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Contemporary Human Behavioral Pharmacology Rodney D. Clark, Ph.D. Department of Psychology and Program in Neuroscience Allegheny College [email protected] 814-332-4960 Orientation • Where did the “problem” with drugs come from? • Drugs are used very frequently in contemporary society. • Misconceptions perseverate. • Misinformation is prevalent. Orientation • • • • Social Influences Discuss legal Issues Discuss moral Issues Applied Behavior Analysts encounter clients with histories of prescribed drug use, recreational drug use, or both. Learning Objectives At the conclusion the workshop participant will be able to: • Describe a general historical context. • Describe the basic actions of the nervous system. • Describe the fundamental actions of drugs. • Describe the environmental determinants of drug action. • Describe basic stimulus properties of drugs. • Describe potential drug interactions. • Describe clinical actions of therapeutic drugs. Workshop Format The format of the workshop will be arranged in the following way: • The workshop will be divided up into six units. • Each unit consists of a sequence of one to three brief lectures with the first six units followed by a short quiz. • The seventh and final unit will be followed by a group discussion and concluding remarks. We Begin The first thing I want to say is: The phrase “drugs and alcohol.” …is grammatically incorrect! the word “drugs” …is a generic or class noun of which alcohol is a member. …That is similar to saying “…sports and baseball.” • Humans are not the only animal to consume psychoactive chemicals on a regular basis. Many other animals do so. • Animals, including humans have receptors in the brain and rest of the body that abused drugs have an affinity for. • We have an interesting cultural context in which many people “understand” how drugs work. • From Robert Louis Stevenson we have the handsome young Dr. Jekyll turning into the hideous Mr. Hyde when he drinks “the formula.” • Many people consider “drugs” to do exactly that! …turn people into monsters! • Reference the descriptions used by early journalists when reporting on the effects of Marijuana. • “Drugs do not create behavior, they modify existing behavior.” 1. Historical Antecedents HISTORY • From the colonial era to the present drugs have been a part of the American fabric. We will take a brief look at what happened. • There has never been a time when drugs were not present. • Drugs have been both praised for their effects and villainized for the same effects. HISTORY in the United States • We only really began to legally regulate drug use in the final quarter of the 19th century. • We only began to require disclosure of the ingredients of “drugs” in the first part of the 20th century. • We only began to really view drugs as “problems” during the first part of the 20th century. Historical Antecedents • • • • • • • • • ALCOHOL MARIJUANA NARCOTICS (OPIOIDS) CAFFIENE PSYCHOMOTOR STIMULANTS SEDATIVE-HYPNOTICS INHALEANTS HALLUCINOGENS TOBACCO ALCOHOL EARLY HISTORY OF DRUG USE • ALCOHOL: – Appears to have been used since 6000 BCE. – Frequently mentioned in the bible and other early religious text. – Egyptians revered wine and associated spiritual qualities to it. – Ancient Hebrews, Greeks, and Romans used alcohol. EARLY HISTORY OF DRUG USE… • ALCOHOL: – The word “alcohol is derived from the Arabic word “Alkuhl” (the essence). – Prominent role of alcohol in U.S. history: • • • • The slave trade Survival of pilgrims Early settlers Temperance DEMON RUM From: PBS “THE AMERICAN EXPERIENCE” MARIJUANA MARIJUANA – Use dates back to 2700 BCE. – Banned in China in 500 BCE. – Used in India for religious purposes. – Greeks and Romans used it for clothes and for intoxicating effects (the Oracle at Delphi). – Used in colonial America for rope. – Early 1900s used by farmworkers and jazz musicians. – Post WWII “Beats” …And the “Hippy” of 1960s NARCOTICS (OPIOIDS): NARCOTICS (OPIOIDS): • NARCOTICS (OPIOIDS): – Opium derivatives made from the plant Papaver somniferum. – Intoxicating and euphoric properties known since 6000 BCE. – Frequently mentioned in writings from ancient Greece and Rome. – The central factor in the war between Britain and China. NARCOTICS (OPIOIDS): – Morphine was derived from opium in 1806. – Many Civil war veterans suffered from morphine addiction (the “Soldier’s Disease”). – Heroin was developed to combat morphine addiction as it was thought to be much safer. MILD STIMULANTS CAFFINE CAFFINE • CAFFINE: – Found in a variety of drinks. – Coffee as an example – Use