Kava drinking associated with suicidal behaviour among young Kanaks using kava in New Caledonia
Christine Hamelin, Inserm, Centre for Research in Epidemiology and Population Health, U1018, Epidemiology of the Social and Occupational Determinants of Health Team, F-94807, Villejuif, France: e-mail: firstname.lastname@example.org
Objective: To examine associations between recreational use of kava and indicators of suicidal behaviour among youth in New Caledonia.
Methods: This cross-sectional community-based survey was administered to 1,400 young people aged 16–25 years. A multivariate analysis tested for associations between lifetime kava use and lifetime suicidal ideation and attempts. Because ethnicity affected the correlation between kava use and suicidal behaviour, data were analysed separately for Kanak youth and youth of other ethnic communities.
Results: Overall, 42% of respondents reported any lifetime kava use, 34% reported past suicidal ideation and 12% any suicide attempts. Among Kanak youth, kava use increased the likelihood of reporting both suicidal ideation (aOR = 2.40, 95% CI: 1.58–3.66) and suicide attempts (aOR = 1.98, 95% CI: 1.11–3.52). No such association was found in the non-Kanak group.
Conclusions: The discrepancy between the effects of kava drinking on suicidal behaviour between Kanak youth and youth of other ethnic groups may be related to differences in patterns and quantity of kava use. In view of the paucity of data on the effects of kava on mental health in young people, further investigation is required.
Implications: The results call for an increased awareness of the potential adverse health effects of kava consumption in New Caledonia where it has spread in recent times and among communities where previously it was never used.
High levels of suicidal behaviour have been reported in the Pacific.1 In New Caledonia, both the public authorities and community leaders have worried about what appears to be an increase in the suicide rate among young men in recent years.2 Tobacco, alcohol, and cannabis use have been shown to be associated with suicidal behaviour in adolescents.3–10 Until now, the association between suicidal behaviour and kava has not been examined. Kava, a psychoactive substance commonly used by youth in New Caledonia is also drunk elsewhere in the region including Australia and New Zealand, where its use has been documented in Aboriginal and Pacific Island communities.11–13
Kava, a beverage made of dried roots of Piper methysticum and water, has traditionally been drunk for social and cultural purposes during male social gatherings in a number of western Pacific societies among which are Fiji, Vanuatu, Tonga, the Samoas, Wallis and Futuna, and Pohnpei.14 It is only in the 1980s that kava, imported from Vanuatu, was introduced in Nouméa, the only real urban zone in New Caledonia (a French-ruled territory). After its introduction, more or less formal outdoor kava bars, open in the late afternoon and evening became popular places for patrons drinking kava for its relaxing effects.15,16 In New Caledonia as in most Pacific Islands today, kava is commercially available and consumed recreationally by both men and women. Unlike other psychoactive substances, kava is not yet regulated in New Caledonia.17 Recently, a survey of psychoactive substance use among adolescents indicated that 11% of year 8 students, 19% of year 10 students and 38% of apprentice training-centre students report experimentation with kava, and 4% of the latter use it regularly.18
The effects of kava are not fully known. Kava's active ingredients, the kavalactones, have been studied as a treatment for mild and moderate anxiety. Although kava has been described as relatively safe for short-term herbal treatment, the safety profile of kava extract has not been investigated in detail.20–22 It is known that kava can potentiate the effects of alcohol and other drugs that affect the central nervous system.23,24 To date, the only reported association of kava with suicidal behaviour comes from forensic reports from New Caledonia, where kavalactones have been identified in the systems of people who committed suicide.25 Other reports of adverse effects suggest an association between heavy kava consumption and neurologic impairments: an isolated case of motor impairment featuring choreiform movements associated with prolonged and heavy kava use, in eastern Arnhem Land (Australia),26 and unusual neurologic episodes associated with heavy kava consumption in Aboriginals, also in Arnhem Land.13
This article presents results from a questionnaire survey ‘Social situation and health behaviours of youth in New Caledonia’ and aims to explore the relationships between suicidal ideation, suicide attempts and kava drinking among youth in New Caledonia. The indigenous Kanak community is the largest ethnic community there, followed by Europeans (i.e. those born in France or of European descent), Polynesians (mostly from Wallis and Futuna islands) and Asians. Preliminary in-depth interviews conducted to prepare the survey questionnaire suggested that while Kanak youth use kava less frequently than their non-Kanak counterparts, they often drink much larger quantities at one time, to the point of intoxication. Unless buying kava in small bowls, two or three youths will jointly buy it in litre-and-a-half plastic water bottles, to drink together.
