Individual and peer factors associated with ketamine use among adolescents in Taiwan

Overdoses and deaths related to the use of ketamine and its analogues: a systematic review

Background: Although the misuse of ketamine constitutes a worldwide issue, ketamine is quickly taking its place as a therapeutic option in the management of several mental disorders. However, the use of ketamine and/or its analogues, as well as combinations with other drugs, can be fatal.Objective: To outline the cases of overdoses and deaths related to the use of ketamine and/or its analogues, as reported in the scientific literature. To investigate if ketamine is safe in a therapeutic context, particularly in its use as an antidepressant.Methods: Electronic searches were performed on three medical databases. Articles describing cases of overdose and/or death associated with ketamine and/or its analogues were included. After the removal of duplicates, title analysis and full-text analysis, 34 articles were included in this review.Results: Eighteen articles described fatal cases and sixteen described overdoses. Poly-substance use was mentioned in 53% of the selected articles. Most cases were males and the ages varied from two to 65 years old. A total of 312 overdose cases and 138 deaths were reported. In both death reports and overdose cases, ketamine was preponderant: 89.1% and 79%, respectively. No cases of overdose or death related to the use of ketamine as an antidepressant in a therapeutic setting were found; most of the deaths occurred in the circumstances of polydrug use and overdoses left no sequelae.Conclusion: There is legitimate concern about the risks involving the use of ketamine and its analogues, especially in recreational settings. On the other hand, ketamine as medicine is considered safe and it is listed as an essential medicine by the World Health Organization. Although clinicians must remain vigilant, this should not deter appropriate prescription.

Ketamine: from prescription anaesthetic to New Psychoactive Substance

Discovered in the United States of America (USA) in the 1960s, ketamine was introduced as an anaesthetic drug to specifically replace phencyclidine. Briefly, the substance moved from the medical world to recreational users, since it was discovered that intense psychedelic experiences were obtained with dosages lower than those prescribed for anesthesia. At the end of the 90's, circulated in London nightclubs as a drug itself and as counterfeit 3,4-methylenedioxymethamphetamine tablets. In 1997, the Drug Enforcement Administration (DEA) alerted the United States (US) government to the increasing diffusion of ketamine in American 'clubs', and in 1999, the substance was added to Schedule III of drugs controlled by federal authorities. In 2002, ketamine epidemics moved to Europe, and the European Monitoring Centre for Drugs and Drug Addiction carried out a risk assessment monitoring of the phenomenon. An estimated ninety-nine percent of all global ketamine seizures occurred in Asia. Its growing popularity is due to the fact that this new psychoactive substance is cheaper than other stimulants such as MDMA that the amount used for recreational purposes does not cause respiratory depression and its legal use as a drug makes it widely available for a diversion towards illicit markets. Nevertheless, acute intoxication and several deaths have been related to exclusive ketamine use both in Europe and internationally. Since 2015, there has been and increasing rise of the illicit ketamine market and currently the drug is being used with unprecedented peaks and a consequent significant increase in seizures and clinical cases worldwide.

A systematic review of therapeutic ketamine use in children and adolescents with treatment-resistant mood disorders

Suicide is the second leading cause of death in the United States among individuals aged 10-24, and severe youth depression is often refractory to the current standards of care. Many studies have demonstrated the efficacy of ketamine in reducing depressive symptoms in adults with treatment-resistant mood disorders, though few studies utilizing ketamine in youth populations exist. This systematic review examines the current state of evidence for ketamine use in children with treatment-resistant mood disorders. We conducted a search utilizing two electronic databases for English-language studies investigating the therapeutic effects and side effect profile of ketamine in youth ≤ 19 years of age with a diagnosis of a treatment-resistant mood disorder. Analysis included subjects with treatment-resistant depression with and without psychotic features and with bipolar disorder. Primary outcome measures included the following scales: Montgomery-Asberg Depression Rating Scale, Children's Depression Rating Scale, Children's Depression Rating Scale Revised, Child Bipolar Questionnaire, Overt Aggression Scale, Yale-Brown Obsessive-Compulsive Scale, and Scale for Suicidal Ideation. Four published studies were identified that investigated therapeutic ketamine use in youth for the primary purpose of treating a treatment-resistant psychiatric disorder. Three additional studies that did not meet eligibility criteria were identified and discussed. Ketamine was shown in youth to generally improve depressive symptoms, decrease acute suicidality, and reduce mood lability, though a number of subjects remained resistant to its treatment. These findings substantiate the need for further longitudinal studies investigating ketamine's long-term safety, its efficacy, and abuse potential in the youth.

