Psychoactive substance definition
- Anything that changes neural functioning
- Not just alcohol, tobacco, cannabis, medications—
- Also many foods.
- …and while we focus a lot on effects on emotions, cognitions, behaviour, there are whole-body effects from
component substances, metabolic processing, and products
How many Australians use substances?
Almost everyone uses something & can be at
risk e.g. Caffeine (most commonly used
stimulant)
How are Psychoactive substance grouped?
- Depressants (sedative effects)—e.g. alcohol, benzodiazepines
- Stimulants e.g. amphetamines
- Hallucinogens - e.g. LSD
What is the most commonly used depressant in Australia
- Any recently? 77% (yes)
- Heavy single-occasion use decreases with age
- But daily use increases with age
- 28% > 2 drinks per occasion regularly or > 4
drinks per occasion sometimes (= health risk)
What’s the trend in drinking in Australia?
Problematic drinking is high, but decreasing
Young people are “delaying” drinking (young people are having their first drink later (16)
Australian consumption: percentage by year
- Tobacco—12% smoking daily
- Illicit drugs—16% (recent users)
▪ cannabis 10.4%
▪ cocaine 2.5%
▪ ecstasy 2.2%
▪ meth/amphetamine 1.4%
▪ injected drugs 0.3% - Misuse of medications (excl. over the counter) —4.8%
and rates of this are either stable or reducing
In terms of DALYS, what causes the most deaths
nicotine/tobacco
What does DALY stand for
Disability-Adjusted Life Year.
Health affects of alcohol
- Liver—fatty liver, alcoholic hepatitis, fibrosis (scar-like tissue), cirrhosis (inflammation, scarring, cell death),
liver failure - Pancreatitis (high single-occasion consumption)
- Cancers—including gastrointestinal tract, liver, breast (known carcinogen)
- Cardiovascular (CVD)-cardiomyopathy, arrhythmias, hypertension, stroke
- Sleep disorders
- Sexual dysfunction
- Weakened immune system, longer recovery from injury
- Neurological/Neurocognitive (e.g., thiamine deficiency & Wernicke-Korsakoff syndrome; neural damage from other mechanisms)
- Foetal alcohol syndrome
Other adverse affects of alcohol
- Financial
- Use of machinery—e.g. road accidents
- Forensic
- Interpersonal-e.g. injury, victim/perpetrator of crime; intimate partner violence
- Occupational – including work accidents
- Recreational
- Exacerbate or co-occur with other physical or psychological disorders
- Obesity
Fiction (FALSE) accusations about alcahol
- Alcohol helps you sleep
- Impaired judgement occurs after clear signs of intoxication (e.g., motor signs )
- Alcohol is not truly addictive, like heroin is
- less dangerous than marijuana
- withdrawal from heroin is more dangerous than withdrawal from alcohol
- everybody drinks alcohol
Fact about Alcohol
- Alcohol interferes with sleep patterns
- Judgment is impaired before clear signs of intoxication
- It is addictive
- more people are treated for problems with alcohol than marijuana
- Chance of death from alcohol withdrawal is higher than for heroin
- lots of people abstain
How much use of a substance may signal ‘problematic use’
- Physical Dependence: tolerance, withdrawal
- Hazardous or risky use (use that carries risk of harm in any way - emotional physical etc)
- Harmful use (continued use despite actual harm)
- Addiction (implies a broader control problem)
How did substance use change from DSM 4 to the DSM 5?