In 2007, a cross-sectional survey was conducted among youth aged 16 to 25 years in New Caledonia. Because existing databases (such as electoral rolls, telephone directories, or even school registries, because of the high proportion of drop-outs) did not enable us to reach this age group, a stratified sample based on 2004 census data19 was constructed for each of the four geographic regions (North Province, Loyalty Islands, the rural Southern Province, and the urban area of Noumea); the stratifying factors were sex, age group (16–18, 19–21 and 22–25) and school enrolment status (still at school or not).
In a preliminary study, in-depth interviews were conducted with 52 young people to prepare the quantitative survey and the standardised questionnaire. For the quantitative survey, 1,400 young men and women (3.7% of the total population in this age group) from all ethnic communities were recruited at selected public places over the entire territory. Sociological observations during the preliminary study identified suitable places for recruiting participants, including the vicinity of schools, bus stations, shopping centres and other places attended by young people. Of the original 1,589 individuals approached to participate, 188 (12%) declined, and one discontinued the interview for personal reasons. The anonymous questionnaire was administered outdoors. The interviewers were deliberately chosen to resemble for the ethnic diversity of the population and were trained to protect the respondents’ confidentiality, to administer the survey, and to understand the importance of standardised interviews and data collection. The respondents did not receive any monetary compensation. They were provided with a list of youth-oriented services, and a special hotline was available during the period of data collection. The survey received the approval of the Institut National de la Santé et de la Recherche Médicale (INSERM) ethics committee and met the standards for data protection outlined by the French Data Protection Authority (Commission Nationale Informatique et Liberté, CNIL).
The 83-item survey covered five topics: demographics, occupation and financial resources, sociality, adverse childhood experiences, and health issues (lifetime and recent psychoactive substance use, risky driving behaviors, sexual health and mental health including lifetime suicidal ideation and attempts). Assessment of lifetime suicidal ideation and attempts was determined by the answer to the following questions “Have you ever thought seriously about killing yourself?” and “Have you ever tried to commit suicide?” Data on lifetime and recent kava and other psychoactive substances use were reported during detailed questioning about substance use, including lifetime use, age at first use, and use during the past month. Early use was defined by the first age quartile reported for each substance: 13 years for tobacco and 15 years for alcohol and cannabis. Lifetime suicidal ideation, lifetime suicide attempts and lifetime kava consumption were categorised as ever or never. The questionnaire also covered a range of items, including same-sex attraction, as well as health problems. Given the lack of mental health assessment tools culturally validated in indigenous communities of the Pacific area, we explored mental health using three questions that assessed non-specific mental health symptoms described according to local linguistic determinants and health representations (sleeping disorders “During the last 12 months, have you felt difficulties to sleep or did you suffer from insomnia?”, concentration disorders “During the last 12 months, have you felt difficulties to concentrate yourself?” and feeling exhausted without reason “During the last 12 months, have you felt exhausted or tired without a reason?”). The answers were combined into one dichotomous variable (at least two persistent symptoms last year versus one or none). Adverse childhood experience was defined as sexual or physical abuse during childhood or growing up in a family with alcohol problems. Young people who reported that they did not have a confidant were classified as without a close friend. Material deprivation during childhood was defined as lack of money for transportation, school fees and clothes during childhood. Current activity was classified in three categories: student or apprentice, employed, or unemployed.
Descriptive statistical analysis was performed on all variables. The main outcomes of interest were lifetime suicidal ideation and suicide attempts. Associations were first analysed with a univariate χ2 test. Logistic modelling was performed in univariate (crude odds ratio) and multivariate analysis (logistic regression) adjusted for age, sex, ethnicity, current activity, early use of tobacco, lifetime use of alcohol and cannabis, and other known risk factors for suicidal behaviour (mental disorders, same-sex attraction, adverse childhood events, low social support and economic disadvantages). Analyses were performed with SAS v9.1, SAS Institute Inc., Cary, NC, USA.
