Further evidence of low baseline cortisol levels in suicide attempters

Background: Many, but not all studies of suicide attempters' cortisol response to stress-either social stress or pharmacological challenge-report an exaggerated response. Recent studies of resting baseline cortisol in past suicide attempters, however, have found lower baseline levels.

Methods: In this study, baseline salivary cortisols were obtained prior to a stress procedure from adults with lifetime diagnoses of a mood disorder (N=69), 31.9% of whom had made a prior suicide attempt. Data were collected during the piloting of this stress procedure, at various times of day and with/without an additional confederate in the room.

Results: Adjusting for procedural, demographic and clinical variables that affect salivary cortisol levels-including time of day of sampling, order of procedure with respect to other assessments, past alcohol abuse, current medication use, and bipolar diagnosis-past suicide attempters had lower baseline cortisol levels compared to non-attempters.

Limitations: This is a pilot study with modest sample sizes using statistical, rather than experimental control of numerous variables affecting salivary cortisol levels.

Conclusions: Results confirm previous studies. Low baseline cortisol levels have been associated with childhood adversity and externalizing disorders, suggesting a potential role in reducing inhibitions for risky and dangerous behaviors. Further research is needed to more fully characterize these associations and their role in suicidal behavior risk.