dates back to 900 CE. – The Koran defines coffee as an intoxicant. – Drinking became very popular in 1600s Europe. PSYCHOMOTOR STIMULANTS PSYCHOMOTOR STIMULANTS • COCAINE: – It is believed that the practice of chewing coca leaves dates back to about 3000 BCE. – First recorded use of coca leaves traced back to 500 CE in present day Peru. – Extract of coca leaves was used in Europe in Vin Mariani’s coca wine. PSYCHOMOTOR STIMULANTS • COCAINE: – Sigmund Freud was an early proponent of the medicinal value of cocaine. – Cocaine was introduced in the original formula for Coca-Cola and other soft drinks. – Tooth drops for teething children. PSYCHOMOTOR STIMULANTS • AMPHETAMINES: – First synthesized in 1887. – Used medicinally since the 1920s. – Became available in the 1930s as an over-thecounter drug. DETECTIVE COKE ENNYDAY (Starring Douglass Fairbanks) DETECTIVE COKE ENNYDAY (Starring Douglass Fairbanks) c. 1916 SEDATIVE-HYPNOTICS: SEDATIVE-HYPNOTICS: • SEDATIVE-HYPNOTICS: – Barbiturates were discovered in the 1860s. – Used to treat anxiety. – Non barbiturates such as bromide were developed in the 1860s as a treatment for epileptic convulsions. – Minor tranquilizers were introduced in the 1950s increasingly used to treat anxiety. SEDATIVE-HYPNOTICS: • INHALENTS: – Solvents, glue, Nitrous oxide, aerosols, gasoline, anesthetics – Used in increasing frequency since the 1940s – Primarily used among teens and young adult populations. HALLUCINOGENS HALLUCINOGENS – Psilocybin use dates back to 2000 BCE. – d-LSD-25 first synthesized in 1938. – N,N,DMT (Dimethyltryptamine) called the “business man’s LSD” because of the short duration. – Gen. Wm. Creasy’s concept of “war without death” suggested spraying the enemy with LSD. …to test this idea some suggested spraying it into the subways of NYC. HALLUCINOGENS • HALLUCINOGENS: – Dr. Sidney Gottlieb, Chief of CIA technical service, was the head of the secret project …MKULTRA. – Sometimes tested on unwilling subjects. – Drs. Timothy Leary & Richard Alpert, Harvard professors experimented with LSD. Nicotine Nicotine As an Example TOBACCO – Use in America traced back prior to the 1400s. – Introduced to Europe in the 1490s and used medicinally. – In late 1800s and early 1900s chewing was more popular than smoking. – Around World War I, smoking became more popular than chewing. – Total U.S. sales have been declining since mid1980s. A FEW THINGS TO THINK ABOUT • Are drugs really a problem? • Is there cultural tolerance toward certain types of drug use? • Do drugs cause violence? • Do drugs cause family problems? • Do drugs cause problems in the workplace? • Can we really be drug free? QUIZ #1 QUIZ #1 Describe some historical antecedents. 1. We have an interesting ____________in which many people “understand” how drugs work. An example may be when …the handsome young Dr. Jekyll turns into the hideous Mr. Hyde when he drinks “the formula.” a. Cultural context b. Mind set c. World view d. Philosophy QUIZ #1 Describe some historical antecedents. 2. Of the following which was not among the social effects of opioids we discussed? a. Morphine was derived from opium in 1806. b. Many Civil war veterans suffered from morphine addiction (the “Soldier’s Disease”). c. Heroin was developed to combat morphine addiction as it was thought to be much safer. d. The disruptive effects of heroin addiction was first observed during the post-World War II era. QUIZ #1 Describe some historical antecedents. 3.Psilocybin use dates back to ____________. a. b. c. d. 2000 BCE 5000 BCE 1,000,000 BCE 200 CE 10 minute break Basic neuroanatomy (Brain & Spinal cord). Basic Principles of Pharmacology • Basic neuroanatomy (Brain & Spinal cord). • Neurochemical functioning (Pharmacology). • Basic methods in pharmacology, Major Body systems, and factors). EXAMPLE OF A MEDIAL VIEW OF THE HUMAN BRAIN. BRAIN SECTIONS The brain: major subdivisions • • • • • • Frontal Lobe: “Planning” Temporal Lobe: Hearing Parietal Lobe: Body sensations Occipital Lobe: Vision Pre-central Gyrus: Motor control Central Sulcus: Divides the frontal and parietal lobes • Postcentral Gyrus: Stimulation from touch THE NERVOUS SYSTEM: • CENTRAL NERVOUS SYSTEM (CNS): composed of the BRAIN and SPINAL CORD • PERIPHERAL (PNS): composed of – AUTONOMIC NERVOUS SYSTEM: Subdivided into the Sympathetic (Symp.) and Parasympathetic (Psymp.) NS • Generally these two systems work in opposition to one another • Drugs that mimic the Symp. Are called Sympathetics • Drugs that mimic the PSymp. Are called Parasympathetics – SOMATIC NERVOUS SYSTEM: Nerves that relay sensory information into the CNS and motor