Mind & Matter is a monthly column by Nick Jikomes, PhD, Leafly’s Director of Science and Innovation.
Can doing drugs make you go crazy? Based on who you ask and how you pose the question, answers can vary considerably.
To address this question seriously, we have to do two things: First, define our terms so we know what we’re talking about. Second, think about the question separately for distinct drug classes, as different types of drugs work in very different ways.
Insane? Psychotic? Let’s get our terms straight
Mental health-related terms are often used in everyday speech. These informal uses tend to refer to experiences that deviate from what is normal. That’s a start, but we need more precision.
Consider any story you have heard about someone “going crazy” on drugs. Perhaps you hear about someone who did too much acid in the 1960s and “went insane.” Whether or not such anecdotes are true, the general phenomenon they hint at is drug-induced psychosis.
What is psychosis?
Psychosis refers to an abnormal state of mind where there is difficulty discerning what is real, defined as the consensus reality perceived by your sober peers. Two good examples of psychotic symptoms are:
- Hallucinations: Sensory perceptions not tied to measurable external stimuli.
- Delusions: False beliefs that persist in the face of clear counter-evidence.
I like to think about these symptoms along three dimensions:
- Acute (temporary) vs. Chronic (lasting)
- Mild vs. Severe
- Spontaneous vs. Externally-triggered
We all experience acute, mild psychotic-like symptoms sometimes. Stare at any good optical illusion and you will experience a mild hallucination:
Or consider any dream you’ve had, which demonstrates the brain’s ability to construct vivid perceptions with elaborate narratives, seemingly out of nothing.
Indeed, there is a sense in which all of perception is a kind of controlled hallucination. Unlike the hallucinations perceived in a state of psychosis, our normal, everyday perceptions generally track measurable changes in the world around us. That’s the key difference.
Video: Neuroscientist Dr. Anil Seth discusses how our brains generate our perceptions.
Schizophrenia: a chronic form of psychosis
By contrast, consider someone with a chronic form of severe psychosis, like schizophrenia. They may hear voices emanating from entities no one else perceives (hallucinations). Or hold fantastical, easily falsifiable beliefs, such as having been chosen by aliens to receive special messages (delusions).
Psychotic episodes can develop spontaneously, during the natural course of brain development in someone with a genetic predisposition. Psychosis can also be triggered by an external trigger (e.g. a stressful event). It may fade quickly, or persist.
The question we’re interested in is whether certain drugs can induce psychosis. We want to know whether different drugs can induce acute, mild, psychotic-like symptoms or more severe forms of lasting psychosis. To explore this, let’s consider the following drugs: amphetamines, psychedelics, and cannabis.
Amphetamines and psychosis
Amphetamine-induced psychosis, or simply “stimulant psychosis,” is a known phenomenon. Psychostimulants activate the nervous system, which tends to elevate dopamine levels in the brain. Roughly speaking, antipsychotic drugs work by dampening the effects of dopamine.
Under certain conditions, psychostimulants can trigger a psychotic state which can include delusions, hallucinations, paranoia, and disorganized behavior. It’s fair to say that clear examples of stimulant-induced psychosis are often temporary but severe. They may fade once the drug is metabolized but can trigger full-blown psychosis.
I once witnessed a man who believed he was invincible (delusion) climb a billboard scaffold, then jump off. More remarkable was his attempt to stand up on his shattered legs (disordered behavior) while screaming that paramedics were trying to hurt him (paranoia).
The role of meth
A common culprit in these cases is methamphetamine. Because of its ability to induce euphoria and grandiosity, people may use it to counterbalance the feelings associated with “diseases of despair” such as depression, alcohol dependency, and suicidal thoughts.
In many urban environments, it’s common to observe signs of amphetamine-induced psychosis among homeless people, who are already more likely to suffer from psychotic disorders than the general population. A predisposition to psychosis, together with the elevated stress levels that accompany homelessness, can lower the threshold for drug-induced psychosis, creating a dangerous feedback loop. Recurrent drug-induced psychosis evolves into chronic psychosis.