Appetitive Motivation and Regulatory Processes in Adolescent Ketamine Users

Ketamine has remained the most commonly used illicit drug among adolescents in Taiwan. A dual process model proposes that addictive behaviors develop in adolescents as a result of an imbalance between an appetitive, approach-oriented system (implicit and explicit attitudes) and a regulatory executive system (cool and hot executive functions). We aimed to examine the appetitive and regulatory processes in adolescent ketamine users in comparison to matched healthy adolescents. Method: The participants were 30 adolescent ketamine users and 32 nondrug controls, matched with gender, age, education years, and education systems. Both groups completed the affective priming task (APT), the stop-signal task (SST), an Iowa Gambling Task (IGT), and finally a Drug Use Disorders Identification Test: Extended (DUDIT-E). Results: The controls had higher positive and negative outcome expectancy with respect to using ketamine compared to the adolescent ketamine users. There was no significant between-group performance difference in APT. The adolescent ketamine users may have shown marginally poorer performance compared to the controls in hot executive functions (IGT), but their cold executive functions (SST) remained intact. Conclusion: The current study reported that the adolescent ketamine users may not have imbalanced dual processes (biased appetitive motivation and impaired regulatory executive process). A different therapeutic focus on adolescent ketamine users may be developed accordingly. More advocacies on ketamine's aversive outcomes are needed, particularly on campus in order to reduce substance misuse.

Mis-anaesthetized society: expectancies and recreational use of ketamine in Taiwan

Background

The popularity of ketamine for recreational use has been increasing in Asia, including Taiwan. Still, little known about the pattern of ketamine expectancies and whether such patterns are related to ketamine use. This study aimed to examine whether the positive and negative ketamine expectancies are differentially associated with ketamine-using behavior, and whether such relationship may differ by early-onset use of tobacco or alcohol.

Methods

Participants were recruited using respondent-driven sampling (RDS) among regular tobacco and alcohol users, aged 18 to 50, residing in Taipei from 2007 to 2010. Totally 1115 participants (with an age distribution skewed to the right, median = 26; interquartile range: 22–32) had information on substance use and completed a 12-item ketamine expectancies questionnaire (with 6 positive and 6 negative statements). Using two axes of High and Low expectancies, the four combinations of binary positive and binary negative ketamine expectancies were created. Each participant’s drug-using experience was categorized into illicit drug naïve, exclusive ketamine use, polydrug ketamine use, or other illicit drug use. Using the weights in the network output by RDS Analysis Tool, multivariable logistic regression analysis was then conducted.

Results

The weighted prevalence was 2.4% for exclusive ketamine use, 9.0% for polydrug ketamine use, and 9.1% for the other illicit drug use. Ketamine users (11.4%) had greater positive expectancies and lower negative expectancies, particularly the combination of High Positive with Low Negative, as compared to the illicit drug-naïve or other illicit drug users. After adjustment for early-onset tobacco (or alcohol) use and sociodemographic characteristics, High Positive, Low Negative, and their combination of High Positive-Low Negative expectancies remained strongly associated with ketamine uses, without evidence of moderation from early-onset use of tobacco or alcohol.

Conclusions

Positive and negative ketamine expectancies were associated in opposite directions with ketamine use, independent of early-onset use of tobacco or alcohol. Our results indicate ketamine expectancies as possible targets for future intervention and prevention of ketamine use, with a less confrontational feedback on decreasing an individual’s positive expectancies is essential in preventing young people from the initiation of ketamine use.

