CENTER FOR CONTINUING EDUCATION
Self Study Article and Self Assessment Test
Prevention, Detection, and Treatment of
Substance Abuse
Physiological Aspects of Substance AbuseAnne ImObersteg (M.S., J.D.)
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Addiction
Addiction is recognized as a chronic disease that is progressive, incurable and potentially fatal. The addict is an individual who engages in a compulsive behavior, even when faced with negative consequences such as a detrimental impact on health, family life, work, and society.
When a chemical substance is used/abused, the user runs the risk of developing dependence on the substance and the development of an addiction. Individuals who are in an environment conducive to drug abuse, have concurring mental disorders, or have a genetic predisposition to compulsion disorders are especially susceptible to developing an addiction. For example, individuals who have a family history of alcoholism have a 60% higher risk for developing an alcohol abuse problem.
An individual who first uses drugs often perceives the use as rewarding, and the brain tends to reinforce the behavior. As a consequence, the individual loses control of limiting the intake of the addictive substance. The need to consume drugs becomes compulsive, due to the effect of the drug on regions in the brain governing impulse, craving, and behavior. For this reason, addictions are classified as a type of compulsivity disorder.
Science’s understanding of how the brain functions leads to an insight on the process of addiction. What is clear, based on decades of research, is that information transmission in the brain occurs through electro-chemical communication from one nerve cell to another. Drugs interfere with this information pathway, and produce changes that promote repeated drug use.
Basic Neurochemistry of the Brain
To send and integrate information, nerve cells (neurons) connect one area of the brain to another area via pathways. There are over 100 billion neurons in the brain that convey messages from one section of the brain to another. One neuron can reach over 1000 other neurons. By maintaining these pathways, and the natural release of the chemicals that enable the transmission, the body can maintain a healthy mental balance. However, this delicate balance is upset by the use of psychoactive drugs.
Psychoactive drugs exert their effects on the brain of the user by interfering with the information pathway. Neurons transmit messages from one to another by relaying the nerve impulse to the end or the nerve, called the buton or nerve terminal. At the nerve terminal, several vesicles of chemical substances (transmitters) are released out of the end of the nerve terminal across a narrow space called the synaptic gap, and slot into receptor sites located on adjacent nerve cells. When enough receptor sites on the adjacent neurons are filled, the message is transmitted. The chemicals left in the synaptic gap are generally reabsorbed through re-uptake gates in the sending neuron or destroyed biochemically. This process continues from one neuron to another, until the message is transmitted to the intended destination.
When the brain relays messages efficiently, and has the correct amount of neurotransmitter chemicals to allow fluid message transmission, the brain is considered to be in a healthy balance (homeostasis). However, drugs will upset this delicate balance by interfering in the message transmission from one neuron to another. The interference occurs by increasing the intensity of the message or blocking the message. This can be achieved in several ways; some drugs affect the release of the transmitter in the nerve terminal, some drugs influence the movement of the chemicals in the synaptic cleft or block the message transmission on the receiving neuron, and some drugs look enough like the transmitter itself that the receiving neuron thinks it is receiving the transmitter.
North American Soccer League v. NLRB (1980), the court found the bargaining unit to be all professional soccer players on clubs that are based in the United States. The court held that the league and its member clubs are joint employers. The key to the decision was the joint employer status of the individual teams and the league. The court, however, was momentarily swayed by the apparent individuality of each team: "Contrary to our first impression, which was fostered by the knowledge that teams in the League compete against each other on the playing fields and for the hire of the best players, * * *." However after further consideration, the court agreed with the NLRB that there was a joint employer relationship among the league and its member clubs; they then designated the league as the appropriate bargaining unit.
Neurotransmitter substances
Changes in behavior through drug use are achieved by affecting the transmitter chemicals in the brain. However, not all transmitters affect all neurons, and not all neurons induce all actions on the brain. For example, if cocaine (which affects dopamine, norepinephrine and serotonin) is consumed, then the actions performed by these chemicals will be changed (increased).
Below is a chart of some neurotransmitters and their primary action:
Neurotransmitter Action Dopamine mood, pleasure and motivation Serotonin (5-HT) mood, appetite, sex and aggression Norepinephrine mood, attention, concentration Endorphins blood pressure, body temperature, mood, pain suppression Acetylcholine mood, memory, movement Gamma Amino Butyric Acid sedation, inhibitions Depending on the drug that is ingested, and the neurotransmitters the drug hinders or stimulates, different effects will be achieved. For example, cocaine and methamphetamine generally utilize dopamine, norepinephrine, and serotonin. However, cocaine and methamphetamine effect the message transmission in slightly different ways. Cocaine acts as a local anesthetic by blocking the reuptake of dopamine, norepinephrine and serotonin by the nerve terminal. In other words, the chemicals are not reabsorbed by the sending neuron, and are left swimming in the synaptic gap, to continue stimulating the neighboring neurons again and again. Methamphetamine acts slightly differently. The structure of methamphetamine is similar enough to norepinephrine and dopamine, that it fools the receiving neuron into thinking it is being stimulated. The net effect of both cocaine and methamphetamine on neurons are the same: over-stimulation.
