A psychoactive drug or psychotropic substance is a chemical that alters brain function, resulting in temporary changes in perception, mood, consciousness, or behaviour. Such drugs are often used for recreational and spiritual purposes, as well as in medicine, especially for treating neurological and psychological illnesses.

Common psychoactive drugs

Note: This overview groups together drugs with different effects and modes of action. Several have properties of many categories.

• Stimulants
  • Cocaine
  • Amphetamine
  • Caffeine
  • Nicotine

• Psychedelics
  • LSD
  • Mescaline
  • Psilocybin
  • Cannabis
  • PCP
  • MDMA ("Ecstasy")
  • DMT
  • Ketamine
  • Salvinorin A
  • DXM

• Narcotics
  • Opiates
    • Morphine
    • Codeine
    • Heroin

• Sedatives
  • Ethyl alcohol
  • Benzodiazepines
    • Valium
  • GHB

• Anti-depressants
  • SSRIs
    • Prozac
    • Zoloft
    • Paxil

• Antipsychotics
  • Haloperidol (Haldol)

• Aphrodisiacs
  • PT-141

• Other
  • Diphenhydramine
  • Datura

• In a broader sense also:
  • Antiemetics
  • Analgesics
  • Antiepileptics

Ways Psychoactive Drugs Affect The Brain

There are many ways in which psychoactive drugs can affect the brain. While some drugs affect neurons presynaptically, others act postsynpatically and some drugs don't even attack the synapse, working on neural axons instead. Here is a general breakdown of the ways psychoative drugs can work.

1. Prevent The Action Potential From Starting
   • Lidocaine, TTX (they bind to voltage-gated sodium channels, so no action potential begins even when a generator potential passes threshold)
2. NT Synthesis
   • Increase - L-Dopa, tryptophan, choline (precursors)
   • Decrease - PCPA (inhibits synthesis of 5HT)
3. NT Packaging
   • Increase - MAO Inhibitors
   • Decreasing - Resperine (pokes holes in the synaptic vesicles of catecholamines)
4. NT Release
   • Increase - Black Widow Spider (Ach)
   • Decrease - Botulinum Toxin (Ach), Tetanus (GABA)
5. Agonists - Mimick the original NTs and activate the receptors
   • Muscuraine, Nicotine (Ach)
   • AMDA, NMDA (Glu)
   • Alcohol, Benzodiazepines (GABA)
6. Antagonists - Bind to the receptor sites and block activation
   • Atropine, Curare (Ach)
   • PCP (Glu)
7. Prevent Ach Breakdown -
   • Insecticides, Nerve Gas
8. Prevent Reuptake
   • Cocaine (DA), Amphetamines (E)
   • Tricyclics, SSRIs

(NT = Neurotransmitter)

- based on information taught in NSC 201, Vanderbilt University

Related articles

• Hallucinogenic drug
• Psychedelic

External links

• Erowid
• Spirit Plants
• Psychotropic Drug Advisory Service
• Drug Wise Newsletter: A Newsletter on Psychotropic Drugs