The vast majority of suicides occur during episodes of depression. The reasons for this are many. Many depressed people are not suicidal. The existence of two or more conditions put someone in high risk. For example, people with serious depression and an anxiety disorder, particularly if they suffer from panic attacks, are at risk.
Suicide is associated with low seretonin functions.
This condition does not only exist in some people with depression, but also some individuals who have other psychiatric disorders, and even in people without mental illness. Another biological marker associated with a high risk of suicide is increased production of cortisol, a stress hormone. High levels of anxiety and the experience of panic attacks put a person with depression at particularly high risk for suicide. Some of the newer anticonvulsants may prove to be as helpful in reducing the risk of suicide, but it is too soon to tell. One substance that increases the risk of suicide is the use of alcohol.