Other biological factors associated with an increased risk for suicidality in BD patients include altered functioning of the HPA-axis with significantly higher levels of corticotropin-releasing hormone (CRH) and bedtime salivary cortisol [15,17], and higher serum testosterone concentrations, lower serum cholesterol, triglyceride, and n-6 arachidonic acid [15]. This evidence concerns the gene CRH and Behcet disease.