PL1101E

Unit 6 Notes – Consciousness & Drugs

Hallucinogens – Stimulate the experience of false perceptions

Drug Effect

Mushrooms Fly agaric mushrooms interacts with GABA and Glutamate

A New World mushroom boosts Serotonin – psychotic state

Mescaline Green peyote cactus – influences Serotonin activity

Phencyclidine(PCP)

Decreases Glutamate and increases Dopamine. Produces psychotic state similar to schizophrenia

Originally anaesthetic, unpleasant effects, makes you aggressive and violent, muscular tone too rigid or flexible, convulsions if a lot

Marijuana Contains cannabinoids – most important is tetrahydro-cannabinol (THC) – interacts with receptors for endogenous cannabinoids which are natural substances that are similar in composition. Receptors are in parts of brain linked with pain, appetite, learning and movement – hippocampus, prefrontal cortex, basal ganglia. Negative effect on memory

Stimulates Dopamine activity which is usually associated with a potential for physical dependency. Young adults double their risk of schizophrenia.

Excitation, vivid imagery, euphoria, distortion of sense of time, distance and speed. Sometimes depression and social withdrawal.

Lysergic AcidDiethylamide(LCD)

Chemically similar to Serotonin and it interacts with Serotonin receptors.

Stimulants – Increase the activity of the nervous system

They increase alertness and mobility but decrease reaction time.

Drug Effect

Caffeine Interferes with the inhibition normally produced by Adenosine. When it’s kept from doing its job, you get increased excitation and alertness.

Produces dependency – headaches and fatigue for ‘addicts’. Sometimes problems with heart rhythms. Crosses the placenta.

Correlated with lower risk of Parkinson’s, Alzheimer’s and other dementia.

Nicotine Mimics the actions of Acetylcholine – increases heart rate and blood pressure, reduces fatigue, improves cognitive performance and causes muscular relaxation.

Chewing tobacco – takes longer to get to peak but is more sustained.

High correlations with later drug and alcohol problems. Likely use by those with disorders.

CocaineAmphetamine

Similar effects. Both boost Dopamine in the brain – direct effect on reward systems so very rapidly addictive.

Moderate doses – alertness, elevated mood, confidence and well-being.

High doses – similar to schizophrenia – hallucinations and delusional fears – repetitive movements like teeth grinding.

Meth is likely to lead to psychosis. Dental decay – meth mouth

Cocaine – Freud used to recommend until aware of addiction.

Amphetamine – used to be asthma treatment and by pilots to ward off fatigue and by housewives as diet aid.

Methylphenidate(Ritalin)

Used for attention problems like ADHD. Ritalin and Adderall still used by ADHD. At clinical doses, do not seem to produce dependence.

Boost activity of Dopamine and Norepinephrine – stay alert and concentrate. But they can affect sleep and appetite.

MDMA(Ecstasy)

Relative of amphetamine and mescaline that increases heart

Drug Effect

rate, blood pressure and body temperature.

Increases sociability by stimulating Serotonin and Oxytocin (romantic and personal bonding).

Seems to have detrimental effects on neurons that release serotonin.

Depressants – Reduces the overall activity of the nervous system

They lead to reductions in alertness and anxiety. Major substances in this category boost activity of the inhibitory GABA.

Drug Effect

Alcohol Relaxation, slows down activity in the judgement area of the cortex, reducing behavioural inhibitions. Dilates blood vessels, warm flushed feeling, reduces anxiety.

Higher doses – aggression, risky behaviours, poor motor coordination

Chronic alcoholism impacts frontal lobes and hippocampus – cognitive and memory deficits.

Benzodiazepines& Barbiturates

Increases inhibition produced by GABA. Powerful dependence.

Legitimate medical uses – anxiety reduction, control of seizures.

Higher doses - euphoria

Opiates – Reduces the overall activity of the nervous system

Poppy is the source of several natural psychoactive opiates such as Morphine and Heroin. They initiate the action of our nation opiates (Endorphins).

Drug Effect

Opiates

Legitimate medical purposes – Pain control, cough suppression and diarrhoea control.

Low doses – euphoria, pain relief, reduced anxiety, muscle relaxation,

Drug Effect

sleep.

Higher doses – tremendous euphoria/rush. Even higher – Depression on breathing

Painkiller Oxycontin – often abused.