Last year, 20% of U.S. adults experienced a mental health disorder (CDC). Mental illness is a leading cause of disease burden worldwide, and therefore, needs to be talked about. Mental health conditions, such as depression, anxiety, bipolar disorder, eating disorders, schizophrenia, drug/alcohol abuse, etc., have devastating consequences on the individual’s quality of life and overall wellbeing. Mental illness emerges from a complex interplay of genetic, psychological, lifestyle, and environmental factors. Environmental exposure is important to consider when looking at mental health, especially at high altitude. Up in the mountains, we must consider oxygen availability on the impact of our mental wellbeing. 

Numerous studies have shown rates of depression and suicide to be higher at high elevations (Figures 1 & 2), even when controlling for other variables such as socioeconomic status and demographics (Kim et al., 2014).

Why is this?

Some researchers propose that low blood oxygen levels from lower atmospheric pressure at altitude (called hypobaric hypoxia) has something to do with it. Animal studies done on rats and short term human studies have found this connection (Kanekar, 2015), and altering brain bioenergetics and serotonin metabolism could have something to do with it. Both pathways are affected by depression, and both are affected by hypoxia (Hwang, 2019). Hypoxia may lead to suppressed mitochondrial functioning, resulting in a change of how our cerebrum uses its energy. Patients with depression have a harder time using energy in their pre-frontal cortex, which makes it harder to concentrate and fight off negative thoughts. If this is already the case at low altitude, being at higher altitude may make moods more unstable and focus even harder to obtain. 

Second, hypoxia may lead to decreased serotonin levels in the brain, which is a very important neurotransmitter targeted in the treatment of anxiety and depression. These medications, known as SSRIs (selective serotonin reuptake inhibitors) allow more serotonin to hang around in the brain. If normal antidepressants are less effective at elevation, we need to take another look at the current treatment plan. Researchers are looking into a medication that is a precursor to serotonin that bypasses the oxygen-dependent phase of the reaction. It is called 5-hydroxytryptophan. Creatine monohydrate may also be effective in treating depression at altitude (Ramseth, 2019). This is an exciting opportunity in mental health at altitude research; one that may yield more effective treatment for people living in the mountains.

However, we cannot be certain that high altitude is causing the increased rates of depression and suicide (Reno, 2018). After all, correlation does not equal causation. There are multiple confounding variables at play, such as population density, characteristics of suicide victims, access to health care, religious beliefs, and ownership and access to firearms. Even though we do not know the cause, the correlation is clear. Because of this, clinical professionals at high altitudes need to be vigilant when exploring this concern with patients. 

Looking at the flip side, multiple studies support positive effects of altitude on mental health. It is well known that physical activity is good for your body and mind. In general, exercise improves symptoms of anxiety, depression, and panic disorder, in addition to increasing quality of life and resilience (Hufner, 2018). An interesting report found that physical activity in the mountains has even more benefits on mental health than exercise at sea level (Ower et al., 2018). This was found to be because building a personal bond to an individual mountain enhances the positive effect of the outdoors on mental health. Think about that the next time you look up at a mountain you once stood on top of. In addition, a mountain hiking program in the Alps has been shown to improve hopelessness, depression, and suicidal ideation when added on to usual care in patients who were at high risk for suicide (Sturm et al., 2012). Programs like these utilize high altitude in a positive way to treat mental health conditions.

Overall, mental health at high altitude is a complex topic that needs more research. The most important thing we must all remember is to seek help when we need it, and to never feel ashamed if you are struggling with a mental health concern. Remember: You are doing your best. 

If you or a loved one are in a crisis but don’t know where to turn, consider calling Colorado Crisis Service toll-free at 1-844-493-TALK (8255) or text TALK to 38255 to speak to a trained professional.

If you are interested in hearing more about this topic, here is an interview with reporter Rae Ellen Bichelle on NPR news discussing mental health at altitude:

https://www.npr.org/player/embed/752292543/752292544

Maggie Schauer is a 2^nd year PA student studying at Des Moines University. She is from Pewaukee, WI and obtained her bachelor’s degree in psychology at UW-La Crosse. After completing her pediatrics rotation at Ebert Family Clinic, Maggie will be going around the Midwest until her final international medicine rotation in Belize! She loves cheese, the Packers, hiking, running, waterskiing, and almost anything outdoors. Her current plan is to become a physician assistant in psychiatry and live somewhere exciting (like the mountains), until eventually moving back to Wisconsin. Her dream is to hike every 14er in Colorado; she currently has two under her belt: Grays and Torreys.

References:

1. Ha, H., & Tu, W. (2018). An Ecological Study on the Spatially Varying Relationship between County-Level Suicide Rates and Altitude in the United States. International journal of environmental research and public health, 15(4), 671. 
2. Hufner, K., Sperner-Unterweger, B., & Brugger, H. (2019). Going to Altitude with a Preexisting Psychiatric Condition. High Altitude Medicine & Biology, 20(3).
3. Hwang, J., DeLisi, L. E., Öngür, D., Riley, C., Zuo, C., Shi, X. , Sung, Y. , Kondo, D. , Kim, T. , Villafuerte, R. , Smedberg, D. , Yurgelun‐Todd, D. and Renshaw, P. F. (2019), Cerebral bioenergetic differences measured by phosphorus‐31 magnetic resonance spectroscopy between bipolar disorder and healthy subjects living in two different regions suggesting possible effects of altitude. Psychiatry Clin. Neurosci., 73: 581-589.
4. Kanekar, S., Bogdanova, O., Olson, P., Sung, Y., D’Anci, K. Renshaw, K. (2015). Hypobaric Hypoxia Induces Depression-like Behavior in Female Sprague-Dawley Rats, but not in Males. High Altitude Medicine & Biology; 16 (1)
5. Kim, J., Choi, N., Lee, Y. J., An, H., Kim, N., Yoon, H. K., & Lee, H. J. (2014). High altitude remains associated with elevated suicide rates after adjusting for socioeconomic status: a study from South Korea. Psychiatry investigation, 11(4), 492–494.
6. Ramseth, L. (2018, July 1). University of Utah research shows high altitude linked to depression and suicidal thoughts. In The Salt Lake Tribune. Retrieved October 17, 2019.
7. Reno, Elaine, et al. (2018). Suicide and High Altitude: An Integrative Review. High Altitude Medicine & Biology, 19(2).