information back out Once again, THE BRAIN BASIC STRUCTURE OF THE HUMAN BRAIN…BASAL VIEW BASIC FUNCTIONS OF SELECTED STRUCTURES OF THE BRAIN • The brain and spinal cord (The CNS). Are composed of several major structures some of which are: – Reticular Activating System (RAS): affects sleep, attention, and arousal. – Hypothalamus: Maintains homeostasis, affects stress, aggressiveness, heart rate, hunger, thirst, consciousness, body temp., blood pressure, and sexual behavior. BASIC FUNCTIONS OF SELECTED STRUCTURES OF THE BRAIN – Limbic System: Plays a key role in memory and emotion. – Medial Forebrain Bundle (MFB): Functions as a communication route between the Limbic system and the Brain Stem; affects “pleasure and reward (reinforcement).” – Basal Ganglia: Affects one’s ability to stand, walk, run, carry, throw, and lift. May produce muscular rigidity of facial, arm, and leg muscles. – Periventricular System: concerned with punishment and avoidance behavior BASIC FUNCTIONS OF SELECTED STRUCTURES OF THE BRAIN – Brain Stem: Regulates vital functions such as breathing, heartbeat, pupil dilation, blood pressure, and the vomiting reflex – Cerebral Cortex: • Hypothalamus: Link between the brain and hormonal output from the pituitary • Cerebrum (Frontal Lobe): coordinates planning, inhibition of inappropriate behavior, and visceral sensations – Cerebellum: • Nucleus Accumbens: believed to play a role in emotional behavior and reinforcement (reward) • Ventral tegmental area: reinforcement (reward) AT THE CELLULAR LEVEL • Neurons (Nerve cells) • Glia (supporting tissue with modulatory functions) • Astrocytes (supporting tissue with some neurotransmitter functions) • Phageocytes (waste disposal function) BASIC STRUCTURE OF THE NEURON (NERVE CELL) • Dendrites: allows nerve impulses to be sent toward the cell body • Axon: allows nerve impulses to be sent away from the cell body • Cell Body (Soma): where basic cellular functions are carried out • Axon Hillock: junction between the axon and cell body • Synapse: the space between an axon and dendrite (about 50 microns across) STYLIZED STRUCTURE OF A GENERIC NEURON EXAMPLE OF FOUR DIFFERENT TYPES OF NEARVE CELLS NEUROTRANSMITTERS NEUROTRANSMITTERS NEUROTRANSMITTERS • NEUROTRANSMITTERS (NT): are chemical substances manufactured in the neuron and released into the synapse. SOME MAJOR NEUROTRANSMITTERS: – Acetylcholine (ACH): An excitatory NT in the skeletal muscles but inhibitory in the heart; affects memory, and linked to aggression and depression. – Serotonin (5HT): Inhibitory NT has a role in regulating sensory perception, eating, pain, sleep, and body temp. SOME MAJOR NEUROTRANSMITTERS: • Gamma-amino butyric acid (GABA): Produces relaxation and sleep. Catacholamines: Affects emotional states; increases lead to stimulation and decreases lead to depression; implicated in mood swings Dopamine (DA) Epinephrine (E) Norepinephrine (NE) SOME MAJOR NEUROTRANSMITTERS: – Glutamate: Excitatory NT plays a role in substance abuse, psychoses, and neurodegenerative disorders. – Peptides: Are substances that link amino acids and include naturally-occurring opioid-like substances called endorphins. • Mu agonists (μ): • Kappa agonists (k): • Delta agonists (δ): * (Sigma agonists) (σ): • *Once thought to be an opioid SOME NEUROTRANSMITTERS AND THEIR FUNCTION NEURAL TRANSMISSION Neural Transmission Neural Transmission A closer look at the electrical signal. • The signal is known as an action potential. • There is a difference in the electrical charge between the intracellular fluid and the extracellular fluid. • The inside is slightly negative relative to the outside. The action potential • This difference is referred to as the Resting potential (averaging about -70mV). • This potential difference is the outcome of an uneven distribution of ions between inside and outside of the cell. • As sodium levels in the cell change, the difference in voltage changes. The action potential • Ions are particles that posses an electrical charge. • The ions responsible for the resting potential are ionized molecules of: – Potassium (K+) – Sodium (Na+) – Chlorine (Cl-) (as an ion it is referred to as Chloride) The action potential • The membrane potential is relative, meaning the inside is compared to the outside. • The outside of the membrane is always at zero. • The reason that the resting potential exist is that the difference in the ratio of negative to positive ions is higher inside the cell. The action potential • There are several processes, both passive and active, that create the uneven distribution of ions. • The resting potential of a neuron is a description of what occurs when there is no stimulation. • As the membrane potential becomes less negative we call it depolarization. ACTION POTENTIAL NEURAL TRANSMISSION EXAMPLE OF NEURAL TRANSMISSION EXAMPLE OF NEURAL TRANSMISSION EXAMPLE OF GABA NEURAL TRANSMISSION / RECEPTOR INTERACTION QUIZ #2 QUIZ #2 Describe the basic actions of the nervous system. 