Difference in long-term relapse rates between youths with ketamine use and those with stimulants use

BACKGROUND

Understanding the relapse risk among different illicit drugs is vital for developing an adequate relapse prevention policy. Therefore, the current study aims to explore the potential difference in long-term relapse rates between youths who use ketamine and those who use stimulants (3,4-Methylenedioxymethamphetamine [MDMA] or methamphetamine).

METHODS

The study's participants included 92 youths with ketamine use (ketamine group, mean age: 16.0 years) and 43 youths with MDMA/methamphetamine use (stimulants group, mean age: 16.1 years) that had undergone a family-oriented treatment program in a medical center in Taiwan. All participants were followed up for a maximum of 7 years in order to observe their long-term outcomes with regard to substance use relapse.

RESULTS

During the follow-up period, compared to the 34.8% relapse rate in ketamine users, their counterparts who used MDMA or methamphetamine had a significantly higher relapse rate (60.5%, Adjusted HR = 1.86, 95%CI: 1.06-3.28, p = 0.032). Of the youths in the ketamine group that relapsed, 65.6% continued to use ketamine in their relapse event, while 34.4% switched to MDMA or methamphetamine. Among the relapsing youths in the stimulants group, 84.6% continued to use MDMA or methamphetamine in their relapse event, while 15.4% switched to ketamine (p = 0.042).

CONCLUSIONS

Compared to adolescents who use ketamine, those using MDMA or methamphetamine had higher relapse rates and were more likely to use the same type of drug upon relapsing. These results can serve as a crucial reference for developing relapse prevention policies of illicit drugs for the youth population.

Low serum level of epidermal growth factor in chronic ketamine users

BACKGROUND

Growth factors play an important role in brain development. Whether epidermal growth factor (EGF) plays a role in the pathophysiology of ketamine related disorders is unexplored. In this study, we examined the serum levels of EGF in chronic ketamine users as compared with healthy controls. The possible correlation between serum EGF levels with the demographic, ketamine use characteristics and psychopathological symptoms were analyzed.

METHODS

Sixty-seven chronic ketamine users and 40 healthy subjects were recruited. Serum EGF levels were measured by enzyme-linked immunosorbent assay. Psychopathological symptoms were assessed using Positive and Negative Syndrome Scale, Beck Depression Inventory and Beck Anxiety Inventory.

RESULTS

The serum level of EGF in the chronic ketamine users was significantly lower than that of healthy subjects (22.34 ± 4.81 pg/ml vs. 87.10 ± 2.96 pg/ml, F = 15.169, p < 0.01). The serum EGF level was negatively correlated with the current average dose of ketamine consumption per day of use (p = 0.015), and positively associated with the Positive and Negative Syndrome Scale positive symptom score (p = .022).

CONCLUSIONS

Serum level of EGF decreased in chronic ketamine users compared with healthy subjects, which may play a role in the pathophysiology of ketamine related disorders.

Ketamine as a rapid antidepressant: the debate and implications

Ketamine, a synthetic derivative of phencyclidine, is a commonly misused party drug that is restricted in high-income countries because of its addictive potential. Ketamine is also used as an anaesthetic in human and veterinary medicine. In the 1990s, research using ketamine to study the pathophysiology of schizophrenia was terminated owing to ethical concerns. Recently, controversy surrounding the drug has returned, as researchers have demonstrated that intravenous ketamine infusion has a rapid antidepressant effect and have therefore proposed ketamine as a novel antidepressant. This article debates the question of ketamine as an antidepressant, considering the drug's addictive potential, ethical concerns about prescribing a hallucinogen, the evidence base and motives behind ketamine trials.

The health belief model and number of peers with internet addiction as inter-related factors of Internet addiction among secondary school students in Hong Kong

BACKGROUND

Students are vulnerable to Internet addiction (IA). Influences of cognitions based on the Health Belief Model (HBM) and perceived number of peers with IA (PNPIA) affecting students' IA, and mediating effects involved, have not been investigated.

METHODS

This cross-sectional study surveyed 9518 Hong Kong Chinese secondary school students in the school setting.

