Opinion: The links between cannabis and psychosis can no longer be ignored

Jared Staudt’s recent essay “Consuming true medicine: Why Catholics should oppose legalizing marijuana” suggested that the use of certain intoxicants—in this case cannabis—does not typically help users grapple with reality; instead, it enables them to try and escape from aspects of reality they find painful or tedious. But, however understandable that desire to escape may be, we cannot escape the need to come to terms with reality, which has always been the goal of both Christian spiritual and sacramental practices and classical psychotherapy.

In his book Missing Out: In Praise of the Unlived Life, the literary scholar and psychoanalyst Adam Phillips flatly insists that “reality matters because it is the only thing that can satisfy us.” All substances of abuse, we can say, inhibit to some degree our ability to face reality square-on, and thus to find such limited and often ambivalent satisfaction as may be available to us here, where we have no lasting home (cf. Heb. 13:14), and where we must always contend with a fallen world.

Catholics, unlike some, have never been absolutists about certain intoxicants nor, worse, moral scolds about alcohol, caffeine, or tobacco. We see them as gifts of creation that can “gladden the heart of man” (Ps. 104:15) in some ways. But prudence must always govern their use.

Some Catholics may wish marijuana to be added to that list of permissible substances to be used prudently, but I am not among them. What follows must be understood in that spirit: not an alarmist but instead a prudential examination of the psychological toll being paid by an increasing number of people. And this is the case as widespread marketing and increasing legalization across the country make marijuana casually available to so many without regard for psychologically disastrous outcomes.

I take no position on marijuana’s medicinal or even very occasional recreational usage. What I am seeing, however, goes far beyond that: hardcore long-term use of weed tipping people into psychosis. This was not noted in Staudt’s essay and is deliberately ignored by the many profiteers racing to see weed legalized in this country.

The role of heavy cannabis use in triggering psychotic episodes has been well documented in the international clinical literature for more than a decade. In my private practice just in the last eleven months alone, I have taken into treatment a half-dozen patients who have become psychotic because of thier heavy use of weed.

That’s a small sample, of course, but it is one supplemented not just by international studies, but also domestic case studies, as here. Additionally, we now have the faintest beginnings of a discussion in California by public health officials who have recently mooted the idea of putting warnings onto cannabis-containing products telling people of possible psychological suffering that might result.

I applaud such actions. My patients’ experience tracks closely with those documented now for many years in North America, Europe, Africa, and elsewhere. A good representation of this research may be found in Marta Di Forti et al (2009), “High-Potency Cannabis and the Risk of Psychosis” (British Journal of Psychiatry 195, 489-495). There and elsewhere we see that the higher the THC content, and the harder/longer the use by the patient, the more the chance of being tipped over into psychosis rises. (THC levels today are often deliberately engineered to be at much higher rate than your grandmother’s pot from the 1960s.)

After that, a 2011 article noted that the earlier the age of use of cannabis, the higher the risk of becoming psychotic. A 2017 article in Psychiatric Times reviews the staggering rise in pot-triggered psychotic disorders in this country. A 2019 European study in the Lancet revealed that using cannabis with a THC concentration greater than 10% increases by threefold the risk of psychosis. A 2021 study in the American Journal of Psychiatry reviews the epidemiological data to come to grips with how widespread the problem is. (There is much more of this literature, but these are good starting points for those with no background.)

In sum, we are encouraging the legalization and consumption of a substance that can send increasing numbers of people into some of the most painful experiences of mental illness possible.

What is psychosis, and what does it feel like?

Psychotic disorders, using current (DSM-V and ICD-11) diagnostic criteria, are typically diagnosed in the presence of delusions (including command and persecutory types) and hallucinations of the auditory, visual, and olfactory type, often accompanied with disorganized thinking, speech, and even movement. These are known as “positive” symptoms, in that something is added to your experience you did not have to deal with before. Other “negative” symptoms are common, too, including an absence of appropriate affect, volition, and even movement (e.g., catatonia).

