Correlations of Kratom (Mitragyna speciosa Korth.) Use Behavior and Psychiatric Conditions from a cross-sectional survey

Abstract

Kratom (Mitragyna speciosa Korth.) use has increased substantially over the past decade outside of its indigenous regions, especially for the self-treatment of psychiatric conditions. An anonymous, cross-sectional, online survey was completed by 4,945 people who use kratom (PWUK) between July 2019 and July 2020. A total of 2,296 respondents completed an extended survey that included clinical scales for measuring attention deficit hyperactivity disorder (ADHD), post-traumatic stress disorder (PTSD), depressive and anxiety disorders.

PWUK and met criteria for ADHD, PTSD, depressive or anxiety disorders were primarily middle-aged (31–50 years), employed, college-level educated, and reported greater concurrent or prior use of kratom with cannabis, cannabidiol, and benzodiazepines. For all psychiatric conditions, PWUK reported decreased depressive and anxious moods than before kratom use. Based on this self-report study, observational and other clinical studies are warranted for kratom.

INTRODUCTION

Kratom, also known as Mitragyna speciosa Korth., is a Southeast Asian plant with a wide variety of traditional uses. Its complex pharmacology produces various reported effects, including analgesia, stimulation, mood enhancement, and mitigation of withdrawal from opioids and other problematic substances, such as alcohol (Babu et al., 2008; Smith, Dunn, et al., 2021; Smith, Rogers, et al., 2022; Swogger & Walsh, 2018). Kratom’s popularity outside of Southeast Asia has grown over the past decade. The main pharmacological active ingredients studied are mitragynine (MG) and 7-hydroxymitragynine (7-OHMG), which bind to the mu-opioid receptor as partial agonists (Hemby et al., 2019). While the potency of MG is relatively lower compared to morphine, 7-OHMG presents with a higher potency, at least as evaluated in cell-based assays and animal experiments (Obeng et al., 2021). Both have been identified to be biased G-protein coupled receptor (GPCR) partial agonists without beta-arrestin recruitment, which is potentially associated with less respiratory depression (Kruegel & Grundmann, 2017; Singh et al., 2016).

The method for consuming kratom leaves depends on the region and the preference of the individual. These methods include smoking or chewing fresh leaves (particularly in Southeast Asia) or using them to brew tea (Singh et al., 2016). A pulverized powder form of dried leaves is also commonly used, either taken in capsules or by brewing a decoction of the powder. Kratom’s effects rely on the amount consumed: lower doses are associated with stimulant effects, while higher doses are associated with sedative and analgesic effects (Singh et al., 2016). Although kratom has been used to attenuate withdrawal symptoms from other substances (opioids, amphetamine, cannabis, barbiturates, nicotine, etc.), some reports indicate that regular kratom use at higher doses can cause dependence (i.e., tolerance and withdrawal symptoms) (Agapoff & Kilaru, 2019; Smith, Dunn, Rogers, Garcia-Romeu, et al., 2022; Smith, Rogers, et al., 2022).

Globally, studies demonstrate that people use kratom as a harm-reduction strategy, substituting kratom for opioids. (Garcia-Romeu et al., 2020; Grundmann, 2017; Singh et al., 2022; Smith & Lawson, 2017; Swogger & Walsh, 2018). This substitution for purposes of harm-reduction has arisen, in part, because kratom is easy to obtain online and in local shops, following purchasing trends that have been common for novel psychoactive substances in recent decades (Schifano et al., 2005). Globally, countries have different kratom regulations. Kratom is currently scheduled as a controlled substance in several countries including Malaysia, Australia, and the United Kingdom. In the United States, kratom regulation varies across states. It is presently banned in Indiana, Arkansas, Alabama, Rhode Island, Vermont, and Wisconsin (Swogger et al., 2022). To date, kratom is not regulated by the US Food and Drug Administration (FDA) and can be legally purchased in different forms, including capsules, powders, flavored tea, and extracts.

US surveys of people who use kratom (PWUK) regularly have found that it is primarily taken by people between 31–50 years old on average, who have a median income of $35,000 or above, and who use it as a nonmedical self-treatment for pain, anxiety, mood disorders, or other health conditions (Bath et al., 2020; Garcia-Romeu et al., 2020; Grundmann, 2017; Smith, Rogers, Schriefer, et al., 2021). It has also been used to enhance energy and focus, and to self-treat attention deficit hyperactivity disorder (ADHD) and post-traumatic stress disorder (PTSD; (Smith, Dunn, Rogers, Grundmann, et al., 2022; Smith, Rogers, Schriefer, et al., 2021)

Kratom research is ongoing, however preliminary data indicate the potential for some kratom alkaloids to act in an antipsychotic or antidepressant manner (Idayu et al., 2011; Johnson et al., 2020). Though kratom has well-established affinity for opioid receptors, some findings suggest it also has affinity for serotonin and dopamine receptors. This may help explain why kratom has been widely used for self-treatment of mood and anxiety symptoms. Taken together, self-report data from PWUK and preclinical findings indicate a need to systematically investigate kratom for its potential medical utility in treating anxiety, mood, and other psychological conditions.

There is also a need because such conditions are persistently endemic while medical treatments remain limited (Smith, Rogers, Schriefer, et al., 2021). In one international meta-analyses, the estimated lifetime PTSD clinical prevalence ranged from 14.5% to 48.8% (Spottswood et al., 2017). Likewise, a cross-national comparison of major depression from 10 population-based surveys estimated lifetime prevalence of Major Depressive Disorder (MDD) in the US at 16.9% (Kessler & Bromet, 2013). Lifetime prevalence of generalized anxiety disorder (GAD) was estimated at 9.0% (Kessler et al., 2012) whereas ADHD was estimated at 8.1% for all age groups (Kessler et al., 2005).

Given this public health burden, the associations between kratom use and these psychological disorders, and the alleviation of psychological symptoms that PWUK report (Smith, Dunn et al., 2022), we aimed to further investigate the associations of these conditions with the demographic characteristics of PWUK. We also aimed to further examine the perceived benefits of kratom use for the non-medical self-treatment of psychological conditions. To do this, we added additional scales measuring physical and psychological health disorders to an ongoing international cross-sectional survey. For respondents who completed this expanded survey, we were able to assess the relationship between respondents’ demographics, general health status, psychological health, and scores on validated psychometric scales for ADHD, PTSD, depression, and anxiety. These were then considered in light of respondents’ reported kratom experiences, including use patterns and perceived benefits from kratom. Given the high rates of comorbidity for psychological disorders and substance use we also assessed reasons for kratom use that included use as a drug substitution, a harm-reduction strategy. Additional data from this large survey have been published elsewhere (Grundmann, Veltri, Morcos, Knightes III, Smith, Singh, et al., 2022).

