs within systems ○​ Cells within organs ○​ Cellular events Social Factors that Influence Behavior/Cognitions ​ Presence of others- facilitation/inhibition ​ Others’ behavior- obedience, conformity ​ Others’ requests- compliance ​ Others’ belief about us- stereotype threat Individual Factors that Influence Behavior/Cognitions ​ Environment ○​ Learning ○​ Biology ○​ Interactions Types of Learning ​ Associative ○​ Social learning  ○​ Classical conditioning ○​ Operant conditioning ​ Non-associative ○​ Physiological basis Classical/Pavlovian/Respondent Conditioning ​ Learned reflexes- associations between stimuli; occur in close temporal proximity ○​ Reflexive = unconditioned ○​ Learned = conditioned ​ Without experience/innate reflex (no learning) ○​ Unconditioned stimulus (UCS)- stimulus that evokes a response ○​ Unconditioned response (UCR)- response evoked by UCS ​ After experience/learning ○​ Neutral stimulus (NS) becomes a conditioned stimulus (CS) ○​ CS evokes a response due to association with UCS ○​ Conditioned response (CR) evoked by CS Classical Conditioning and Drug-Related Phenomena ​ Placebo effects ​ Nacebo effects ​ Withdrawal ​ Tolerance ​ Compensatory effects Operant Conditioning ​ Association between behaviors and consequences ​ Behavior is influenced by its consequences (in a context) ​ Antecedent: Behavior → Consequence ○​ Consequences are defined by their influence on behavior ○​ Consequence of behavior- reinforcement/punishment ​ Reinforcement- increase likelihood behavior will occur ○​ Positive- add stimulus ○​ Negative- subtract stimulus ​ Punishment- decrease likelihood behavior will occur ○​ Positive- add stimulus ○​ Negative- subtract stimulus Schedules of Reinforcement (Operant Conditioning) ​ Continuous reinforcement- availability of reinforcement follows every emission of target response ​ Intermittent reinforcement- availability of reinforcement only part of the time that a target behavior is emitted ○​ Slower acquisition ○​ More resistant to extinction  ○​ Fixed v. variable ​ fixed= set number/value ​ variable= varying number/value ​ Made available after two types of behaviors ​ Interval- waiting for time lapse ​ Ratio- emitting responses ​ Immediate v. delayed ○​ Delay discounting- given choice between two equal reinforcers…available now? Or available in the future Non-Associative Learning ​ Likely physiological ​ Habituation- simplest form of learning; decreased responsiveness as a result of repeated exposure ​ Sensitization- increased responsiveness following presentation of a single strong stimulus Why Do People Use Drugs? ​ All behavior takes place in a context ○​ Context = behaviors + consequences + environment ○​ Choices made between reinforcers ○​ Drugs v. all other reinforcers ○​ Drug choice endorses higher relative reinforcement Behavioral Economics ​ Origins ○​ Operant theory alone = good at predicting behavior ○​ Economic theory = predict human behavior in a natural economy (results equivalent to chance) ○​ Synthesize economic and behavioral theories ​ “Spending” behavior ○​ Spending = allocation of resources to gain access to reinforcers ​ Behavior = money ​ Reinforcers = goods/services ○​ Variables that influence “spending”- spending is affected by reinforcers ​ Delay ​ Price ​ Quality ​ Alternative reinforcer availability ​ certainty Biological Bases of Behavior Studying Biology ​ Cannot behave without biology ​ Behavior has consequences, some are biological  ​ Environment changes biology and vice versa ○​ Reductionism- analyze behavior on several levels ○​ Social → individuals → nervous system of individuals → organs within systems → brain regions → cells → synaptic events → neurotransmission The Nervous System ​ Drugs can affect all facets of the nervous system ​ Two major divisions 1.​ Central nervous system (CNS) 2.​ Peripheral nervous system (PNS) Peripheral Nervous System ​ All neurons outside CNS ​ Somatic nervous system- voluntary movement ​ Autonomic nervous system- involuntary movement ○​ Sympathetic- fight or flight ○​ Parasympathetic- rest and digest/eat, off my feet Central Nervous System ​ Brain ​ Spinal cord The Brain ​ Part of CNS ​ Cortex (cerebrum) ○​ 2 hemispheres ○​ 4 lobes ​ Parietal- senses ​ Occipital- vision ​ Temporal- audition ​ Frontal- “executive control”; motor function; prefrontal cortex ​ Subcortical structures (forebrain and midbrain) ○​ Thalamus- relay center for senses (except olfaction) ○​ Hypothalamus- regulate biological needs ○​ Limbic system- regulates emotion ​ Cerebellum, pons (hindbrain)- motor control ​ Medulla (hindbrain)- vital signs (circulation, breathing) Cells of Nervous System ​ Glia- structure, nutrients, waste-removal, myelin, communication with neurons, blood-brain barrier, blood flow ​ Neurons- data transmission between/among cells; cells of the nervous system The Neuron ​ Individual transmission cells of nervous system ​ Structure of a neuron  ○​ Dendrites- receive information ○​ Axon- transmission ○​ Presynaptic terminal/terminal buttons- vesicles, chemical release ○​ Soma- cell body ○​ Nodes of ranvier ○​ Myelin sheath Neurotransmitters ​ Chemical data released from neurons ​ Precursors- materials from blood supply ​ Uptake- chemical process by which molecules enter cell ​ Synthesis- process of neurotransmitter packaging ​ Enzymes- facilitate neurotransmitter synthesis ​ Vesicles- storage for neurotransmitter Receptors ​ Sites of a neuron (on dendrites) that receive neurotransmitters from other neurons ​ Receptor sites throughout the body Action Potential ​ Electrochemical process by which neurotransmitters are released ​ Electrical signal transmitted along axon ​ All or none law ○​ spatial/temporal summation ​ Chemical release of neurotransmitters Synapse ​ Space between axon terminal of one neuron and dendrite of another After an Action Potential ​ Release of neurotransmitters into synapse ​ Three outcomes 1.​ Binding to postsynaptic cell at receptor sites 2.​ Reuptake- transporter cells 3.​ Degradation- metabolism Possible Drug Actions (Varies by Drug) 1.​ Agonist- drugs that occupy receptors and activate them/causes similar effects 2.​ Antagonist- drugs that occupy receptor sites, but do not activate them; block neurotransmitter from having effects a.​ Agonist- full activation b.​ Agonist and antagonist- less activation c.​ Antagonist- no activation 3.​ Changes activity of an enzyme that creates or destroys neurotransmitter 4.​ Alter reuptake (speeds or impedes) 5.​ Change amount of neurotransmitter released in response to action potential Common Neurotransmitters ​ Dopamine- excitatory/inhibitory ​ GABA- inhibitory ​ Serotonin- inhibitory ​ Acetylcholine- excitatory/inhibitory ​ Endorphins- inhibitory Mechanism of Action- Dopamine ​ Drugs act on neurotransmitter systems → dopamine implicated in experience of reinforcement ​ Most drugs act directly/indirectly on dopamine system (including alcohol) ○​ Increase dopamine production ○​ Reduce reuptake in postsynaptic cell ○​ False transmitters (block receptors) Drugs vs. Natural Reinforcers ​ Food consumption and sexual behavior have natural satiation mechanisms ○​ Drugs do not have natural limits to reinforcing abilities ​ Drugs quickly flood brain’s reward system ○​ Stronger and more immediate than drug- free reinforcers Mesolimbic Dopamine Pathway ​ pleasure/reward pathway of brain ​ Drug stimulation = reinforcing effects ​ electrical/artificial stimulation = reinforcing effects ​ Damage = loss of reinforcing effects (behavior does not respond to stimulation) Combination Effects of Drugs ​ Primary system and dopamine ○​ Alcohol- gaba and dopamine ○​ Nicotine- epinephrine, dopamine, acetylcholine ​ Hybrid drugs- multiple primary systems ○​ MDMA- serotonin and dopamine (hallucinogen and stimulant) Pharmacokinetics Pharmacokinetics ​ What the body does to the drug ​ Movement and time Evolutionary Perspective ​ Big brain = altered perception ​ Non-human animals use drugs ​ Humans v. nonhumans- ability to synthesize drugs; social and cultural implications/environments for drug use Four Biological Processes 1.​ Absorption  2.​ Distribution 3.​ Metabolism 4.​ Excretion ​ Four biological processes determine bioavailability of drug at its receptors ○​ Bioavailability- how much of the drug that is administered actually reaches its target and how long it persists there Drug Absorption- processes and mechanisms by which a drug passes into the bloodstream ​ Routes of drug administration ○​ Oral- most common; pills, cannabis, “edibles” ​ Lipid solubility allows for absorption after oral administration ○​ Inhalation- smoking, huffing ○​ Intranasal- snorting ○​ Injections- intramuscular, intravenous, subcutaneous ○​ Administration through skin- transdermal patches ○​ Rectal administration Drug Distribution- one absorbed into bloodstream, drug is distributed throughout the body by the circulating blood, passing across various barriers to reach its target (site of action/receptors) ​ Drug enters bloodstream ○​ Amount available for distribution depends on amount that reaches heart ​ Factors that alter drug distribution ○​ Drug dosage ○​ Food and beverage ○​ Age ○​ Biological sex ○​ Other drug use ○​ Stimulation of enzyme systems ○​ Depression of enzyme systems ​ Drugs affect the brain when they cross… ○​ Blood-brain barrier ​ Glia (astrocytes) surround blood supply, wrapping around capillaries of brain and forming “tight junction” ​ Lipophilic compounds pass (fat) ​ Hydrophilic compounds do not pass (water) ​ Active transport- glucose, important amino acids, gas ○​ Placental barrier ​ Fetus and mother are separate individuals with separate blood supplies ​ Receives nutrients and eliminates waste via maternal circulation ​ Fat soluble compounds pass placenta readily ​ Fetal and maternal concentrations of drug are similar Metabolism  ​ Biotransformation- process whereby active drug molecules are metabolized to molecules that are more readily eliminated from the body 1.