Insulin and glucagon in plasma and cerebrospinal fluid in suicide attempters and healthy controls.

Mental disorders and related behaviors such as suicidality and violence have been associated to dysregulation of e g carbohydrate metabolism. We hypothesized that patients after suicide attempt, compared to healthy controls, would have higher insulin and lower glucagon levels in plasma and cerebrospinal fluid and that these changes would be associated to violent behavior. Twenty-eight medication-free patients (10 women, 18 men), hospitalized after suicide attempt, and 19 healthy controls (7 women, 12 men) were recruited with the aim to study risk factors for suicidal behavior. Psychological/psychiatric assessment was performed with SCID I and II or the SCID interview for healthy volunteers respectively, the Karolinska Interpersonal Violence Scale (KIVS) for assessment of lifetime violence expression behavior, the Montgomery-Åsberg-Depression-Scale (MADRS) and the Comprehensive Psychological Rating Scale (CPRS) for symptomatic assessment of depression and appetite. Fasting levels of insulin and glucagon were measured in plasma (P) and cerebrospinal fluid (CSF). Suicide attempters had higher insulin- and lower glucagon-levels in plasma- and CSF compared to controls. Except for P-glucagon these associations remained significant after adjusting for age and/or BMI. Patients reported significantly more expressed interpersonal violence compared to healthy volunteers. Expressed violence was significantly positively correlated with P- and CSF-insulin and showed a significant negative correlation with P-glucagon in study participants. These findings confirm and extend prior reports that higher insulin and lower glucagon levels in plasma and cerebrospinal fluid are associated with suicidal behavior pointing towards a potential autonomic dysregulation in the control of insulin and glucagon secretion in suicidal patients.