METHODS

We report how we determined all data exclusions, all manipulations to the raw data, and all measures in the study. No sample size was calculated but we instead determined the length of the survey availability prior to starting the survey.

Survey setting, approval, and data collection

This anonymous survey was conducted online between July 2019 and July 2020. Data were collected using Qualtrics (Qualtrics, Provo, UT) (Grundmann, Veltri, Morcos, Knightes III, Smith, Singh, et al., 2022; Snow & Mann, 2013). A snowballing technique was used for the distribution of the survey in North America, Europe, and Southeast Asia via social media channels and kratom-related social media groups. Kratom vendors also distributed survey information as did the American Kratom Association (https://www.americankratom.org/). No incentives were provided for survey participation. Inclusion criteria were attestation of being ≥18 years and acknowledgment of the consent statement. Repeated responding was prevented by intermittently storing internet protocol addresses that were deleted once a respondent completed the survey or remained inactive for 48 hours. All study procedures were approved by the Institutional Review Board at the University of Florida (IRB #2019–01121).

Survey instrument

A locally developed kratom survey instrument was designed using the consensus input and expertise of the study team (see supplementary material for instrument). Here, we focused on the following survey domains:

Demographics: country of residence, age, gender, marital status, ethnicity, employment status, and education.

General health status was measured using the 5-level EQ-5D (Oppe et al., 2014).

Overall health was measured by asking participants to rate their overall health using a visual analogue scale (VAS) (Gudex et al., 1996). Participants were also asked to provide reasons for healthcare visits, self-rated pain (VAS), and to report any health conditions ever diagnosed by a medical professional. Participants were also asked how kratom use affected their health conditions and provided either beneficial or detrimental effects than before use.

Kratom use experience was measured by asking participants to respond to questions pertaining to aspects that comprise kratom use in the greater context of their health. Kratom use questions included length of use (less than 6 months to more than 5 years), amount used per dose (under 1 gram to more than 8 grams), frequency of use per day (sporadic to more than 4 times/day), and product characterization (e.g., powdered kratom, capsules or tablets, chewing or smoking of leaves).

Extended survey questions on psychological health disorders included the Adult ADHD Respondents were assigned by the Qualtrics software to complete the extended survey with the goal to enroll about half of participants at random. Self-Report Scale v 1.1 (Hines et al., 2012), the Primary Care PTSD Screen for DSM-5 (Prins et al., 2016), and the Symptom Checklist-90-Revised (SCL-90) for depressive and anxiety disorders (Morgan et al., 1998). For a respondent to be considered as having met clinically significant diagnostic criteria for a given condition, the evaluation criteria and cut-off points for each scale had to be met. For ADHD, respondents had to select “often” or more frequently on four out of six questions in part A to meet criteria. For PTSD, at least three out of five questions had to be answered with “yes” to meet criteria. For the depression and anxiety dimensions of the SCL-90, a respondent had to select a three or four (“quite a bit” or “extremely”) in seven out of thirteen questions for the depression dimension and six out of ten for the anxiety dimension. As no psychiatrist confirmed the diagnosis, the evaluations based on self-report can only reflect a greater presence of symptoms for each disorder and the likely need for medical care.

Data analysis

Data were analyzed in GNU PSPP (http://www.gnu.org/software/pspp/, version 0.10.4-g50f7b7) and SPSS Statistics (version 26, IBM, Armonk, NY). Correlational analyses were conducted using either a chi-square or logistic regression analysis. Chi-square analysis was performed for nominal and ordinal variables against expected values for goodness of fit. Odds ratios were calculated using binomial logistic regression with one level set as the comparator with a 95% confidence interval. Logistic regression models included all pertinent independent variables in the same model comparing all levels against each other (Bonferroni adjustment for comparisons among levels, post-survey power calculation resulted in at least 85% power and 93% confidence for all models). Materials and analysis code for this study are available by emailing the corresponding author. This study was not preregistered.

RESULTS

A total of 7,381 responses were collected. Only respondents that completed at least 80% of the survey including the demographics section were considered valid responses (5,152; 69.8%). Any respondents who had never heard of kratom (n=971) or had never used kratom (n=888) were directed to the end of the survey, not considered valid responses, and excluded from analysis. Of the valid responses, 2,296 (44.6%) respondents answered the extended survey questions assessing psychiatric conditions which were included in the analyses. Those who used kratom but did not meet criteria for any psychiatric condition composed the comparator (i.e., negative) group. All respondents are either past or current kratom consumers with a length of use ranging from <6 months to >5 years.

Demographics

Most respondents were male between the ages of 31–60 years (65.52%), married, white non-Hispanics, employed, and had some college education (73.02%). Anxiety, depression, PTSD, and ADHD were the most commonly self-reported psychiatric conditions diagnosed by a healthcare provider (Table 1).

Table 1:

Demographics, self-reported health diagnoses, and kratom use experience of people who use kratom and met the inclusion criteria for ADHD, PTSD, anxiety disorders, or depressive disorders. NA: not applicable. VAS score: visual analogue score only applies to the diagnosed health condition and the change in condition after initiation of kratom use on a 0–10 scale, with 5 being no change, >5 to 10 being improvement, and 0 to <5 being worsening of the condition. The mean VAS score is given for each condition.

