Tutorial 04 Flashcards
Addicere
Enslavement – 5th cent BC
Addict
To attach
Risky substance use
Refers to quantity/frequency of consumption
Criteria for Substance Use Disorder (4)
Defined by criteria: biological, psychological, behavioral, social
Addiction
Most severe stage of SUD, significant loss of control and presence of compulsive behaviors despite desire to stop
Dopamine plays a role in …
Motivation, motor function, cognition, hormonal regulation
Pathway for motivation
Mesolimbic pathway
Pathway for motor function
Nigrostriatal pathway
Pathway for hormonal regulation
Tuberoinfundibular pathway
Pathway for Cognition
Mesocortical pathway
Mesocortical pathways goes from… to …
From VTA to the cortex
Mesolimbic pathway goes from … to …
From VTA to NAC (nucleus accumbens)
Nigrostriatal pathway goes from … to …
From SN (substantia nigra) to Striatum
Tuberoinfundibular pathway goes from … to …
From Hypothalamus to Pitutitary
Reward prediction error
Reward prediction error consist of the differences between received and predicted rewards
No reward after conditioned stimulus -> dopamine neurons pause firing
Baseline dopamine
Sun, non-rem deep rest, exercise/movement
Enteral route
Drugs are administered via the human gastrointestinal tract
Topical route
Application of drugs to the skin or an orifice
Parenteral route
Drugs given by routes other than enteral and topical
Agonists
Drugs that enhance the activity of a neurochemical
Anatgonists
Drugs that reduce the activity of a neurochemical
Mechanisms of drug effects -> production of …
Production of neurochemicals, neurochemical storage, neurochemical release, receptor effects, reuptake and enzymatic degradation
Stimulant examples
Caffeine, amphetamine, cocaine, nicotine
Caffeine
Increase alertness and
attentional performance.
Side effects: May create
dependence.
Nicotine
Improves alerting and
orienting attention and
episodic working memory.
Side effects: Has major negative
health effects if
smoked or chewed.
Amphetamine
Improves cognitive functions,
inhibitory control, episodic and
working memory, aspects of
attention , performance on effortful
tasks.
Side Effects: Possible dependence
accompanied by severe
“crash” with depression as
drug effects wear off,
particularly if smoked or
injected
Cocaine
Leads to increase alertness,
feelings of well-being and
euphoria, increased energy and
motor activity, feelings of
competence and enhanced
sexual vigor.
Side Effects: Decreased appetite,
headache
Depressants examples
Alcohol, Benzodiazepines(e.g. Valium, Xanax), Barbiturates(e.g.,Phenobarbital), Inhalants
Alcohol
Slow brain function;
impairs memory,
attention and judgment.
Side Effects:
Long-term use raises
risks for liver disease,
cardiovascular problems,
and dementia in older
adults
Benzodiazepines
Reduced anxiety, but
impairs memory and
concentration, especially
with extended use.
Side Effects:
High risk of dependency,
tolerance and
withdrawal.Long-term
use is linked to cognitive
decline and possible
dementia.
Barbiturates
Deep sedation; reduces
memory, attention and
coordination.
Side Effects:
High overdose risk; long-
term use leads to
dependency and
potentially dangerous
withdrawal
Inhalants
Induce euphoria and
disorientation by slowing
brain function.
Side Effects:
Long-term use can cause
memory loss, motor
issues, and brain cell
damage, particularly in
areas controlling
movement and cognition
Opioids
A class of drugs that bind to opioid
receptors in the brain and spinal cord, reducing
the perception of pain. They can be natural,
semi-synthetic, or fully synthetic.
Symptoms of opioids
Slowing of many body functions,
constipation, respiratory and cardiac
depression, and the rapid development of
tolerance.
Side effects of opioids
Restlessness, irritability, headache,
tremors(Heroin and Morphine), nausea,
vomiting, severe abdominal pain.
Cannabis
consumption include alterations in
perception, cognition, motor behaviour,
memory, and learning, but also psychotic
episodes in the case of long-term use.
Cannabis activates …
Activates cannabinoid receptors and leads
to a decrease in adenylate activity. Also
decreases GABA release, which leads to
an increase in synaptic dopamine levels
(similar to opioids)
Hallocinogenes
The chemical compositions of the hallucinogens are
similar to the neurotransmitters serotonin and
epinephrine, and they act primarily by mimicking them.
Effects of hallucinogenes
euphoria, therapeutic insight, and mystical
experiences, anxiety and panic.
Physical dependence
the state of an individual who has repeatedly taken a drug and experiences
unpleasant physiological symptoms if they stop taking it
(also called physiological dependence)
Tolerance
a condition, resulting from persistent
a syndrome that develops after cessation of
use of a drug, characterized by:
- a markedly diminished
effect with regular use of
the same dose of the drug
- a need to increase the dose
markedly over time to achieve
the same desired effect
Withdrawal
a syndrome that develops after cessation ofBprolonged, heavy consumption of a substance.
Symptoms vary by substance but generally
include physiological, behavioral, and cognitive
manifestations, such as nausea and vomiting,
insomnia, mood alterations, and anxiety
Rat park experiment
Overview: The Rat Park experiment, conducted by Bruce Alexander, examined the role of
environment in addiction. Rats placed in an enriching, social “rat park” showed reduced
interest in drug-laced water compared to isolated rats.
Findings: Rats in social settings with stimulating environments were less likely to develop
a preference for drugs
The Biopsychosocial Model of Addiction
Biological factors, social factors, psychological factors
Biological factors
Genetics and brain chemistry (e.g., dopamine release) increase susceptibility to addiction, impacting tolerance and withdrawal
Psychological factors
Mental health, personality traits, and coping skills play key roles in how individuals respond to drugs
Social factors
Environmental influences (peer groups, family, and socioeconomic status) affect vulnerability to addiction
Reward system dysfunction
Long-term exposure to drugs is theorized to cause permanent changes in the substance reward circuit, including
the ventral tegmental area, basal forebrain (amygdala), dopaminergic connections between the ventral tegmental area
and basal forebrain, and OFC
Chronic drug use causes the prefrontal cortex damage that underlies impaired response inhibition and salience
attribution (iRISA) while changes with abstinence and recovery with treatment suggest plasticity of these same brain
regions and functions.
Risk of psychosis
• Cannabinoids: Induce psychotic symptoms.
• Synthetic Cannabinoids: Severe psychotic syndromes.
• Synthetic Cathinones: Delirium-like symptoms and impulsivity.
• Cocaine and Amphetamines: Associated with psychotic episodes.
• Hallucinogens: Induce transient psychotic symptoms.
Link to other mental health issues
Substance use disorders also co-occur at high prevalence with mental disorders, such as depression and bipolar disorder, ADHD, psychotic illness,borderline personality disorder, and antisocial personality disorder.
