User:Cooper lab/Neuropharmacology

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The study of drugs: their origin, preparations, properties, uses, actions and effects. The goal of this course is to introduce students to the basic principles of neuropharmacology by investigating the mechanisms through which drugs influence neural systems and induce changes in behavior. The course will focus on the molecular, biochemical and behavioral characterization of several classes of drugs including the psychostimulants, depressants, opiates, hallucinogens, marijuana and various psychiatric medications.

Template:Learning Goals

Course Syllabus-PSYC 4132 Behavioral Neuropharmacology Spring 2010 Room: Tuesday & Thursday 2:00-3:15 Professor: Dr. Don C. Cooper Office: Muenzinger E2 Office hours: Wed: 1 p.m.- 3 p.m. or by appointment Office Phone: (303) 335-0248 Email: or

Required Textbook: Meyer, J.S. and Quenzer, L.F., (2005) Psychopharmacology: Drugs, the Brain, and Behavior. Sinauer & Associates.

Course description and organization: This course is designed to give students a fundamental understanding of the biochemical basis of behavior as well as the effects of drugs on the central nervous system and behavior.

The course is divided into the following four sections:

1. Principles of pharmacology

2. Brain neurotransmitter systems

3. Addiction and the mechanisms of psychoactive drug action

4. The biochemical bases of psychiatric disorders

Four exams will cover material covered in the lectures and required readings from the textbook, as well as additional readings distributed in class or posted on the course web page.

Grading: Each exam is worth 100 points. 100 points x 4 exams = 400 possible points from exams. The format of the exams is multiple choice, fill-in-the-blank, and short answer questions. Make-up exams will not be administered except under the University, Department and course policies (see below). If you miss an exam without prior notice and approval...Attendance is expected and will be “informally” incorporated into your grade. Attendance sheets will be randomly distributed during class and will be considered in borderline grades at the discretion of the professor.

Letter Grade Points Percentages A 372 to 400+ 93.00 to 100+ A- 360 to 371 90.00 to 92.75 B+ 346 to 359 86.50 to 89.75 B 332 to 345 83.00 to 86.25 B- 320 to 331 80.00 to 82.75 C+ 306 to 319 76.50 to 79.75 C 292 to 305 73.00 to 76.25 C- 279 to 291 69.75 to 72.75 D+ 266 to 278 66.50 to 69.50 D 252 to 265 63.00 to 66.25 D- 240 to 251 60.00 to 62.75 F 0 to 239 0.00 to 59.75

Class Date Topic Reading 1 12-Jan Introduction 2 14-Jan Pharmacokinetics 1 3 19-Jan Pharmacodynamics 1 4 21-Jan Neurophysiology 2 5 26-Jan Neuroanatomy 2 6 28-Jan Neurotransmission I 3 7 02-Feb Neurotransmission II 3 8 04-Feb Methods 4 9 09-Feb Review/Catch-up 1-4 10 11-Feb EXAM 1 1-4 11 16-Feb Catecholamines 5 12 18-Feb Acetylcholine 6 13 23-Feb Serotonin 6 14 25-Feb Glutamate and GABA 7 15 02-Mar 16 04-Mar Review/Catch-up 5-7 17 09-Mar EXAM 2 5-7 18 11-Mar Addiction 8 19 23-Mar Opiates 10 20 25-Mar Alcohol 9 21 1-Apr Psychostimulants 11 22 6-Apr Nicotine and Caffeine 12 23 8-Apr Cannabinoids 13 24 12-Nov EXAM 3 8-13 25 17-Nov Depression 16 26 19-Nov Anxiety 17 27 24-Nov FALL BREAK-No class Enjoy! 28 26-Nov FALL BREAK-No class Enjoy! 29 1-Dec Schizophrenia 18 30 3-Dec Learning and Memory Hand-out 31 8-Dec NO CLASS! Enjoy! 32 10-Dec Review/Catch Up 16-18, Hand-outs 12-Dec Saturday: FINAL EXAM: 1:30 p.m. - 4:00 p.m. 16-18, Hand-outs


