Niacin Flushing as Marker of Cannabis Effects on Arachidonic Acid Pathways in Schizophrenia

Increasing evidence suggests modulating effects of cannabinoids on time of onset, severity, and outcome of schizophrenia. Efforts to discover the underlying pathomechanism have led to the assumption of gene x environment interactions including premorbid genetical vulnerability and worsening effects of continuing cannabis use. For a main characteristic of psychoactive delta-9-tetrahydrocannabinol is its affinity to biological membranes, which are known to be disturbed in schizophrenia patients and genetic high-risk populations. Here we assess an hypothesised association between premorbid lipid disturbance and metabolic effects of external cannabinoids in schizophrenia. Intensity of niacin (methylnicotinate) skin flushing, indicating disturbed prostaglandin-mediated processes, is used as peripheral marker of lipid-arachidonic acid pathways and investigated in cannabis consuming and non-consuming schizophrenia patients and in healthy controls. Methylnicotinate is applied in three concentrations onto the forearm skin. Flush response is assessed in three minute intervals over 15 min using optical reflection spectroscopy.