Novel methods for the remote investigation of emerging substances: Application to kratom

Chemical Analysis and Alkaloid Intake for Kratom Products Available in the United States

Previously, we used ecological momentary assessment (EMA) to evaluate motivations and temporal patterns of kratom use for 15 days among US adult kratom consumers (N = 357). Here we present the content analyses of the products used during that nationwide study, with quantification of 10 kratom alkaloids. The samples (N = 341) were primarily whole-leaf products, not extracts, and were similar to each other in their alkaloid composition, closely matching the chromatographic-mass spectrometry fingerprint expected for Mitragyna speciosa leaf material. We found no evidence of adulteration with illicit or prescription drugs. With participants' self-reported data on kratom amount per use, we calculated mitragynine intake per use: mean 31.3 mg and median 25.4 mg (range 2.0-205.9 mg). With self-reported data on frequency, we calculated mitragynine intake per day, it ranged from 78.3 to 134.6 mg (mean) or 50.8 to 101.6 mg (median). This is the most comprehensive analysis of US whole-leaf kratom products to date. The coupling of self-report and product sample-analysis data to quantify daily alkaloid intake is foundational for designing controlled clinical trials of kratom in healthy volunteers. These findings on kratom products' chemical composition and daily kratom alkaloid consumption can also inform clinicians, policymakers, and consumers, particularly for whole-leaf material.

At least four groups of kratom consumers in the United States: latent-class analysis of motivations for kratom use

Background: Kratom is a plant with alkaloids acting at opioid, serotonergic, adrenergic, and other receptors. Consumers report numerous use motivations.Objectives: To distinguish subgroups of kratom consumers by kratom-use motivations using latent-class analysis.Methods: From July to November 2022, we utilized convenience sampling and surveyed regular kratom consumers (n = 395, 38.1 years (SD 11.2), 54.9% male, 81.3% White) regarding demographics, lifetime and past-year substance use and preferences, substance use disorder history, healthcare barriers, kratom-use motivations, and general health. We used latent-class analysis to identify subgroups by use motivation and calculated conditional probabilities (Pc) for variables in each class.Results: A four-class model best fit our data. The largest class (32.4%) was characterized by the use of kratom for self-treatment of chronic pain (Pc = .91). The smallest class (19.2%) also reported using kratom for self-treatment, but usually as a long-term replacement for other substances (Pc = .75). The other two classes (24.8% and 23.5%) reported using kratom for management of anxiety (Pc = .87-.95) and depressive symptoms (Pc = .61-.89) and for recreation (Pc = .56- .86). These were distinguished from one another by probability of at least moderate kratom use disorder (Pc = .17 vs. .53), with greater probability observed in the class with greater anxiety (Pc = .13 vs. .50) and depressive (Pc = .34 vs. .82) symptom severity and more likely recreational use motivation (Pc = .56 vs. .86).Conclusion: Kratom consumers can be classified by their use motivations. As with other psychoactive substances, the range of motivations is consistent with the range of likely effects. It is not yet clear whether some motivations might indicate the risk of problems.

Kratom (Mitragyna speciosa) use for self-management of pain: Insights from cross-sectional and ecological momentary assessment data

Kratom (Mitragyna speciosa) is increasingly used in the US for self-management of pain, despite limited research on its efficacy and safety. To better understand how and why people use kratom for pain self-management, we analyzed baseline survey data (N = 395) and 15-day ecological momentary assessment (EMA) data (N = 357) from kratom consumers across the US. Although we recruited participants based on their kratom use, not on whether they used it for pain management, nearly half (49.1 %) met criteria for chronic pain, with many reporting substantial pain relief and high effectiveness of kratom in managing pain. A majority (69.2 %) reported difficulties in obtaining adequate pain treatment, and most indicated that these challenges impacted their decision to try kratom. Most participants did not report concerns about overuse or significant side effects. EMA data showed that, regardless of chronic-pain status, pain relief was the most frequently endorsed primary motivation for daily kratom use. There were no significant association between daily pain levels and kratom use frequency, and no difference in the daily kratom use between those with vs. without chronic pain. Recent kratom use was associated with lower current pain levels. Stronger subjective effects of kratom were associated with lower pain levels. This effect was significantly moderated by chronic-pain status: those with chronic pain showed a stronger link between subjective kratom effects and pain reduction. These findings underscore the urgent need for systematic, rigorous research on long-term implications, efficacy, and safety of kratom in pain management to guide informed clinical practices and regulatory policies. PERSPECTIVE: This study reveals that chronic pain is common among kratom consumers, who frequently use it for pain self-management and report significant relief, as shown by ecological momentary assessment. There is an urgent need for research into kratom's safety, efficacy, and mechanisms to guide clinical practice and inform policies.