1. Principles of Pharmacology

Pharmacology: The Science of Drug Action

Pharmacokinetic Factors Determining Drug Action

Methods of drug administration influence the onset of drug action

Multiple factors modify drug absorption

Drug distribution is limited by selective barriers

Depot binding alters the magnitude and duration of drug action

Biotransformation and elimination of drugs contributes to bioavailability

Section Summary

Pharmacodynamics: Drug–Receptor Interactions

Extracellular and intracellular receptors have several common features

Dose–response curves describe receptor activity

The therapeutic index calculates drug safety Receptor antagonists compete with agonists for binding sites Biobehavioral Effects of Chronic Drug Use Repeated drug exposure can cause tolerance Chronic drug use can cause sensitization Section Summary Recommended Readings BOX 1.1. Pharmacology in Action: Herbal Medicine—Panacea or Hazard? BOX 1.2. Pharmacology in Action: Naming Drugs BOX 1.3. Pharmacology in Action: Drug Categories 2. Structure and Function of the Nervous System

Cells of the Nervous System Neurons have three major external features Characteristics of the cell membrane are critical for neuron function Glial cells provide vital support for neurons Section Summary Electrical Transmission within a Neuron Ion distribution is responsible for the cell’s resting potential Local potentials are small, transient changes in membrane potential Sufficient depolarization at the axon hillock opens voltage-gated Na+ channels, producing an action potential Drugs and poisons alter axon conduction Section Summary Organization of the Nervous System The nervous system comprises the central and peripheral divisions CNS functioning is dependent on structural features The CNS has six distinct regions reflecting embryological development The cerebral cortex is divided into four lobes, each having primary, secondary, and tertiary areas Section Summary Recommended Readings BOX 2.1. Clinical Applications: Epilepsy BOX 2.2. The Cutting Edge: Finding Your Way in the Nervous System 3. Chemical Signaling by Neurotransmitters and Hormones

Chemical Signaling between Nerve Cells Neurotransmitter Synthesis, Release, and Inactivation Neurotransmitters encompass several different kinds of chemical substances Classical transmitters and neuropeptides are synthesized by different mechanisms Chemicals that don’t act like typical neurotransmitters are sometimes called neuromodulators Neurotransmitter release involves the exocytosis and recycling of synaptic vesicles Several mechanisms control the rate of neurotransmitter release by nerve cells Neurotransmitters are inactivated by reuptake and by enzymatic breakdown Section Summary Neurotransmitter Receptors and econd-Messenger Systems There are two major families of neurotransmitter receptors Second messengers work by activating specific protein kinases in a cell Tyrosine kinase receptors mediate the effects of neurotrophic factors Pharmacology of Synaptic Transmission Section Summary The Endocrine System Endocrine glands can secrete multiple hormones Mechanisms of hormone action vary Why is the endocrine system important to pharmacologists? Section Summary Recommended Readings Box 3.1. The Cutting Edge: Just Say NO Box 3.2. Pharmacology in Action: Stress, Glucocorticoids, and Psychostimulants 4. Methods of Research in Neurobehavioral Pharmacology

Techniques in Neuropharmacology

Multiple Neurobiological Techniques for Assessing the CNS Stereotaxic surgery is needed for accurate in vivo measures of brain function Neurotransmitters, receptors, and other proteins can be both quantified and visually located in the CNS New tools are used for imaging the structure and function of the brain Genetic engineering helps neuroscientists to ask and answer new questions Section Summary Techniques in Behavioral Pharmacology

Evaluating Animal Behavior Animal testing needs to be valid and reliable to produce useful information A wide variety of behaviors are evaluated by psychopharmacologists Operant conditioning techniques provide a sensitive measure of drug effects Section Summary Recommended Readings BOX 4.1. The Cutting Edge: Using the Techniques of Neuropsychopharmacology BOX 4.2. Clinical Applications: Drug Development and Testing 5. Catecholamines

