As with marijuana, though, studies like these are the exception, not the rule. It is very, very difficult to do research on psychedelic compounds because they, like pot, are classified as Schedule I controlled substances, meaning they have a very high potential for misuse and no accepted uses. Schedule II drugs also have a high potential for abuse, but are considered to have potential benefits. These include OxyContin, fentanyl, Percocet and even opium.

To engage in research in Schedule I drugs, scientists have to get approval from the Drug Enforcement Administration. To obtain a license, research labs must have inspections to prove that they are capable of storing the drugs and protecting them from misuse. In Britain, the added costs of licensing and security can cost a lab about £5,000 a year, or nearly $6,500. Unfortunately, the costs in the United States are not as well documented.

Because of this, much of the research on these drugs is old; a lot of it took place before the United States and other countries categorized these drugs in the 1960s. What research has occurred since has often taken place in countries that are more permissive in their experiments.

Given the potential dangers inherent in these drugs, it’s important to stress that research would need to be closely monitored. Although the drugs are relatively safe compared with substances like heroin or cocaine, and aren’t nearly as addicting, they still pose psychological and physical risks.

People with a family or personal history of psychotic or psychiatric disorders should be particularly wary, and perhaps be excluded from trials. Research requires safety monitoring, careful planning and significant support throughout. We need to watch carefully for adverse outcomes, both expected and unexpected. We need to make sure protocols are transparent and reproducible.

We also need to acknowledge that we need more research before anyone attempts to use these drugs as medicine. They’re typically coupled with professional therapy in studies, and we still aren’t sure there are benefits.

But it may be time to time to reconsider our current classification of controlled substances. Clearly we must continue to be vigilant about whether drugs pose physical harm to patients. But we could assess drugs using additional measurements, including the potential for dependence; social costs through damaged family and social life; and financial costs through health care, social care and the need for police involvement.