Use of Cannabinoids by People Who Consume Kratom in the United States

OBJECTIVES

To estimate lifetime, past-year, and past-month prevalence of kratom, cannabis, and cannabidiol-only product use among adults 18 years and older in the United States, using 2 independent datasets.

METHODS

Utilizing ( a ) the 2022 National Survey on Drug Use and Health (NSDUH) and ( b ) a 2022 online national convenience sample of adults who use kratom regularly (from our research group at the National Institute on Drug Abuse [NIDA]), we examined key demographic information as well as lifetime, past-year, and past-month substance use and preferences.

RESULTS

Among the full sample of adults from the 2022 NSDUH, the prevalence of lifetime use was 49.69% for cannabis, 34.09% for cannabidiol-only products, and 1.93% for kratom. When solely examining participants who have used kratom, both independent datasets showed higher proportions of cannabis use over the lifetime-92.81% (95% confidence interval: 90.31-95.31) in the NSDUH subset and 92.16% (95% confidence interval: 89.37-94.95) in our NIDA sample.

CONCLUSIONS

Our study demonstrates that people are co-using kratom with cannabis and/or cannabidiol-only products at the same time or during the same time period, though more research is needed to understand people's motivations and practices for such co-use. Co-use might result in herb-herb interactions that may impact research findings and clinical outcomes for people who use kratom.

Prevalence of Kratom Use Disorder Among Kratom Consumers

OBJECTIVES

Kratom leaf products are increasingly consumed in the United States, with many consumers reporting they experience beneficial effects from kratom use. However, there is a growing concern for kratom's potential to result in dependence when used regularly. As such, we sought to assess, using Diagnostic and Statistical Manual of Mental Disorders , (DSM-5) , diagnostic criteria for substance use disorder, the prevalence of "kratom use disorder" (KUD) among kratom consumers.

METHODS

Our cross-sectional study used an online, anonymous survey between February and May 2023. Through nonprobability sampling, we recruited people older than 18 years who currently consume kratom. Participants were asked about their kratom consumption patterns, adverse effects perceived to stem from kratom consumption, comorbid diagnoses, and components for a DSM-5 , substance use disorder, adapted for kratom.

RESULTS

Among the total sample ( N = 2061), KUD criteria were met by 25.5% of participants ( n = 525); the most commonly reported symptoms were tolerance ( n = 427, 81.3%) and withdrawal ( n = 357, 68.0%). After adjusting for age, gender, daily frequency of kratom consumption, and history of either a substance use disorder or a mental health condition, those with a concurrent diagnosis of another substance use disorder had 2.83 times higher odds of meeting KUD criteria (95% CI, 2.19-3.67) compared with those without one.

CONCLUSIONS

In this large cross-sectional study, most participants who met the criteria for a KUD diagnosis were categorized as having a mild or moderate KUD. Individual characteristics associated with KUD were related to being male, young, consuming kratom frequently, and having psychiatric and substance use disorder comorbidities.

Effects of kratom on driving: Results from a cross-sectional survey, ecological momentary assessment, and pilot simulated driving Study

OBJECTIVES

Despite widespread kratom use, there is a lack of knowledge regarding its effects on driving. We evaluated the self-reported driving behaviors of kratom consumers and assessed their simulated-driving performance after self-administering kratom products.

METHODS

We present results from: 1) a remote, national study of US adults who regularly use kratom, and 2) an in-person substudy from which we re-recruited participants. In the national study (N = 357), participants completed a detailed survey and a 15-day ecological momentary assessment (EMA) that monitored naturalistic kratom use. For the remote study, outcomes were self-reported general and risky driving behaviors, perceived impairment, and driving confidence following kratom administration. For the in-person substudy, 10 adults consumed their typical kratom products and their driving performance on a high-fidelity driving simulator pre- and post-kratom administration was evaluated.