Catecholamine Synthesis, Release, and Inactivation Tyrosine hydroxylase catalyzes the rate-limiting step in catecholamine synthesis Catecholamines are stored in and released from synaptic vesicles Catecholamine inactivation occurs through a combination of reuptake and metabolism Section Summary Organization and Function of the Dopaminergic System Two important dopaminergic cell groups are found in the midbrain There are five main subtypes of dopamine receptors organized into D1- and D2-like families Dopamine receptor agonists and antagonists affect locomotor activity and other behavioral functions Section Summary Organization and Function of the Noradrenergic System The ascending noradrenergic system originates in the locus coeruleus The cellular effects of norepinephrine and epinephrine are mediated by á- and â-adrenergic receptors Adrenergic agonists can stimulate arousal and eating behavior A number of medications work by stimulating or inhibiting peripheral adrenergic receptors Section Summary Recommended Readings BOX 5.1. Clinical Applications: Parkinson’s Disease—A “Radical” Death of Dopaminergic Neurons? BOX 5.2. The Cutting Edge: Using “Gene Knockout” Animals to Study the Dopaminergic System 6. Acetylcholine and Serotonin


Acetylcholine Synthesis, Release, and Inactivation Acetylcholine synthesis is catalyzed by the enzyme choline acetyltransferase Many different drugs and toxins can alter acetylcholine storage and release Acetylcholinesterase is responsible for acetylcholine breakdown Section Summary Organization and Function of the Cholinergic System Cholinergic neurons play a key role in the functioning of both the peripheral and central nervous systems There are two acetylcholine receptor subtypes, nicotinic and muscarinic Section Summary Serotonin

Serotonin Synthesis, Release, and Inactivation Serotonin synthesis is regulated by the activity of tryptophan hydroxylase and by the availability of the serotonin precursor tryptophan The processes that regulate storage, release, and inactivation are similar for serotonin and the catecholamines Section Summary Organization and Function of the Serotonergic System The serotonergic system originates from cell bodies in the brain stem and projects to all forebrain areas There is a large family of serotonin receptors, most of which are metabotropic Section Summary Recommended Readings BOX 6.1. Pharmacology in Action: Botulinum Toxin—Deadly Poison, Therapeutic Remedy, and Cosmetic Aid BOX 6.2. Clinical Applications: Alzheimer’s Disease—A Tale of Two Proteins BOX 6.3. Pharmacology in Action: Fen–Phen and the Fight against Fat 7. Glutamate and GABA


Glutamate Synthesis, Release, and Inactivation Neurons generate glutamate from the precursor glutamine Glutamate is released from vesicles and removed from the synaptic cleft by both neuronal and glial transport systems Section Summary Organization and Function of the Glutamatergic System Glutamate is the neurotransmitter used in many excitatory pathways in the brain Both ionotropic and metabotropic receptors mediate the synaptic effects of glutamate NMDA receptors play a key role in learning and memory High levels of glutamate can be toxic to nerve cells Section Summary GABA

GABA Synthesis, Release, and Inactivation GABA is synthesized by the enzyme glutamic acid decarboxylase Specific transporter proteins are used to transport GABA into synaptic vesicles and nerve terminals following release Section Summary Organization and Function of the GABAergic System Some GABAergic neurons are interneurons, while others are projection neurons The actions of GABA are mediated by ionotropic GABAA receptors and metabotropic GABAB receptors Section Summary Recommended Readings BOX 7.1. The Cutting Edge: Role of Glutamate Receptors in Long-Term Potentiation BOX 7.2. Pharmacology in Action: What Is the Endogenous Ligand for the Benzodiazepine Receptor? 8. Drug Abuse, Dependence, and Addiction

Introduction to Drug Abuse and Addiction Drugs of abuse are widely consumed in our society Drug use in our society has increased and become more heavily regulated over time Features of Drug Abuse and Dependence Drug addiction is a chronic, relapsing behavioral disorder There are two types of progressions in drug use Which drugs are the most addictive? Section Summary Models of Drug Abuse and Dependence The physical dependence model emphasizes the withdrawal symptoms associated with drug abstinence The positive reinforcement model is based on the rewarding and reinforcing effects of abused drugs Two recent approaches to drug addiction are the incentive-sensitization and opponent-process models The disease model treats addiction as a medical disorder Toward a Comprehensive Model of Drug Abuse and Dependence Three types of factors are involved in experimental substance use Different factors are involved in the development and maintenance of compulsive substance use Section Summary BOX 8.1. Concepts in Pharmacology: The “Gateway” Theory of Drug Use BOX 8.2. The Cutting Edge: Drugs of Abuse and the Neural Mechanisms of Reward 9. Alcohol

