In the United States alone, it is estimated that upwards of fifteen million people suffer from depression. This equates to seven percent of the country’s population. However, of this seven percent, thousands upon thousands of Americans suffering from a form of this widespread mental illness go undiagnosed every year. The difficulty surrounding diagnosis of mental illness derives from the challenges faced when identifying the symptoms of depression, which tend to be nonspecific or “invisible”. The unsettlingly high rate of undiagnosed depression has provided stress on the issue of catching mental illness early on and further prompted researchers to investigate more thoroughly and consider a greater number of factors when screening and diagnosing for mental illness. This has led to significant results. In more recent studies, scientists have found that there is a clear connection between nightmares and the presence of depression.

Michael Nadorff, a psychologist at Mississippi State University, has worked with his team of researchers to study the correlation between nightmares and depression, along with the more specific correlation between nightmares and suicide. Five years’ worth of studies have garnered much insight on risk factors which could strongly aid in the diagnosis of patients- especially those who may not exhibit clear symptoms. In a 2011 study published in the journal Sleep, Nadorff and his colleagues evaluated suicide risk in undergraduate students, after which they proceeded to examine how factors such as anxiety, depression and nightmares were related to that risk. Nardoff’s findings from a 2013 study published in Suicide and Life-Threatening Behavior further demonstrate that in addition to the initial presence of nightmares, how long the person has been experiencing nightmares is also significant. In other words, the longer someone experiences constant nightmares, the higher their risk of suicide.

Though depression and suicide are exceptionally relevant issues in the United States, which has highest rate of mental illness in the world, the study of mental illness and research conducted to further scientists’ understanding in the mental health sector is an international affair. One of the most prominent studies regarding the pressing matter of suicide is a 2015 Finnish study. The study, which utilized information from the National FINRISK Study, a series of health surveys of the Finnish adult population, including nearly fourteen thousand adults from the ages of twenty-five to seventy-four, concluded that the depression symptom of “negative attitude toward self” was one of the strongest independent risk factors associated with nightmares, as 28.4% of the participants who had severe depression reported experiencing persistent nightmares, as opposed to just 3.9% of the healthy participants. In an interview with Science Daily, lead author Nils Sandman, a researcher at the Center for Cognitive Neuroscience at the University of Turku in Finland, explained that “Our study shows a clear connection between well-being and nightmares… This is most evident in the connection between nightmares and depression, but also apparent in many other analyses involving nightmares and questions measuring life satisfaction and health”.

According to further information obtained by the Finland National Death Register and analyzed by researchers at the University of Turku, frequent nightmares increased the risk of death by suicide more than twofold. Sandman noted that although the study did not allow for an examination of causality, “it might be possible that nightmares could function as early indicators of onset of depression and therefore have previously untapped diagnostic value”.

In order to emphasize the significance of the research found in the correlation between nightmares and depression, it is important to understand why nightmares in particular could play such a significant role in relation to suicide. First and foremost, the situational context is important. Waking up from a nightmare in a blind panic can cause a heightened sense of anxiety and despair. For someone with severe suicidal thoughts, such a moment can be the difference between life and death. According to a 2014 study published in Sleep, suicide is already more likely to occur at night, especially between midnight and 6 a.m.. These factors highlight the importance of researching risk factors of depression and suicide, which will aid researchers in their diagnosis.

That being said, however compelling the research provided by various studies may be, nightmares alone cannot be used for the screening of early-onset depression, as depression most manifests itself through a number of different symptoms. The specific utilization of nightmares in the realm of mental health aside, doctors are now provided with another indicator for depression, which can aid in the diagnosis of depression and ultimately help save lives.