Psychoactive substance
Is a chemical compound ingested to alter mood or behaviour (or both
Substance use
is the ingestion of
psychoactive substances in moderate amounts that does not significantly interfere
with social, educational or occupational functioning
–> can include legal or illicit substances
Substance Intoxication
is a physiological reaction
to an ingested substance (e.g., drunkenness or “getting high”)
It may involve:
- impaired judgment
- mood changes
- lowered motor ability
Substance use DISORDER
Substance use disorder - often described as “addiction”
- Defined by the specific impact on the individual, not the amount of substance
used.
Physiological Dependence
Tolerance
greater amounts of the drug are required to experience the same effect
Physiological Dependence
Withdrawal
negative physical reaction when the substance is no longer ingested
Psychological / behavioural effects
Loss of control over use, life activities are altered, drug
seeking behaviours
DSM history
- In early editions of the DSM, alcohol and drug use were considered symptoms of
other problems - Considered a sign of moral weakness
- In 1980, DSM-III introduced the term Substance Abuse
- Recognised the complex biological & psychological nature of the problem
DSM current criteria for substance use disorder
- Removal of distinction between ‘abuse’ and
‘dependence’ - 11 symptoms form criteria used for diagnosis.
Severity indicated based on number of symptoms
present from:
Mild: Presence of 2-3 symptoms
Moderate: Presence of 4-5 symptoms
Severe: Presence of 6 < symptoms
Co morbidity
75% have additional
symptoms of other disorder can complicate diagnosis
DSM-5 aims to distinguish whether or not a
symptom results from substance abuse
Brain Chemistry
- neurotransmitters- chemical used to transmit messages between neurons
- each receptor is sensitive to specific neurotransmitters
- Psycho- active substances appear to bind to specific brain receptor sites
- substances can mimic neurotransmitters and block receptor sites
Depressants
Decrease CNS activity
- reduce levels of physiological arousal due to inhibitory centres in the brain being slowed down
Common:
- sedatives
- alcohol:
==> impacts a number of neuroreceptor systems
–> initial effect: apparent stimulation, feelings of wellbeing
–> continued drinking: depresses more areas of the brain, impedes our functioning
–> long term effects: Withdrawal, withdrawal delirium (hallucinations), organ damage
–> Fetal Alcohol Syndrome (FAS): combination of problems that occur when mother drinks during pregnancy eg. learning difficulties, behaviour problems, characteristic facial features
Sedatives, Hypnotics, Anxiolytics
Sedative: calming
Hypnotic: sleep inducing
Anxiolytic: anxiety reducing
