Further evidence of low baseline cortisol levels in suicide attempters

- Previous studies have found low cortisol levels in depressed patients with suicidal behavior.
- This study examined salivary cortisol levels at various times of day during clinical assessment.
- Controlling for sampling variations, past suicide attempters had lower cortisol levels.
- Study is limited by the lack of rigorous experimental control during pilot phase testing.
- Results confirm previous findings of low tonic cortisol levels in suicide attempters.

BackgroundMany, 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.MethodsIn 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.ResultsAdjusting 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.LimitationsThis is a pilot study with modest sample sizes using statistical, rather than experimental control of numerous variables affecting salivary cortisol levels.ConclusionsResults 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.