Clinical assessment of high-risk suicide attempters : intent, violence and biomarkers

Background: One of the most important but also difficult tasks that a physician is responsible for is to assess the suicide risk of a patient. Understanding the complex role of distal and proximal risk factors and their impact on the prediction of repetition of suicidal behavior is important to consider when assessing the risk of suicide. The aim of this PhD project was to investigate structured suicide risk assessment scales in the detection of the risk of suicide in high-risk clinical cohorts of suicide attempters with a long-term follow-up. Furthermore, we aimed to investigate the neurobiological underpinnings of well-documented sex differences in suicidal behavior focusing on the main male sex hormone, testosterone.

Methods: A total of 209 patients having their clinical follow-up after a recent suicide attempt at the Psychiatric Department of the Karolinska University Hospital between 1988 and 2005, participated in three clinical studies of biological & psychological risk factors involving suicidal behavior. Patients were assessed using the following scales: the Suicide Intent Scale (SIS), the Beck Hopelessness Scale, the Karolinska Interpersonal Violence Scale (KIVS), the Freeman Scale and the Karolinska Scales of Personality. Patients in this study were followed up for mortality in the Swedish Cause of Death Register. Suicide deaths were ascertained from death certificates. CSF and plasma testosterone as well as cortisol levels were assessed in 28 patients and 19 healthy volunteers.

Results: Studies 1 & 2: Suicide Intent Scale ratings were higher in seven patients who committed suicide during an average follow up time of 13 years. The Positive Predictive Value of SIS was 16.7% and the AUC was 0.74. When combined, SIS + KIVS gave a somewhat higher PPV of 18.8% and an AUC of 0.83. Study 3: Seventeen patients out of 209 committed suicide over an average follow-up period of 10-22 years. Men had a higher suicide risk compared to women. The mean Freeman total score differentiated between completed suicide and survivors with a PPV of 10.7% and an AUC of 0.73. Study 4: Male suicide attempters had higher levels of CSF and plasma testosterone compared to age-matched healthy male volunteers. Regarding female suicide attempters, there were, however, no significant differences in CSF and plasma testosterone levels compared to healthy female volunteers. Testosterone levels were not significantly different in suicide victims versus survivors. The CSF testosterone/cortisol ratio was significantly and positively correlated with both impulsivity & aggressiveness and in male suicide attempters.

Conclusions: The findings indicate that an assessment of suicide intent and reversibility of the suicide attempt method, as well as interpersonal violence, may indicate a heightened long term suicide risk among clinically high-risk groups of suicide attempters. Higher CSF testosterone results may be associated with suicide attempts in young males through further association alongside both impulsivity and aggressiveness, in conjunction with stress system regulation. Young men may experience higher CSF testosterone levels in association with attempted suicide, aggression/impulsivity, as well as stress system regulation.

List of scientific papers

I. Stefansson J, Nordström P, Jokinen J. Suicide Intent Scale in the prediction of suicide. Journal of Affective Disorders. 2012;136:167-171.
https://doi.org/10.1016/j.jad.2010.11.016

II. Stefansson J, Nordström P, Runeson B, Åsberg M, Jokinen J. Combining the Suicide Intent Scale and the Karolinska Interpersonal Violence Scale in suicide risk assessments. BMC Psychiatry. 2015;15(1):226.
https://doi.org/10.1186/s12888-015-0607-6

III. Stefansson J, Nordström P, Åsberg M, Jokinen J. Severity of Suicide Attempts and the Prediction of Long-Term Risk of Completed Suicide. [Manuscript]

IV. Stefansson J, Chatzittofis A, Nordström P, Arver S, Åsberg M, & Jokinen J. CSF and plasma testosterone in attempted suicide. Psychoneuroendocrinology. 74, 1-6. 2016.
https://doi.org/10.1016/j.psyneuen.2016.08.009