Psychopharmacology of Alcohol Alcohol has a long history of use What is an alcohol and where does it come from? The pharmacokinetics of alcohol determine its bioavailability Chronic alcohol use leads to both tolerance and physical dependence Alcohol affects many organ systems Section Summary Neurochemical Effects of Alcohol Animal models are vital to alcohol research Alcohol acts on multiple neurotransmitters Section Summary Alcoholism Defining alcoholism and estimating its incidence prove difficult The causes of alcoholism are multimodal Multiple treatment options provide hope for rehabilitation Section Summary BOX 9.1. Clinical Applications: Fetal Alcohol Syndrome BOX 9.2. Pharmacology in Action: The Role of Expectation in Alcohol-Enhanced Human Sexual Response BOX 9.3. Drugs and Society: Alcohol and Aggression 10. The Opiates

Narcotic Analgesics The opium poppy has a long history of use Minor differences in molecular structure determine behavioral effects Bioavailability predicts both physiological and behavioral effects Opioids have their most important effects on the CNS and on the gastrointestinal tract Opioid Receptors and Endogenous Neuropeptides Receptor binding studies identified and localized opioid receptors Three major opioid receptor subtypes exist Several families of naturally occurring opioid peptides bind to these receptors Opiate receptor-mediated cellular changes are inhibitory Section Summary Opioids and Pain The two components of pain have distinct features Opioids inhibit pain transmission at spinal and supraspinal levels Opioid Reinforcement, Tolerance, and Dependence Animal testing shows significant reinforcing properties Dopaminergic and nondopaminergic components contribute to opioid reinforcement The consequences of long-term opiate use include tolerance, sensitization, and dependence Several brain areas contribute to the opioid abstinence syndrome Neurobiological adaptation and rebound constitute tolerance and withdrawal Environmental cues have a role in tolerance, drug abuse, and relapse Treatment Programs for Opiate Addiction Detoxification is the first step in the therapeutic process Treatment programs rely on pharmacological support and counseling Section Summary BOX 10.1. Pharmacology in Action: Opiate Bioassay BOX 10.2. The Cutting Edge: Role of NMDA Receptors in Tolerance and Dependence BOX 10.3. Clinical Applications: Narcotics Anonymous 11. Psychomotor Stimulants: Cocaine and the Amphetamines


Background and History Basic Pharmacology of Cocaine Mechanisms of Cocaine Action Section Summary Acute Behavioral and Physiological Effects of Cocaine Cocaine stimulates mood and behavior Cocaine’s physiological effects are mediated by the sympathetic nervous system Dopamine plays a key role in the subjective and behavioral effects of cocaine and other psychostimulants Brain imaging allows researchers to explore the neural mechanisms of psychostimulant action in human subjects The behavioral and subjective effects of psychostimulants involve activation of both D1 and D2 receptors Section Summary Cocaine Abuse and the Effects of Chronic Cocaine Exposure Experimental cocaine use may escalate over time to a pattern of cocaine abuse and dependence Chronic psychostimulant exposure can give rise to tolerance or sensitization Binge cocaine use has been linked to a specific dependence syndrome Repeated or high-dose cocaine use can have serious health consequences Pharmacological, behavioral, and psychosocial methods are used to treat cocaine abuse and dependence Section Summary The Amphetamines

Background and History Basic Pharmacology of Amphetamine Mechanisms of Amphetamine Action Behavioral and Neural Effects of Amphetamine Amphetamine is a psychostimulant that has therapeutic uses High doses or chronic use of amphetamine or methamphetamine can cause psychotic reactions as well as brain damage MDMA—The Entactogenic Amphetamine Section Summary Recommended Readings BOX 11.1. Pharmacology in Action: Your Brain on Cocaine BOX 11.2. Clinical Applications: Psychostimulants and ADHD 12. Nicotine and Caffeine


Background and History Basic Pharmacology of Nicotine and Its Relationship to Smoking Mechanisms of Action Section Summary Behavioral and Physiological Effects Nicotine elicits different mood changes in smokers compared to nonsmokers Nicotine enhances cognitive function Nicotine’s reinforcing effects are mediated by activation of the mesolimbic dopamine system Nicotine produces a wide range of physiological effects Nicotine is a toxic substance that can be fatal at high doses Chronic exposure to nicotine induces tolerance and dependence Section Summary Cigarette Smoking How many people smoke, and who are they? Cigarette smokers progress through a series of stages in their smoking behavior Why do smokers smoke? Smoking is a major cause of illness and premature death Behavioral and pharmacological strategies are used to treat tobacco dependence Section Summary Caffeine