Although these examples tend to involve hard street drugs used by vulnerable populations, it’s hard not to wonder about the effects of prescription amphetamines, which are used at astounding levels (e.g., Adderall for ADHD). As with almost any drug effect, the likelihood of stimulant-induced psychosis depends on the frequency and dose of ingestion.
Classic psychedelics and psychosis
Classic psychedelics like LSD and psilocybin are a different kind of drug, famous for their ability to induce “crazy” hallucinations. The hallucinations experienced during a psychedelic trip can be considered psychotic-like symptoms. Another scientific term for this is psychotomimetic—a drug effect mimicking a psychotic symptom. This is not to say that a psychedelic trip is synonymous with a psychotic state, just that there is directional overlap.
While the hallucinations are temporary, the subjective effects of psychedelics are so powerful that even psychologically healthy individuals should proceed with great care. It’s often said that psychedelics can trigger latent schizophrenia in predisposed individuals, which seems plausible. Nonetheless, “often said” is not the same as scientifically confirmed.
I was curious if any such cases have been formally documented, so I searched the scientific literature.
Do studies confirm the anecdotes?
The result: I’m unable to locate clear examples from recent scientific literature (the last 15 years or so) documenting psychedelic-induced psychosis. What I do find are older reports, like this 1983 paper describing people with “LSD psychosis.” When I dig into it those reports, they tend to look at patients hospitalized for psychotic symptoms. It was apparently normal to classify them as having “LSD psychosis” if their symptoms appeared after self-reported LSD ingestion. One gets the impression that anyone with psychotic symptoms who reported taking LSD in their past was subject to this diagnosis, without further verification.
Psychiatry literature from the 1950s and 60s is even more indiscernible. While there are various reports, most read like strange pseudo-studies conducted under dubious circumstances. For example, someone gave a 25-year old woman who had been diagnosed with psychopathy and alcoholism a five-session LSD treatment. The details are unclear, but she went on to murder her boyfriend a couple days after the final dose. Like other cases, hers was labeled “LSD psychosis.”
Remember, this was the era of One Flew Over the Cuckoo’s Nest. Psychiatrists were still giving lobotomies and insulin shock therapy.
Looking for links
More recent surveys of large numbers of people fail to find a positive correlation between psychedelic use and psychosis, let alone evidence of a causal relationship. There are even findings associating past psychedelic use with reduced psychological distress.
Overall, there does not seem to be a compelling link between severe, persistent psychosis and psychedelic use, despite the acute psychotomimetic effects of these drugs. Nonetheless psychedelics are so powerful that it’s safe to assume that anyone under psychological duress, or who has a family history of psychosis, is best advised to steer clear.
What about cannabis?
Moving on to cannabis: If you smoke a lot of pot as a teenager, are you risking the development of psychosis in adulthood? This has long been an area of controversy.
Let’s start with the basics of acute THC intoxication, briefly summarize the historical scientific findings, then review the latest and most compelling research.
As with psychedelics, some of THC’s acute effects are psychotomimetic. This includes disordered thinking and paranoia. A little disordered thinking isn’t necessarily a bad thing. The enhanced creativity people often report from cannabis probably has something to do with normal cognition becoming lightly disordered.
When thoughts become heavily disordered, though, it’s difficult to behave intelligibly. That’s why severe cases of psychosis render a person unable to hold a job or perform complex tasks. Getting really stoned isn’t the same thing as a psychotic break, but the effects can mimic aspects of psychosis.
Paranoia is a good example of a dose-dependent psychotomimetic effect. Some people get paranoid when they consume THC, and this paranoia is more likely to emerge with high doses of THC. We’ve all heard a story about someone who ate a pot brownie that had more THC than they realized. Naive high-dose THC experiences like this often involve getting stuck in strange thought loops (disordered thinking) or having paranoid delusions (“my cat is working for the FBI”).
