Altitude is a risk factor for completed suicide in bipolar disorder

Abstract

Summary Bipolar disorder (BD) is a severe brain disease that is associated with a significant risk for suicide. Recent studies indicate that altitude of residence significantly affects overall rate of completed suicide, and is associated with a higher incidence of depressive symptoms. Bipolar disorder has shown to be linked to mitochondrial dysfunction that may increase the severity of episodes. The present study used existing data sets to explore the hypothesis that altitude has a greater effect of suicide in BD, compared with other mental illnesses. The study utilized data extracted from the National Violent Death Reporting System (NVDRS), a surveillance system designed by the Centers for Disease Control and Prevention (CDC) National Center for Injury Prevention and Control (NCIPC). Data were available for 16 states for the years 2005–2008, representing a total of 35,725 completed suicides in 922 U.S. counties. Random coefficient and logistic regression models in the SAS PROC MIXED procedure were used to estimate the effect of altitude on decedent’s mental health diagnosis. Altitude was a significant, independent predictor of the altitude at which suicides occurred (F = 8.28, p=0.004 and Wald chi-square=21.67, p < 0.0001). Least squares means of altitude, independent of other variables, indicated that individuals with BD committed suicide at the greatest mean altitude. Moreover, the mean altitude at which suicides occurred in BD was significantly higher than in decedents whose mental health diagnosis was major depressive disorder (MDD), schizophrenia, or anxiety disorder. Identifying diagnosis-specific risk factors such as altitude may aid suicide prevention efforts, and provide important information for improving the clinical management of BD.

Risk factors for suicide in bipolar disorder: A systematic review

“…Table 1 provides an overview of all studies included in the final sample and of all data elements used during the data analysis process. Study designs included one case report (Kerner et al, 2013), seven transversal studies (Goldstein et al, 2012;Kheirabadi et al, 2012;Undurraga et al, 2012;De Abreu et al, 2012;Algorta et al, 2011;Evans et al, 2012;Gomes et al, 2010), nineteen cohort studies (Parmentier et al, 2012;Huber et al, 2014;Ruengorn et al, 2012;Etain et al, 2013;Cassidy, 2011;Baldessarini et al, 2012;Bellivier et al, 2011;Sears et al, 2013;Jiménez et al, 2013;Leon et al, 2012;Finseth et al, 2012;Oquendo et al, 2010;Kenneson et al, 2013;Gilbert et al, 2011;Shabani et al, 2013;Acosta et al, 2012;Song et al, 2012;Suttajit et al, 2013), and fifteen case-control studies (Eroglu et al, 2013;Antypa et al, 2013;Ryu et al, 2010;Manchia et al, 2013;Neves et al, 2010;Magno et al, 2011;Yoon et al, 2011;Arias et al, 2013;Clements et al, 2013;Kamali et al, 2012;de Moraes et al, 2013;Azorin et al, 2013;…”

“…Risk factors associated with sociodemographic components (seven studies) (Huber et al, 2014;De Abreu et al, 2012;Ruengorn et al, 2012;Algorta et al, 2011;Cassidy, 2011;Antypa et al, 2013;Ryu et al, 2010); Risk factors associated with genetic components (six studies) (Manchia et al, 2013;Sears et al, 2013;Neves et al, 2010;Magno et al, 2011;Jiménez et al, 2013;Kerner et al, 2013); Risk factors associated with Medicines and Drugs in general that interfere with bipolar disorder (eight studies) (Bellivier et al, 2011;Yoon et al, 2011;Leon et al, 2012;Arias et al, 2013;Clements et al, 2013;Finseth et al, 2012;Oquendo et al, 2010;Kenneson et al, 2013); Risk factors associated with Biological components (three studies) (Kamali et al, 2012;Evans et al, 2012;Gomes et al, 2010); Risk factors associated with Psychological causes (seven studies) (Parmentier et al, 2012;Shabani et al, 2013;Acosta et al, 2012;Song et al, 2012;Suttajit et al, 2013;Stewart et al, 2009); and Risk factors associated with components of Religious and Spiritual (three studies) components (Azorin et al, 2013;Dervic et al, 2011;. Among the 42 studies, 8 discussed about "suicide risk factors in Bipolar Affective disorder" -more broadly (Goldstein et al, 2012;Eroglu et al, 2013;Kheirabadi et al, 2012;Undurraga et al, 2012;…”

“…In fact, it is estimated that BD may account for one-quarter of all completed suicides (American Psychiatric Association, 2013; Huber et al, 2014).…”

“…Moreover, the altitude was seen as a significant risk factor (Huber et al, 2014). Several biological theories may explain an altitude-suicide association.…”

“…Dopamine and serotonin are neurotransmitters associated with pleasure, reward, and mood. Decreased levels of serotonin and increased levels of dopamine and norepinephrine associated with hypoxia at higher altitudes may lead to increased irritability, depression, and suicide (Huber et al, 2014;Trouvin et al, 1986;Jou et al, 2009).…”