SUBSTANCE-RELATED DISORDERS
,Description
Substance use disorders are a cluster of disorders in which cognitive, behavioral, and
physiological symptoms indicate that a person continues using a substance despite
significant substance-related problems
Psychiatric symptom clusters may be related to substance use, discontinuation of substance use,
or withdrawal from habitual substance use.
Substance use disorders lead to changes in brain circuits and physiological functions that lead to
a need for detoxification and a possible need for long-term treatment.
The word substance can describe a drug of abuse, a medication, or a toxin
that produces psychoactivation and alters cognitive, behavioral, and affective
perceptions.
Dependence: repeated use of a substance with or without physical dependence
Abuse: use that is inconsistent with sociality use patterns
Misuse: usually applies to a prescribed substance
Intoxication: reversible syndrome caused by a specific substance affecting memory, judgment,
behavior, or social or occupational functioning
Withdrawal: substance-specific symptoms that occur after stopping or reducing use
Tolerance: needing more of the substance to get the desired effect
Etiology
Multiple theories ranging from psychological to neurobiological
Probable multifactorial etiological profile
Two common types of theories: psychodynamic and biological
Psychodynamic theory
Behaviors of abuse are seated in oral-stage fixation.
A person seeks gratification through oral behaviors.
Maladaptive regressive behaviors can become overlearned, fixed, and reinforced through
dysfunctional family patterns.
Sociocultural factors attempt to explain population-based differences in substance abuse rates.
, Biological theory
Genetic loading
People with a strong genetic vulnerability to addiction are thought to have defects in the working
of the reward center of the brain, which predisposes them to stronger-than-normal positive
rewards that draw them to substance use.
Gender differences
Ethnic differences
A person is predisposed to stronger-than-normal negative rewards, making it more
difficult to stop abuse once it has begun.
Involves two neurobiological processes:
1. Reinforcement
Brain-based changes in structure and function can lead to addictive behavior.
The process of positive and negative rewards is physiologically linked to memory
function.
Changes appear to occur with any drug of abuse.
Reinforcement results in “feel good” sensations when a drug of abuse is used and in “feel
bad” sensations when the drug exits the body.
Positive rewards of reinforcement result in the social rewards commonly associated with
drug use, such as disinhibition, euphoric mood, and anxiety reduction. Mediated by
dopamine (DA) pathways.
Negative rewards are aversive, such as increased anxiety and dysphoria. Mediated by the
gamma amino butyric acid (GABA) pathways .
Reinforcement occurs in the ventral tegmental area and the nucleus accumbens of the
brain, collectively called the reward center.
DA release within the reward center is enhanced further by the release of natural
morphine-like neurotransmitters called neuropeptides (enkephalins, beta-endorphins).
Neuropeptides further enhance the reinforcing pleasure experienced by the person.
With repeated drug use, the DA system becomes increasingly sensitized.
Eventually, associated drug use stimuli (e.g., pictures of drug paraphernalia) can cause
DA release, leading to reinforcement of use and often to increased drug use.
2. Neuroadaptation
,Description
Substance use disorders are a cluster of disorders in which cognitive, behavioral, and
physiological symptoms indicate that a person continues using a substance despite
significant substance-related problems
Psychiatric symptom clusters may be related to substance use, discontinuation of substance use,
or withdrawal from habitual substance use.
Substance use disorders lead to changes in brain circuits and physiological functions that lead to
a need for detoxification and a possible need for long-term treatment.
The word substance can describe a drug of abuse, a medication, or a toxin
that produces psychoactivation and alters cognitive, behavioral, and affective
perceptions.
Dependence: repeated use of a substance with or without physical dependence
Abuse: use that is inconsistent with sociality use patterns
Misuse: usually applies to a prescribed substance
Intoxication: reversible syndrome caused by a specific substance affecting memory, judgment,
behavior, or social or occupational functioning
Withdrawal: substance-specific symptoms that occur after stopping or reducing use
Tolerance: needing more of the substance to get the desired effect
Etiology
Multiple theories ranging from psychological to neurobiological
Probable multifactorial etiological profile
Two common types of theories: psychodynamic and biological
Psychodynamic theory
Behaviors of abuse are seated in oral-stage fixation.
A person seeks gratification through oral behaviors.
Maladaptive regressive behaviors can become overlearned, fixed, and reinforced through
dysfunctional family patterns.
Sociocultural factors attempt to explain population-based differences in substance abuse rates.
, Biological theory
Genetic loading
People with a strong genetic vulnerability to addiction are thought to have defects in the working
of the reward center of the brain, which predisposes them to stronger-than-normal positive
rewards that draw them to substance use.
Gender differences
Ethnic differences
A person is predisposed to stronger-than-normal negative rewards, making it more
difficult to stop abuse once it has begun.
Involves two neurobiological processes:
1. Reinforcement
Brain-based changes in structure and function can lead to addictive behavior.
The process of positive and negative rewards is physiologically linked to memory
function.
Changes appear to occur with any drug of abuse.
Reinforcement results in “feel good” sensations when a drug of abuse is used and in “feel
bad” sensations when the drug exits the body.
Positive rewards of reinforcement result in the social rewards commonly associated with
drug use, such as disinhibition, euphoric mood, and anxiety reduction. Mediated by
dopamine (DA) pathways.
Negative rewards are aversive, such as increased anxiety and dysphoria. Mediated by the
gamma amino butyric acid (GABA) pathways .
Reinforcement occurs in the ventral tegmental area and the nucleus accumbens of the
brain, collectively called the reward center.
DA release within the reward center is enhanced further by the release of natural
morphine-like neurotransmitters called neuropeptides (enkephalins, beta-endorphins).
Neuropeptides further enhance the reinforcing pleasure experienced by the person.
With repeated drug use, the DA system becomes increasingly sensitized.
Eventually, associated drug use stimuli (e.g., pictures of drug paraphernalia) can cause
DA release, leading to reinforcement of use and often to increased drug use.
2. Neuroadaptation
