Suicide: A Sad State of Affairs

• Suicide is the second largest killer of young people, the 10th cause of death for all age groups

• Worldwide, one suicide occurs every 40 seconds globally

• Current interventions are just “band-aids”

• 30% increase in suicide in the last 20 years

• Psychiatry is the only discipline of medicine that does not have a biological basis

• Stigma has prevented significant research

The Immune System is Part of the Brain

• The nervous and immune systems are interconnected

• Many studies show that the brain controls immune function

• The Pavlov study is an example of how the brain can be taught to control immune function

• If specific nerves from the brain are severed, the immune function increases or decreases depending on the nerve

• All major immune organs are innervated

• It is impractical to access the brain to quantitatively assess suicidal thoughts

• The Campbell Score is based on using immune markers to understand what is going on in the brain

Evidence that Immune System Can Cause Suicide

• Interferon alpha is an immune stimulant used for leukemia and hepatitis C

• Interferon alpha activates IL-6 and microglia

• Chronic activation of microglia causes brain damage

• Microglia enzyme indolamine 2,3 deoxygenase reduces tryptophan and generates kynurenine, which is a depressive molecule

• Associations between interferon administration and suicide

• Associations between numerous other cancer immunotherapies and suicide

Interleukin 6 as a Marker of Suicidal Ideations

• Up-regulated in plasma of patients suffering from causes of suicide

• MDD, Schizophrenia, PTSD

• Up-regulated in plasma of suicidal patients

• Found in brain biopsy of suicide victims

• Can be altered based on successful therapy

• Can be altered by anti-inflammatory drugs or psychotherapy

Patients who Commit Suicide have Higher Levels of Inflammatory Cytokines

Elevation of IL-6 in MDD Patients

Findings:
In this graph, blood was taken from healthy controls (HC) and patients with Major Depressive Disorder (MDD). Levels of IL-6 were measured. On average patients with depression had more IL-6
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6414189/

Elevation of IL-6 in PTSD

Findings:
Blood was taken from healthy controls and PTSD patients. IL-6 was measured in unstimulated and stimulated (LPS) blood. IL-6 was higher in PTSD patients regardless of stimulation.
https://bmcpsychiatry.biomedcentral.com/articles/10.1186/1471-244X-13-40/figures/1 

Elevation of IL-6 in Schizophrenia

Findings:
Blood was taken from patients with schizophrenia before and after treatment with mood stabilizing drugs and after as well from healthy controls. IL-6 was highest before treatment and was significantly reduced after treatment. Healthy controls had the lowest IL-6.
https://www.researchgate.net/figure/Serum-concentrations-of-IL-1b-IL-6-and-TNF-a-in-schizophrenia-patients-after-treatment_fig1_333968438