	Frequency		Percent	VAS score	Chi-square
Age
18–20 years	33		1.33%	NA	p<0.0001
21–30 years	277		11.16%
31–40 years	636		25.61%
41–50 years	564		22.71%
51–60 years	427		17.20%
61 years and older	359		14.46%
Sex
Female	1021		41.12%	NA	p<0.0001
Male	1264		50.91%
Transgender	7		0.28%
Marital status
Single/never married	495		19.94	NA	p<0.0001
Married	1097		44.18
Partnered	272		10.95
Divorced	358		14.42
Widowed	52		2.09
Race/Ethnicity
Black or African-American	11		0.44%	NA	p<0.0001
Asian	47		1.89%
Hispanic or Latino/a	49		1.97%
White (Non-Hispanic)	2074		83.53%
American Indian or Alaska Native	22		0.89%
Other	48		1.93%
Employment status
Employed for wages	1080		43.50%	NA	p<0.0001
Self employed	358		14.42%
Out of work for 1 year or more	56		2.26%
Out of work for less than 1 year	49		1.97%
Homemaker	124		4.99%
Student		67	2.70%
Retired		230	9.26%
Unable to work		264	10.63%
Employed – currently off sick		17	0.68%
Education
Did not complete High school		54	2.17%	NA	p<0.0001
High School graduate or equivalent		393	15.83%
Some college (e.g. AA, AS, or no degree)		1028	41.40%
Bachelor’s degree (e.g. BA, BS, AB)		537	21.63%
Advanced degree (e.g. MBA, MS, PhD, JD, MD)		248	9.99%
Have you been told by a physician or medical professional that you have any of the conditions listed below (select all that apply)? Due to multiple selection of conditions, percentages do not add up to 100%.
Anxiety		1338	53.89%	8.96	NA
Back pain		1295	52.15%	8.90
Chronic pain		1269	51.11%	8.84
Depression		794	31.98%	8.92
Acute pain		543	21.87%	8.89
Other		406	16.35%	NA
ADHD/ADD (Attention Deficit Hyperactivity Disorder/Attention Deficit Disorder)		408	16.43%	9.00
Fibromyalgia		389	15.67%	8.76
PTSD (Post-Traumatic Stress Disorder)		333	13.41%	9.02
Rheumatoid arthritis		265	10.67%	8.98
Substance use disorder (alcohol, prescription drugs, illicit drugs)		191	7.69%	9.20
Bipolar disorder		200	8.05%	9.12
Personality disorder		81	3.26%	9.10
Schizophrenia or other psychotic disorder		22	0.89%	8.80
How did you find out about kratom?
Internet search		958	38.6%
Friend		694	28.0%
Family member		299	12.0%
Social media		246	9.9%
Other		235	9.5%
Health care provider (physician, nurse, pharmacist)		51	2.1%
If you have ever used or are currently using Kratom, what is/are your sources for obtaining Kratom (select all that apply)?
Online (legal)		2061	83.0%
Smart shop or other shops		464	18.7%
Other		203	8.2%
Food/Nutrition store		195	7.9%
Friends/Family		148	6.0%
Darkweb (illegal)		8	0.3%
Clubs/Nightlife		5	0.2%
Pharmacy		2	0.1%
How long have you been affected by a medical condition prior to taking Kratom?
Less than 1 year		53	2.1%
1–2 years		163	6.6%
2–5 years		384	15.5%
More than 5 years		1635	65.8%
Not applicable		248	10.0%
How long has it been since you first consumed Kratom?
Less than 6 months		207	8.3%
6 months-1 year		262	10.6%
1–2 years		676	27.2%
2–5 years		929	37.4%
More than 5 years		409	16.5%
What is the usual amount of Kratom you take/have taken per dose?
Less than 1 gram		102	4.1%
1–3 grams		840	33.8%
3–5 grams		772	31.1%
5–8 grams		427	17.2%
More than 8 grams		197	7.9%
How many times on average do you use/have used Kratom per day?
I had sporadic use in the past		67	2.7%
Less than once per day		192	7.7%
Once per day		323	13.0%
2 times/day		604	24.3%
3 times/day		725	29.2%
4 times/day		355	14.3%
More than 4 times/day		211	8.5%
How do you usually use/have used Kratom?
Powdered Kratom consumed with beverage		1257	50.6%
Powdered Kratom (pure or in pill/tablet/capsule form)		799	32.2%
Self-prepared Kratom tea/infusion		312	12.6%
Other		63	2.5%
Powdered Kratom consumed with food		33	1.3%
Store-bought liquid Kratom (shot)		17	0.7%
Chewing it		2	0.1%
Smoking it		0	0.0%
Did you increase the regular dose of Kratom over the course of time?
Yes		792	31.9%
No		1668	67.2%
Do not wish to answer		10	0.4%

Distinct demographic patterns associated with psychiatric conditions

For respondents who met ADHD criteria, most were between age 31–50 (50.50%), male, married, white non-Hispanic, employed, and had some college education (80.30%). Of those who met PTSD criteria, most respondents were between age 31–50 (56.80%), female, married, white non-Hispanic, employed, and had some college education (84.40%). Most respondents who met criteria for a depressive disorder were of age 31–50 years (51.6%), male, married, white non-Hispanic, employed, and had some college education (80.00%). For those meeting criteria for an anxiety disorder, most were of age 31–50 (53.4%), equally affecting male and female participants, married, white non-Hispanic, employed, and had some college education (80.60%) (Table 2).

Table 2:

Percentages of demographic variables by psychiatric conditions compared to average kratom users not meeting inclusion criteria for a psychiatric condition.

Variable	N	Average	ADHD	PTSD	Depression	Anxiety
		Negative	Positive	Positive	Positive	Positive
Age
18–20 years	61	1.15%	2.60%	2.30%	1.90%	1.80%
21–30 years	640	10.18%	20.30%	14.50%	14.00%	14.20%
31–40 years	1407	27.75%	27.20%	35.00%	27.30%	28.80%
41–50 years	1209	25.10%	23.30%	21.80%	24.30%	24.60%
51–60 years	918	19.43%	17.40%	18.60%	18.20%	17.30%
61 years and older	710	15.65%	1.70%	7.70%	7.70%	13.40%
Sex
Female	2265	43.25%	48.10%	57.70%	46.30%	49.40%
Male	2650	56.38%	51.90%	42.30%	53.40%	50.30%
Marital status
Single/Never married	1085	19.7%	28.53%	22.57%	26.65%	25.02%
Married	2418	51.85%	41.65%	41.15%	41.73%	42.84%
Partnered	544	11.40%	12.85%	14.16%	12.39%	13.37%
Divorced	733	15.12%	14.40%	19.03%	16.63%	16.62%
Widowed	122	1.94%	2.57%	3.10%	2.61%	2.14%
Race/Ethnicity
Black or African-American	29	0.43%	0.80%	0.90%	0.40%	0.40%
American Indian or Alaska Native	40	1.13%	0.80%	0.50%	1.00%	1.00%
Asian	111	2.18%	1.00%	1.40%	1.50%	1.10%
Hispanic or Latino/a	113	2.18%	3.40%	0.90%	2.30%	2.40%
White (Non-Hispanic)	4446	92.0%	90.60%	94.10%	92.40%	92.60%
Other	110	2.13%	3.40%	2.30%	2.40%	2.40%
Employment status
Employed for wages	2401	50.00%	39.00%	46.10%	44.50%	45.40%
Self employed	731	17.28%	13.10%	8.80%	14.00%	14.20%
Out of work for 1 year or more	105	1.80%	5.00%	4.10%	3.60%	3.50%
Out of work for less than 1 year	83	1.65%	3.70%	0.90%	3.20%	3.30%
Homemaker	298	5.28%	6.50%	6.90%	6.00%	6.60%
Student	150	2.38%	5.80%	2.80%	3.60%	3.60%
Unable to work	463	10.15%	19.10%	20.70%	14.70%	14.00%
Retired	581	10.95%	6.50%	7.40%	9.40%	8.60%
Employed – currently off sick	33	0.53%	1.30%	2.30%	1.00%	0.90%
Education
Did not complete High school (reference)	109	2.43%	1.80%	1.80%	2.70%	2.00%
High school graduate or equivalent	863	17.55%	18.00%	13.70%	17.30%	17.40%
Some college (e.g. AA, AS, or no degree)	2254	45.35%	49.50%	50.70%	46.30%	47.30%
Bachelor’s degree (e.g. BA, BS, BA)	1127	23.40%	21.20%	23.70%	23.30%	23.30%
Advanced degree (e.g. MBA, MS, PhD, JD, MD)	520	11.28%	9.60%	10.00%	10.40%	10.00%

