Kratom and Pain Tolerance: A Randomized, Placebo-Controlled, Double-Blind Study.

Background: Kratom has a long history of traditional medicine use in Southeast Asia. Consumption of kratom products has also been reported in the US and other regions of the world. Pain relief is among many self-reported kratom effects but have not been evaluated in controlled human subject research. Methods: Kratom effects on pain tolerance were assessed in a randomized, placebo-controlled, double-blind study. During a 1-day inpatient stay, participants received a randomized sequence of kratom and placebo decoctions matched for taste and appearance. Pain tolerance was measured objectively in a cold pressor task (CPT) as time (seconds) between the pain onset and the hand withdrawal from the ice bath. Health status, vital signs, objective, and subjective indicators of withdrawal symptoms, self-reported data on lifetime kratom use patterns, and assessments of blinding procedures were also evaluated. Results: Twenty-six males with the mean (SD) age 24.3 (3.4) years were enrolled. They reported the mean (SD) 6.1 (3.2) years of daily kratom consumption. Pain tolerance increased significantly 1 hour after kratom ingestion from the mean (SD) 11.2 (6.7) seconds immediately before to 24.9 (39.4) seconds 1 hour after kratom consumption (F(2,53.7)=4.33, p=0.02). Pain tolerance was unchanged after consuming placebo drinks: 15.0 (19.0) seconds immediately before and 12.0 (8.1) seconds 1 hour after consumption of placebo (F(2,52.8)=0.93, p=0.40). No discomfort or signs of withdrawal were reported or observed during 10-20 hours of kratom discontinuation. Conclusions: Kratom decoction demonstrated a substantial and statistically significant increase in pain tolerance. Further rigorous research on kratom pain-relieving properties and a safety profile is needed.

The prevalence of psychotic symptoms in kratom (Mitragyna speciosa Korth.) Users in Malaysia.

BACKGROUND: Kratom is a traditional medicinal herb widely used in Malaysia and Thailand. Despite its widespread use and statements by regulatory agencies on the potential for kratom-associated psychosis, there is little data regarding the prevalence of psychotic symptoms among kratom users. This study investigated the prevalence of psychosis among kratom users, described psychotic symptomatology and severity, while examining associations between kratom use characteristics and the occurrence of psychotic symptoms. METHODS: This cross-sectional clinical survey recruited 150 regular kratom users. The Mini International Neuropsychiatric Interview (MINI) and Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM-V) diagnostic criteria were used to evaluate psychotic symptomatology among kratom users, and the Brief Psychiatric Rating Scale (BPRS) was used to assess the severity of psychiatric symptoms. Chi-square tests with Yate's correction were performed to determine the association between kratom use characteristics and the occurrence of psychotic symptoms among kratom users in this study. RESULTS: Six out of 150 kratom users (4%) presented with any psychotic symptoms. The psychotic symptoms reported were positive symptoms and thought alienation, with a mean BPRS score of 33 (i.e., mild severity). Variables related to kratom use (such as intake of kratom with diphenhydramine, duration of kratom use, and quantity and frequency of daily kratom use) were not associated with the occurrence of psychotic symptoms among kratom users. CONCLUSION: Although psychotic symptoms could occur among regular kratom users, they were rare and not significantly associated with kratom use characteristics. We found no evidence of elevated psychosis among regular users.

Severity of Kratom (Mitragyna speciosa Korth.) Psychological Withdrawal Symptoms.

Kratom leaves (Mitragyna speciosa Korth.) are traditionally used in Southeast Asia for their medicinal value. Self-report studies suggest that cessation from chronic kratom tea consumption (freshly brewed kratom tea) was associated with unpleasant psychological symptoms. This study sought to assess the severity of anxiety and depression during kratom cessation. Regular kratom users (N = 150) were recruited from the northern state of Penang (Malaysia) for this retrospective study. The Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI) scales were used to assess the severity of the symptoms of anxiety and depression. Most respondents (70%) experienced symptoms of mild anxiety, while 81% experienced symptoms of mild depression during kratom cessation. Those who consumed higher quantities of kratom tea daily (≥4 glasses) had higher odds of reporting longer duration of kratom use history (OR = 4.8, 95% CI 2.3 -10.1, p < 0.001), higher frequency of daily kratom use (≥4 times) (OR = 72, CI 9.5- 543.1, p < 0.001), and were more likely to experience moderate symptoms of depression (OR = 2.9, CI 1.1-7.3, p = 0.020) during kratom cessation than those who consumed between one and three glasses of kratom tea per day. Cessation from regular and long-term kratom tea consumption was not associated with symptoms of high anxiety or depression.