BDNF in antipsychotic naive first episode psychosis: Effects of risperidone and the immune-inflammatory response system

Brain-derived neurotrophic factor (BDNF) and the immune-inflammatory response system (IRS) have been implicated in the pathophysiology of schizophrenia. However, no research examined the associations between BDNF and immune activation both before and after treatment in antipsychotic-naïve first episode psychosis (AN-FEP). This study aims to examine serum BDNF levels and their association with IRS and the compensatory immune-regulatory reflex system (CIRS) in AN-FEP before and after risperidone treatment. We included 31 AN-FEP and 22 healthy controls. AN-FEP showed reduced levels of BDNF as compared to controls, and BDNF levels normalized after treatment with risperidone. BDNF levels were inversely correlated with a greater IRS response. Higher levels of IRS/CIRS biomarkers were associated with lower levels of BDNF including M1 macrophage, T-helper (Th)-1, Th-2, and Th-17, and T-regulatory (Treg) cell responses. Our findings indicate that AN-FEP is characterized by decreased levels of BDNF, which are normalized after treatment with risperidone. BDNF levels were inversely associated with activated immune-inflammatory pathways. The findings support the hypothesis that, increased IRS is linked to neurotoxicity, and that a decrease in BDNF may be part of the IRS/CIRS responses in FEP and, thus, be involved in the development of psychosis.

Activation of the immune-inflammatory response system and the compensatory immune-regulatory system in antipsychotic naive first episode psychosis

Psychotic disorders are accompanied by activation of the immune inflammatory response system (IRS). The compensatory immune-regulatory system (CIRS) is a regulatory immune response that is induced by the IRS but exerts negative feedback through increased levels of anti-inflammatory cytokines such as interleukin (IL)-4, IL-13 and IL-10. This study aims to examine the IRS and CIRS components, including macrophagic M1, T-helper (Th)-1, Th-2, Th-17 and T-regulatory (Treg) phenotypes, in antipsychotic-naïve first episode psychosis (AN-FEP) before and after risperidone treatment. We included 31 AN-FEP and 22 healthy controls. AN-FEP showed increments in M1, Th-1, Th-2, Th-17 and Treg phenotypes and a relatively greater IRS response (especially granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6 and IL-12) as compared with the CIRS response. Inflammatory markers, especially IL-6 and IL-8, were significantly correlated with negative, psychotic, affective and excitation symptom dimensions. Treatment with risperidone significantly suppressed the IRS and CIRS. Baseline levels of CIRS biomarkers, especially higher soluble tumor necrosis factor receptor-1 and IL-10 predicted clinical improvement after treatment. Our findings indicate that AN-FEP is characterized by robust IRS (M1 + Th-1 + Th-17) and CIRS responses, suggesting that monocytes, macrophages, Th-1, Th-2, Th-17 and Treg cells are activated. The findings indicate that (a) FEP patients are prone to the detrimental effects of M1, Th-1, Th-17 and Th-2 cells, which may contribute to long-lasting abnormalities in brain circuitry; and (b) in FEP, the CIRS may contribute to recovery from the acute phase of illness. Enhancing the CIRS might be a new drug target to treat FEP.

Is religiosity a protective factor against suicidal behavior in bipolar I outpatients?

BACKGROUND

Several risk factors have been associated with suicidal behavior (SB) in bipolar disorder (BD), but little is known regarding possible protective factors. Religiosity has been related to favorable outcomes in mental health and to a reduction in the risk of SB, although the relation between BD, religiosity and SB remains under-investigated. The objective of this study was to evaluate the association between religiosity and SB in euthymic bipolar I outpatients.

METHOD

In this study, 164 outpatients with BD type I with and without a history of suicide attempts were assessed and compared using a questionnaire to collect clinical and sociodemographic characteristics, the Structured Clinical Interview for DSM-IV, the Hamilton Depression Rating Scale, the Young Mania Rating Scale, the Duke Religious Index, and the Barratt Impulsivity Scale.

RESULTS

The suicide attempters (SA) group had more psychiatric comorbidity (p=0.007), more rapid cycling (p=0.004), higher levels of impulsivity in all domains (p=0.000), and less religious affiliation (p=0.006) compared with the non-SA group. In the multivariate analysis, after controlling for covariates, non-organizational religious activities (OR, 0.66; 95% CI, 0.50-0.86) and intrinsic religiosity (OR, 0.70; 95% CI, 0.60-0.81) were associated with less SB.

LIMITATIONS

A small sample size, the cross-sectional design that precluded the possibility of assessing cause and effect relationships, and the infeasibility of determining the time lapse between the last suicide attempt and the period when the patients were evaluated.

CONCLUSION

Non-organizational religious activities and intrinsic religiosity dimensions exert a protective effect against SB in bipolar I outpatients, even when controlling for variables that may affect the outcome in question.