Of the 1,400 young people recruited, 48% identified themselves as members of the Kanak community. Table 1 details the distribution of gender, age, place of residence and activity status matched that of the census data.
Table 1. Demographic characteristics of the youth involved in the study, both Kanak and other ethnic groups.
|Age group||16–18 years (n=471)||32%||35%||34%||34%|
|19–21 years (n=421)||31%||29%||30%||30%|
|22–25 years (n=508)||37%||35%||36%||36%|
|Geographic region||Great Nouméa (n=857)||37%||83%||61%||61%|
|Rural South (n=107)||9%||6%||8%||8%|
|Loyalty Islands (n=138)||19%||1%||10%||10%|
|Current activity status||Student/apprentice (n=659)||40%||53%||47%||40%|
In all, 42% of respondents reported ever using kava, and 12% using it in the past 30 days. Compared with the non-Kanak group (Europeans, Polynesians and Asians), a smaller proportion of Kanak youth reported kava use (30% versus 52% for lifetime use and 9% versus 15% for the last 30 days, p<0.001 [data not shown]).
Over one-third of all respondents (34%) had experienced suicidal ideation and 12% reported ever attempting suicide. As shown in Table 2, reports of suicidal ideation and attempts were more common among girls than boys (41% versus 27% for suicidal ideation, p<0.001, and 16% versus 8% for attempts, p<0.001). There were no significant differences associated with age, ethnic affiliation, geographic region or activity status.
Table 2. Lifetime suicidal ideation and suicide attempts and risk factors in young people in New Caledonia in 2007 – Univariate analysis.
|Female (n=694)||41%|| ||16%|| |
|Age group||16–18 years (n=470)||32%||0.41||9%||0.11|
|19–21 years (n=421)||34%|| ||12%|| |
|22–25 years (n=506)||36%|| ||14%|| |
|Geographic region||Greater Noumea (n=855)||34%||0.96||13%||0.20|
|Rural South (n=107)||35%|| ||15%|| |
|North (n=298)||33%|| ||9%|| |
|Loyalty Islands (n=137)||36%|| ||10%|| |
|Ethnic affiliation||Kanak (n=672)||36%||0.13||12%||0.58|
|Other ethnic groups (n=725)||32%|| ||11%|| |
|Current activity status||Student/apprentice (n=658)||34%||0.75||12%||0.92|
|Employed (n=389)||33%|| ||12%|| |
|Unemployed (n=350)||36%|| ||11%|| |
|First tobacco use before age 13||Yes (n=310)||43%||<0.001||17%||<0.001|
|No (n=1,087)||32%|| ||10%|| |
|First alcohol consumption before age 15||Yes (n=460)||39%||0.01||14%||0.05|
|No (n=937)||32%|| ||11%|| |
|First cannabis use before age 15||Yes (n=384)||38%||0.06||14%||0.14|
|No (n=1,013)||33%|| ||11%|| |
|Lifetime kava use||Yes (n=581)||40%||<0.001||14%||0.03|
|No (n=816)||30%|| ||10%|| |
|Lifetime cannabis use||Yes (n=953)||38%||<0.001||14%||<0.001|
|No (n=444)||25%|| ||7%|| |
|Lifetime alcohol use||Yes (n=1,326)||35%||<0.001||12%||0.20|
|No (n=71)||18%|| ||7%|| |
|Kava use (past month)||Yes (n=170)||43%||<0.01||19%||<0.01|
|No (n=1,225)||33%|| ||11%|| |
|Symptoms of mental disorder||Yes (n=605)||47%||<0.001||17%||<0.001|
|No (n=792)||24%|| ||8%|| |
|Same sex attraction||Yes (n=84)||65%||<0.001||34%||<0.001|
|No (n=1,311)||32%|| ||10%|| |
|Adverse childhood experience||Yes (n=630)||47%||<0.001||19%||<0.001|
|No (n=766)||24%|| ||6%|| |
|No close friend||Yes (n=400)||38%||0.06||15%||<0.05|
|No (n=996)||33%|| ||11%|| |
|Material deprivation during childhood||Yes (n=116)||46%||<0.01||22%||<0.001|
|No (n=1,279)||33%|| ||11%|| |
Respondents who had ever used kava were more likely to report suicidal behaviour than those who never had (see Table 2). Recent kava drinking was also associated with lifetime suicidal ideation and attempts.
