Cholecystokinin (CCK) level is higher among first time suicide attempters than healthy controls, but is not associated with higher depression scores.

Suicide and suicide attempts are dramatic events for both the individuals concerned and for their social environments. Efforts have been made to identify reliable biological predictors of suicide and suicide attempts. In the present study, we focused on one potential marker, cholecystokinin (CCK), among first time suicide attempters. A total of 25 suicide attempters (mean age: 30 years; 80% females) and 23 healthy controls were enrolled in the present cross-sectional study. Experts rated participants' symptoms of depression (Hamilton Depression Rating Scale; HDRS). Blood levels of CCK levels were assessed. Suicide attempters had CCK levels 22.67 times higher and HDRS scores 14.33 higher than healthy controls. CCK levels were only weakly associated with HDRS scores. CCK appears to be a fairly reliable biomarker for suicide attempts. However, CCK levels were not associated with depression scores, making it difficult to match biological markers to depressive behaviour.