Chapter 12: Substance-Related Disorders
• The pathological use of substances falls into two categories: substance
abuse and substance dependence. Substance dependence is
characterized by DSM-IV-TR as the presence of at least three of the
The person develops tolerance, indicated by either (1) larger doses of
the substance being needed to produce the desire effect or (2) the
effects of the drug becoming markedly less if the usual amount is
Withdrawal symptoms – negative physical and psychological effects –
develop when the person stops taking the substance or reduce the
The person uses more the substance or uses it for a longer time than
The person recognizes excessive use of the substance; he or she may
have tried to reduce usage but has been unable to do so.
Much of the person’s time in spent in efforts to obtain the substance or
recover from its effects.
Substance use continues despite psychological or physical problems
caused or exacerbated by the drug.
The person gives up or cuts back a participation in many activities
(work, recreation, socializing) because of the use of the substance.
• For the less serious diagnosis of substance abuse, the person must
experience one of the following as a result of recurrent use of the drug:
Failure to fulfill major obligations
Exposure to physical dangers
Persistent social or interpersonal problems.
• Substance intoxication is diagnosed when the ingestion of substance
affects the central nervous system and produces maladaptive cognitive
and behavioural effects.
Alcohol Abuse and Dependence
• The term abuse is often used to refer to both aspects of the excessive and
harmful use of alcohol.
• Some research suggests that tolerance results from changes in the
number of sensitivity of GABA or glutamate receptors.
• The person who abuses alcohol, in contrast to the person physically
dependent on it, experiences negative social and occupational effects
from the drug but does not show tolerance, withdrawal, or the compulsive
drinking patterns seen in the person who is alcohol dependent.
• Alcohol abuse or dependence is often part of polydrug (or polysubstance)
abuse, using or abusing more than one drug at a time. Short-Term Effects of Alcohol
• Because drinking alcoholic beverages is accepted in most societies,
alcohol is rarely regarded as a drug. But it is indeed a drug, and it has a
biphasic effect. This means that the initial effect of alcohol is stimulating –
the drinker experiences an expansive feeling of sociability and well-being
as the blood-alcohol level rises – but after the blood-alcohol level peaks
and begins to decline, alcohol acts as a depressant that may lead to
• It stimulates GABA receptors, which may be responsible for reducing
• Alcohol also increases levels of serotonin and dopamine, and this may be
the source of its ability to produce pleasurable effects. Finally, alcohol
inhibits glutamate receptors, which may cause the cognitive effects of
alcohol intoxication, such as slurred speech and memory loss.
Long-Term Effects of Prolonged Alcohol Abuse
• Prolonged alcohol use with reduction in the intake of proteins contributes
to the development of cirrhosis of the liver, a potentially fatal disease in
which some liver cells become engorged with fat and protein, impeding
their function; some cells die, triggering an inflammatory process. When
scar tissue develops, blood flow is obstructed.
• Heavy alcohol consumption during pregnancy is the leading cause of
mental retardation. The growth of the fetus is slowed, and cranial, facial,
and limb anomalies are produced, a condition known as fetal alcohol
• French paradox: despite diets rich in saturated fats, the French have
relatively low cholesterol levels. Some hypothesize that consumption of
low to moderate amounts of red wine may lower cholesterol levels.
Nicotine and Cigarette Smoking
• Nicotine is the addicting agent of tobacco. It stimulates receptors, called
nicotinic receptors, in the brain. Molecular biology studies suggest that the
main receptor mediating nicotine dependence is the nicotinic acetylcholine
• Female smokers have substantially greater changes in cognitive activity
after nicotine exposure.
Consequences of Second-Hand Smoke
• The smoke coming from the burning end of a cigarette, so-called second-
hand smoke, or environmental tobacco smoke (ETS), contains higher concentrations of ammonia, carbon monoxide, nicotine, and tar than does
the smoke actually inhaled.
• Marijuana consists of the dried and crushed leaves and flowering tops of
the hemp plant, Cannabis sativa. It is most often smoked, but it may be
chewed, prepared as a tea, or eaten in bakes goods. Hashish, much
stronger than marijuana, is produced by removing and drying the resin
exudate of the tops of high-quality cannabis plants.
Effects of Marijuana
• The major active chemical in marijuana is delta-9-tetradyrocannabinol
• The CB receptors in the brain are located in various regions, and it is
believed that receptors in the hippocampus account for the short-term
memory loss that sometimes follows smoking marijuana.