Generally speaking, early substance use was associated with a higher likelihood of reporting suicidal behaviour (see Table 2). Those who had smoked tobacco before the age of 13 were more likely to report suicidal ideation and suicide attempts than those who were not early smokers (see Table 2). Same trend was detected among those who were intoxicated by alcohol before the age of 15 (p<0.01 for suicidal ideation) and among early cannabis users (but the p-value was not significant). In addition, respondents reporting lifetime cannabis use were more likely to report suicidal ideation and suicide attempts compared to non-users. Suicidal ideation was less common among young people who had never drunk alcohol, but no significant association was found with suicide attempts. The same trend of increased risk of suicidal ideation and suicide attempts was found with same-sex attraction, adverse childhood experiences, having no close friend and material deprivation during childhood. Finally, results for symptoms of mental disorders were also correlated with suicidal behaviour indicators (see Table 2).
On further analysis, a significant interaction was observed between kava use and ethnicity in the association with both indicators of suicidal behaviour (see Table 3). Among Kanak respondents, those who reported kava consumption had higher rates of suicidal ideation and of suicide attempts than those who had never used kava. These associations were not found in the non-Kanak group. An interaction was also found with recent kava use and suicidal ideation. Subsequently, the association between kava use and suicidal behaviour was studied separately for Kanaks, and non-Kanaks. Because age at first use of both alcohol and cannabis was highly correlated with age at first cigarette, only early tobacco use and lifetime cannabis use were kept in the multivariate analysis.
Table 3. Interaction of kava use and ethnic affiliation with suicidal behaviour.
|Lifetime kava use||Yes||51%||<0.001||35%||0.15||18%||<0.01||12%||0.78|
|No||30%|| ||30%|| ||10%|| ||11%|| |
|Recent kava use (past month)||Yes||52%||<0.01||37%||0.22||23%||<0.01||17%||<0.05|
|No||34%|| ||31%|| ||11%|| ||10%|| |
Table 4 presents the logistic regression results. Among the Kanak youth, lifetime kava use increased the likelihood of reporting suicidal ideation and suicide attempts. The association remained after adjustment, with an adjusted odds ratio (aOR) of 2.40 (95% CI: 1.58–3.66) for suicidal ideation and 1.98 (95% CI: 1.11–3.52) for suicide attempts. No association was found in the non-Kanak group between kava use and suicidal behaviour.
Table 4. Lifetime suicidal ideation and suicide attempts and kava use among youth in the Kanak and other ethnic communities in New Caledonia in 2007. Crude and adjusted odds ratios (multivariate logistic regression).
| ||Crude OR||95% CI||aOR||95% CI||Crude OR||95% CI||aOR||95% CI||Crude OR||95% CI||aOR||95% CI||Crude OR||95% CI||aOR||95% CI|
|Lifetime kava use (ref: no)||2.42||1.73–3.40||2.40||1.58–3.66||1.26||0.92–1.72||1.00||0.69–1.44||2.11||1.32–3.38||1.98||1.11–3.52||1.07||0.67–1.69||0.62||0.36–1.07|
|Female (ref: male)||1.95||1.42–2.69||2.41||1.66–3.51||1.71||1.25–2.34||1.38||0.97–1.96||2.57||1.56–4.25||3.32||1.86–5.95||2.12||1.32–3.42||1.68||0.99–2.86|
|16–18 years (ref.)||1.00|| ||1.00|| ||1.00|| ||1.00|| ||1.00|| ||1.00|| ||1.00|| ||1.00|| |
|Current activity status|
|Employed (ref.)||1.00|| ||1.00|| ||1.00|| ||1.00|| ||1.00|| ||1.00|| ||1.00|| ||1.00|| |
|First tobacco use before age 13 (ref>13)||2.01||1.30–3.09||1.48||0.89–2.46||1.53||1.09–2.13||1.37||0.94–2.00||2.71||1.58–4.65||2.17||1.15–4.11||1.45||0.90–2.35||1.46||0.84–2.54|