​ Initial reaction involving cytochrome P450 enzymes to break apart the drug molecules 2.​ Conjugation reactions primarily involving glucuronidation, where a larger sugar molecule is bound to the drug to make it larger, bulkier, less able to pass back into the brain, and once filtered by the kidneys, less able to be reabsorbed and thus excreted in urine ​ Enzymes deactivate drug molecules in liver ​ Factors affecting metabolism ○​ Genetics ○​ Drug interaction ​ First pass metabolism- process in which a drug or substance is metabolized by the liver (or gut wall) before it reaches systemic circulation ○​ Amount of drug metabolized and excreted before reaching the heart for the first time Excretion ​ termination/drug deactivation- inactivation/elimination of drugs ​ Kidneys- excrete metabolites formed in liver; regulate amount of drug in bloodstream Time Course of Drug Action ​ Time course: ○​ Onset (can be affected by route of administration) ○​ Duration (can be affected by route of administration) ○​ Termination ○​ Difference across absorption/activation/elimination across individuals and drugs ​ Cumulative effects occur when… ○​ Doses taken in close temporal proximity ○​ Maximal blood plasma levels increase Half-Life ​ Applies to all drugs except alcohol ​ Time needed for drug blood plasma levels to reduce by 50% ​ Half-life independent of amount of drug in body ​ Example) ○​ Caffeine has half-life of 4 hours → time for 75% reduction → 6 hours Pharmacodynamics Range of Effects ​ Physiological- what the body does ​ Subjective effects- how the drug makes you feel ​ Behavioral effects- how the drug makes you do/change behavior (frequency) Tolerance  ​ Reduced responsiveness to drug after repeated administration ​ Physiological and behavioral ​ Tolerance → withdrawal in absence of drug ​ Types of tolerance 1.​ Metabolic tolerance a.​ Repeated exposure to drug increases number of enzymes that metabolize a drug b.​ Larger dose is required to achieve same blood plasma level c.​ Receptor sensitivity has not changed d.​ Same blood level produces same effect as seen before tolerance 2.​ Pharmacodynamic tolerance a.​ Cellular adaptive b.​ Understood at level of receptors (reduced number of receptors; reduced sensitivity of receptors) c.​ Same blood levels, reduced effectiveness 3.​ Behavioral tolerance a.​ Repeated opportunity to engage in behavior in presence of a drug reduces the magnitude of its behavioral effects b.​ “Intoxicated practice” c.​ Very slight changes in environment can immediately diminish behavioral tolerance 4.​ Cross-drug tolerance a.​ Use of one drug may lead to tolerance of similar (with respect to mechanism) drugs ​ Sensitization- enhanced responsiveness to a drug wit repeated exposure (theory) ​ Homeostasis ​ Determining tolerance ○​ Before induction of tolerance- establish dose-effect relationship or determine effect of single dose ○​ Induce tolerance- expose to drug chronically ○​ Redetermine effects- re-establish dose-effect relationship or re-determine effect of single dose ○​ Rightward shift in dose-response curve → tolerance Compensatory Effects ​ “Conditioned tolerance” ​ Develop tolerance through context ​ Body does opposite of drug effects in preparation for drug Dose-Response Relations ​ When a drug response/effects depend on dose ○​ IV = dose  ○​ DV = response/effect ​ Measured on dose-response curve ​ Types of dose-response curves ○​ Individual- response rate vs. dose ○​ Quantal- percentage affected v. dose ​ As dose increases, larger percentage of population will experience effect ​ As dose increases, effects may change ​ Important dose-response ○​ ED50 (effective dose 50)- drug produces desired effect in 50% of subject ○​ LD50 (lethal dose 50)- dose is lethal to 50% of subjects ○​ ED99- drug produces desired effect to 99% of subjects ○​ LD1- drug is lethal to 1% of subjects ​ Therapeutic index- LD50/ED50 = TI ○​ LD should always be greater than ED ○​ TI > 1 ○​ Higher TI = safer the drug ○​ Margin of safety- difference between ED and lowest toxicity levels ​ Ideal difference is high ​ Help most while harming few Drugs and Toxins ​ Drugs are taken for advantageous effects; not always psychoactive ​ Toxins- no advantageous effects; some drugs are toxins at high doses ○​ Toxicity- amount of drug resulting in damage or adverse effects Side Effects ​ Effects of drugs that are not therapeutic ​ Used to decide if drug will be approved and at what dose Potency ​ Amount of drug needed to produce desired effects ​ Less needed/lower ED50 = more potent ​ More needed = less potent → increased likelihood of side effects Substance Use Disorder ​ Physical symptoms- drug needed to prevent withdrawal syndrome ​ Psychological symptoms- drug needed to maintain a cognitive sense of well-being ​ Substance use disorder may include withdrawal with discontinued use ​ Withdrawal- physiological reaction to discontinued use ○​ Symptoms typical