Rehabilitating psychedelic drugs: Another key to treating severe mental health disorders
Lori Tipton's life was a cascade of trauma that even a soap opera would not dare inflict upon a character: a mentally unstable family; a brother who died of a drug overdose; the shocking discovery of the bodies of two persons her mother had killed before turning the gun on herself; the devastation of Hurricane Katrina that savaged her hometown of New Orleans; being raped by someone she trusted; and having an abortion. She suffered from severe PTSD.
“My life was filled with anxiety and hypervigilance,” she says. “I was constantly afraid and had mood swings, panic attacks, insomnia, intrusive thoughts and suicidal ideation. I tried to take my life more than once.” She was fortunate to be able to access multiple mental health services, “And while at times some of these modalities would relieve the symptoms, nothing really lasted and nothing really address the core trauma.”
Then in 2018 Tipton enrolled in a clinical trial that combined intense sessions of psychotherapy with limited use of Methylenedioxymethamphetamine, or MDMA, a drug classified as a psychedelic and commonly known as ecstasy or Molly. The regimen was arduous; 1-2 hour preparation sessions, three sessions where MDMA was used, which lasted 6-8 hours, and lengthy sessions afterward to process and integrate the experiences. Two therapists were with her every moment of the three-month program that totaled more than 40 hours.
“It was clear to me that [the therapists] weren't going to heal me, that I was going to have to do the work for myself, but that they were there to completely support my process,” she says. “But the effects of MDMA were really undeniable for me. I felt embodied in a way that I hadn't in years. PTSD had robbed me of the ability to feel safe in my own body.”
Tipton doesn’t think the therapy completely cured her PTSD. “But when I completed the trial in 2018, I no longer qualified for the diagnosis, and I still don't qualify for the diagnosis today,” she told an April workshop on psychedelics as mental health treatment by the National Academies of Sciences, Engineering and Medicine, or NASEM.
A Champion
Rick Doblin has been a catalyst behind much of the contemporary research into psychedelics. Prior to the DEA clamp down, the Boston psychotherapist had seen that MDMA and other psychedelics could benefit some of his patients where other measures had failed. He immediately organized efforts to question the drug rescheduling but to little avail. In 1986, he created the nonprofit Multidisciplinary Association for Psychedelic Studies (MAPS), which slowly laid the scientific foundation for clinical trials, including the one that Tipton joined, using psychedelics to treat mental health conditions.
Now, only slowly, have researchers been able to explore the power of these drugs to treat a broad spectrum of severely debilitating mental health conditions, including trauma, depression, and PTSD, where other available treatments proved inadequate.
“Psychedelic psychotherapy is an attempt to go after the root causes of the problems with just a relatively few administrations, as contrasted to most of the psychiatric drugs used today that are mostly just reducing symptoms and are meant to be taken on a daily basis,” Doblin said in a 2019 TED Talk. Most of these drugs can have broad effect but “some are probably more effective than others for certain conditions,” he added in a recent interview with Leaps.org. Comparative head-to-head studies of psychedelic therapies simply have not been conducted.
Their mechanisms of action are poorly understood and can vary between drugs, but it is generally believed that psychedelics change the activity of neurons so that the brain processes information differently, says Katrin Preller, a neuropsychologist at the University of Zurich. A recent important study in Nature Medicine by Richard Daws and colleagues used functional magnetic resonance imaging (fMRI) of the brain and found that “functional networks became more functionally interconnected and flexible after psilocybin treatment…implying that psilocybin's antidepressant action may depend on a global increase in brain network integration.”
Rosalind Watts, a clinical investigator at the Imperial College in London, believes there is “an overestimation of the importance of the drug and an underestimation of the importance of the [therapeutic] context” in psychedelic research. “It is unethical to provide the drug without the other,” she says. Doblin notes that “psychotherapy outcomes research demonstrates that the therapeutic alliance between the therapist and the patients is the single most predictive factor of outcomes. [It is] trust and the sense of safety, the willingness to go into difficult spaces” that makes clinical breakthroughs possible with the drug.
Excitement and Challenges
Recurrent themes expressed at the NASEM workshop were exciting glimpses of the potential for psychedelics to treat mental health conditions combined with the challenges of realizing those potentials. A recent review paper found evidence that using psychedelics can help with treating a variety of common mental illnesses, but the paper could identify only 14 clinical trials of classic psychedelics published since 1991. Much of the reason is that the drugs are not patentable and so the pharmaceutical industry has no interest in investing in expensive clinical trials to bring them to market. MAPS has raised about $135 million over its 36-year history to conduct such research, says Doblin, the vast majority of it from individual donors and none from foundations.
