ACTA ENDOCRINOLOGICA (BUC)

Context. Hypothalamic-pituitary-adrenal (HPA) axis irregularities have been described both in bipolar disorder and suicidal behaviour, but few studies have examined the relationship between suicidal behaviours and cortisol levels in bipolar disorder. Objective. We compared HPA axis activity in bipolar I (BPD I) individuals with and without suicidal ideation and behaviour through multiple measurement of serum and salivary cortisol. Design. Cross-sectional, observational study. Subjects and Methods. 75 BPD I patients were assigned into 3 groups (no history of suicidal behaviour, history of suicidal ideation, history of suicide attempt), according to the C-SSRS. Socio-demographical and clinical data was obtained by using MINI 6.0 and a semi-structured questionnaire. Salivary samples were collected using Sarstedt Cortisol Salivette synthetic swab system for two consecutive days at 08:00, 16:00, 23:00 and salivary cortisol concentrations were determined by ELISA technique. A unique 1mg dose of dexamethasone was administered on the first day, at 23:00, after the collection of the saliva sample. Blood was collected on the first day at 8:00 AM and basal morning serum cortisol levels were determined by immunoassay with fluorescence detection. Results. Cortisol parameters in our BPD I sample did not vary significantly in respect to suicidal history. However, patients with a history of suicidal ideation have significantly higher total cortisol outputs than patients with no history of suicidal behaviour in the 18 to 40 age category compared with the above 40 age category. Conclusions. Total cortisol daily output varies significantly in an age-dependent manner in respect to suicidal thoughts in BPD I individuals.

Context. Suicide is a global public health issue. Bipolar disorder (BPD) has the highest suicide risk among individuals suffering from mental disorders. Serotoninergic dysfunctions have been linked to suicidal behaviour and platelet serotonin is recognised as a reliable index for the presynaptic serotonin activity. Objective. Our aim was to assess whether alterations occur in platelet serotonin concentrations in BPD type I in respect to suicide attempters compared with nonattempters. Design. This was a cross-sectional, observational study. Subjects and Methods. Plasma platelet serotonin concentrations were measured using ELISA technique in 71 BPD I patients. The participants were assigned into 3 groups (non-attempters, low lethality and high lethality suicide attempters), according to the Columbia-Suicide Severity Rating Scale. Socio-demographical and clinical data was obtained by using MINI 6.0 and a semi-structured questionnaire designed specifically for this research. Results. Our study showed significant lower levels of platelet serotonin in suicide attempters compared with non-attempters (p = 0.030) and in high-lethality attempters compared with low-lethality attempters (p = 0.015). The study recorded a higher number of total lifetime and lifetime depressive episodes for suicide attempters with BPD I. Conclusions. Our results subscribe to the importance of platelet serotonin as a reliable biomarker in suicide risk assessment.