Background Basic Pharmacology of Caffeine Behavioral and Physiological Effects Acute subjective and behavioral effects of caffeine are dependent on dose and prior exposure Regular caffeine use leads to tolerance and dependence Mechanisms of Action Section Summary BOX 12.1. Pharmacology in Action: Why Do Tobacco Plants Make Nicotine? BOX 12.2. The Cutting Edge: Is Caffeine a Substance of Abuse? 13. Marijuana and the Cannabinoids

Background and History of Marijuana Basic Pharmacology of Marijuana Section Summary Mechanisms of Action Cannabinoid effects are mediated by cannabinoid receptors Endocannabinoids are cannabinoid agonists synthesized by the brain Section Summary Acute Behavioral and Physiological Effects of Cannabinoids Cannabis consumption produces a dose-dependent state of intoxication in humans Marijuana use can lead to deficits in cognition and psychomotor performance Animals show a variety of behavioral and physiological responses to cannabinoid administration Cannabinoids are reinforcing to both humans and animals Section Summary Cannabis Abuse and the Effects of Chronic Cannabis Exposure Cannabis use typically begins in adolescence and peaks during young adulthood Tolerance and dependence can develop to chronic cannabinoid exposure Chronic cannabis use may lead to adverse behavioral and health effects Section Summary BOX 13.1. Clinical Applications: Therapeutic Uses of Cannabinoids BOX 13.2. The Cutting Edge: Does Chronic Cannabis Use Cause Persistent Cognitive Defects? 14. Hallucinogens, PCP, and Ketamine

Hallucinogenic Drugs

Mescaline Mescaline is obtained from the peyote cactus Psilocybin, DMT, and 5-MeO-DMT “Magic mushrooms” are the source of psilocybin and other hallucinogens Other naturally occurring hallucinogens include DMT and 5-MeO-DMT LSD LSD is a synthetic compound based on ergot alkaloids Pharmacology of Hallucinogenic Drugs Different hallucinogenic drugs vary in potency but have a similar time course of action Hallucinogens produce a complex set of psychological and physiological responses Hallucinogenic drugs share a common indoleamine or phenethylamine structure Hallucinogens are 5-HT2 receptor agonists What is the neural mechanism by which hallucinations are produced? Hallucinogenic drugs cause problems for some users Section Summary PCP and Ketamine

Background and History Pharmacology of PCP and Ketamine PCP and ketamine produce a state of dissociation PCP and ketamine exhibit potent reinforcing effects PCP and ketamine are noncompetitive antagonists of NMDA receptors Ketamine is an increasingly popular drug of abuse PCP and ketamine have provided new insights into the neurochemistry of schizophrenia Section Summary Pharmacology of PCP and Ketamine BOX 14.1. History of Psychopharmacology: The Discovery of LSD BOX 14.2. Pharmacology in Action: Getting High on Cough Syrup 15. Inhalants, GHB, and Anabolic–Androgenic Steroids


Background Behavioral and Neural Effects Many inhalant effects are similar to alcohol intoxication Reinforcing effects have been demonstrated in animals Inhalants reduce central nervous system (CNS) excitability by acting on specific ionotropic receptors Significant health risks are associated with inhalant abuse Section Summary Gamma-Hydroxybutyrate

Background Behavioral and Neural Effects GHB is a CNS-depressant and behaviorally sedating drug Evidence for GHB reinforcement in animal studies has been inconsistent There are two major hypotheses concerning the mechanism of action of GHB GHB use and abuse has been growing Section Summary Anabolic–Androgenic Steroids

Background and History Anabolic steroids are structurally related to testosterone Anabolic steroids were developed to help build muscle mass and enhance athletic performance Anabolic steroids are taken in specific patterns and combinations Pharmacology of Anabolic Steroids The mechanism of action of anabolic steroids is not fully understood Many adverse side effects are associated with anabolic steroid use Do anabolic steroids cause dependence? Section Summary BOX 15.1. Drugs and Society: “Date Rape” Drugs BOX 15.2. Drugs and Society: Anabolic Steroids and “’Roid Rage” 16. Affective Disorders