• The short-term side effects of marijuana include blood-shot and itchy
eyes, dry mouth and throat, increased appetite, reduced pressure within
the eye, and somewhat raised blood pressure.
• One marijuana cigarette is the equivalent of four tobacco cigarettes in tar
intake, five in carbon monoxide intake, and 10 in terms of damage to cells
lining the airway.
• Reverse tolerance is the direct opposite of the tolerance that occurs with
an addicting drug, such a heroin. The substance THC, after being rapidly
metabolized, is stored in the body’s fatty tissue and then released very
slowly, perhaps for a month, which may explain reverse tolerance for it.
• THC and related drugs can reduce the nausea and loss of appetite that
accompany chemotherapy for some cancer patients.
• Marijuana is also a treatment for the discomfort of AIDS, as well as
glaucoma, epilepsy, and multiple sclerosis.
Sedative and Stimulants
• Addiction to drugs, including sedatives, was disapproved of but tolerated
in the U.S until 1914, where the Harrison Narcotics Act made the unauthorized use of various drugs illegal and those addicted to them
criminals. The drugs we discus here, some of which may be obtained
legally with prescription, can be divided into two general categories:
sedative and stimulants.
• The major sedatives, often called downers, slow the activities of the body
and reduce is responsiveness. This group of drugs includes the opiates-
opium and its derivatives, morphine, heroin, and codeine – and the
synthetic barbiturates and tranquilizers, such as secobarbital (Seconal)
• The opiates are a group of addictive sedatives that relieve pain and induce
sleep when taken in moderate doses.
• Opium: One of the opiates, the dried, milky juice obtained from the
immature fruit of the opium poppy. This addictive narcotic produces
euphoria and drowsiness and reduces pain.
• In 1806, the alkaloid morphine, named after Morpheus, the Geek god of
dreams, was separated from raw opium. This bitter –tasting powder
proved to be a powerful sedative and pain reliever.
• In 1874, they found that morphine could be converted into another
powerful pain-relieving drug, which they named heroin. Used initially as a
cure for morphine addiction, heroin was substituted for morphine in cough
syrups and other patent medicines.
Psychological and Physical Effects
• Opium and its derivatives, morphine and heroin, produce euphoria,
drowsiness, reverie, and a lack of coordination. Heroin has an additional
initial effect: the rush, feeling of warm, suffusing ecstasy immediately
following an intravenous injection.
• Opiates produce their affects by stimulating neural receptors of the body’s
own opioid system. Heroin, for example, is converted into morphine in the
brain, and then binds to opioid receptors. The body produces opioids,
called endorphins and enkephalins, and opium and its derivatives fit into
their receptors and stimulate them.
• Barbiturates, another major type of sedative, were synthesized as aids for
sleeping and relaxation.
• Sedatives relax the muscles, reduce anxiety, and in small doses produce a mildly euphoric state. Like alcohol, they are thought to produce these
psychological effects by stimulating the GABA system. With excessive
doses, however, speech becomes slurred and gait unsteady. Judgement,
concentration, and ability to work may be severely impaired.
• Stimulants or uppers such as cocaine, act on the brain and the
sympathetic nervous system to increase alertness and motor activity.
• Chen isolated an alkaloid from this plant belonging to the genus Ephedra,
and the result, ephedrine, proved highly successful in treating asthma. But
relying on the shrub for the drug was not efficient, and so efforts to
develop a synthetic substitute began. Amphetamines resulted from these
• The first amphetamine, Benzedrine was synthesized in 1927. Almost as
soon as it became commercially available in the early 1930s as an
inhalant to relieve stuffy noses, the public discovered its stimulating
effects. Physicians thereafter prescribed it and the other amphetamines
that were soon synthesized to control mild depression and appetite.
Soldiers on both sides in the Second World War were supplied with the
rugs to ward off fatigue, and today amphetamines are sometimes used to
treat hyperactive children.
• Amphetamines, such as Benzedrine, Dexedrine, and Methedrine, produce
their effects by causing the release of norepinephrine and dopamine and
blocking the reuptake of these neurotransmitters.
• As tolerance increases, the user may stop taking pills and inject
Methedrine, the strongest of the amphetamines, directly into the veins.
• The alka