Hallucinogens: Effects, Uses, and Mechanisms of Action
Hallucinogens: Perceiving Sensory Things That Aren’t Actually There
Turn Off the Default Mode Network
When the default mode network is engaged, there is more activity in the brain regions associated with self-referential thinking and memory. This can lead to rumination, anxiety, and depression.
Quiet Internal Monologue and Detach You from Yourself
Hallucinogens can help to quiet the internal monologue and detach you from your sense of self. This can lead to a more open and receptive state of mind, which can be beneficial for creativity, problem-solving, and spiritual experiences.
Quieting Down Your Obsessive Compulsions
Hallucinogens can also help to quiet down obsessive compulsions. This can be beneficial for people with PTSD, anxiety, OCD, and addiction.
Mechanism of Action
Hallucinogens work by targeting serotonin receptors in the brain. The most important of these receptors are the 5-HT2A and 5-HT2C receptors.
The 5-HT2A receptor is responsible for the hallucinogenic effects of psychedelics. When activated, this receptor can cause changes in perception, thought, and emotion.
The 5-HT2C receptor is also involved in the effects of psychedelics. This receptor is thought to play a role in the cognitive and emotional effects of these drugs.
Uses of LSD and Psilocybin
LSD and psilocybin have been shown to be useful in the treatment of addiction, treatment-resistant depression, and end-of-life anxiety.
In addiction treatment, LSD and psilocybin have been shown to help people to break free from their addictions to nicotine, alcohol, and other drugs.
In treatment-resistant depression, LSD and psilocybin have been shown to be effective in reducing symptoms of depression in people who have not responded to other treatments.
In end-of-life anxiety, LSD and psilocybin have been shown to help people to reduce their anxiety and fear of death.
Classes of Hallucinogens
There are three main classes of hallucinogens: phenethylamines, tryptamines, and lysergamides.
Phenethylamines include mescaline and MDMA (Ecstasy).
Tryptamines include psilocybin and DMT.
Lysergamides include LSD.
All three classes of hallucinogens work by targeting serotonin receptors in the brain.
Serotonin 2A Receptor
The serotonin 2A receptor is a G-protein coupled receptor that is expressed in high levels in the brain and various tissues in the body.
The 5-HT2A receptor is involved in a variety of brain functions, including mood, epilepsy, and sensory perception.
Hallucinogens activate the 5-HT2A receptor, which leads to changes in perception, thought, and emotion.
Affinity of Tryptamines at the 5HT2Ar
The affinity of a drug for a receptor is a measure of how tightly the drug binds to the receptor.
The affinity of tryptamines for the 5HT2Ar receptor is as follows:
- LSD: 0.4
- Serotonin: 11.6
This means that LSD binds to the 5HT2Ar receptor more tightly than serotonin.
Affinity of Phenethylamines at the 5HT2Ar
The affinity of phenethylamines for the 5HT2Ar receptor is as follows:
- Mescaline: 1500
This means that mescaline binds to the 5HT2Ar receptor less tightly than LSD.
Trace Amine Associated Receptors
Trace amine associated receptors (TAARs) are a family of G-protein coupled receptors that are found in the axon terminal.
TAARs are involved in a variety of brain functions, including mood, anxiety, and addiction.
Psychedelics have been shown to activate TAARs, which may contribute to their therapeutic effects.
Non-Human Research
Non-human research on hallucinogens is limited.
However, some studies have shown that hallucinogens can alter fly physiology, visual processing, social interaction, and circadian behavior.
In fish, LSD has been shown to reduce anxiety and increase swimming as a group.
People
In people, LSD has been shown to increase heart rate, blood pressure, and body temperature.
Psilocybin has been shown to increase positive mood and reduce amygdala reactivity in response to negative stimuli.
Single doses of psilocybin have been shown to be effective in reducing anxiety and depression in cancer patients.
Psilocybin has also been shown to be beneficial in the treatment of alcohol abuse.