In their recent article (Effects of Schedule I drug laws on neuroscience research and treatment innovation. Nature Rev. Neurosci. 14, 577–585 (2013))1, Nutt and colleagues show how the over-regulation of controlled substances lacks practical or scientific reasoning, hinders treatment innovation and shifts focus from curbing drug abuse to fighting substances that are less harmful and less addictive. Continuing this important and timely discussion, we evaluate the impact of drug laws on experimental (basic) research.

Animal models are indispensable for neuropsychiatric research2. Addressing 'grand' challenges in mental health3 (Supplementary information S1 (box)), basic studies of hallucinogens may alleviate human suffering4,5,6 by uncovering evolutionarily conserved mechanisms of drug-evoked brain disorders. However, over-reaching controlled-substance laws markedly limit this field. For example, classifying drugs under Schedule I creates negative bias, so that animal studies are often deemed as 'less clinically relevant' if they focus on psychedelic rather than on more traditional, well-studied substances. Applying for special licences is also particularly arduous for basic scientists in the field1. Although many researchers may wish to study hallucinogens7,8, time-consuming US Food and Drug Administration (FDA) approval is required for the federal Drug Enforcement Administration (DEA) licence, followed by licensing by the States' Boards of Pharmacy. Any new drug must be 'added' to the licence, which also takes time and leads to 'interesting' complications. For example, after our recent order of tetrahydrocannabinol resulted in approval for drug-containing cigarettes, it took an additional 4 weeks (with new paperwork and calls to various offices to explain that animals do not smoke) to obtain the ethanol-based drug solution.

The lack of reasonable and affordable access to psychotropic drugs is another obstacle for basic researchers. For example, 3,4-methylenedioxy-N-methylamphetamine from Sigma-Aldrich costs over US$400 for 50 mg, or over $7000 for a single-dose zebrafish experiment9. Another problem is the availability of certain controlled drugs. Consider ibogaine, an extremely potent, unique anti-addictive agent that combines pharmacological mechanisms of all known hallucinogens10. Currently, ibogaine is not produced by any US commercial vendor except for the US National Institute on Drug Abuse (NIDA) Drug Supply Program (Supplementary information S2 (box)). Without a Schedule I licence and access to this US National Institutes of Health (NIH) resource, our animal research10 would have been impossible — the misfortune of many laboratories worldwide where ibogaine is not offered by biomedical suppliers. Clearly, critical new knowledge can go undiscovered because of such limitations on translational preclinical drug research.

In summary, the growing interest in studying psychotropic drugs meets dated over-regulation that hinders translational biomedical research. As basic scientists, we are joining clinicians1 to increase public awareness of the current situation and convince legislators to remove unnecessary obstacles in this field. Potential practical solutions may include removing hallucinogens from Schedule I and/or placing all controlled drugs that are specifically used in basic research into a separate category (for example, in a 'Schedule VI' created especially for research-grade drugs). Finally, governments and funding bodies must encourage further basic studies of both the negative and positive effects of psychotropic controlled substances. Studying anti-addictive mechanisms of the hallucinogenic drug ibogaine is just one of many examples of how preclinical studies may offer important insights in this field. Despite the efforts of a few dedicated scientists1, new treatments for psychiatric disorders will continue to be greatly hindered unless the current stranglehold on generating clinical and basic knowledge is alleviated.