The Addiction Process
Several neurotransmitters have been identified as major players in the process of addiction. Over the years, studies have identified serotonin as one of the major neurotransmitters that control impulsivity and compulsions. Human and animal studies have shown that decreases in serotonin (5-HT) increase impulsive behavior. In addition, addicts develop a reduced supply of dopamine, which can result in increased stress, lack of motivation, and depression. These unwanted feelings stimulate a craving for substances such as alcohol, carbohydrates, cocaine, heroin, and nicotine, all which stimulate the release of dopamine and bring temporary relief. Aside from the temporary relief from chemical imbalances, drugs also alter the amount of neurotransmitters in the pleasure/reward system of the body.
The mesocorticolimbic pathway (MCLP) is the route to major pleasure/reward centers. It is in these centers that one seeks and craves lifeŐs essentials such as food, water, and social contact. Natural rewards such as food, water, sexual activity and nurturing allow the subject to feel pleasure. These pleasurable feelings reinforce the behavior so that it will be repeated.
Drugs also stimulate the pleasure pathway. For example, the ventral tegmental area (VTA), the nucleus accumbens and the prefrontal cortex of the brain are part of the pleasure pathway. The VTA is connected to both the nucleus accumbens and the prefrontal cortex via the pathway, and it sends information to these structures via neurons. The neurons of the VTA contain the neurotransmitter dopamine, which is released in the nucleus accumbens and in the prefrontal cortex. The result is increased pleasure.
Central Nervous System (CNS) stimulants (cocaine, methamphetamine), CNS depressants (alcohol, barbiturates, benzodiazepines etc.), hallucinogens, LSD, PCP, and narcotic analgesics (heroin, codeine etc.) all target the brainŐs MCLP. These drugs have an increased potential for producing addictive behavior, since the user will need to continue taking the drug to remain in an acceptable level of pleasure.
The impact of this artificial stimulus on the brainŐs chemical balance can be devastating. Constant stimulation of the reward pathway leads to an adaptation of the brain to expecting the heightened feeling as ŇnormalÓ. The drug user becomes conditioned to the higher pleasure induced by the drugs, and no longer finds satisfaction with the initial level. This means that when the drug-user stops taking the drug, the brain creates an intense craving in order to bring the pleasurable feeling back. The repeated intense craving for the drug also results in the development of dependence. Since the neurons have adapted to the repeated drug exposure, addicts only function normally in the presence of the drug. When the drug is withdrawn, physiological reactions occur that can be life threatening. Many addicts will use the drug again merely to avoid the withdrawal syndrome.
Addiction Treatment
As the brain becomes accustomed to the drug-induced chemical changes, it changes the normal production and release of natural neurotransmitters. Undoing this damage can be difficult, if not impossible. The only remedy an addict has is to undergo aggressive treatment
The goal of treatment is to return the individual to productive functioning. However, since this goal involves the changing of behavior and lifestyle, treatment processes are complex and varied. There are a variety of approaches to drug addiction treatment. Some psychologists have heralded certain approaches as effective, while others have cautioned that drug abuse treatment is a life-long process to manage the chronic disorder of drug addiction.
A comprehensive drug treatment program should address biological, psychological and sociological concerns. A program should include:
- An initial assessment
- A detailed treatment plan
- Counseling and behavioral therapy
- Self-Help support groups (NA, AA etc.)
- Substance abuse monitoring (urine drug tests)
- Pharmacotheraphy (LAAM, naloxone etc.)
- Clinical and case management
There have been a variety of treatment approaches that have been developed and tested for efficacy through research supported by the National Institute on Drug Abuse (NIDA). Some of these treatments are as follows:
Relapse Prevention: Individuals learn to identify and correct problematic behaviors. Behavioral patterns are identified and the individual learns how to cope with the impulses. Strategies intended to enhance self-control are learned. Various learning techniques are used, including exploring the consequences of continued drug use, and recognition of situations that increase the desire to use.
The Matrix Model: This approach includes relapse prevention, therapy, drug education, and self-help participation. Participation in self-help groups is stressed. The program also includes therapy with a trained therapist, and education on addiction issues.
Supportive-Expressive Psychotherapy: This therapy has two main components: supportive techniques that encourage the discussion of personal experiences and expressive techniques that enable the subject to work through interpersonal relationship issues.
Individualized Drug Counseling: By setting short-term behavioral goals, this method focuses on reducing or stopping the addict's drug use. Individualized drug counseling assists the subject in developing coping strategies for abstaining from drug use and maintaining abstinence.
Motivational Enhancement Therapy: This is a client-centered counseling approach that initiates behavioral change by helping the subject actively engage in treatment and abstinence. This therapy consists of an initial assessment battery session, followed by two to four individual treatment sessions with a therapist. Motivation for abstinence and coping strategies for high-risk situations are developed.
