Option D.10 – Mind-Altering Drugs
D.10.1 – Describe the effects of lysergic acid diethylamide (LSD), mescaline, psilocybin and tetrahydrocannabinol (THC)
Lysergic Acid Diethylamide (LSD)
This is a powerful hallucinogen, meaning that it causes perceptions that are not based on reality or any stimulus. It mimics the neurotransmitter serotonin in the brain, affecting nerve impulses. Users have altered perception and experience psychedelic hallucinations. It can have bizarre mental side effects, and in some cases, causes permanent personality changes.
The indole ring is part of a fused ring system, with other functional groups attached.
Mescaline
This is different from LSD and psilocybin because it does not have the complete indole ring. It is also a hallucinogen, but is less potent. Users experience different hallucinations, in that they are based on their actual experience, but more intense. Mescaline mimics norepinephrine, leading to increased heart rate, blood flow and the release of glucose from energy stores.
Psilocybin
This also mimics serotonin, having a similar effect to LSD, but is less potent.
Tetrahydrocannabinol (THC)
This is also called cannabis, marijuana or ganja. It has sedative-hypnotic properties and alters perception, thought and feeling. It contains a phenol group, ether groups, C=C bonds and a carbon chain attached to the benzene ring.
It is taken using a number of methods – chewing, drinking, inhalation or injection. It depresses the nervous system, causes mental relaxation and euphoria. It is effective within 15 minutes and lasts up to 4 hours. Users lose inhibitions and have altered perception. It also causes palpitations, loss of concentration, light-headedness, weakness and a sense of floating. When taken in higher doses, it depresses the respiratory system and may cause collapse. Use during pregnancy can impair the development of the baby, often leading to lower birth weight. Withdrawal symptoms include insomnia, anxiety, irritability and restlessness. Long-term use is thought to cause sluggishness and poor memory.
THC binds to the cannabinoid receptors in the brain, affecting the release of neurotransmitters such as acetylcholine, noradrenaline and dopamine. It can be used as a pain-killer, as well as causing relaxation, euphoria, altered perception, disorientation, fatigue and increased appetite.
D.10.2 – Discuss the structural similarities and differences between LSD, mescaline and psilocybin
All three molecules have a benzene ring. Their structure is based on the indole ring a fused heterocyclic ring
D.10.3 – Discuss the arguments for and against the legalisation of cannabis