1. Depolarization refers to… a. b. c. d. e. An increase in the resting potential. A decrease in the resting potential. Spontaneous fluctuations in the resting potential. Small leaks of neurotransmitters. Inhibition. Glutamate… 2. a. b. c. d. e. Is a major excitatory transmitter. Primarily acts as an inhibitory transmitter. Potentiates GABA. Works at the Sigma receptor. Both “a” and “d.” QUIZ #2 Describe the basic actions of the nervous system. 3. The system in the brain that mediates both pain and punishment is… • • • • • The Raphe’ system. The RAS. The basal ganglia. The periaqueductal grey. The medial forebrain bundle. 10 minute break Basic Principles of Pharmacology WHAT IS PHARMACOLOGY? – Relationship or interaction between drugs and living organisms. – Drugs that produce profound effects and act quickly are more likely to be abused. III. IMPORTANT DEFINITIONS AND CONSIDERATIONS • DRUG: – Any substance, natural or synthetic, that alters the biological functioning of living organisms. • DRUG USE: – Consuming drugs for therapy or recreation. III. IMPORTANT DEFINITIONS AND CONSIDERATIONS • DRUG MISUSE: – The use of a prescribed drug in quantities more than what is allowed. The use of a drug in greater amounts than or for purposes other than prescribed. • DRUG ABUSE: – Excessive use to the point of disrupting normal activity. I. FOUR BASIC PRINCIPLES OF PSYCHACTIVE DRUGS 1. Drugs, per se, are not good or bad. 2. Every drug has multiple effects. 3. Both the size and the quality of a drug’s effect depend largely on the amount the individual has taken. 4. The effect of any psychoactive drug also depends on the individual’s history. II. FOUR PHARMACOLOGICAL REVOLUTIONS 1. 2. 3. 4. VACCINES: ANTIBIOTICS: PSYCHOPHARMACOLOGY & BEHAVIORAL PHARMACOLOGY: ORAL CONTRACEPTIVES: VACCINES For the first time in history drugs worked well in controlling … • Communicable diseases. • Insect-borne pathogens • Pathologies related to microorganisms ANTIBIOTICS For the first time in history drugs were used in the… • Prevention of infection • Cure of infection PSYCHOPHARMACOLOGY and BEHAVIORAL PHARMACOLOGY – The1920s saw the founding of a systematic and methodical approach to the study of drug effects on behavior. – Development of the scientific approach. ORAL CONTRACEPTIVES • For the first time in human history drugs have altered the pattern of sexual behavior and reproduction. MEASURMENTS TERMINOLOGY and CLASSIFICATION • DRUGS MAY BE CLASSIFIED ON THE BASIS OF: – Molecular structure – Physiological actions – Behavioral actions – Therapeutic usage MEASURMENTS TERMINOLOGY and CLASSIFICATION • Generally use metric system of measurement • A milligram is a 1/1000 gram. • A gram is 1/1000 kilogram. MEASURMENTS, TERMINOLOGY and CLASSIFICATION • DOSAGE: – Threshold Dose: smallest dose to achieve an effect. – Effective Dose (ED): dose needed to achieve a desired effect. – Lethal Dose (LD): amount needed to achieve a lethal effect. – Safety margin: generally the difference between the effective dose and the lethal dose. The larger the difference the safer the drug. MEASURMENTS, TERMINOLOGY and CLASSIFICATION • Effective Dose 50 (ED50): the dose at which 50% of subjects show the desired effect. • Lethal Dose 50 (LD50): the dose at which 50% of subjects die. IMPORTANT DEFINITIONS AND CONSIDERATIONS • Drugs may be identified by a variety of names. • CHEMICAL NAME: – 1(1-Phenylcyclohexyl) Piperedine • GENERIC NAME: – Phencyclidine • TRADE NAME: – Sernylan • SLANG NAME: – Angel Dust BASIC METHODS: PHILOSOPHICAL PERSPECTIVES • BEHAVIORAL PHARMACOLOGY: – – – – – Operant procedures Respondent procedures Unconditioned behavior Locomotor Selectionistic • PSYCHOPHARMACOLOGY: – Cognitive performance – Locomotor – Mentalistic PHARMACOLOGICAL INTERACTIONS • Interactions with the brain and the CNS: • Interactions with neurotransmission. • Drug actions: • Agonist: • Antagonist: • Interactions with receptors: ROUTES OF ADMINISTRATION – Oral (PO): – Intravenous (IV): – Intramuscular (IM): – Subcutaneous (SC or Sub-Q): – Topical or transdermal (TD): – Inhalation (IH): PLOTTED EXAMPLES ROUTES OF ADMINISTRATION (from Poling, 1986) FATE OF A DRUG (PHARMACOKINETICS) • ABSORPTION: – How drugs get into the body. • DISTRIBUTION: – How