Adolescent cannabis use
Because the acute effects of THC can be psychotomimetic, it’s natural to wonder whether consuming too much THC, especially during key phases of brain development, might increase the odds of developing chronic psychosis. Indeed, many studies have shown a clear correlation between adolescent cannabis use and adult psychosis: Higher rates of adolescent cannabis consumption correlate with higher rates of adult psychosis.
The difficulty with these studies is that establishing causality is usually not feasible. There are many confounding factors correlating with both cannabis use and psychosis, including other drug consumption, socioeconomic variables, and genetics. So when scientists find a correlation between two variables, they often can’t tell whether one thing (cannabis use) drives the other (psychosis), or whether other factors are driving both.
It’s a classic correlation vs. causation problem.
Finding more clarity by studying twins
One way to disentangle complex problems like this is by using twin studies. Identical and fraternal twins share 100% and 50% of their genes, respectively, and usually grow up in similar environments. Twins provide a unique opportunity to test whether causal relationships likely exist between variables. Across many twin pairs, there will be examples where one twin deviates from the other in some way, such as cannabis use.
Imagine two identical twins. They have the same genes, grow up in the same household, and behave in the same way–mostly. But even identical twins aren’t 100% the same in every way. Biology is noisy, creating diversity even between twins. Perhaps one starts consuming cannabis in their teenage years, while one doesn’t.
With enough data like this, it’s possible to discern whether adolescent cannabis use is a driving factor for psychosis. If it is, you should see adult psychosis much more frequently in the twin who consumed cannabis compared to the one that did not. Alternatively, if you see psychosis develop at the same rate in both twins, you know that some other shared factor—such as genetics or a shared family environment—was the culprit.
Twin studies control for genetics and environment
I recently spoke to clinical psychologist Dr. Jonathan Schaefer, who performed such a study. When he looked at all of the twins as individuals, ignoring the twin pairs they belonged to, he found the same basic result seen historically: Those who reported the highest levels of cannabis use in adolescence had the highest score on their measure of psychosis.
When he took into account the twin pairs, allowing him to statistically control for their shared genetics and environment, however, this relationship went away.
He explained: “On average, the twins who reported using more cannabis were scoring just as high on our measure of psychoticism as twins who were using less cannabis. That sort of flies in the face of this hypothesis that it’s actually the cannabis exposure in adolescence that is causing psychotic symptoms that stick with people for most of their lives.”
Podcast: Dr. Jonathan Schaefer discusses twin studies examining adolescent cannabis use.
While this result suggests that adolescent cannabis use is not a causal driver of adult psychosis, it does not mean that heavy use in adolescence is without risk. In another recent study, Dr. Schaefer found that there was evidence that heavy adolescent use may impair academic functioning, with a downstream impact on socioeconomic status. Like the previous study, that one found little evidence for a causal relationship between adolescent cannabis use and adult mental health or cognitive ability.
Drug use and mental health
The impact any psychoactive drug will have on your mental health depends on what kind of drug it is, the dose it’s consumed at, and often you take it. Are you microdosing psilocybin four times a week or taking a heroic dose once per year? Are you taking your prescription amphetamines (ADHD meds) every single day, or just on occasion? Are you hitting the dab rig on a daily basis, or smoking an occasional joint?
There are no universal answers to these questions. There is no one-size-fits all prescription for optimizing your brain and mental health. By definition, psychoactive drugs will affect your brain. The effects might be temporary, or lasting. They can improve your mental health, or hurt it.
A recurring theme of this series has been that the type of drug, the dose it’s taken in, and the frequency of consumption are crucial determinants of the outcomes you will experience. You should educate yourself before diving in—but there is no sure guide to sanity.
Heed this ancient wisdom
In my experience, the best advice has been around for centuries. At the Temple of Apollo in Greece there are three maxims inscribed in stone, widely known among the Ancient Greeks and still visible to this day:
- “Know thyself”
- “Nothing in excess”
- “Certainty brings insanity”
Who knows, maybe they were on drugs.