opposite of drug action ○​ and/or psychological reaction The Effects of Social Contact on Drug Use Role of Proximal Social Contact in Drug Use  ​ Predictors of whether an adolescent or young adult will use drugs is whether his/her friends use drugs ​ Proximal social factors- factors immediately present at time of drug use ​ Distal social factors- factors present in an individual’s broader social environment, but may not be immediately present when drug use occurs ​ Social learning models of behavior- members of group model group-accepted behaviors, leading others to imitate those behaviors ○​ Behaviors adhering to group norms = reinforced ○​ Behaviors deviating from standards = punished ○​ Drug use established through imitation of peer-modeled drug use and then maintained by social reinforcement from peers ​ rewarding/reinforcing effects of drugs depend on… 1.​ Whether other individuals are immediately present 2.​ Whether those individuals are also using drugs Social Contact and Drug-Seeking Behavior: Conditioned Place Preference ​ Conditioned place preference (CPP) procedure measures positive affected states produced by a stimulus and is often used to measure drug-seeking behavior ○​ Association formed between stimulus and distinctive environmental context ○​ Expose subjects to stimulus in one context and withhold in another ○​ Given free access to both context → measure time in each context ○​ Subject expresses of stimulus-paired environment → stimulus produced positive affective state ​ Drug-induced CPP is suggestive of drug’s rewarding effects and abuse potential ​ Rewarding effects of peer-peer interactions ​ “Dose-dependent” effect of social contact ​ Greater degrees of social contact = greater preference ​ Drug use more rewarding in presence of peers ​ Rewarding effects of social contact may “outweigh” the rewarding effects of drug use Social Contact and Drug-Taking Behavior: Drug Self-Administration ​ Drug self-administration procedure ○​ Drug administration contingent on an operant response ○​ Drug = positive reinforcer ​ Social contact increasing drug intake ○​ Social interaction with an intoxicated peer, as opposed to merely the presence of an intoxicated peer ○​ Behavior of a peer, as opposed to merely the presence of a peer, is a critical factor determining how social housing determines ethanol self-administration ○​ Partners behavior (whether or not they are also self-administering a drug) determines whether drug self-administration will be facilitated or inhibited by social contact Behavior Mechanisms Controlling Drug Intake ​ Imitation and modeling- repeating a novel behavior for which there in no instinctive drive ​ Social reinforcement- primary reinforcing effects of social contact; various words and actions that are directed from one individual to another in the form of attention, praise, and nonverbal gestures ○​ Social contact as reinforcement ​ Social facilitation- presence of a social partner can increase arousal and thereby increase activity/contact with environmental contingencies ○​ Selectively increases rate of high-probability behaviors at expense of low -probability behaviors ​ Local enhancement- experience drug users may draw attention to place and locales in which drug use is likely to rewarded; close physical proximity to places in which drug use is a high-probability event that is likely to be reinforced ​ Stimulus enhancement- increased attention to a particular object; drugs and stimuli associated with their use acquire increased salience and induce subjective states of craving in drug-experienced individuals ​ Emulation- a process in which individuals learn operant contingencies by observing others, but in which they develop novel behavioral strategies to produce similar consequences ○​ Goal emulation- an individual observes the actions of a demonstrator, but uses a different sequence of responses to produce the same result ○​ Human drug users may develop novel methods of drug administration after observing the consequences of drug administration in their peers ​ ie) root of administration- snorting v. smoking v. injecting ​ Peers as discriminative stimuli- individual from that environment may serve as discriminative stimuli signaling that drug use will be reinforced ○​ Manipulations that increase or decrease drug use in some group members will likely produce corresponding increases or decreases in the drug use of other members ​ Peers as conditioned reinforcers- if some individuals are consistently present during episodes of drug use, then those individuals may become conditioned/secondary reinforcers because of their association with the unconditioned/primary reinforcing effects of drugs ​ Reinforcement enhancement- in addition to their primary reinforcing effects, many drugs can increase or enhance the reinforcing effects of other stimuli Translational Implications ​ Social environment may be changed to reduce drug use and prevent drug abuse