Elevated Suicide Rates at High Altitude: Sociodemographic and Health Issues May Be to Blame

Journal of Addiction Medicine

Kondo

et al. 2012

Objectives Recently, increased rates of suicide in counties at higher altitudes have been noted. Due to the documented association between cocaine use and suicide, we hypothesized that there would be a correlation between incidence of cocaine use and altitude of residence. Methods Cocaine use data was obtained from the Substate Substance Abuse Estimates from the 1999-2001 National Surveys on Drug Use and Health. Data related to the percentages of people 12 years or older who used cocaine in the past year. Average elevation for United States counties was calculating using the Shuttle Radar Topography Mission elevation dataset and subject region elevation was calculated by averaging the weighted elevations of each region's relevant counties. The correlation between elevation of a substate region and cocaine use in that region was calculated using Pearson correlation coefficients. Results A significant correlation exists between mean altitude of a substate region and cocaine use in that region (r=0.34; p < 0.0001). Regression analysis controlling for age, gender, race, education level, income, unemployment, and population density was performed. Altitude remained a significant factor (p = 0.007), while male sex (p = 0.008) and possessing less than a college education (p < 0.0001) were also significant predictors of self-reported cocaine use in the past year. It is important to note that cocaine use was assessed in isolation of other drugs of abuse, an additional confounding variable. Conclusions This study demonstrates a significant correlation between altitude of substate region of residence and cocaine use. It is possible that stress response due to hypoxia is responsible, however, this requires further investigation. However, because other substance use was not assessed, specificity of this association is unknown Additionally, this correlation may help to explain the elevated rate of suicide in areas of higher elevation.

mentioning

confidence: 76%

Cocaine Use in the Past Year Is Associated With Altitude of Residence

Fiedler

Journal of Addiction Medicine

Kondo

et al. 2012

“…Despite some controversies,54,55 previous epidemiological studies have consistently suggested that high altitude of residence might contribute to the increased incidence of psychiatric problems including suicide,46,56 severe psychological distress and major depressive episodes,45 and cocaine abuse 30. These phenomena are also closely associated with alterations of DA and 5-HT levels in the brain 57,58.…”

Section: Discussionmentioning

confidence: 99%

Altitude May Contribute to Regional Variation in Methamphetamine Use in the United States: A Population Database Study

Kondo

et al. 2014

Psychiatry Investig

ObjectiveMethamphetamine (MA) use rates in the United States (US) have consistently demonstrated geographical variation and have been higher in the West and Midwest. This uneven pattern of use could be explained by regional differences in MA manufacturing and distribution, but may also result from differences in altitude. The hypobaric hypoxia found at high altitude alters neurotransmitter synthesis in the brain, which may contribute to MA use. The present study investigated the relationship between mean altitude and MA use rate in the 48 contiguous US states and the District of Columbia.MethodsState-level estimates of past year MA use were extracted from the National Survey on Drug Use and Health report. The mean altitude of each state was calculated using the Shuttle Radar Topography Mission altitude data set.ResultsThere was a significant positive correlation between mean state altitude and MA use rate (r=0.66, p<0.0001). Multivariate linear regression analysis showed that altitude remained a significant predictor for MA use rate (β=0.36, p=0.02), after adjusting for age, ethnicity, education, socioeconomic level, employment, MA laboratory incidents, subpopulations, and other substance use.ConclusionAltitude appears to a possible contributing factor for regional variation of MA use in the US. Further studies will be required to determine biological changes in neurotransmission resulting from chronic mild hypoxia at high altitude in MA users.

“…It was speculated that in higher altitude regions, metabolic stress with mild hypoxia might lead to a worsening of mood disorder symptoms and thus to higher suicide rates Kim et al, 2011). These findings have been criticised for not controlling for possible confounding factors such as sociodemographic variables and the availability of mental health care, alleged to be a more plausible explanation for higher suicide rates in high-altitude regions (Betz et al, 2011(Betz et al, , 2012. Nevertheless, altitude is also known to have an effect on the pharmacokinetics and has been shown to significantly influence lithium pharmacokinetics in healthy humans (Arancibia et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Does altitude moderate the impact of lithium on suicide? A spatial analysis of Austria

et al. 2013

Abstract. Suicide, the tenth leading cause of death worldwide, is a complex phenomenon. Models aiming to explain the interaction of ambient variables such as socioeconomic factors, lithium content of drinking water and altitude are poorly developed. While controlling for several risk factors, this research bridges two different, but complementary research lines by investigating statistically the relationship on suicide mortality between lithium levels in drinking water in response to altitude above sea level. Besides regression models with main effects, a multiplicative interaction model between lithium and altitude has been developed providing estimates at the district-level for Austria where spatial autocorrelation was accounted for through spatial filtering. The correlation results showed a negative association between lithium levels and altitude. The regression confirmed a negative association of lithium levels and suicide mortality. Altitude was found to be positively associated with suicide mortality. On the other hand, lithium effects on suicide mortality were found to be moderated by altitude. In lower altitude regions the effect turned out to be negatively related to suicide mortality, while lithium had a positive association in high-altitude regions. These results provide evidence for the fact that the relationship between lithium, altitude and suicide rates is more complex than hitherto assumed. Further research on the effects of ambient variables such as low levels of lithium on suicide is needed and particularly the lithium-altitude interaction is worth further investigation to understand possible underlying neurochemical processes.