The workshop participants’ views also were colored by the history of drug crackdowns and a fear that research might easily be shut down in the future. There was great concern that use of psychedelics should be confined to clinical trials with high safety and ethical standards, instead of doctors and patients experimenting on their own. “We need to get it right this time,” says Charles Grob, a psychiatrist at the UCLA School of Medicine. But restricting access to psychedelics will become even more difficult now that Oregon and several cities have acted to decriminalize possession and use of many of these drugs.
The experience with ketamine also troubled Grob. He is hoping to “mitigate the rush of rapid commercialization” that occurred with that drug. Ketamine technically is not a psychedelic though it does share some of their potentially euphoric properties. In 2019, soon after the FDA approved a form of ketamine with a limited label indication to treat depression, for profit clinics sprang up promoting off label use of the drug for psychiatric conditions where there was little clinical evidence of efficacy. He fears the same thing will happen when true psychedelics are made available.
If these therapies are approved, access to them is likely to be a problem. The drugs themselves are cheap but the accompanying therapy is not, and there is a shortage of trained psychotherapists. Mental health services often are not adequately covered by health insurance, while the poor and people of color suffer additional burdens of inadequate access. Doblin is committed to health care equity by training additional providers and by investigating whether some of the preparatory and integration sessions might be handled in a group setting. He says it is important that the legal aspects of psychedelics also be addressed so that patients “don't have to go underground” in order to receive this care.
Schizophrenia is a debilitating mental health condition that affects around 24 million people worldwide. Patients experience hallucinations and delusions when they develop schizophrenia, with experts referring to these new thoughts and behaviors as positive symptoms. They also suffer from negative symptoms in which they lose important functions, suffering from dulled emotions, lack of purpose and social withdrawal.
Currently available drugs can control only a portion of these symptoms but, on August 8th, Karuna Therapeutics announced its completion of a phase 3 clinical trial that found a new drug called KarXT could treat both positive and negative symptoms of schizophrenia. It could mean substantial progress against a problem that has stymied scientists for decades.
A long-standing problem
Since the 1950s, antipsychotics have been used to treat schizophrenia. People who suffer from it are thought to have too much of a brain chemical called dopamine, and antipsychotics work by blocking dopamine receptors in the brain. They can be effective in treating positive symptoms but have little impact on the negative ones, which can be devastating for a patient’s quality of life, making it difficult to maintain employment and have successful relationships. About 30 percent of schizophrenia patients don't actually respond to antipsychotics at all. Current drugs can also have adverse side effects including elevated cholesterol, high blood pressure, diabetes and movements that patients cannot control.
The recent clinical trial heralds a new treatment approach. “We believe it marks an important advancement for patients given its new and completely different mechanism of action from current therapies,” says Andrew Miller, COO of Karuna.
Scientists have been looking to develop alternatives. However, “the field of drug treatment of schizophrenia is currently in the doldrums,” says Peter McKenna, a senior researcher at FIDMAG Research Foundation in Spain which specialises in mental health.
In the 2000s there was a major push to target a brain receptor for a chemical called glutamate. Evidence suggested that this receptor is abnormal in the brains of schizophrenia patients, but attempts to try glutamate failed in clinical trials.
After that, many pharmaceutical companies dropped out of the race for a more useful treatment. But some companies continued to search, such as Karuna Therapeutics, led by founder and Chief Operating Officer Andrew Miller and CEO Steve Paul. The recent clinical trial suggests their persistence has led to an important breakthrough with their drug, KarXT. “We believe it marks an important advancement for patients given its new and completely different mechanism of action from current therapies,” Miller says.
How it works
Neurotransmitters are chemical messengers that pass signals between neurons. To work effectively, neurotransmitters need a receptor to bind to. A neurotransmitter called acetylcholine seems to be especially important in schizophrenia. It interacts with sites called muscarinic receptors, which are involved in the network of nerves that calm your body after a stressful event. Post mortem studies in people with schizophrenia have shown that two muscarinic receptors in the brain, the M1 and M4 receptors, are activated at unusually low levels because they don’t receive enough signals from acetylcholine.