Kratom use experience in psychiatric conditions

Like prior surveys, most respondents meeting inclusion criteria for a psychiatric condition learned about kratom either online or from a friend (66.6%) and 83% purchase kratom legally from online retailers (Table 1). About two-thirds (68.3%) had a diagnosed medical condition for more than five years prior to taking kratom and about the same percentage (64.6%) have been using kratom for one to five years. The survey did not distinguish between past or current kratom use, i.e., that a respondent may have used kratom for a period of time and then stopped using. Those who met inclusion criteria for a psychiatric condition reported improvement of their medical condition with the use of kratom on a VAS scale (1–4 rating indicates worsening, 5 indicates unchanged, and 6–10 indicates improvement of the condition), but to a lesser extent than those who did not meet inclusion criteria (Figure 1). More than half of respondents (64.9%) consume between one and five grams of kratom per dose and use kratom two to three times per day (53.5%) (Table 1). Most (82.8%) consume kratom in powder form with a beverage or the powder in a pill, capsule or tablet form whereas only two respondents reported chewing the leaves and none smoked kratom (Table 1).

Figure 1:

Change in medical condition visual analogue scale (VAS) with kratom use for each psychiatric condition and the average score of participants not meeting inclusion criteria. A score from 1–4 indicates worsening of the condition, a score of 5 indicates no change in the condition, and scores from 6–10 indicate an improvement of the condition.

Prior or concomitant use of other substances with kratom in psychiatric conditions

Respondents who reported a psychiatric condition (ADHD, anxiety, depression, and PTSD) and used kratom were more likely to use benzodiazepines (ADHD, 7.51% vs. 4.43%; Anxiety, 8.28% vs. 2.21%; Depression, 7.72% vs. 2.34%; PTSD, 8.61% vs. 4.56%) and cannabis (ADHD, 19.37% vs. 11.38%; Anxiety, 15.71% vs. 11.65%; Depression, 16.80% vs. 8.31%; PTSD, 18.85% vs. 11.87%). Use of cannabidiol (CBD) oil with kratom was more likely among respondents reporting ADHD and depressive disorders (ADHD, 15.50% vs. 10.64%; Depression, 14.95% vs. 7.51%). Among respondents reporting depressive disorders, concomitant kava or cocaine use with kratom was more likely (kava, 3.78% vs. 2.02%; cocaine, 0.80% vs. 0.08%) (Table 3).

Table 3:

Prior or concomitant use of other substances with kratom in psychiatric conditions.

	ADHD				PTSD				Depression				Anxiety
	N (%)	OR	95% CI	p-value	N (%)	OR	95% CI	p-value	N (%)	OR	95% CI	p-value	N (%)	OR	95% CI	p-value
If yes, which of the following drug(s)/substance(s) have/are you taking Kratom with (select all that apply)?
CBD (Cannabidiol) oil	64 (15.50)	1.54	1.14–2.09	0.007	33 (13.52)	1.29	0.87–1.91	0.211	186 (14.95)	2.17	1.67–2.82	<0.01	157 (13.26)	1.21	0.9–1.62	0.195
Ketamine or other anesthetic/dissociative drugs	4 (0.97)	2.31	0.6–7.71	0.198	0		NA		8 (0.64)	1.6	0.52–4.9	0.406	9 (0.76)	2.59	0.56–12.02	0.184
Benzodiazepines	31 (7.51)	1.75	1.14–2.68	0.013	21 (8.61)	1.97	1.21–3.22	0.011	96 (7.72)	3.49	2.29–5.33	<0.01	98 (8.28)	3.99	2.3–6.93	<0.01
Amphetamine	13 (3.15)	1.63	0.86–3.1	0.149	9 (3.69)	1.92	0.9–3.992	0.103	36 (2.89)	2.28	1.26–4.13	0.005	40 (3.38)	3.92	1.65–9.29	<0.01
Cannabis (marijuana, hashish)	80 (19.37)	1.87	1.41–2.48	<0.01	46 (18.85)	1.72	1.22–2.44	0.003	209 (16.80)	2.23	1.73–2.86	<0.01	186 (15.71)	1.41	1.07–1.87	0.015
Fentanyl or other synthetic opioids	9 (2.18)	1.22	0.58–2.57	0.605	4 (1.64)	0.95	0.34–2.69	0.924	27 (2.17)	1.7	0.91–3.16	0.091	24 (2.03)	1.15	0.57–2.31	0.696
Heroin	0		NA		2 (0.82)	5.91	0.98–35.54	0.08	2 (0.82)	1.5	0.25–8.96	0.657	3 (0.24)	1.72	0.18–16.57	0.625
Tryptamines	3 (0.73)	1.98	0.51–7.68	0.349	0		NA		6 (0.48)	1.2	0.36–3.93	0.767	5 (0.42)	0.95	0.23–4.01	0.949
Synthetic cannabinoids	0		NA		0		NA		0		NA		0		NA
Methadone or other prescribed medications to treat opioid/heroin dependence	1 (0.24)	0.92	0.11–7.89	0.938	2 (0.82)	3.54	0.68–18.36	0.175	4 (0.32)	1	0.25–3.99	0.995	3 (0.25)	0.57	0.12–2.84	0.497
Mephedrone or any other synthetic cathinones	0		NA		0		NA		0		NA		0		NA
Phenylethylamines (e.g. 2C-E, AL-LAD, 4-HO-MiPT)	2 (0.48)	1.53	0.31–7.63	0.614	0		NA		7 (0.56)	3.5	0.73–16.88	0.087	6 (0.51)	3.45	0.41–28.7	0.19
Kava	18 (4.36)	1.62	0.94–2.8	0.097	11 (4.51)	1.7	0.8–3.298	0.135	47 (3.78)	1.91	1.17–3.12	0.008	47 (3.97)	1.71	0.96–3.04	0.058
Cocaine	1 (0.24)	0.46	0.06–3.59	0.409	2 (0.82)	1.96	0.4–9.142	0.424	10 (0.80)	10.03	1.28–78.49	0.003	10 (0.84)	0.63	0.61–0.66	0.003
Hallucinogenic mushrooms	5 (0.22)	1.28	0.47–3.47	0.635	3 (1.23)	1.39	0.41–4.75	0.609	15 (1.21)	1.67	0.73–3.83	0.22	16 (1.35)	1.31	0.54–3.21	0.544
Others (please specify):	44 (10.65)	1.25	0.88–1.78	0.217	24 (9.84)	1.14	0.73–1.79	0.561	137 (11.01)	1.68	1.27–2.23	<0.01	128 (10.81)	1.18	0.86–1.63	0.296