RESULTS

Over 90% of participants surveyed self-reported driving under the influence of kratom. Most reported low rates of risky driving behavior and expressed high confidence in their driving ability after taking kratom. This was consistent with EMA findings: participants reported feeling confident in their driving ability and perceived little impairment within 15-180 min after using kratom. In the in-person substudy, there were no significant changes in simulated driving performance after taking kratom.

CONCLUSIONS

Using kratom before driving appears routine, however, self-reported and simulated driving findings suggest kratom effects at self-selected doses among regular kratom consumers do not produce significant changes in subjective and objective measures of driving impairment. Research is needed to objectively characterize kratom's impact on driving in regular and infrequent consumers.

Ecological Momentary Assessment of Self-Reported Kratom Use, Effects, and Motivations Among US Adults

Importance

Kratom products, which are sold legally in most of the US, contain alkaloids with opioidergic, adrenergic, and serotonergic activity. Millions of people use kratom to relieve pain, improve mood, or self-manage substance use disorders (SUDs). Kratom use has primarily been examined via surveys, in which recall biases among satisfied users may lead to minimization of transient negative outcomes. Further prospective study of kratom use, such as with ecological momentary assessment (EMA), is needed.

Objective

To characterize proximal motivators, effects, and patterns of kratom use and to assess whether use frequency is associated with motivations, effects, past-year criteria for SUD for kratom (KUD), or other substance use.

Design, Setting, and Participants

For this prospective cross-sectional study, an intensive longitudinal smartphone-based EMA in which participants' current behaviors and experiences were repeatedly sampled in real time was conducted between July 1 and October 31, 2022. Participants comprised a convenience sample of US adults who used kratom at least 3 days per week for at least 4 weeks at the time of online screening. Criteria for past-year KUD were based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Data analysis was performed between November 2022 and November 2023.

Exposure

The exposure was 13 401 kratom-use events across 15 days.

Main Outcomes and Measures

A baseline survey covering demographics, health, kratom attitudes and behaviors, use motivations, other substance use, and KUD was administered before EMA. Data for the following EMA entries were then collected: event-contingent entries for kratom use (product, dose, and proximal motivations), follow-up entries (short-term effects and consequences of use events), random-prompt entries (mood), beginning-of-day entries (effects of kratom on sleep), and end-of-day entries (daily subjective descriptions of kratom effects). Bayesian regression was used to estimate means and credible intervals.

Results

A total of 357 participants completed the EMA. Their mean (SD) age was 38.0 (11.1) years; more than half were men (198 [55.5%]). Participants reported overall motivators of use on the baseline survey that involved managing psychiatric and SUD problems, but proximal motivators evaluated during the EMA involved situation-specific needs such as increasing energy and productivity and decreasing pain. Acute effects were considered congruent with daily obligations. Use patterns, despite having some distinguishing features, were generally similar in their motivators and effects; participants used kratom predominantly during the daytime and seemed to find use frequencies that suited their needs. Higher use patterns were associated with symptoms of physical dependence (eg, withdrawal or tolerance). Co-used substances included caffeine, nicotine, vitamins, and cannabis.

Conclusions and Relevance

Most participants in this study reported using kratom in a seemingly nonproblematic way. When such use appeared problematic, the key element was usually that withdrawal avoidance became a proximal motivator. Longitudinal studies examining changes in kratom use patterns and effects over time are needed.

An update on the clinical pharmacology of kratom: uses, abuse potential, and future considerations

INTRODUCTION

Kratom (Mitragyna speciosa) has generated substantial clinical and scientific interest as a complex natural product. Its predominant alkaloid mitragynine and several stereoisomers have been studied for activity in opioid, adrenergic, and serotonin receptors. While awaiting clinical trial results, the pre-clinical evidence suggests a range of potential therapeutic applications for kratom with careful consideration of potential adverse effects.

AREAS COVERED

The focus of this review is on the pharmacology, pharmacokinetics, and potential drug-drug interactions of kratom and its individual alkaloids. A discussion on the clinical pharmacology and toxicology of kratom is followed by a summary of user surveys and the evolving concepts of tolerance, dependence, and withdrawal associated with kratom use disorder.

EXPERT OPINION

With the increasing use of kratom in clinical practice, clinicians should be aware of the potential benefits and adverse effects associated with kratom. While many patients may benefit from kratom use with few or no reported adverse effects, escalating dose and increased use frequency raise the risk for toxic events in the setting of polysubstance use or development of a use disorder.