|Lifetime cannabis use (ref: no)||1.88||1.32–2.68||1.34||0.85–2.10||1.75||1.23–2.50||1.63||1.04–2.56||2.56||1.41–4.67||1.76||0.86–3.59||2.21||1.23–3.96||2.26||1.07–4.79|
|Lifetime alcohol use (ref: no)||2.14||1.26–3.61||1.75||0.92–3.31||1.21||0.78–1.89||0.88||0.51–1.53||6.85||1.65–28.38||5.88||1.27–27.21||1.21||0.78–1.89||0.93||0.38–2.23|
|Symptoms of mental disorder (ref: no)||2.62||1.89–3.62||1.93||1.34–2.78||2.90||2.10–4.01||2.43||1.72–3.44||1.96||1.23–3.13||1.13||0.66–1.92||3.42||2.06–5.68||2.26||1.07–4.79|
|Same sex attraction (ref: no)||7.35||2.05–26.31||4.69||1.23–17.90||4.02||2.40–6.73||2.77||1.59–4.82||7.73||2.64–22.66||7.47||2.16–25.91||4.27||2.40–7.60||3.02||1.59–5.75|
|Adverse childhood experience (ref: no)||3.84||2.71–5.44||3.06||2.1–4.47||2.21||1.60–304||1.84||1.29–2.62||3.83||2.17–6.79||3.06||1.64–5.70||3.66||2.27–5.91||2.70||1.60–4.57|
|No close friend (ref: no)||1.15||0.84–1.58||1.12||0.76–1.66||1.63||1.18–2.26||1.50||1.01–2.21||0.76||0.48–1.22||0.84||0.47–1.50||2.84||1.78–4.53||2.49||1.45–4.26|
|Material deprivation during childhood (ref: no)||2.03||1.27–3.23||1.72|| 1.00–2.97||1.10||0.54–2.25||0.68||0.31–1.50||2.55||1.44–4.55||2.86|| 1.44–5.67||1.67||0.67–4.16||0.87||0.32–2.39|
After adjustment for confounding factors, suicidal behaviour remained associated with non-specific symptoms of mental disorder, same-sex attraction and adverse childhood experiences in both the Kanak and non-Kanak groups. Among young Kanaks attracted to the same sex, the adjusted odds ratios were particularly high for suicidal ideation and for suicide attempts. In the Kanak group, being female and deprivation during childhood remained significantly associated with both suicidal ideation and attempts, while early tobacco use and lifetime alcohol consumption remained significantly associated only with suicide attempts. In the non-Kanak group, lifetime cannabis use and having no close friends/confidants were associated with both indicators of suicidal behaviour.
When kava use during the past month replaced lifetime kava use in the model, it was no longer associated with suicidal ideation among Kanak youth (crude OR = 2.08 [95% CI: 1.23–3.50] and aOR= 1.56 [95% CI: 0.87–2.81]), but the relation for suicide attempts remained significant (crude OR = 2.32 [95% CI: 1.21–4.42] and aOR= 2.13 [95% CI: 1.02–4.45]). In these models, the same trends were observed for other covariates (data not shown).
Our analysis shows a strong association between suicidal behaviour and kava use among Kanak young people, an association that was not found in the non-Kanak group of youth of diverse ethnicity. This finding calls for a number of comments. It might be due to differences in patterns of kava drinking among Kanaks and non-Kanaks that was underlined by the in-depth interviews conducted with 16–25 years old to prepare the cross-sectional survey. Another hypothesis is that kava drinking accounts for higher psychological distress among Kanak than non-Kanak young people. However, the frequency of mental health problems did not differ between the two groups.
Finally, the difference in the association of kava use and suicidal behaviour between Kanaks and non-Kanaks could be related to the representations of kava bars in youth sociality. These evening outdoor bars, devoted to serving kava bowls, where people sit together without talking very much or very loud, may be viewed as a kind of oceanian neo-traditional healing circle by Kanak adolescents suffering psychological distress and searching social support. Non-Kanak youth, on the other hand, may view kava bars as a place of exotic recreation. An in-depth ethnographic study on this topic should further document this issue.