Self-reported beneficial effects of kratom use in psychiatric conditions

The most beneficial effects of kratom use reported across all four psychiatric conditions evaluated were: fewer depressive symptoms (ADHD, 79.9% vs. 66.33%; PTSD, 86.89% vs. 67.09%; Depression, 79.8% vs. 58.03%; Anxiety, 78.13% vs. 60.62%), decreased anxiety symptoms (ADHD, 79.18% vs. 65.65%; PTSD, 86.07% vs. 66.34%; Depression, 76.45% vs. 59.56%; Anxiety, 78.63% vs. 58.85%), and decreased PTSD symptoms (ADHD, 27.60% vs. 15.49%; PTSD, 52.46% vs. 14.15%; Depression, 24.04% vs. 11.62%; Anxiety, 25.34% vs. 9.73%). Kratom users ever diagnosed with ADHD were less likely to report sleep improvement (47.94% vs. 55.74%) and decreased pain (ADHD, 83.29% vs. 87.99%) whereas those who met PTSD or anxiety criteria were more likely to report decreased pain (PTSD 91.39% vs. 86.31%; Anxiety, 88.77% vs. 84.96%) and experience an elevated mood, euphoria or “high” (ADHD, 33.17% vs. 25.18%; Depression, 31.83% vs. 21.15%; Anxiety, 31.50% vs. 23.75%). Sleep improvement, (61.48% vs. 52.93%), sexual enhancement (18.44% vs. 11.82%), and increased focus (64.75% vs. 58.19%) were more commonly experienced by those meeting PTSD criteria. Among respondents reporting depression and anxiety, reducing or stopping other substance use (Depression, 18.25% vs. 13.64%; Anxiety, 18.58% vs. 14.45%) and experiencing an increase in empathy (Depression, 21.95% vs. 17.51%; Anxiety, 23.06% vs. 17.40%) were more likely to be reported (Table 4).

Table 4:

Self-reported beneficial and detrimental effects of kratom use in psychiatric conditions.