In more common parlance, having psychotic hallucinations and delusions means believing, seeing, hearing, and occasionally smelling things that cannot be perceived by others. While that might sound to some like an exotic and perhaps even thrilling experience, it is for most people a profoundly isolating and terrifying one. The patients who try to describe psychosis to me rarely succeed, instead stammering from a place of utter barrenness and isolation intolerable in its terror.

Those who are psychotic—and under this heading we also include schizophrenic disorders—may well be surrounded by people, but they often live as though connections between them and their fellow human beings have been severed. Here I follow one of the most important essays ever written, “Attacks on Linking” (1959), by the English psychiatrist W.R. Bion whose work on psychosis remains invaluable more than 40 years after his death.

The psychotic mind severs links between its own internalized thoughts and objects, resulting often in incoherent and fantastical utterances which are often insensible to outside listeners. The psychotic mind (especially when joined with persecutory delusions) may view others as threatening, so it often makes itself inhospitable to and undesirable of others’ companionship and community. Those who want to help may be seen as the most threatening of all. (I have had—following Bert Karon’s pioneering clinical techniques—to say to some patients, in all seriousness, “In our work together, I promise not to kill you.”)

Belief that others may well try to kill them often leads psychotic people to absent themselves from society. Thus, it is estimated that the vast majority of psychotic people today live on America’s streets and in its jails.

If one were to put the psychotic experience into roughly comparable theological terms, one could say, with only slight risk of exaggeration, that it feels, for many people, like classical conceptions of hell: utter desolation and the total absence of any sense of loving communion with anyone else. If heaven is a banquet table around which we are all united, the hell of psychosis has neither unity nor community but chaos and the “abomination of desolation” well captured in Daniel’s vision (Dan.12:11).

The good news is that many people can and do recover from this. The sooner a psychotic episode is caught, the greater the likelihood of successful treatment. Those who are psychotic because of cannabis can be helped by immediately stopping the weed. It may take days or weeks for the hallucinations and delusions to lessen or even disappear, but they usually will.

For those in more advanced stages of psychotic disorders, including schizophrenia, I must beg them and those who care for them not to give up. It has—with gross recklessness and cruel carelessness—often been said for years that a schizophrenia diagnosis is for life, and your life is ruined. Rubbish!

This ignores a great deal of evidence, going back to the 1950s, showing that patients who are given intensive psychotherapeutic treatment (including, in some cases, psychopharmacological treatment, though the side-effects of even so-called atypical or second-generation neuroleptics are notorious and often intolerable, leading many patients to discontinue them) can make at least a partial, and sometimes a full, recovery. Some of the “greats” of Anglo-American psychiatry—Frieda Fromm-Reichmann, W.R. Bion, Silvano Arieti, Harold Searles, and more recently Ira Steinman, Andrew Lotterman, and Michael Garrett—have published extensively on their successes in treating and curing patients. I have read most of their writings, and recently completed advanced training with Garrett out of New York, whose book Psychotherapy for Psychosis: Integrating Cognitive-Behavioral and Psychodynamic Treatment (Guilford Press, 2019) is among the most useful published for clinicians.

Recent research is investigating new methods for treatment, including one pioneered here in Indiana showing promise in clinical trials: metacognitive therapy. Paul Lysaker and Reid Klion reveal the details of this in their Recovery, Meaning-Making, and Severe Mental Illness: A Comprehensive Guide to Metacognitive Reflection and Insight Therapy (Routledge, 2017). I have done some training with Lysaker at IU’s School of Medicine in Indianapolis.

In sum, there are longstanding and serious reasons for hope in the face of psychotic disorders if the right treatment can be pursued for as long as necessary.

But before one should have to think about seeking out treatment, one should be carefully noting, and resisting, efforts to blindly and greedily promote widespread access to cannabis. Much like the mad rush to prescribe opioids widely from the end of the last century until recently, when the devastation finally became too much to ignore, I expect we will soon come to regret making weed so easily available. Reality has a way of making us pay attention to suffering no matter how much American capitalism has tried to do otherwise.