I’ve seen this posted around a few times and decided to do a little more poking. The early research (1997) noted a relationship between low cholesterol and suicide, though in later research (2000, 2001, 2012) it was suspected that the mechanism of operation was depression as the observational relationship between low cholesterol and depression was also made. However, we also (2008) get an increase in lethality of suicide attempt with lowered cholesterol. What is particularly interesting is that while there is a relationship between cholesterol and depression and suicide and depression, we don’t seem to see an increase in suicidaility in depressive non-suicidal patients though their depression may be worsened by low cholesterol (2017). In 2019 we also get confirmation of low cholesterol increasing the lethality of suicide attempts made suicidal depressive patients.