	ADHD				PTSD				Depression				Anxiety
	N (%)	OR	95% CI	p-value	N (%)	OR	95% CI	p-value	N (%)	OR	95% CI	p-value	N (%)	OR	95% CI	p-value
Which positive or beneficial effects have you experienced when using Kratom? (select all that apply)
Increased energy	328 (79.42)	1.14	0.88–1.49	0.309	194 (79.51)	1.08	0.78–1.5	0.628	956 (38.50)	0.86	0.71–1.04	0.121	936 (50.27)	1.18	0.95–1.48	0.141
Decreased pain	344 (14.89)	0.68	0.51–0.91	0.012	223 (9.32)	1.68	1.06–2.68	0.019	1095 (44.10)	1.22	0.96–1.54	0.1	1051 (56.44)	1.4	1.06–1.85	0.018
Increased focus	249 (10.77)	1.1	0.88–1.37	0.393	158 (6.61)	1.32	1–1.74	0.047	738 (29.72)	1.05	0.9–1.24	0.513	718 (38.56)	1.18	0.97–1.43	0.091
Less depressive mood	330 (79.90)	2.02	1.56–2.61	<0.01	212 (86.89)	3.25	2.22–4.76	<0.01	993 (79.82)	2.86	2.39–3.42	<0.01	993 (78.13)	2.32	1.89–2.85	<0.01
Less anxious mood	327 (79.18)	1.99	1.54–2.57	<0.01	210 (86.07)	3.13	2.16–4.55)	<0.01	951 (76.45)	2.2	1.85–2.62	<0.01	951 (78.63)	2.57	2.09–3.16	<0.01
Reduced or stopped use of opioid painkillers	189 (45.76)	0.92	0.74–1.14	0.432	127 (52.05)	1.21	0.93–1.58	0.16	594 (47.75)	0.99	0.84–1.15	0.86	578 (48.82)	1.09	0.9–1.32	0.358
Reduced PTSD symptoms	114 (27.60)	2.08	1.62–2.67	<0.01	128 (52.46)	6.69	5.06–8.85	<0.01	299 (24.04)	2.41	1.94–2.99	<0.01	300 (25.34)	3.15	2.36–4.19	<0.01
Elevated mood, euphoria or feeling “high”	137 (33.17)	1.47	1.17–1.86	<0.01	71 (2.97)	1.14	0.85–1.53	0.378	396 (31.81)	1.74	1.45–2.09	<0.01	373 (20.03)	1.48	1.19–1.83	<0.01
Other (please specify)	56 (13.56)	1.46	1.06–2.01	0.024	28 (11.48)	1.2	0.79–1.82	0.41	128 (5.16)	1.01	0.78–1.31	0.921	131 (11.06)	1.03	0.76–1.4	0.843
No positive or beneficial effects from Kratom use	0		NA		0		NA		2 (0.08)	1	0.14–7.08	0.997	2 (0.11)	1.15	0.1–12.66	0.911
Reduced or stopped the use of other drugs (e.g. heroin, cocaine, ketamine, cannabis)	75 (18.16)	1.21	0.92–1.6	0.185	48 (19.67)	1.31	0.93–1.83	0.127	227 (18.25)	1.41	1.14–1.76	0.002	220 (18.58)	1.35	1.04–1.75	0.021
Increased empathy	94 (22.76)	1.23	0.95–1.59	0.113	57 (23.36)	1.26	0.92–1.73	0.155	273 (21.95)	1.32	1.09–1.62	0.005	273 (23.06)	1.42	1.12–1.81	0.004
Sexual enhancement	56 (13.56)	1.17	0.85–1.6	0.343	45 (18.44)	1.69	1.19–2.39	0.005	153 (12.30)	1	0.79–1.27	0.981	158 (13.34)	1.18	0.89–1.58	0.248
Sleep improvement	198 (47.94)	0.73	0.59–0.9	0.004	150 (61.48)	1.42	1.08–1.86	0.011	672 (54.02)	1.01	0.86–1.18	0.926	659 (35.39)	1.13	0.93–1.36	0.211
Which negative effect(s) did you experience with the use of Kratom? (select all that apply)
Nausea	119 (28.81)	2.37	1.85–3.04	<0.01	52 (21.31)	1.34	0.96–1.85	0.089	274 (22.03)	2.04	1.64–2.53	<0.01	267 (22.55)	1.88	1.45–2.43	<0.01
Vomiting	49 (11.86)	2.4	1.67–3.43	<0.01	28 (11.48)	2.03	1.32–3.13	0.003	110 (8.84)	2.31	1.64–3.25	<0.01	104 (8.78)	2.16	1.41–3.29	<0.01
Diarrhea	7 (1.69)	1.91	0.79–4.63	0.174	4 (1.64)	1.69	0.57–4.96	0.369	17 (1.37)	1.89	0.84–4.26	0.114	18 (1.52)	3.47	1.02–11.84	0.023
Heart palpitations (rapid heart beat, tachycardia)	11 (2.66)	2.57	1.22–5.4	0.019	4 (1.54)	1.31	0.45–3.77	0.629	4 (1.64)	2.92	1.36–6.25	0.003	26 (2.20)	2.51	1.03–6.14	0.028
Shortness of breath	9 (2.18)	5.26	2.02–13.72	<0.01	4 (1.64)	2.54	0.83–7.78	0.136	16 (1.29)	8.06	1.85–35.12	<0.01	15 (1.27)	4.34	0.99–19.02	0.021
Constipation	116 (28.09)	2.13	1.66–2.73	<0.01	47 (19.26)	1.16	0.83–1.63	0.39	280 (22.51)	2.11	1.7–2.62	<0.01	264 (22.30)	1.78	1.38–2.31	<0.01
Pain	1 (0.24)	0.51	0.06–4.03	0.485	3 (1.23)	2.42	0.67–8.73	0.217	7 (0.56)	1	0.35–2.85	0.994	6 (0.51)	1.72	0.35–8.55	0.489
Stomach upset	49 (11.86)	2.01	1.42–2.86	<0.01	25 (10.25)	1.5	0.96–2.34	0.087	25 (10.25)	2.4	1.73–3.34	<0.01	118 (9.97)	2.03	1.38–3	<0.01
Dizziness or drowsiness	46 (11.14)	1.59	1.12–2.26	0.013	22 (9.02)	1.13	0.71–1.8	0.608	138 (11.09)	2.37	1.74–3.23	<0.01	143 (12.08)	2.77	1.87–4.12	<0.01
Fainting	0		NA		0		NA		0		NA		0		NA
Irritability or agitation	44 (10.65)	3.26	2.19–4.84	<0.01	19 (7.79)	1.89	1.13–3.15	0.022	80 (6.43)	2.3	1.54–3.43	<0.01	78 (6.59)	2.1	1.3–3.41	<0.01
High blood pressure (hypertension)	5 (1.21)	2.9	0.94–8.9	0.08	2 (0.82)	1.61	0.35-.7.29	0.561	12 (0.96)	4.01	1.13–14.26	0.016	11 (0.93)	3.17	0.7–14.34	0.091
Other (please specify)	40 (0.69)	1.47	1.01-.213	0.048	16 (9.30)	0.9	0.53–1.53	0.682	109 (8.76)	1.63	1.1–2.239	0.002	105 (8.84)	1.55	1.0–2.266	0.019
No negative effects from Kratom use	1 (0.24)	1.53	0.16–14.78	0.722	1 (0.41)	2.94	0.3–28.4	0.398	3 (0.24)	2.99	0.31–28.81	0.308	0		NA
Dry mouth	31 (7.51)	2.18	1.41–3.39	<0.01	16 (6.56)	1.7	0.98–2.96	0.073	68	1.73	1.16–2.58	<0.01	70 (5.91)	2.3	1.36–3.9	0.001
Problems urinating	20 (4.84)	3.06	1.73–5.43	<0.01	6 (2.46)	1.21	0.51–2.86	0.678	37 (2.97)	2.5	1.37–4.58	<0.01	33 (2.79)	1.92	0.94–3.91	0.061
Aching of muscles/bones	6 (1.45)	1.73	0.67–4.46	0.274	3 (1.23)	1.26	0.37–4.26	0.717	15 (1.21)	1.67	0.73–3.83	0.22	14 (1.18)	2.02	0.66–6.15	0.192
Hyperpigmentation of your skin (darker patches observed on your skin)	0		NA		0		NA		7 (0.59)	5.01	1.1–22.92	0.016	10 (0.80)	1.34	0.34–5.19	0.668
Hair loss	15 (3.63)	1.36	0.76–2.45	0.311	6 (2.46)	0.8	0.34–1.85	0.585	52 (4.18)	2.53	1.51–4.23	<0.01	44 (3.72)	1.71	0.94–3.09	0.067
Sleep problems (insomnia, sleep too much)	18 (4.36)	1.5	0.87–2.58	0.157	13 (5.33)	1.83	0.99–3.38	0.068	50 (4.02)	1.81	1.13–2.9	0.011	45 (3.80)	1.87	1.02–3.44	0.034
Reduced appetite, weight loss	20 (4.84)	1.67	0.99–2.82	0.063	7 (2.87)	0.88	0.4–1.93	0.74	52 (4.18)	1.82	1.15–2.89	0.009	58 (4.90)	2.86	1.52–5.36	0.034
Reduced concentration	9 (2.18)	1.6	0.75–3.45	0.245	3 (1.23)	0.85	0.26–2.8	0.785	28 (2.25)	3.15	1.48–6.7	0.001	28 (2.36)	4.08	1.43–11.69	<0.01
Anger, hostility, aggression	16 (3.87)	5.42	2.63–11.2	<0.01	3 (1.23)	1.02	0.31–3.38	0.979	23 (1.85)	2.9	1.29–6.51	0.006	22 (1.86)	2.55	0.96–6.76	0.002
Seizures	0		NA		0		NA		0		NA		0		NA
Involuntary (unwanted) movements of the limbs/tremors	9 (2.18)	1.44	0.67–3.06	0.363	4 (1.64)	1.1	0.39–3.14	0.857	25 (2.01)	1.67	0.88–3.19	0.112	25 (2.11)	2.42	0.99–5.92	0.037
Psychotic symptoms (e.g. hallucinations, paranoia, delusions)	2 (0.48)	4.61	0.65–32.85	0.144	1 (0.41)	2.21	0.25–19.81	0.515	0		NA		0		NA
Sexual problems (e.g. erectile dysfunction, reduced libido/pleasure)	25 (6.05)	2.12	1.31–3.44	0.004	10 (4.10)	1.2	0.61–2.35	0.607	66 (5.31)	2.96	1.83–4.79	<0.01	61 (3.28)	2.25	1.29–3.93	0.002
Liver problems (e.g. elevated liver enzymes in blood tests)	1 (0.24)	1.53	0.16–14.78	0.722	0		NA		3 (0.24)	2.99	0.31–28.81	0.308	0		NA