drugs move to the site of action. • BIOTRANSFORMATION (METABOLISM): – How drugs are converted into other chemicals. • EXCRETION: – How drugs leave the body. FATE OF A DRUG (PHARMACOKINETICS) from NIDA monograph 73, 1986 SOME BASIC CHEMISTRY • STEREOISOMERS: – Many molecules appear in two forms that are mirror images of one another. These are known as STEREOISOMERS, which interact quite differently from each other when combining with receptor sites on the surface of a neuron. EXAMPLE OF A STEREOISOMER. • They can be thought of as “mirror images” of one another. The structure on the left is termed: Levo and the structure on the right is termed: Dextro. The combination is referred to as the racemic mixture or the Racemate. STEREOISOMERS • The different Isomers as well as the racemate interact differently with the receptor. • A good analogy is to place your right hand into the print of your left hand. DRUGS & MAJOR BODY SYSTEMS • Endocrine system: • Cardiovascular system: • Respiratory system: • Gastrointestinal system: DRUGS & MAJOR BODY SYSTEMS • ENDOCRINE SYSTEM: – Composed of structures that release hormones directly into the bloodstream. • CARDIOVASCULAR SYSTEM: – Transports drugs throughout the body. DRUGS & MAJOR BODY SYSTEMS • RESPIRATORY SYSTEM: – Important for drug administration and excretion. • GASTROINTESTINAL SYSTEM: – Important in oral drug administration and distribution. FACTORS AFFECTING DRUG EFFECTS • • • • • • • AGE: GENDER (BIOLOGICAL SEX): DOSAGE: PURITY AND POTENCY: DRUG INTERACTIONS: TOLERANCE: SET AND SETTING: FACTORS AFFECTING DRUG EFFECTS • AGE: – Infants and the elderly are more sensitive to drugs mainly because they are less able to metabolize and excrete drugs. – A substantial percentage of newborns in America are exposed to both licit and illicit drugs prior to birth. – As one ages the percentage of adipose tissue increases, when drugs accumulate in body fat sensitivity to particular drugs also increases. FACTORS AFFECTING DRUG EFFECTS • GENDER (biological sex): – There are differences in how males and females respond to drugs. – Body adipose tissue. – Water content. – Hormones. – Drugs that cause damage to the fetus are called teratogenic. FACTORS AFFECTING DRUG EFFECTS • DOSAGE: – Threshold Dose – Effective Dose (ED) – Lethal Dose (LD) – Safety margin FACTORS AFFECTING DRUG EFFECTS • Doses are usually expressed in metric terms. • Amount of drug per unit of the organism’s body weight. • THUS: mg of drug per kg of body weight. • EXAMPLE 10.0 mg/kg FACTORS AFFECTING DRUG EFFECTS • SET AND SETTING: – SET: refers to the drug user’s behavioral history or “mood, expectations, personality, etc.” when taking the drug. – SETTING: refers to the social and physical environment where the drugs are taken. FACTORS AFFECTING DRUG EFFECTS • PURITY AND POTENCY: – Purity refers to the quality of the drug. – Potency refers to the drug’s ability to produce an effect relative to other drugs. FACTORS AFFECTING DRUG EFFECTS • DRUG INTERACTIONS: – Additive: The cumulative effects of two or more substances added together. – Antagonistic: Refers to a drug’s ability to negate the effects of another drug. – Synergistic: Refers to the combined effects of two drugs that are greater than if they were simply added together. FACTORS AFFECTING DRUG EFFECTS • TOLERANCE: – Pharmacological / Physiological refers to the body adjusting to the presence of a particular drug. – Behavioral refers to the individual’s behavior adjusting to the presence of a particular drug. – Cross refers to the tolerance to a particular drug resulting from tolerance to a chemically similar drug. – Reverse refers to the drug user experiencing the desired effects from lesser amounts of the drug. TOLERANCE (from Poling 1986) Quiz #3 Quiz #3 Describe the fundamental actions of drugs. A milligram is… 1. a. b. c. d. e. 1/10 of a gram. 1/100 of a gram. 1/1000 of a gram. 1/10,000 of a gram. 1000 grams. 2. The LD50 / ED50 is the … a. b. c. d. e. Lethal ratio. Therapeutic ratio Index of safety Therapeutic Index Ratio of Safety Quiz #3 Describe the fundamental actions of drugs. 