The Effects of Hallucinogenic Drugs

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The Effects of Hallucinogenic Drugs

14 June, 2019Articles, News

How do Hallucinogens Work?

Classic hallucinogens are thought to produce their perception-altering effects by acting on neural circuits in the brain that use the neurotransmitter serotonin (Passie, 2008; Nichols, 2004; Schindler, 2012; Lee, 2012). Specifically, some of their most prominent effects occur in the prefrontal cortex—an area involved in mood, cognition, and perception—as well as other regions important in regulating arousal and physiological responses to stress and panic.

What are the Short-Term Effects of Hallucinogens?

Ingesting hallucinogenic drugs can cause users to see images, hear sounds, and feel sensations that seem real but do not exist. Their effects typically begin within 20 to 90 minutes of ingestion and can last as long as 12 hours. Experiences are often unpredictable and may vary with the amount ingested and the user’s personality, mood, expectations, and surroundings. The effects of hallucinogens like LSD can be described as drug-induced psychosis—distortion or disorganization of a person’s capacity to recognize reality, think rationally, or communicate with others. Users refer to LSD and other hallucinogenic experiences as “trips” and to acute adverse or unpleasant experiences as “bad trips.” On some trips, users experience sensations that are enjoyable and mentally stimulating and that produce a sense of heightened understanding. Bad trips, however, include terrifying thoughts and nightmarish feelings of anxiety and despair that include fears of losing control, insanity, or death.

Like LSD and psilocybin, DMT produces its effects through acting on serotonin (5-HT) receptors in the brain (Strassman, 1996). Some research has suggested that DMT occurs naturally in the human brain in small quantities, leading to the hypothesis that the release of endogenous DMT may be involved in reports of alien abductions, spontaneous mystical experiences, and near-death experiences, but this remains controversial (Barker, 2012).

Specific short-term effects of LSD, psilocybin, peyote, DMT, and ayahuasca include:


• Increased blood pressure, heart rate, and body temperature

• Dizziness and sleeplessness

• Loss of appetite, dry mouth, and sweating

• Numbness, weakness, and tremors

• Impulsiveness and rapid emotional shifts that can range from fear to euphoria, with transitions so rapid that the user may seem to experience several emotions simultaneously.

Psilocybin (i.e. Mushrooms)

• Feelings of relaxation (similar to effects of low doses of marijuana)

• Nervousness, paranoia, and panic reactions

• Introspective/spiritual experiences

• Misidentification of poisonous mushrooms resembling psilocybin could lead to unintentional, potentially fatal poisoning.


• Increased body temperature and heart rate

• Uncoordinated movements (ataxia)

• Profound sweating

• Flushing.


• Increased heart rate

• Agitation

• Hallucinations frequently involving radically altered environments as well as body and spatial distortions.


• Increased blood pressure

• Severe vomiting (induced by the tea)

• Profoundly altered state of awareness and perceptions of otherworldly imagery

Long-Term Effects

One result of the repeated use of hallucinogens is the development of tolerance to these drugs. Studies show that LSD users develop a high degree of tolerance for the drug very quickly. This means they have to take increasingly larger amounts to get the same effects.

Research indicates that if a user develops a tolerance to one drug in the hallucinogen class, he or she will also have a tolerance for other drugs in the same class. For example, if someone has developed a tolerance to LSD, they will also have a tolerance to psilocybin and mescaline.

They will not, however, have a tolerance to drugs that affect other neurotransmitter systems, such as amphetamines and marijuana.

Tolerance to hallucinogens is not permanent. If the person stops taking the drug for several days, the tolerance will disappear.

Also, chronic users of hallucinogens typically do not experience any physical withdrawal symptoms when they stop using these drugs, unlike users who have become dependent on other drugs or alcohol.

Persistent Psychosis and Flashbacks

Two of the more serious long-term effects of using hallucinogenics are persistent psychosis and flashbacks, otherwise known as hallucinogen persisting perception disorder (HPPD). Many times these conditions will occur together. According to the NIDA, here are some of the specific long-term effects of hallucinogen use:

• Persistent Psychosis

• Visual disturbances

• Disorganized thinking

• Paranoia

• Mood disturbances

• Hallucinogen Persisting Perception Disorder (Flashbacks)

• Hallucinations

• Other visual disturbances (such as seeing halos or trails attached to moving objects).

These symptoms are sometimes mistaken for neurological disorders (such as a stroke or a brain tumour). Although rare, the occurrence of these conditions is as unpredictable as having a bad trip. Flashbacks and psychosis can happen to anyone, but research has shown that they are more often observed in patients with a history of psychological problems.


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