Self-reported detrimental effects of kratom use in psychiatric conditions

As shown in Table 4, gastrointestinal symptoms (nausea and vomiting) (ADHD, 40.67% vs. 19.91%; PTSD, 32.79% vs. 22.86%; Depression, 30.87% vs.16.23%; Anxiety, 31.33% vs. 17.70%) and irritability/agitation (ADHD, 10.65% vs. 3.53%; PTSD, 7.79% vs. 4.28%; Depression, 6.43% vs. 2.91%; Anxiety, 6.59% vs. 3.24%) were commonly reported detrimental kratom effects across all psychiatric condition groups. Respondents reporting symptoms of anxiety experienced heart palpitations (Depression, 2.09% vs. 0.73%; Anxiety 2.20% vs. 0.88%), shortness of breath (ADHD, 2.18% vs. 0.42%; Depression, 1.29% vs. 0.16%; Anxiety, 1.27% vs. 0.29%), diarrhea (Anxiety, 1.52% vs. 0.44%), and constipation (ADHD, 28.1% vs. 15.49%; Depression, 22.5% vs. 12.11%; Anxiety, 22.3% vs. 13.86%) at a higher rate. Those with greater depression and anxiety reported more sleep problems (insomnia, sleep too much, etc.) (Depression 4.02% vs. 2.26%; Anxiety 3.80% vs. 2.06%), reduced appetite (Depression, 4.18% vs. 2.34%; Anxiety, 4.90% vs. 1.77%), reduced concentration (Depression, 2.25% vs. 0.73%; Anxiety, 2.36% vs. 0.59%), and higher anger or aggression (Depression, 1.85% vs. 0.65%; Anxiety, 1.86% vs. 0.74%). Increased hair loss (4.18% vs. 1.69%) and fewer hyperpigmentation of skin (0.80% vs. 0.16%) was reported by respondents reporting depressive disorders. Sexual problems (e.g., erectile dysfunction, reduced libido/pleasure) were significant across all conditions except PTSD (ADHD, 6.05% vs. 2.95%; Depression, 5.31% vs. 1.86%; Anxiety, 5.15% vs. 2.36%).

Quality-of-life and current pain is significantly worse in psychiatric conditions

Those with PTSD, ADHD, depression, and anxiety symptoms presented with lower quality-of-life as evaluated by a visual analogue scale (Figure 2). Kratom users meeting PTSD criteria had the lowest quality-of-life (6.82 vs. 7.93, p<0.01).

Figure 2:

Quality of Life (QoL) visual analogue scale (VAS) scores for each psychiatric condition and the average score of participants not meeting inclusion criteria. A lower score indicates a lower QoL. All psychiatric conditions present with a lower QoL compared to the average negative score.

Respondents in any of the four psychiatric condition groups presented with greater self-reported current pain compared to those who did not meet diagnostic criteria for any of the disorders assessed (Figure 3). Those who met PTSD criteria ranked their pain the highest, with the worst average pain (5.61) compared to those with other conditions (Depression: 5.09; ADHD: 4.93; Anxiety: 5.14) or respondents not meeting criteria for these psychological conditions (average: 4.80).

Figure 3:

Current pain visual analogue scale (VAS) scores for each psychiatric condition and the average score of participants not meeting inclusion criteria. A higher number indicates more severe self-reported pain. Participants meeting post-traumatic stress disorder (PTSD) inclusion criteria present with more severe pain compared to the average negative and other psychiatric conditions.

DISCUSSION

Given the increasing popularity of kratom for the self-treatment of health conditions, the congruence of self-reported health conditions and kratom use, the extent of psychiatric symptoms reported in this survey was unsurprising. In this survey, we found that the demographic and kratom use characteristics of those meeting diagnostic criteria for psychological conditions were similar to users who did not meet criteria. However, some distinct differences were found that align with prior work.

Psychiatric conditions more common among young and single kratom users

All four psychological conditions examined were more common among younger kratom users who were single. For PTSD, about two-thirds of diagnosed patients in primary care settings are female which aligns with this survey’s findings (Spottswood et al., 2017). Mood disorders, particularly depressive disorders, are more prevalent among younger patients that are single and have a history of a substance use disorder (SUD) which impacts their ability to work compared to older adults (Serafini et al., 2018).

Higher substance co-use among kratom users with psychiatric conditions

Several licit (or medical) and illicit (or nonmedical) substances were used either concomitantly or prior to kratom use initiation. Both CBD and cannabis products were more commonly used by respondents reporting ADHD or depressive symptoms than by those who did not report such symptoms. The role of cannabinoids in treating ADHD and PTSD remains controversial, and both detrimental and positive effects of cannabis are reported for mood and anxiety disorders (Marco et al., 2011; Walsh et al., 2017). The use of kratom with cannabinoids may result in adverse effects that cannot be predicted. Given the widespread use of cannabis products, co-ingestion with kratom requires further study. Benzodiazepines were also commonly used by respondents with psychiatric symptoms. In a small patient cohort using high-dose benzodiazepines, those with ADHD performed worse in cognitive function and had lower quality of life (Federico et al., 2021). Kratom, especially in lower doses (Warner et al., 2016), may be used as a stimulant self-treatment to mitigate ADHD symptoms and benzodiazepine adverse effects.

The prior or concomitant use of non-medical or prescribed benzodiazepines with katrom, like in ADHD patients, may suggest a counterbalancing of adverse effects to provide less sedation. Depressive and anxiety disorders can present with a range of symptoms, such as insomnia, irritability, or pain that can be treated with benzodiazepines (Kolacz et al., 2022). Theoretically, some of the benzodiazepine effects may be additive to kratom (potentiating sedation, muscle relaxation) while others are counteracting (stimulant). Because benzodiazepines play a central role in the treatment of anxiety disorders, it is unsurprising to find an increased use of this drug class in those subjects reporting depression and anxiety. Among kratom users in Malaysia who also recreationally used benzodiazepines, the combined use was indicated as serving multiple therapeutic purposes, such as increasing euphoria, reducing stimulant dependence, promoting sleep, and decreasing kratom use (Singh et al., 2020). This would indicate that at least some kratom users utilize benzodiazepines to mitigate adverse and withdrawal effects from their kratom use.

