Over the last few months, media outlets ranging from NPR to The Guardian and the Times of India have featured stories on psilocybin and depression. Psilocybin is the active ingredient in “magic mushrooms”. It is a powerful hallucinogen traditionally used in vision ceremonies and other religious rituals. Increasing counter-cultural use led to its criminalization in the 1960’s. However, psilocybin and other hallucinogens have recently gained attention as potential treatments for a variety of mental health woes. In 2015, noted science writer Michael Pollan published a lengthy article on the topic, which featured two research teams studying psilocybin and depression. In December of 2016, these researchers published their findings from their studies at New York University and Johns Hopkins University. Both studies looked at severely depressed patients with life-threatening cancers. The patients were given a single dose of psilocybin in a supportive, safe setting. Up to 80% of the people receiving the drug not only felt better immediately, but were also less depressed six months later. The most common reported side effects were headache and increased heart rate and blood pressure. Up to 32% reported a brief period of anxiety, paranoia, or other psychological distress. None of the participants experienced major side effects or required medical intervention.
Does this prove that psilocybin is safe and effective for depression? Not at all. These are only the results of two studies involving fewer than 80 patients. Two systematic reviews on hallucinogens and mental health were published in 2016. In June, a research team from the University of Sao Paulo reviewed studies of hallucinogens for anxiety, depression, and addiction. They found a total of 151 published studies, but only 6 studies were the randomized controlled trials needed to prove effectiveness. Only four, involving a total of 46 patients, were on psilocybin. In December, a team from Johns Hopkins University published a more focused review on hallucinogens and depression. They analyzed 19 relevant studies involving a total of 423 participants, and found that 79% of participants experienced improvement. However, none of the included studies were on psilocybin.
One key focus of future research should be safety. Unlike in standard home or hospital settings, every participant in the cancer studies at New York University and Johns Hopkins received special on-going monitoring and counselling. As summarized in the Johns Hopkins review on hallucinogens for depression, the reported risks of hallucinogens are very low compared to some other medications such as opiates. However, they are known to cause paranoia and psychosis. There are also reports of people endangering themselves and others while “tripping”. The researchers cautioned that larger, longer-term studies are needed before we decide if and how psilocybin can be used safely.
These new studies add to a small but promising body of evidence on psilocybin and depression. Up to 30% of depressed patients do not respond to existing medications, leaving millions of global sufferers in need of new options. According to an editorial by leading researchers, current regulations on hallucinogens make it nearly impossible to carry out needed studies. In the future, we hope there will be an adequate evidence base to assess effectiveness and safety via a Cochrane systematic review. These ancient substances may offer insight into new doorways out of depression for modern-day sufferers.