A new study published online December 15 by the Journal of Psychoactive Drugs found regular kratom users suffered no significant cognitive impairment.
The study, conducted by kratom scientist Darshan Singh and others, focused on 100 participants from the Teluk Kumbar area, a town on the Penang Island of Malaysia. Seventy-five participants had been regular kratom tea drinkers for at least two years, and continued drinking the tea, without using other drugs, during the five-month study period from September 2016 to February 2017. The remaining 25 participants, acting as a control group, did not take kratom tea.
Six cognitive tests were given to each of the participants: Motor Screening Task (MOT), Paired Associates Learning (PAL), Delayed Matching to Sample (DMS), Spatial Working Memory (SWM), Reaction Time (RTI), and Attention Switching Task (AST).
Kratom users showed no significant impairment and diplayed similar results to that of the control group in all but one test.
The only exception was in the Paired Associates Learning (PAL) task, where kratom users performed poorly relative to controls; this is an indication of impairments in visual memory and new learning. Taken together [with the other tests], it can be concluded that kratom tea consumption does not impair memory function, as it does not affect visual matching ability and short-term visual recognition memory, and retention and manipulation of visuospatial information.
The result of the PAL test is the kind of detail the FDA will highlight in their next public condemnation of kratom, ignoring the context of the study and the fact that, overall, kratom did not show cognitive impairment. The authors did include a suggestion for the FDA:
Indeed, the Food and Drug Administration (FDA) has announced that there is no reliable evidence to support the use of kratom as a treatment for opioid use disorder (OUD); however, nine researchers continue to assert that kratom is not dangerously addictive, and is not similar to “narcotics like opioids” (Science Letter on Kratom 2018). These researchers claim that scheduling kratom under Schedule 1 of the Controlled Substances Act (CSA) could put users at risk of relapse to opioid use with potential consequence of overdose deaths…
Findings from a recent comprehensive review, on the other hand, showed that kratom had low potential for abuse, and did not cause serious public health problems. It may therefore be premature to criminalize its use under Schedule 1 of the Controlled Substances Act
Singh, D., Ph.D, Narayanan, S., Ph.D, Müller, C. P., Ph.D, Vicknasingam, B., Ph.D, Yücel, M., Ph.D, Ho, E., Ph.D, Hassan, Z., Ph.D, & Mansor, S. M., Ph.D (2019). Long-Term Cognitive Effects of Kratom (Mitragyna speciosa Korth.) Use. Journal of psychoactive drugs, 51(1), 19–27. https://doi.org/10.1080/02791072.2018.1555345