Unlike lifetime kava use, consumption of kava during the past month was not significantly associated with suicidal ideation after adjustment. This could be because suicidal ideation was assessed only on a lifetime basis and could have occurred with past but not current kava use. The sample size might also have been insufficient. However, the association between kava use during the past month and suicide attempts remained significant after adjustment.
Other well-known correlates of suicidal behaviour, such as female sex, mental disorders, adverse childhood experiences and material deprivation, were also found in the New Caledonian survey. A previous Violence Against Women in New Caledonia survey showed that sexual and physical violence are frequent in New Caledonia,27–29 and this study corroborate those findings: 15% of respondents, nearly equal percentages of each sex, reported abuse of some kind, and 17% of girls and 5% of boys reported sexual abuse before age 16.
As reported in various other cultural and social settings,30–39 same-sex attraction and homosexuality were highly correlated with suicidal behaviour in New Caledonia, especially among Kanak youth, probably related to strong homophobia in the Kanak community. The relationships between suicidal behaviour and early tobacco use,4,7,8,40 alcohol consumption and cannabis use3–10 have long been known. Here however, after adjustment, the association decreased slightly or was no longer significant after adjustment. Having no confidant was associated with suicidal behaviour among non-Kanak but not Kanak youth. Finally, no association was found between suicidal behaviour and current activity status. Nonetheless, the association observed with childhood material deprivation in the Kanak community suggests that poverty and social difficulties may play a role. These results show that addressing the issues of youth mental health is a major public health challenge in today New Caledonia society, calling for comprehensive programs that include awareness campaigns, education targeting several concerns including substance use but also sexual abuse and homophobia.
Some limitations of the study must be acknowledged. The lack of any database from which participants could be randomly selected led to a stratified recruitment. However, the in-depth preliminary phase, the methodological efforts during recruitment, the excellent participation rates, and the large number of participants together provided a sample of good quality. The cross-sectional design of the survey prevents any conclusion about a causal relationship between kava use and suicidal behaviour in young people, because the temporal sequence of kava drinking and suicidal events was not documented in the questionnaire. In this sample, median age at first kava use was 16 years, and median age at suicidal ideation/attempt was 17. Another limitation of the study is that the association between different levels of kava use and suicidal behaviour cannot be properly assessed due to the lack of accurate data on patterns of drinking and on quantity of kava used. It has been shown that measuring exposure to kava consumption faces particular challenges.41 Moreover, quantity of kava usage is hard to assess given the lack of standardised measurements (there are various sizes of bowls) and the variation in quality of kava root powder used in each beverage.
Because existing measurement scales for depression have not been validated in the indigenous populations of the Pacific region, mental health was assessed by questions on sleep disorders, concentration difficulties, and depressive symptoms (i.e. to feel tired or exhausted without a reason) over the previous 12 months. Although such indicators of mental health cannot be used as predictors of lifetime suicidal attempts, strong correlations observed between history of suicidal behaviour and indicators of psychological distress suggest that the latter do reflect mental health status.
The findings shed light on the link between kava use and suicidal behaviour and suggest that the possibility of a depressant effect by kava on mood cannot be completely ruled out. Conversely, in view of kava's anxiolytic effects, evening attendance at kava bars might be a form of self-medication for psychological distress by some young people.
The results call for an increased awareness of the potential adverse health effect of Kava consumption in New Caledonia where it has spread in recent times and among communities where previously it was never used. The discrepancy between the effects of kava drinking on suicidal behaviour between Kanak youth and youth of other ethnic groups may be related to differences in patterns and quantity of kava use. Overall, in view of the high rates of non-traditional kava use in the Pacific region today and the association we found between kava drinking and suicidal behaviour among the Kanaks of New Caledonia, the possible relationship between kava use and increased psychological distress should be further investigated. It could be done so in Australia and New Zealand where different patterns of consumption have been described: alone and steadily in Aboriginal communities in Arnhem Land13 or during binge drinking sessions as among Tongan born men living in Auckland.11
This research was funded by the Government of New Caledonia, the Mission Interministerielle de Lutte contre les Drogues et Toxicomanies (Interministerial Mission in the Fight against Drug and Drug Addiction) and the Agence Nationale de Recherche sur le Sida et les Hépatites virales (The French National Agency for Research on AIDS and Viral Hepatitis).