The only lowered risk of kratom use and an anxiety disorder concerned the use of cocaine (Sareen et al., 2006). In general, respondents with an anxiety disorder were more likely to use cocaine but, among those who use both kratom and cocaine, there may be a reduced risk of cocaine use. This mirrors findings in prior research, wherein amphetamine users report a reduction in amphetamine and methamphetamine use and withdrawal symptoms following kratom initiation (Saref et al., 2020).

Beneficial and detrimental symptoms of kratom use centered on psychological effects

Although respondents reported improvement of their medical condition with the use of kratom, those meeting inclusion criteria for a psychiatric condition did not perceive the improvement to be as good as those who were not meeting inclusion criteria. This aligns with the overall quality of life and current pain outcome. For those with greater psychological disorder symptoms across any of the four groups, the primary perceived beneficial effects of kratom use were less depressive and anxiety symptoms than prior to kratom consumption. This dovetails with pre-clinical trials reporting an antidepressant and antipsychotic effect of kratom, findings that may eventually translate to human use (Johnson et al., 2020). Animal trials also indicate changes in neuronal circuitry related to depression, anxiety, and analgesia following chronic administration of kratom (Buckhalter et al., 2021). Combined, these data sources indicate the need for further investigation.

Relatedly, respondents with greater anxiety and depressive symptoms also were more likely to report decreased pain with kratom use, whereas ADHD respondents were less likely to do so. Although few trials have investigated a relationship between pain sensitivity and ADHD, one study indicates that increased pain sensitivity in adolescent ADHD patients is associated with more severe emotional dysregulation (Bruton et al., 2022). Those with ADHD may be more sensitive to pain and kratom (or other analgesics) may not be beneficial at typical therapeutic doses.

Detrimental effects of kratom use primarily included increased irritability or agitation and increased anger, hostility, or aggression. Irritability, agitation, or emotional outbursts are not uncommon among many psychiatric conditions and were found to be positively associated with ADHD, PTSD, anxiety, and depressive disorders (Palm et al., 2021). Based on this study it is not clear whether kratom use or withdrawal from other substances may contribute to or exacerbate detrimental effects in patients with psychiatric conditions.

Nausea and vomiting have been associated with kratom and may depend on the dose amount or frequency of consumption (Grundmann, 2017). While average kratom dose and frequency were not higher among respondents with a psychiatric condition, other than a SUD (Grundmann, Veltri, Morcos, Knightes III, Smith, Singh, et al., 2022), it is unclear how kratom may interact with other medications commonly taken among people with the conditions assessed here. Because of the potential for drug interactions, kratom consumption may lead to a higher incidence of adverse effects in patients taking a range of prescription medicines, especially medications metabolized by CYP 2D6, CYP 3A, and CYP 2C9 (Hanapi et al., 2021). Inhibition of these enzymes may increase the blood concentration of several antidepressant and anxiolytic medications that are used concomitantly with kratom in the self-treatment of psychiatric disorders. Common adverse effects of antidepressants that appear to be increased in several of the investigated disorders are vomiting, nausea, dry mouth, sexual problems, and constipation. Of concern is the increased self-reported rate of heart palpitations which may require further clinical investigation.

LIMITATIONS

Although this survey was launched prior to the COVID-19 pandemic and concluded during the pandemic, (Johnson et al., 2020)(Grundmann, Veltri, Morcos, Knightes III, Smith, Singh, et al., 2022) we do not suspect that kratom availability was affected by the COVID-19 pandemic overall, but it cannot be excluded for all respondents (Grundmann, Veltri, Morcos, Knightes III, Smith, & Rogers, 2022). The survey did include responses from various countries, but most responses (96.43%) were collected from the US and Canada (Grundmann, Veltri, Morcos, Knightes III, Smith, Singh, et al., 2022) and the generalizability of findings should therefore be limited to these two countries. Because of the inherent bias of self-reported survey data, the results should be interpreted with caution and may be skewed towards a positive perception of kratom. Moreover, psychiatric symptom evaluation is based on self-reported scales and/or previous healthcare evaluation reported by the respondents. A further bias could be represented by a possible exclusion of respondents reporting early detrimental effects after the use of kratom and who subsequently discontinued use and disengaged from kratom-using communities. Specifically, PWUK only intermittently or who stopped using likely would not have been reached by the recruiting methods we employed. Online data collection and the use of an English-language survey may also have skewed the sample younger, urban and sub-urban population (rather than rural and without Internet access), and to those with English-language proficiency. These limitations are offset by the overall size of the sample and the inclusion of validated instruments not previously used in kratom survey studies.

CONCLUSIONS

Despite the subjective benefit of kratom use reported among respondents in this survey and others, controlled trials, human laboratory experiments, and longitudinal investigations on kratom are lacking. The utilization of kratom products in the self-treatment of psychiatric conditions seems to remain a strong motivator of use, yet scientists have not followed up on this real-world phenomenon. Polydrug use involving kratom also seems to be a continued trend. Here, kratom was generally either used concomitantly or following cessation of cannabis products, CBD, or benzodiazepines. This, too, warrants greater scrutiny. Although kratom was reported as improving depressive and anxiety symptoms in those with a psychiatric condition, indicating some perceived therapeutic benefit, its concomitant use with prescription psychiatric medications may produce or exacerbate adverse effects. That we found further indication, specifically among those with greater psychiatric symptoms, that kratom may reduce stimulant use is of particular interest given the high rates of opioid and stimulant co-use and the lack of pharmacotherapy for stimulant use disorder (Smith, Rogers, & Strickland, 2021; Strickland et al., 2021).

Ultimately, kratom seems to consistently present as a self-medication strategy for psychological disorder symptoms but with fewer reported detrimental effects than traditional drugs of abuse. Indeed, kratom seems to be reducing use of some such drugs of abuse. However, any possible protective effect of kratom needs to be confirmed with safety and tolerability studies, clinical trials, and randomized controlled trials. Kratom use should be assessed by healthcare professionals and its use carefully monitored, particularly among patients with psychiatric conditions and who are prescribed medications.

Public significance statement.

Kratom users meeting criteria for attention-deficit hyperactivity disorder, post-traumatic stress disorder, depression, or anxiety reported a higher likelihood of using cannabis, cannabidiol, or benzodiazepines either together or prior to kratom initiation. Kratom users meeting criteria for attention-deficit hyperactivity disorder, post-traumatic stress disorder, depression, or anxiety also reported significantly lower quality of life and more severe pain compared to those users not meeting criteria. Kratom should be screened in the clinical assessment of patients with these mental health conditions, as well as those with chronic pain or polysubstance use histories.