RESULTS

In this self-reported study, the majority (82.6%) reported that they had peers with IA. Based on the Chinese Internet Addiction Scale (cut-off =63/64), the prevalence of IA was 16.0% (males: 17.6%; females: 14.0%). Among the non-IA cases, 7.6% (males: 8.7%; females: 6.3%) perceived a chance of developing IA in the next 12 months. Concurring with the HBM, adjusted logistic analysis showed that the Perceived Social Benefits of Internet Use Scale (males: Adjusted odds ratio (ORa) = 1.19; females: ORa = 1.23), Perceived Barriers for Reducing Internet Use Scale (males: ORa = 1.26; females: ORa = 1.36), and Perceived Self-efficacy for Reducing Internet Use Scale (males: ORa = 0.66; females: ORa = 0.56) were significantly associated with IA. Similarly, PNPIA was significantly associated with IA ('quite a number': males: ORa = 2.85; females: ORa = 4.35; 'a large number': males: ORa = 3.90; females: ORa = 9.09). Controlling for these three constructs, PNPIA remained significant but the strength of association diminished ('quite a number': males: multivariate odds ratio (ORm) = 2.07; females: ORm = 2.44; 'a large number': males: ORm = 2.39; females: ORm = 3.56). Hence, the association between PNPIA and IA was partially mediated (explained) by the three HBM constructs. Interventions preventing IA should change these constructs.

CONCLUSIONS

In sum, prevalence of IA was relatively high and was associated with some HBM constructs and PNPIA, and PNPIA also partially mediated associations between HBM constructs and IA. Huge challenges are expected, as social relationships and an imbalance of cost-benefit for reducing Internet use are involved. Perceived susceptibility and perceived severity of IA were relatively low and the direction of their associations with IA did not concur with the HBM. Group cognitive-behavioral interventions involving peers with IA or peers recovered from IA are potentially useful to modify the HBM constructs and should be tested for efficacy.

A family-oriented therapy program for youths with substance abuse: long-term outcomes related to relapse and academic or social status

OBJECTIVE

The abuse of illegal substances by youths in Taiwan has become a major public health issue. This study explores the outcomes (relapse rate and academic or social status) of a family-oriented therapy program conducted for substance-using youths who were referred by a judge to participate in it.

METHODS

The present study includes 121 participants categorized into three groups: 36 youths underwent a weekly ten-session outpatient motivational enhancement psychotherapy (MEP) group program; 41 youths participated in a program that combined the aforementioned MEP program with an additional weekly ten-session parenting skill training (PST) program for their guardians (MEP + PST group); and 44 adolescents who received standard supervision by the court served as the control group. All participants were followed-up for a maximum of 2 years.

RESULTS

Of the 121 participants (mean age: 16.1±1.1 years), 33.1% relapsed into substance use during the follow-up period. The probability of relapse did not differ significantly between the MEP group (36.1%) and the control group (40.9%), but the youths in the MEP + PST group (22.0%) were at a lower risk of relapse than the control group participants (adjusted hazard ratio =0.48, 95% confidence interval [CI] =0.21-1.09). By the end of the study follow-up period, participants in both the MEP group and the MEP + PST group were more likely to be attending school (MEP group: adjusted odds ratio [aOR] =6.61, 95% CI =1.60-27.35; MEP + PST group: aOR =8.57, 95% CI =1.94-37.82) or employed (MEP group: aOR =7.75, 95% CI =1.95-30.75; MEP + PST group: aOR =7.27, 95% CI =1.76-29.97), when compared to the control group.

CONCLUSION

This study revealed that a family-oriented treatment approach may be a more effective option for preventing youths' relapsing into substance abuse. In comparison to individuals who received standard supervision by the court, those who received MEP experienced a better school attendance or social outcome over the follow-up period.

A family-oriented treatment program for youths with ketamine abuse and their caregivers: a pilot study in Taiwan

OBJECTIVE

The abuse of ketamine by youths has grown into a serious public health issue. However, a reliable and efficient treatment has still not been found for youths who abuse ketamine. This pilot study investigated the effects of a family-oriented treatment program for ketamine-using youths and their caregivers.

