1. Explaining Drug Use and Abuse Chapter 2
PPT Series 2B

2. Biological Explanations for the Use and Abuse of Drugs
Biological explanations for drug addiction include genetic theories and the disease models.
The disease model, in particular explains drug abuse as an illness in need of treatment or therapy
According to biological theories, (genetics) drug abuse has a beginning stemming from physical characteristics that cause certain individuals to either experiment with, and/or crave drugs to the point of abuse.

3. Biological Explanations for the Use and Abuse of Drugs
Genetic and Biophysiological Theories
Addiction is based on genes, brain dysfunction, and biochemical patterns
Biological explanations emphasize the effects of drugs on the central nervous system (CNS)
Reward centers in some people are more sensitive to drugs, resulting in more pleasure and greater rewarding experiences from the use of drugs
as compared to other individuals who may find the use of drugs unpleasant (or significantly less pleasant)

4. Biological Explanations for the Use and Abuse of Drugs
ALL major biological explanations of drug abuse assume that the drugs exert the psychoactive effects of altering brain chemistry or neuronal activity, specifically interfering with the neurotransmitters.
There are three principle biological theories on why drugs are abused and those individuals who are at risk:
Abused Drugs Are Positive Reinforcers
Drug Abuse and Psychiatric Disorders
Genetic Explanations

5. Biological Explanations for the Use Three Principle Biological Theories
Abused Drugs Are Positive Reinforcers
Most drugs with abuse potential enhance pleasure centers by causing the release of specific brain neurotransmitters such as dopamine.
Overstimulation of the dopamine neurotransmitter produces euphoric feelings and promotes continued use/abuse.
Brain cells will become accustomed to the heightened presence of dopamine and crave them when absent
Overstimulation of these regions of the brain “exhausts” the dopamine systems and leads to depression and anhedonia.

6. Biological Explanations for the Use Three Principle Biological Theories
Drug Abuse and Psychiatric Disorders
Biological explanations are thought to be responsible for the substantial overlap that exists between drug addiction and mental illness.
Drug abuse is a mental illness because it changes the normal hierarchy of needs and desires, changes priorities, and promotes compulsive behaviors that occur despite the negative and harmful consequences
Many people who are addicted to drugs are also diagnosed with other mental disorders, and vice versa. Thus, drug abuse and mental disorders are often comorbid, and interactions between these illnesses often exacerbate both.

7. Biological Explanations for the Use Three Principle Biological Theories
Drug Abuse and Psychiatric Disorders
Comorbid disorder of mental illness and drug abuse may exist because:
Drug abuse may bring about symptoms of mental illness
Mental disorders may lead to drug abuse because of self-medication. (ex. Patients suffering from anxiety or depression may rely on alcohol, tobacco, and other drugs to temporarily relieve symptoms)
See also (“These disorders could also be caused by common risk factors” p.78, right column, text) categories: 1) Overlapping genetic vulnerabilities; 2) Overlapping environmental triggers; 3) Involvement of similar brain regions; and, 4) Drug use disorders and other mental illnesses are developmental disorders

8. Biological Explanations for the Use Three Principle Biological Theories
Genetic Explanations
This theory propose that inherited traits can predispose some individuals to drug addiction.
Some studies estimate that drug vulnerability due to genetic influences account for approximately 38% of all cases, whereas environmental and social factors account for the balance.
Other studies have proposed that the receptors for dopamine in certain individuals are altered (genetics) in a manner that increases drug use vulnerability

9. Biological Explanations for the Use Three Principle Biological Theories
Genetic Explanations
Theoretically, genetic factors can directly or indirectly contribute to drug abuse vulnerability by:
Taking drugs of abuse may relieve psychiatric disorders that are genetically determined
Reward centers may be “genetically enhanced” to be more sensitive to addictive drugs, and these individuals would experience a high euphoria from taking drugs of abuse
Some individuals may have a reduction of activity in the prefrontal cortex so rational thought is more difficult and thus promoting compulsive behavior

10. Biological Explanations for the Use Three Principle Biological Theories
Genetic Explanations
Theoretically, genetic factors can directly or indirectly contribute to drug abuse vulnerability by:
Character traits, such as insecurity and vulnerability that often lead to drug abuse behavior may be genetically determined predisposing addiction
Factors that determine the ability to recover from drug addiction, causing severe craving.

11. Psychological Explanations for the Use and Abuse of Drugs
Psychological theories regarding drug use and addiction mostly focus on mental or emotional states of drug users, which are often associated with or enhanced by social and environmental factors.
Psychologists propose several possible causes of addiction: 1) people may engage in harmful behaviors due to psychopathology; 2) people learn unhealthy behaviors in response to their environment, and, 3) people’s thoughts and beliefs create their “feelings”. These feelings determine their behavior.

12. Psychological Explanations for the Use and Abuse of Drugs
Because of the similarities between , and the co-existence of, substance-related mental disorders and primary psychiatric disorders, it is sometimes difficult to distinguish between both.
Both substance abuse and substance dependence together are known as substance use disorder.
The relationship between substance abuse dependency and mental illness is often termed dual diagnosis.

13. Psychological Explanations for the Use and Abuse of Drugs
The following relationships are possible when mental illness and substance abuse occur simultaneously (co-occurring disorder) :
Drugs and alcohol are used for self-medication
Drug and alcohol use intensifies mental illness.
Drugs and alcohol cause symptoms of mental illness for the first time in someone who has not be diagnosed with mental illness
Men are more likely than women and persons of low SES, military veterans, persons with more general medical illnesses, are more likely to develop a co-occurring disorder.

14. Theories Based on Learning
Humans acquire drug use behavior (social learning) by the close association or pairing of one significant reinforcing stimulus (like friendship and intimacy) with another less significant or neutral stimulus (e.g., initial use of alcohol, marijuana, ecstasy, cocaine). In learning to use drugs the following occurs:
Conditioning: The close association of significant reinforcing stimulus with another less significant or neutral stimulus
Habituation: Repeating certain patterns of behavior until they become established or habitual
“Addiction to pleasure” theory: Assumes it is biologically normal to continue a pleasure stimulus when once begun

15. Who Is at Risk?
People who are at a high risk for drug use and addiction are often known as drug sensation-seeking individuals or simply, sensation-seekers.
Sensation-seekers continually search for new or novel thrills in their experiences, and are known to have a relentless desire to pursue physical and psychological stimulation often involving dangerous behavior.
Sensation-seekers attracted to drug are more likely to maintain a constant preoccupation with altering their consciousness (getting high).

16. Social Psychological Learning Theories
Based on the premise that positive social influences by drug using peers reinforce the attraction to drugs, thus, social interaction, peer camaraderie, social approval and drug use work together as possible reinforces to sustain drug use “If the effects of drug use become personally rewarding, or become reinforcing through conditioning, the chances of continuing to use are greater than stopping” (Akers 1992, p. 86)

17. Social Psychological Learning Theories
Differential reinforcement is the ratio between favorable and unfavorable reinforcers for sustaining drug use behavior.
Primary conditions determining drug use are:
Amount of exposure to drug-using peers vs. non-using peers.
Extent (preference) of drug use in a given neighborhood or community
Age of first use (exposure to drugs at younger ages results in greater difficulty in stopping drug use)
Frequency of drug use among peers
END OF PPT SERIES 2B