3. Of the following, which might alter the affects of drugs? a. age b. gender (biological sex) c. dosage d. purity and potency e. all of the above 10 minute break Environmental Determinants of Drug Action. Environmental determinants of drug action. We can review the basic principles of behavior and Segway into the stimulus properties of drugs. We will use the following definition • Behavior: Any muscular movement, neural, or glandular activity. Basic Principles of Behavior • Stimuli in the physical environment, including people, can develop into drug modulating events. • This occurs because of “learning.” • Behavioral change via Classical conditioning and Operant conditioning. CLASSICAL CONDITIONING CLASSICAL CONDITIONING • All organisms are born with a set of “reflexes,” but the types of reflexes are particular to the species. • These relationships are invariant and are biologically based. CONDITIONING In every day language people may call operant conditioning: “VOLUNTARY BEHAVIOR” In every day language people may call respondent conditioning: “INVOLUNTARY BEHAVIOR” CLASSICAL CONDITIONING PRIOR TO CONDITIONING • We refer to the eliciting event as the unconditioned stimulus (UCS). No prior conditioning or learning history. • We refer to the response as the unconditioned response (UCR). No prior conditioning or learning history. CLASSICAL CONDITIONING AFTER CONDITIONING • CONDITIONED STIMULUS (CS) Prior conditioning history is necessary. • CONDITIONED RESPONSE (CR) Prior conditioning history is necessary. • NEUTRAL STIMULUS (NS) Neutral with respect to the conditioning procedure. Basic Principles of Behavior BASIC RESPONDENT RELATION OPERANT CONDITIONING B.F. Skinner THE ROLE OF OPERANT CONDITIONING STIMULI D S , + S ) Discriminative: Any stimulus in whose presence reinforcement is presented during a particular response. (SΔ, S-) Any stimulus in whose presence reinforcement is NOT presented (or extinction is occurring) during a particular response. THE ROLE OF OPERANT CONDITIONING (SR) Reinforcing: A condition, event or stimulus that increases the future probability of a behavior (response) it may follow. (SP) Punishing: A condition, event, or stimulus that decreases the future probability of a behavior (response) it may follow. THE ROLE OF OPERANT CONDITIONING • The Operant: Defined by an effect that maybe specifiable in physical terms and refers to a class of responses that are all maintained by the same consequent event. • Repertoire: The set of skills, what an organism (human or non-human) can do. THE ROLE OF OPERANT CONDITIONING • THE MOTIVATING OPERATION (MO). THEY ALTER: a) The momentary effectiveness of reinforcers or punishers. b) The frequency of operant response classes related to those particular consequences. (i) reinforcer-establishing / abolishing effect (ii) punisher-establishing / abolishing effect THE ROLE OF OPERANT CONDITIONING Quiz #4 Quiz #4 In classical conditioning we refer to the eliciting event as the ______________. No prior conditioning or learning history is necessary. a. b. c. d. Unconditioned stimulus (UCS). Conditioned stimulus (CS). Neutral stimulus (NS). Conditioned response (CR) Quiz #4 The Operant may be defined by an effect that maybe specifiable in physical terms and refers to a ____________ that are all maintained by the same consequent event. a. b. c. d. Class of stimuli Class of environmental events Class of responses None of the above Stimulus Properties of Drugs And Drug-Behavior Interactions Stimulus Properties of Drugs THE ROLE OF CLASSICAL CONDITIONING… • All drugs have unconditioned stimulus (UCS) properties. • Classical conditioning can modulate LDs and EDs. THE ROLE OF CLASSICAL CONDITIONING… Experiments have shown that conditioned stimuli (CS) can produce drug-like effects. CSs play an enormous role in… • Drug abuse: Heroin overdose phenomenon. • Modulation of Immune Function THE ROLE OF CLASSICAL CONDITIONING… • Drug tolerance may be viewed as a conditioned response (CR). • Siegel et al., 1982 suggested deaths resulted from a failure of tolerance. • When a drug is administered in the usual context, the CSs that counteract the drug allow for a large dose. When the context changes, the CSs are not present. The drug dose may then be sufficient to kill user. THE ROLE OF CLASSICAL CONDITIONING… • Immune function can come under the control of the environment and may be viewed as a conditioned response (CR). • Stimuli (CS) correlated with immunosuppressive drugs may suppress immune function (CR) • The accidental discovery of the immunosuppressive effects of Cyclophosamide. THE ROLE OF CLASSICAL CONDITIONING… • Sometimes stimuli that have been paired with drugs produce internal conditioned responses (CR) that are opposite to the unconditioned (UCR) effects of the drug. • EXAMPLE insulin injections (UCS)produce reduction in blood sugar insulin-paired stimuli (CS) produce increases in blood sugar. THE ROLE OF OPERANT CONDITIONING Drugs may function as: • • • • Discriminative Stimuli (SD) Reinforcing Stimuli (SR) Punishing Stimuli (SP) Motivating Operations (MO) THE ROLE OF OPERANT CONDITIONING A drug may come to