Substance misuse

• - Intoxication
• - Harmful use
• - Dependency
• - Withdrawal

• 1.a Compulsion
• 1.b Difficult controlling use - starting, stopping, or amounts used

2. Tolerance

• 3. Withdrawal - physiological withdrawal state
• a) characteristic withdrawal state 
• b) substance use to prevent/relieve withdrawal symptoms

• 4.a. Continued used despite harm
• 4.b. Salience (primacy)
• stinence
• 5. Narrowing of repertoire

6. Reinstatement after ab

Dopaminergic 'reward' pathway in the barin. 

Cocain and amphetamine block dopamine reuptake. Alcohol and opiates also increase dopamine.

Ethanol is metabolised to acetaldehyde, by aldehyde dehydrogenase. 

East Asian, a variant enzyme -> acetaldehyde accumulates, causing flushing, palpitations and nausea.

units = (volume of drink in mL x % alcohol)/1000

• Safe
• - women: 2-3/day, 14/w
• - men: 3-4/day, 21/w

• Harmful
• - women: >6, >35
• - men: > 8, >50

ALcohol is a CNS depressant, stimulate GABA inhibitory system to reduce brain excitability. 

Suddenly stop drinking -> neural pathway become hyper-excitable and seizures

Delirium tremens

• 1. Organic
• ^{(not to assume}: confusion, ataxia, or psychotic symptoms are solely due to s misuse; 
• Beware: head injury, subdural haematoma)

• 2. Psychiatric illness: primary or comorbid
• dual diagnosis
• DDx
• - depression/mania
• - functional psychosis
• - anxiety disorder

- personality disorder

• - Which problem came first?
• - Do the psychiatric symptoms 'fit' with known symptoms of that substance?
• - Have psy symptoms continued after abstinence?
• - Is there a FHx or prev diag?

• - Long acting benzodiazepines
• - Thiamine

• Prevention:
• - Disulfiram (mimic flush reaction)

• 1. pinpoint pupils
• 2. 'runs' (diarrhoea, vomitting, lacrimation, and rhinorhoea)
• 3. Naloxone - opiate antagonist 
• 4. Methadone (full agonist) & buprenorphine (partial agonist)
• 5. Naltrexone - opiate antagonist

Formication - sensation of insects crawling on/below skin, also known as cocaine bugs

Cocaine is a powerful vasoconstrictor and snorting it damages the nasal mucosa, causing necrosis and septal perforation.

Treated with flumazenil, a benzo anatagonist