Characteristics of Affective Disorders Major depression damages the quality of life In bipolar disorder moods alternate from mania to depression Risk factors for mood disorders are biological and environmental Animal Models of Depression Therapies for Affective Disorders Monoamine oxidase inhibitors are the oldest antidepressant drugs Tricyclic antidepressants are highly effective Second-generation antidepressants have different side effects Third-generation antidepressants have distinctive mechanisms of action Electroconvulsive therapy is safe and highly effective Transcranial magnetic stimulation is easy to administer Drugs for treating bipolar disorder stabilize the highs and the lows Section Summary Neurochemical Basis of Mood Disorders Serotonin dysfunction contributes to mood disorders Norepinephrine activity is altered by antidepressants Norepinephrine and serotonin modulate one another Section Summary Neurobiological Models of Depression Section Summary Recommended Readings BOX 16.1. Drugs and Society: Mood Disorders and Creativity BOX 16.2. Clinical Applications: Sleep Deprivation Therapy BOX 16.3. Pharmacology in Action: Stress–Diathesis Model of Depression 17. Anxiety Disorders

Characteristics of Anxiety Disorders Anxiety is important for survival Anxiety disorders are different from everyday worry Animal models of anxiety are useful for drug testing Drugs for Treating Anxiety Barbiturates are the oldest sedative hypnotics Benzodiazepines are highly effective for anxiety reduction Second-generation anxiolytics produce distinctive clinical effects Antidepressants relieve anxiety and depression Section Summary Neurochemical Basis of Anxiety and Anxiolytics Multiple neurotransmitters mediate anxiety Section Summary Recommended Readings BOX 17.1. Clinical Applications: Neurobiological Model of OCD BOX 17.2. Clinical Applications: Treating Insomnia BOX 17.3. Pharmacology in Action: Early Experience and Stress 18. Schizophrenia

Characteristics of Schizophrenia There is no defining cluster of schizophrenic symptoms Long-term outcome depends on pharmacological treatment Preclinical Models of Schizophrenia Classic Neuroleptics and Atypical Antipsychotics Phenothiazines and butyrophenones are traditional neuroleptics Dopamine receptor antagonism is responsible for antipsychotic action Side effects are directly related to neurochemical action Atypical antipsychotics are distinctive in several ways Section Summary Etiology of Schizophrenia Abnormalities of brain structure and function occur in individuals with schizophrenia Genetic, environmental, and developmental factors interact Neurochemical Models of Schizophrenia Abnormal dopamine function contributes to schizophrenic symptoms The neurodevelopmental model integrates anatomical and neurochemical evidence Glutamate modulates dopamine activity Other neurotransmitter systems contribute to symptoms Section Summary Recommended Readings BOX 18.1. Clinical Applications: The Functional Neuroanatomy of Hallucinations BOX 18.2. Pharmacology in Action: Animal Model—Prepulse Inhibition of Startle BOX 18.3. Clinical Applications: The Genain Quadruplets It is always essential to understand the meaning of a subject matter of interest to in order to appreciate that particular field of study. The most convenient and fundamental thing to do is define the core concepts. In line with this we define the following as;


Neuropharmacology includes indications, contra-indications, selective activity (activity whereby a drug acts on a particular part of the body at a time for treatment). Neuropharmacology enables us to study the interaction of living cells and organisms with the drug molecules they encounter when we take in drugs. It includes researching how drugs produce beneficial and adverse effects, and improving the way drugs are tested to give greater benefit in the treatment of disease.

Cautious use of Drugs for relief not attractive colors for addiction, Image provided by courtesy of


A chemical substance, which has a selective activity or value in the treatment of a disease or can affect living things/processes. In other words they are, biologically active compounds given to humans or animals with the intention of changing the state of body functioning: to relieve pain, treat conditions, eliminate infection or improve health in any way or to investigate the functions of the body.


Application of drugs in the prevention, diagnosis and treatment of a disease(s) or to alter a normal body function (e.g. oral contraceptive) The area is at the core of the nursing profession especially for maintaining health and sometimes longetivity. The main objective of therapeutics is to provide maximum benefit of the drug and minimum harm to the organism.