function as a discriminative stimulus (SD) with an appropriate history of conditioning. Consider the following example: While he is in a bar and is intoxicated (SD) a man tells jokes (R) and people laugh (SR). THE ROLE OF OPERANT CONDITIONING When he is in the bar again and is not intoxicated (SΔ) …the man tells the same jokes (R) and no one laughs (no reinforcement). If he begins to tell jokes more frequently when he is intoxicated and not tell jokes when he is sober, we may say that the Alcohol has come to function as an SD. Discriminative Stimuli (SD) THE ROLE OF OPERANT CONDITIONING… • Drugs may come to function as Reinforcing stimuli (SR). • Animal models have been employed to study the reinforcing properties of drugs since the early 1960s. • The abuse potential of a drug may be thought of as its reinforcing liability. THE ROLE OF OPERANT CONDITIONING… (from Seiden & Dykstra 1977) Drug use is considered to be an operant response. THE ROLE OF OPERANT CONDITIONING… We measure the “strength” of a drug as a reinforcer by infering from the rate of responding. But there are problems with rate as a dependent variable: • Some drugs may stimulate responding. • Some drugs may have effects that interfere with the organism’s ability to make the response. THE ROLE OF OPERANT CONDITIONING… • …as a result, many studies will employ Progressive Ratio (PR) schedules. • In PR schedules the response requirement changes after each reinforcer presentation. • For example The response requirement may begin with one. Following the first reinforcer presentation, the requirement changes to two, and then four, then eight, then 16 and so forth. THE ROLE OF OPERANT CONDITIONING… • So with the PR schedule the particular ratio where the animal stops is considered the “break point.” • Most non humans will self-administer virtually the same drugs as humans with a couple of noted exceptions (with considerable difficulty): • Marijuana • LSD Internal and external environments Quiz # 5 Quiz # 5 Describe the environmental determinants of drug action. 1. In operant terms, abuse potential can be thought of as the ______ of a drug. a. b. c. d. e. Reinforcing liability Potency Ability to create emotional dependence Ability to create tolerance Habituation Quiz # 5 2. The rate of self-administration is not a good measure of the relative reinforcing capacity of different drugs. This is because of which of the following? a. Drugs may have effects that can interfere with the organism’s ability to make the response. b. Some drugs may have the effect of stimulating the response. c. It has been shown that the rate of responding does not reflect the reinforcing properties of any stimulus. d. All drugs are so reinforcing that the animal responds at the maximum rate possible. e. Both “a” and “b” are correct. Describe potential drug interactions. Clinical Considerations Drug – Behavior Interactions and Clinical Considerations. In this segment we take a look at: • The wide variety of ways in which drugs may alter behavior. • Clinically efficacious drugs and just exactly what they do. Drug – Behavior Interactions and Clinical Considerations • • • • Some history Basic pharmacological effects Potential hazards Psychiatric uses Drug – Behavior Interactions and Clinical Considerations The barbiturates have a long history in psychiatric medicine as sedative agents • The barbiturates were developed by Beyer labs in the 1860s • The barbiturates are synthesized from chemicals found in urine. • The first of the barbiturates (Barbital) was introduced in 1903. Drug – Behavior Interactions and Clinical Considerations • The non-barbiturate chloral hydrate is what was referred to, in turn of the century jargon, as the infamous “MICKY FINN” …or “knock out” drops. = = Drug – Behavior Interactions and Clinical Considerations • The barbiturates are classified by their duration of action. – Ultrashort – Short (under 4 hrs.) – Intermediate (4-6 hrs.) – Long acting (over 6 hrs.). Drug – Behavior Interactions and Clinical Considerations • • • • • SOME EFFECTS OF BARBITURATES Reduced attention span Impaired behavior Confusion Poor judgment Slurred speech and inadequate emotional control Drug – Behavior Interactions and Clinical Considerations SOME EFFECTS OF BARBITURATES • Moderate side effects: – Nausea – Vertigo – Vomiting – Emotional upset – Diarrhea Drug – Behavior Interactions and Clinical Considerations SOME EFFECTS OF BARBITURATES Potentially hazardous effects or serious side effects: – Shock – Coma – Death Drug – Behavior Interactions and Clinical Considerations • • • • • THE BENZODIAZEPINES Antianxiety