Michelle Campbell

The Beliefs about Paranoia Scale: Preliminary Validation of a Metacognitive Approach to Conceptualizing Paranoia

This study reports the development of a self-report measure to assess metacognitive beliefs about paranoia in non-patients. We aimed to test the specific hypotheses that positive beliefs about paranoia would predict frequency of paranoia, and that negative beliefs about paranoia would predict distress associated with delusional ideation. Three-hundred and seventeen non-patient participants were asked to complete questionnaires assessing beliefs about paranoia, paranoia, dimensions of delusional ideation and trait anxiety. The results showed that four empirically distinct subscales were measured by the beliefs about paranoia scale (negative beliefs about paranoia, beliefs about paranoia as a survival strategy, general positive beliefs and normalising beliefs). The scales possessed acceptable internal consistency and were associated with the measures of paranoia, delusional ideation and anxiety. Consistent with predictions, it was found that beliefs about paranoia as a survival strategy were associated with frequency of paranoia, and negative beliefs were associated with distress associated with delusional ideation. These findings suggest that a metacognitive approach to the conceptualization of paranoia as a strategy for managing interpersonal threat may have some utility. The clinical implications of the findings are also discussed.

Reasoning about highly emotional topics: Syllogistic reasoning in a group of war veterans

Previous studies have generally found that emotion impairs logical reasoning. However, laboratory experiments have typically involved relatively mild levels of emotion where affect is not linked to personal experience. In this study we examined how army veterans reasoned about syllogisms of three types: neutral, generally emotional, and combat-related emotional. We also measured intensity of combat experience. Veterans were more likely to provide logically accurate answers when reasoning about combat-related compared to neutral problems. Participants with more intense combat experiences showed a reduced advantage in reasoning about combat-related emotional problems.

The psychological consequences of combat exposure: The importance of appraisals and post‐traumatic stress disorder symptomatology in the occurrence of delusional‐like ideas

OBJECTIVE The aim of the current study is to explore the association between combat experience and the occurrence of delusional-like beliefs. It is hypothesized that negative post-trauma appraisals and positive beliefs about paranoia will be associated with vulnerability to delusional ideas and that veterans who meet criteria for post-traumatic stress disorder (PTSD) will be more likely to hold delusional-like ideas. DESIGN A small-scale survey design was employed in order to ensure that detailed information was gathered concerning battle exposure. METHODS Forty-one British war veterans completed questionnaires relating to combat experience, delusional ideation, beliefs about paranoia, appraisals of combat trauma and PTSD symptomatology. RESULTS Negative post-trauma cognitions and positive and negative beliefs about paranoia were associated with increased predisposition to delusional beliefs; however, the severity of combat experience was not. It was also found that veterans who met criteria for PTSD were more likely to hold delusional-like ideas compared with those who did not. Furthermore, the PTSD group held more negative post-trauma cognitions and more positive beliefs about paranoia. CONCLUSIONS These findings suggest that PTSD symptoms may confer vulnerability to delusional beliefs and that this may be mediated by negative appraisals about the self, the world and dysfunctional beliefs about paranoia. However, it is possible that psychotic-like phenomena confer vulnerability to PTSD. The implications of these findings are discussed.

IL-15 suppresses colitis-associated colon carcinogenesis by inducing antitumor immunity

IL-15 regulates the development, survival, and proliferation of multiple innate and adaptive immune cells and plays a dual role, inducing both tumor cell growth and antitumor immunity. However, the role of IL-15 in inflammation-induced cancer remains unclear. To explore this, we have compared the colon carcinoma burden of Il15−/− and Il15rα−/− mice with wild type (WT) mice after induction of colitis-associated colon carcinogenesis utilizing the AOM/DSS model. Compared to WT mice, Il15−/− but not Il15rα−/− mice showed reduced survival, along with higher tumor incidence, colon weight, and tumor size. This suggests that low affinity IL-15 signaling via the shared IL-2Rβ/γc decreases the risk for developing colitis-associated cancer. CD11c-Il15 mice, in which IL-15 expression is reconstituted in Il15−/− mice under the control of the CD11c-promoter, showed that selective reconstitution of IL-15 in antigen-presenting cells restored the CD8+ T and NK cell compartments, serum levels of IFNγ, G-CSF, IL-10, and CXCL1 and reduced tumor burden. After demonstrating IL-15 expression in human colorectal cancer (CRC) cells in situ, we investigated the role of this cytokine in the modulation of key colonic oncogenic pathways in the tumor. While these pathways were found to be unaltered in the absence of IL-15, tumor transcriptome analysis showed that the loss of IL-15 upregulates key inflammatory mediators associated with colon cancer progression, such as IL-1β, IL-22, IL-23, Cxcl5, and Spp1. These findings provide evidence that IL-15 suppresses colitis-associated colon carcinogenesis through regulation of antitumor cytotoxicity, and modulation of the inflammatory tumor micromilieu.