The M4 receptor appears to play a role in psychosis. The M1 receptor is also associated with psychosis but is primarily thought to be involved in cognition. KarXT, taken orally, works by activating both of these receptors to signal properly. It is this twofold action that seems to explain its effectiveness. “[The drug’s] design enables the preferential stimulation of these muscarinic receptors in the brain,” Miller says.
How it developed
It all started in the early 1990s when Paul was at pharmaceutical company Eli Lilly. He discovered that Xanomeline, the drug they were testing on Alzheimer's patients, had antipsychotic effects. It worked by stimulating M1 and M4 receptors, so he and his colleagues decided to test Xanomeline on schizophrenia patients, supported by research on the connection between muscarinic receptors and psychosis. They found that Xanomeline reduced both positive and negative symptoms.
Unfortunately, it also caused significant side effects. The problem was that stimulating the M1 and M4 receptors in the brain also stimulated muscarinic receptors in the body that led to severe vomiting, diarrhea and even the temporary loss of consciousness.
In the end, Eli Lilly discontinued the clinical trials for the drug, but Miller set up Karuna Therapeutics to develop a solution. “I was determined to find a way to harness the therapeutic benefit demonstrated in studies of Xanomeline, while eliminating side effects that limited its development,” Miller says.
He analysed over 7,000 possible ways of mixing Xanomeline with other agents before settling on KarXT. It combines Xanomeline with a drug called Trospium Chloride, which blocks muscarinic receptors in the body – taking care of the side effects such as vomiting – but leaves them unblocked in the brain. Paul was so excited by Miller’s progress that he joined Karuna after leaving Eli Lilly and founding two previous startups.
“It's a very important approach,” says Rick Adams, Future Leaders Fellow in the Institute of Cognitive Neuroscience and Centre for Medical Image Computing at University College London. “We are in desperate need of alternative drug targets and this target is one of the best. There are other alternative targets, but not many are as close to being successful as the muscarinic receptor drug.”
Clinical Trial
Following a successful phase 2 clinical trial in 2019, the most recent trial involved 126 patients who were given KarXT, and 126 who were given a placebo. Compared to the placebo, patients taking KarXT had a significant 9.6 point reduction in the positive and negative syndrome scale (PANSS), the standard for rating schizophrenic symptoms.
KarXT also led to statistically significant declines in positive and negative symptoms compared to the placebo. “The results suggest that KarXT could be a potentially game-changing option in the management of both positive and negative symptoms of schizophrenia,” Miller says.
Robert McCutcheon, a psychiatrist and neuroscientist at Oxford University, is optimistic about the side effects but highlights the need for more safety trials.
McKenna, the researcher at FIDMAG Foundation, agrees about the drug’s potential. “The new [phase 3] study is positive,” he says. “It is reassuring that one is not dealing with a drug that works in one trial and then inexplicably fails in the next one.”
Robert McCutcheon, a psychiatrist and neuroscientist at Oxford University, said the drug is an unprecedented step forward. “KarXT is one of the first drugs with a novel mechanism of action to show promise in clinical trials.”
Even though the drug blocks muscarine receptors in the body, some patients still suffered from adverse side effects like vomiting, dizziness and diarrhea. But in general, these effects were mild to moderate, especially compared to dopamine-blocking antipsychotics or Xanomeline on its own.
McCutcheon is optimistic about the side effects but highlights the need for more safety trials. “The trial results suggest that gastrointestinal side effects appear to be manageable,” he says. “We know, however, from previous antipsychotic drugs that the full picture regarding the extent of side effects can sometimes take longer to become apparent to clinicians and patients. Careful ongoing assessment during a longer period of treatment will therefore be important.”
The Future
The team is currently conducting three other trials to evaluate the efficacy and long-term safety of KarXT. Their goal is to receive FDA approval next year.
Karuna is also conducting trials to evaluate the effectiveness of KarXT in treating psychosis in patients suffering from Alzheimer’s.
The big hope is that they will soon be able to provide a radically different drug to help many patients with schizophrenia. “We are another step closer to potentially providing the first new class of medicine in more than 50 years to the millions of people worldwide living with schizophrenia,” says Miller.
Podcast: The Friday Five weekly roundup in health research
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Here are the promising studies covered in this week's Friday Five:
- Using graphene to repair shoulders
- Testing for PTSD with saliva
- Cancer detection with a microchip
- Best posture for pill taking
- Resilient food for climate change
And an honorable mention goes to research on a new way to induce healthy fat.