drugs. Controls seizures. Interferes with rem sleep. Interferes with sex drive and performance. May cause birth defects (e.g. cleft palate). Drug – Behavior Interactions and Clinical Considerations Rohypnol (Flunitrazepam) “ROOFIES” • The “date-rape” drugs. • Related to valium. + + = Drug – Behavior Interactions and Clinical Considerations One of the many properties of the benzodiazepines is disruption of memory. • A person can recall previously learned information but recalling new information (while under the influence) is difficult. • Several drugs in this class, including Rohypnol, are used for nefarious purposes. MEDICATIONS FOR MENTAL ILLNESSES • • • • • What is mental illness? Issues defining mental illness. The medical model. Mental illness and medicine. Types of disorders. Issues in defining mental illness. – What is acceptable behavior? – Should a person who exceeds acceptable behavior be identified as mentally ill or simply different? – Should social norms dictate appropriate behavior? – What is normal? Drug – Behavior Interactions and Clinical Considerations • ANTIDEPRESSANTS – TRICYCLICS – MAOIs – SSRIs • ANTIPSYCHOTICS – CONVENTIONAL – ATYPICAL Drug – Behavior Interactions and Clinical Considerations • • • • TREATMENT PRIOR TO THE1950s AND TREATMENT AFTER THE1950s. Primitive approaches. Early pharmacotherapy Psychosurgery. Electroconvulsive therapy. Drug – Behavior Interactions and Clinical Considerations • • • • Major increase in the use of drugs. In some cases an exclusive reliance on drugs. There is no real “cure” (eliminated). People may be “maintained” on drug therapy. Drug – Behavior Interactions and Clinical Considerations PROBLEMS • In understanding exactly what mental disorders are. • Patient compliance with drug treatments. • social stigma Prolonged use drugs for the management of clinical disorders have many side effects Drug – Behavior Interactions and Clinical Considerations • • • • • ANTIPSYCHOTICS Known as major tranquilizers. Also known as neuroleptics. Discovered by accident by French surgeon. Chlorpromazine introduced in the U.S. in mid1950s Revolutionized the treatment of mental illness. Drug – Behavior Interactions and Clinical Considerations CONVENTIONAL • Blocking of the d2 receptor is the primary mechanism of action. • These drugs also block other types of receptors as well. • Very commonly prescribed • Erratic absorption pattern makes it hard to establish the effective dose (ED). • effects may be teratogenic. Drug – Behavior Interactions and Clinical Considerations ANTIDEPRESSANTS • In excess of 500,000 people are treated for depression. • Depression is a primary factor in suicide. • Treatment is complicated because everyone is depressed at some point. TRICYCLICS • Originally used to treat psychotic patients. • Useful in the treatment of phobias. • Can be toxic Quiz # 6 Quiz # 6 Describe the clinical actions of therapeutic drugs. 1. After taking antipsychotic drugs for a period of time, about 30 percent of patients show a condition called… a. b. c. d. e. Epilepsy. Tardive dyskinesia Delirium tremens. Akathisia. Physical dependence. Quiz # 6 Describe the clinical actions of therapeutic drugs. 2. Prozac is which type of antidepressant? a. b. c. d. e. TCA SSRI MAOI First generation antidepressant None of the above. Prozac is a tranquilizer FOR GROUP DISCUSSION Drug Abuse / Misuse and Ethical Issues. In this segment we discuss: • Why drugs are self-administered and what constitutes abuse and misuse. • What are the major ethical issues involved? FOR DISCUSSION • Controversy. …should psychologists be allowed to prescribe drugs? • The DSM-5. • Diagnostic categories. Ethical/Legal Issues for Discussion • Behavioral Pharmacology • Behavioral Toxicology • Behavioral Teratology Behavioral Teratology Exposure to drugs and other toxic agents in utero may alter behavioral functioning of the newborn Review • • • • Describe a general historical context. Describe the basic actions of the nervous system. Describe the fundamental actions of drugs. Describe the environmental determinants of drug action. • Describe basic stimulus properties of drugs. • Describe potential drug interactions. • Describe clinical actions of therapeutic drugs. Conclusions • The interactions between drugs and human behavior is poorly understood by the general population. • The behavioral effects of drugs are lawful. • The behavioral effects of drugs are dependent upon an array of behavioral and pharmacological variables. Thank You! Rodney D. Clark, Ph.D. Department of Psychology and Program in Neuroscience Allegheny College [email protected] 814-332-4960