A recent study, conducted in August, 2013 by a group of researchers involved with Indianapolis VA medical Center and the Indiana University School of Medicine, explored the notion of how a blood biomarker could potentially help detect if the patient is suicidal. Currently, a self-report is the most common way to detect is someone is suicidal.
Many people with depression or suicidal thoughts are not willing to speak out, which makes it difficult for many to get the help they need. The goal of this study was to find a way to track and predict states of heightened risk of suicidal.
The results from this study are ‘strong,’ but I will say that their study should be taken lightly. While the results are very telling, they are also very limited. The subjects in this study were all men who have been previously diagnosed with bipolar disorder and the majority of these men were Caucasian.
In this study, bipolar men had a clinical interview regarding their mental health and a base-line blood test with three follow-up blood tests in 3 to 6 month intervals.
During each of their follow-up blood tests, they were also given a psychiatric rating. In some of the subjects, the level of activity of their SAT1 gene was altered throughout the testing periods.
The researchers believed that the spike in activity of this specific gene might be related to a suicidal state or the subject having suicidal thoughts. Nine men showed severe alterations in SAT1 activity, at first exhibiting no signs of suicide and later demonstrating multiple suicidal tendencies.
SAT1, found on the X chromosome, is a rate-limiting enzyme in the catabolic pathway of polyamine metabolism and is involved with the regulation of the intracellular concentration of polyamines and their transport in and out of cells.
While polyamines are not fully understood, lack or inhibition of these organic compounds have been found to be related to cell death and sometimes dysfunction of cell growth. SAT1 has also been found to create an enzyme that facilitates spermidine, a component of cell membranes which may promote hair growth or be related to alterations in skin tissue. There is still a lot of about SAT1 that is unclear in the scientific field.
After this finding, the researchers decided to visit a coroner’s office and obtain blood samples to test. The blood from nine different men who had killed themselves had severely high SAT1 levels.
These results may suggest that the SAT1 enzyme is involved in suicide more generally than just their subjects because, as far as the researchers are aware of, the men from the coroner’s office had not been diagnosed with bipolar disorder.
Next, the researchers observed bipolar men who were looking to be hospitalized for suicidal behavior. They found that men who had higher SAT1 levels were more likely to be admitted than those with lower levels.
Overall, it is suggested that a higher activity level of SAT1 in bipolar men means they are most likely suicidal.
This group of researchers is known for providing that first proof-of-principle for the use of blood gene expression biomarkers to predict mood-related symptoms related to brain activity. But as you can see, this study is very new and very limiting.
The findings for SAT1 did not involve women at all, and it primary targeted men of one race. It also only primarily targeted those with bipolar disorder. Many other questions may include: how can you make someone take a blood test?
And is it expensive to run all these samples? Will there eventually be standards where one must be tested every three months to be evaluated? Can these high activity levels be signaling something else?
These limited results may not tell scientists and the public much, but they are creating a path for future studies to investigate how gene activity levels may be able to help us predict who is at risk for suicide, or even those in a depressive state.
The main point of this study is to show that progress is being made in the psychiatric field and researchers are trying to find biomarkers to help those who are suicidal and are not necessarily able to help themselves.
—Delaney Fisher ’15 is a neuroscience major.