Aggression as an independent entity even in psychosis- the role of inflammatory cytokines.

Background: Aggression is very common in psychosis (prevalence ranging from 34% to 70%) and is often the main or first symptom for which the patient receives medical attention. Studies have associated alteration in cytokine profiles among healthy persons with aggressive traits. We hypothesise that even among those with psychosis, aggression is an independent entity, irrespective of psychotic state and is associated with cytokine alterations. To our knowledge, this is the first study attempting to look at the inflammatory cytokines in aggressive psychotic patients.

Methods: Study included 80 participants divided into four groups viz. aggressive diseased, non aggressive diseased, aggressive non diseased and non aggressive non diseased depending upon presence or absence of aggression and psychosis. Interferon gamma(IFN-G), Interleukin 10(IL10) plasma concentrations and their ratio were measured using ELISA based assay kits read at absorbance of 450 nm wavelength using Double beam spectrophotometer. The four groups were compared on measures of aggression, psychosis, Interferon Gamma levels, Interleukin 10 levels, Proinflammatory: Antiinflammatory cytokine ratio using standard statistical instruments.

Results: In patients with psychosis, the cytokines IFN-G and IL10 were significantly lower compared to those without. The cytokines IFN-G and IL10 are both significantly associated both with aggression and psychosis. IL10, but not IFN-G is associated with aggression in absence of psychosis. The proinflammatory: antiinflammatory cytokine ratio, is more significantly associated with aggression, irrespective of psychosis. In fact, there is no significant relationship between the above ratio and psychosis. Strong correlation exists between the proinflammatory: antiinflammatory cytokine ratio and aggression scores, even after controlling for severity of psychosis.

Conclusions: It may be concluded from this study that in spite of a high prevalence of aggression in patients of psychosis, it is more likely to be an independent entity associated with individual cytokine changes and increased proinflammatory: antiinflammatory cytokine ratio as its hallmark.