Drug Addiction

Drug Addiction: Understanding the Signs, Symptoms, and Effects Drug Addiction: Signs, Symptoms, Effects and Testing

Drug addiction is not a new problem, but it is a stubborn one for contemporary society. What may start as medical or so-called recreational use of controlled drugs can tip over into craving and addiction, with dire consequences for the user’s well-being and, frequently, consequences for the community as well. Find out how to recognize the signs and symptoms of drug addiction in someone you care about.


What is drug addiction?

Drug addiction, involves the repeated and excessive use of a drug to produce pleasure or escape reality despite its destructive effects.

In such situations, even a small amount of an illegal or improperly consumed substance can alter how your brain works, and if you can’t function normally under the influence of that substance, its use constitutes abuse. More dangerously, the short-term effects of the drug — whether they involve euphoria, extra energy, sensory enhancement, or heightened performance — tend to become so alluring that the drug takes over the user’s life, disrupting his or her relationships, work, and peace of mind. How drug use can lead to addiction

You cross the line from drug abuse to drug addiction when using drugs stops being a choice and becomes a necessity, when it controls you and not the other way around. You’re convinced that the drug is necessary for you to have a feeling of well-being or even just to get through the day. Your craving for your drug of choice crowds out most other thoughts, and your pursuit and use of the drug become what takes up most of your time. Nothing is more important than getting high: not your job, not your kids, not your spouse, not your folks. Getting high, in fact, becomes so important that you’re willing to sacrifice your work, family, and home, even as you deny that you have a problem.

At the same time, the drug is not only something you want but something your brain and body come to need. In fact, your brain and body get used to the amount of the substance you’ve been using and require increasingly larger doses in order to achieve the same high. That phenomenon, called tolerance, is one hallmark of physical addiction. Another is withdrawal, the development of debilitating physical symptoms if you stop using the drug. Signs and symptoms of drug abuse and addiction

Substance abusers are often the last ones to recognize their own symptoms of abuse, dependence and addiction. Even when they know they have a problem, drug abusers often try to downplay their drug use and conceal their symptoms. But if you suspect that a friend or loved one is abusing drugs, there are a number of warning signs you can look for. Behavioral symptoms of drug abuse

  • Angry outbursts, mood swings, irritability, manic behavior, or overall attitude change
  • Talking incoherently or making inappropriate remarks
  • Risky behavior, such as driving under the influence of drugs, starting a fight, or engaging in unprotected sex
  • Secretive or suspicious behavior: frequent trips to the restroom, basement, or other isolated areas for privacy while using drugs
  • Deterioration of physical appearance and grooming
  • Wearing sunglasses and/or long-sleeved shirts frequently or at inappropriate times
  • Frequent absences from work or school; drop-off in quality of work or grades
  • Neglect of family responsibilities
  • Evidence of money problems: frequent borrowing, selling possessions, or stealing items from employer, home, or school
  • Legal problems rooted in drug use: arrest for driving under the influence, possession of a controlled substance, disorderly conduct, or stealing
  • Using drugs first thing in the morning
  • Using increasing doses of a drug

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Tip: Thought question: Are potato chips addictive?

Social symptoms of drug abuse

  • Abandoning or spending less time on activities such as hobbies, sports, and socializing
  • Inability to relax or have fun without doing drugs
  • Associating with known drug users and dropping friends who don’t use drugs
  • Talking about drugs all the time and encouraging others to use
  • Estrangement from old friends and loved ones

Physiological signs of drug abuse

  • Frequent exhaustion or weakness
  • Unexplained injuries and infections
  • Blackouts
  • Flashbacks
  • Delusions
  • Paranoia
  • Withdrawal symptoms such as nausea, tremors, and sweating

Different illegal and misused substances produce different physiological symptoms; several articles listed in the Related Links below can provide information about substance-specific signs of drug abuse. Classifications of abused drugs

Almost all drugs, including common household items such as caffeine and aspirin, have the potential for abuse and dependence. However, the majority of drug problems not related to alcohol involve use of the substances listed below. These drugs affect users’ brains and bodies in different ways, producing symptoms of intoxication and abuse that are unique to each substance.


Smoke free cigarettes

Propofol article

Memory Erasure

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  • Define agonist and antagonist

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