DSM-4: had two separate diagnoses
Substance Abuse → milder problems
Substance Dependence → more severe, physiological symptoms
DSM-5: merged these into one diagnosis — Substance Use Disorder (SUD)
Severity is now shown with specifiers:
Mild (2–3 criteria)
Moderate (4–5)
Severe (6+)
Reflects a spectrum model rather than two distinct categories
The chapter name broadened to “Substance-Related and Addictive Disorders”
Recognises behavioral addictions too
Gambling Disorder was added (previously Pathological Gambling in DSM-IV Section 3)
Name changed to reduce stigma (“pathological” → “disorder”)
Diagnostic criteria for (substance) Use Disorder
A problematic pattern of use leading to clinically significant impairment or distress with
> 2 of 11 features in a 12-month period:
Problems with control
* Larger amounts or longer periods than intended
* Persistent desire or unsuccessful attempts to control
* Craving/strong desire or urge
Priority given to substance use rather than other activities or roles
* Substantial time spent obtaining, using or recovering
* Failure to fulfil major role obligations
* Important activities given up or reduced
Continued use despite problems
* Use despite social/interpersonal problems
* Recurrent use when physically hazardous
* Use despite knowledge that a physical or psychological problem is caused/exacerbated by it
Physical dependence
* Tolerance**
* Withdrawal
Alcohol withdrawal, DSM-5 Criteria
2 or more of:
* Autonomic hyperactivity
* Hand tremor
* Insomnia
* Nausea, vomiting
* Transient visual, tactile, or auditory hallucinations/illusions.
* Psychomotor agitation
* Anxiety
* Seizures
Occurrence after heavy or prolonged drinking, distress or impairment, no other attribution
OR
Another closely related substance, such as benzodiazepines, is used to relieve or avoid
withdrawal
Definition of Tolerance
- markedly diminished effect with continued use of the same amount
- markedly increased amounts to achieve intoxication or desired effect
What is severe alcohol withdrawl?
- A condition in the DSM
- Typically begins 8 hrs after last drink, peaks 72hrs—may have reducing symptoms to 5- 7 days
- Occurs in phases—e.g. hallucinations typically ≈ 12-48 hrs after last drink
- Grand mal seizures ≈ 24-48 hrs
- Potentially fatal—1-4%
- Treatment typically includes benzodiazepines
- For safety, may involve hospitalisation/institutionalisation
Severe Alcohol Withdrawal as a process
Timeline: unfolds over several days.
First 1–2 days: highest seizure risk.
Following days: mild symptoms peak → severe symptoms may develop.
Mild symptoms: anxiety, tremors, sweating, nausea/vomiting.
Severe symptoms: confusion, paranoia, hallucinations, delirium tremens (life-threatening).
Management: must be done under medical supervision due to serious health risks.
Non-substance related addiction parallels
Similar to substance addiction because:
control, craving, priority, continued behaviour despite problems e.g. internet addiction. Sometimes similar phenomena to tolerance, withdrawal
(e.g. gambling)
What are the specifiers in gambling disorder?
Criterion B:
Gambling behaviour not better explained by a manic episode.
Episodic:
Meets full criteria at multiple points, with symptom-free periods lasting several months between episodes.
Persistent:
Continuous symptoms for multiple years.
Early remission:
No criteria met for ≥3 months but <12 months after previous diagnosis.
Sustained remission:
No criteria met for ≥12 months after previous diagnosis.
Severity Specifiers
Mild: 4–5 criteria met
Moderate: 6–7 criteria met
Severe: 8–9 criteria met
DID DSM include internet gaming disorder in its manual?
No but the ICD (WHO paper) did include it
Criteria for Internet Gaming disorder (In ICD) and in the future studies part of the DSM
Recognised by WHO in ICD-11 as a medical condition.
Both require persistent/repetitive gaming ≥12 months.
DSM-5 (proposed):
Must show 5 of 9 symptoms (e.g., preoccupation, withdrawal, tolerance, loss of control, continued use, deception, escape, impairment).
Includes physiological signs (withdrawal, tolerance).
ICD-11:
Needs 3 core features:
Impaired control
Priority given to gaming
Continued use despite harm
Biological cause of substance addiction
- “addicting properties”, including via neural reward circuits and endogenous opioid peptides
- genetics, via inherited predisposition for alcohol dependence
