Substance use and addictive disorders
Wednesday, September 29, 2021 9:31 PM
• Facts
○ Alcohol abuse and addiction is the third leading cause of preventable death and
disability in the US
○ 15% are “problem drinkers” & half of these are alcoholics; this 15% consumes 80+
of the alcohol used in the US.
○ Binge drinking and heavy alcohol use are highest among young adults 18 to 25
○ 14 million Americans use illicit drugs
○ Marijuana is the most commonly used illicit drug in US
○ We are currently facing a resurgence in heroin abuse as heroin increasingly
supplants the abuse of prescribed opiates
• Costs r/t Substance Abuse
Health Care Overall
tobacco $96 billion $193 billion
○
Alcohol $30 billion $235 billion
Illicit Drugs $11 billion $193 billion
• Substances Most Commonly Misused by College Students
○ Alcohol (80% drink, 50% binge)
○ Marijuana use (34%)
○ Medically unsupervised amphetamines (10%)
○ Medically unsupervised sedatives/tranquilizers (6.6%)
○ Ecstasy/3,4-methylenedioxymethamphetamine (5%)
○ Prescription opioid narcotics, cocaine, and hallucinogen misuse (slightly under 5%)
○ Inhalants, gamma hydroxybutyrate, ketamine, and heroin (less than 5%)
• Cultural Issues
○ Alcohol use is highest among Native Americans and Mexican=American adolescent
males
○ African American youth use both licit and illicit substances at lower rates than do
Caucasians, but experience more related health and legal problems; alcohol is the
most widely used drug by African Americans
○ Mexican American men report the most frequent, heavy drinking and alcohol -
related problems
S bt b i l t Ai d P ifi I l d dC b A i
, ○ Substance abuse is lowest among Asian and Pacific Islanders and Cuban Americans
○ Men abuse chemicals more than women
• Definitions
○ Use: when one drinks, swallows, smokes, sniffs, inhales or injects a mind-altering
substance
○ Abuse: use of alcohol or drugs for the purpose of intoxication, or, in the case of
prescription drugs, for purposes beyond their intended use
○ Addiction: an irresistible psychological and/or physiological need to continue the
substance use or behavior despite the harm it causes; may or may not include
physical dependence.
○ Physical Dependence: physiological requirement for the substance by the brain, as
evidenced by development of tolerance and withdrawal when use decreases or
stops
○ Craving: an urgent desire for a substance or behavior to which one is addicted, ofte
in response to triggers, that is very difficult to resist6
○ Tolerance: physiological adaptation to a substance such that increasing amounts a
needed to achieve the same effect
○ Cross tolerance: substances that are pharmacologically interchangeable in terms o
how the body responds, e.g. alcohol and most benzodiazepines; i.e. if one develop
tolerance to alcohol, he also has tolerance for benzodiazepines and would require
higher dose of the benzodiazepines to achieve their usual effect. We take advantag
of this property to treat dependence, e.g. we replace alcohol with benzodiazepines
and gradually reduce their dosage during medically supervised detoxification. Note
there may be limited cross tolerance between alcohol and narcotic analgesics.
○ Withdrawal: state characterized by adverse physical and psychological symptoms
occurring when on ceases using a substance to which the brain has acclimated
○ Trigger: anything which cues or prompts a response, e.g. seeing a bar may trigger a
craving for alcohol (the bar is the trigger)•Detoxification: safely withdrawing a
person from an addictive substance, usually under medical supervision, by providin
a substance for which there is cross tolerance in gradually decreasing amounts
○ Relapse: the recurrence of alcohol or drug dependent behavior in an individual wh
has previously abstinence for a significant time beyond the period of detoxification
• Diagnostic Criteria
○ Substance-Related and Addictive Disorders are disorders wherein one has great
difficulty refraining from using a substance (e.g. alcohol, amphetamines, cannabis
[marijuana], cocaine, hallucinogens, inhalants, nicotine, opioids, phencyclidine,
sedative–hypnotics, anxiolytics, nicotine, caffeine, etc) or engaging in a behavior
(e.g. gambling) despite significant resulting harm. These disorders include:
§ \abuse of a substance
, § \abuse of a substance
§ addiction and/or dependence on a substance
§ intoxication or withdrawal from a substance
§ behavioral addictions9
• A word about tox screens
○ Substances screened for in a standard tox screen can vary with the lab doing the
test, and screens do not test for all abusable substances
○ Even when a screen tests for a substance (e.g. opioids) some related substances
may not show up, e.g. synthetic opioids such as fentanyl
○ Some common meds can cause false positives for other drugs, e.g. using
dextromethorphan may cause a false positive for PCP
○ Bottom line: don’t assume that a neg tox screen means the person is not abusing
substances, nor that a positive tox screen means the person is abusing substances
• Theories about Addiction
○ Chemical hook theory—the nature of the substance itself reinforces its use—once
the brain has been exposed, it “has to have it”. E.g. rats exposed to the drug and
then offered a choice of water that contains the drug and plain water will choose
the water with the drug, and will continue to consume it even to their own
detriment.
○ Alexander experiment—addicted rats were divided into two groups, one placed in
“rat park” with toys and tunnels and food and company, while the other was in a
traditional rat cage lacking amenities. This time, when offered the drugged water
and plain water, the rats in the rat park chose the plain water, while the rats in the
standard cage continued to abuse the drug. Conclusion: if we have what we need
we will not self medicate with drugs.
○ Impaired Response Inhibition and Salience Attribution (iRISA)—with accumulating
exposure to rewarding activities/substances, the brain narrows its focus to just
those behaviors/substances, resulting in an every increasing focus on thoughts and
actions that cue evokes (i.e. the brain attributes greater salience to these behavior
and substances); a common manifestation is the selective attention to cues r/t tha
substance or behavior (e.g. seeing white powder).
○ At the same time the brain becomes less and less able to control one’s responses t
those cues (e.g. seeking cocaine after seeing white powder) irrespective of resultin
consequences. 12