Benefits of treatment
Not all treatments are successful, and not all addicts respond to treatment. A treatment program generally has a 40-60% chance of being truly effective in reducing drug use. This statistic may seem low to some critics of treatment programs. However, even moderate success greatly benefits the addict and society. The benefits to the addict are obvious; the successful individual can move forward in a healthy state of mind that will certainly be reflected in his/her interpersonal relationships and career prospects. The benefit to society includes a reduction in crime by 60%, an increase in employment prospects by 40%, an increase in workplace productivity, and a decrease in drug-related accidents.
Summary
Addiction is recognized as a chronic disease that is progressive, incurable and potentially fatal. The roots of addiction lie in the regions of the brain connected to the pleasure/reward pathway, and the change in brain chemistry that relays information from one section of the brain to another. Once addicted, the process of undoing the damage caused by drug use is complex and often not successful.
References and Suggestions for Further Reading:
Azrin, N.H.; Acierno, R.; Kogan, E.; Donahue, B.; Besalel, V.; and McMahon, P.T. Follow-up results of supportive versus behavioral therapy for illicit drug abuse. Behavioral Research & Therapy 34(1): 41-46, 1996.
Azrin, N.H.; McMahon, P.T.; Donahue, B.; Besalel, V.; Lapinski, K.J.; Kogan, E.; Acierno, R.; and Galloway, E. Behavioral therapy for drug abuse: a controlled treatment outcome study. Behavioral Research & Therapy 32(8): 857-866, 1994.
Budney, A.J.; Kandel, D.B.; Cherek, D.R.; Martin, B.R.; Stephens, R.S.; and Roffman, R. College on problems of drug dependence meeting, Puerto Rico (June 1996). Marijuana use and dependence. Drug and Alcohol Dependence 45: 1-11, 1997.
Carroll, K.; Rounsaville, B.; and Keller, D. Relapse prevention strategies for the treatment of cocaine abuse. American Journal of Drug and Alcohol Abuse 17(3): 249-265, 1991.
Carroll, K.; Rounsaville, B.; Nich, C.; Gordon, L.; Wirtz, P.; and Gawin, F. One-year follow-up of psychotherapy and pharmacotherapy for cocaine dependence: delayed emergence of psychotherapy effects. Archives of General Psychiatry 51: 989-997, 1994.
Crits-Cristoph, P.; Siqueland, L.; Blaine, J.; Frank, A.; Luborsky, L.; Onken, L.S.; Muenz, L.; Thase, M.E.; Weiss, R.D.; Gastfriend, D.R.; Woody, G.; Barber, J.P.; Butler, S.F.; Daley, D.; Bishop, S.; Najavits, L.M.; Lis, J.; Mercer, D.; Griffin, M.L.; Moras, K.; and Beck, A. Psychosocial treatments for cocaine dependence: Results of the NIDA Cocaine Collaborative Study. Archives of General Psychiatry (in press).
Huber, A.; Ling, W.; Shoptaw, S.; Gulati, V.; Brethen, P.; and Rawson, R. Integrating treatments for methamphetamine abuse: A psychosocial perspective. Journal of Addictive Diseases 16: 41- 50, 1997.
Luborsky, L. Principles of Psychoanalytic Psychotherapy: A Manual for Supportive-Expressive (SE) Treatment. New York: Basic Books, 1984. Marlatt, G. and Gordon, J.R., eds. Relapse Prevention: Maintenance Strategies in the Treatment of Addictive Behaviors. New York: Guilford Press, 1985.
McLellan, A.T.; Arndt, I.; Metzger, D.S.; Woody, G.E.; and O'Brien, C.P. The effects of psychosocial services in substance abuse treatment. Journal of the American Medical Association 269(15): 1953-1959, 1993.
McLellan, A.T.; Woody, G.E.; Luborsky, L.; and O'Brien, C.P. Is the counselor an 'active ingredient' in substance abuse treatment? Journal of Nervous and Mental Disease 176: 423-430, 1988. Miller, W.R. Motivational interviewing: research, practice and puzzles. Addictive Behaviors 61(6): 835-842, 1996.
Rawson, R.; Shoptaw, S.; Obert, J.L.; McCann, M.; Hasson, A.; Marinelli-Casey, P.; Brethen, P.; and Ling, W. An intensive outpatient approach for cocaine abuse: The Matrix model. Journal of Substance Abuse Treatment 12(2): 117-127, 1995.
Stephens, R.S.; Roffman, R.A.; and Simpson, E.E. Treating adult marijuana dependence: a test of the relapse prevention model. Journal of Consulting & Clinical Psychology, 62: 92-99, 1994.
Woody, G.E.; McLellan, A.T.; Luborsky, L.; and O'Brien, C.P. Psychotherapy in community methadone programs: a validation study. American Journal of Psychiatry 152(9): 1302-1308, 1995.
Woody, G.E.; McLellan, A.T.; Luborsky, L.; and O'Brien, C.P. Twelve month follow-up of psychotherapy for opiate dependence. American Journal of Psychiatry 144: 590-596, 1987.
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