METHODS

To carry out this study, 42 youths with ketamine use (mean age 16.6±1.1 years) who were referred to take part in a 10-week treatment program based on motivational enhancement principles were selected, as were their principal caregivers (mean age 46.4±7.1 years), who were similarly referred to take part in a 10-week training program for parenting skills. The study had the youths complete the Chinese Craving Beliefs Questionnaire, the Adolescents' Behavior problem Scale, and the Family APGAR both immediately before and after the program. Likewise, the youths' caregivers completed the Family APGAR, the 12-item version of the Chinese Health Questionnaire, and the Parenting Stress Index.

RESULTS

Of the 42 youth-caregiver pairs that took part in this study, 37 (88%) completed the 10-week program and both sets of assessments. After the treatment, the participating youths' substance cravings declined (t=3.88, P<0.001), while family function, as perceived by the participating caregivers, significantly increased (t=2.22, P=0.033). The improvement in caregivers' perceptions of family function were positively related to the improvement of the caregivers' health status (r=-0.36, P=0.022).

CONCLUSION

According to its results, this pilot study submits that family-oriented treatment programs may be considered a potentially effective treatment option for youths who abuse ketamine. Additional studies with larger sample sizes, as well as longer follow-up periods, are necessary to verify whether this type of treatment also prevents youths using ketamine from relapsing.

Neurocognitive Profiles of Methamphetamine Users: Comparison of Those With or Without Concomitant Ketamine Use

OBJECTIVE

Methamphetamine (MAMP) and ketamine are neurotoxic drugs whose chronic use has been linked with a cognitive decline in some users. This paper aims to assess the possible effect of concomitant ketamine use on the neurocognitive performance of MAMP users.

METHODS

This study divides 42 MAMP users into MAMP users who use ketamine (MAMP+K, n = 16) and MAMP users who do not use ketamine (MAMP-K, n = 26). The performance of these two groups was compared using the Brief Assessment of Cognition in Schizophrenia (BACS), Conners' Continuous Performance Tests (CPT), the Wisconsin Card Sorting Test (WCST), the Iowa Gambling Task (IGT), and the Barratt Impulsiveness Scale (BIS).

RESULTS

In comparison to the MAMP-K group, the MAMP+K group showed worse performances in verbal fluency, executive function and composite score in BACS; worse performances in total errors, perseverative errors, nonperseverative errors and conceptual level response in WCST; and greater levels of total scores and novelty-seeking in BIS. Neither the attention function evaluated with CPT nor the decision-making behavior evaluated with IGT was associated with previous ketamine use.

CONCLUSION

This study detected worse executive function and higher impulsivity level among MAMP users with additional ketamine use versus their counterparts without ketamine use. Further studies with a longitudinal design and a large sample size are necessary to clarify the connection between cognitive deficits and concomitant use of MAMP and ketamine.

Repeated ketamine administration alters N-methyl-D-aspartic acid receptor subunit gene expression: implication of genetic vulnerability for ketamine abuse and ketamine psychosis in humans

For more than 40 years following its approval by the Food and Drug Administration (FDA) as an anesthetic, ketamine, a non-competitive N-methyl-D-aspartic acid (NMDA) receptor antagonist, has been used as a tool of psychiatric research. As a psychedelic drug, ketamine induces psychotic symptoms, cognitive impairment, and mood elevation, which resemble some symptoms of schizophrenia. Recreational use of ketamine has been increasing in recent years. However, little is known of the underlying molecular mechanisms responsible for ketamine-associated psychosis. Recent animal studies have shown that repeated ketamine administration significantly increases NMDA receptor subunit gene expression, in particular subunit 1 (NR1 or GluN1) levels. This results in neurodegeneration, supporting a potential mechanism where up-regulation of NMDA receptors could produce cognitive deficits in chronic ketamine abuse patients. In other studies, NMDA receptor gene variants are associated with addictive behavior. Here, we focus on the roles of NMDA receptor gene subunits in ketamine abuse and ketamine psychosis and propose that full sequencing of NMDA receptor genes may help explain individual vulnerability to ketamine abuse and ketamine-associated psychosis.