Social defeat and psychosis proneness : an exploration of underlying mechanisms

Abstract

There is now consistent evidence linking environmental factors to the development of Psychotic disorder. One of the most well received hypotheses put forward to explain these associations is the Social Defeat Hypothesis, which postulates the key mechanism underlying these factors be a chronic experience of social defeat. A wide body of evidence has gathered in support of this hypothesis. The majority of this research, has however, tended to focus on associations between social defeat experiences and psychosis. Other facets of social defeat, such as related cognitive and affective mechanisms, have received little attention. The current thesis aimed to explore two such mechanisms, namely perceptions of social defeat (negative social comparisons) and sensitivity to social defeat, within a Chinese population, and their relations to psychosis proneness. It intended to do this in two ways: Firstly through developing psychometrically valid measures of these mechanisms for use within a Chinese population, and secondly through employing one of these measures to explore the relationship between perceptions of social defeat and psychosis proneness. Study 1 examined the psychometric properties of the Chinese Social Comparison scale (SCS-C) and its associations with measures of psychopathology. A two-factor structure, including 10 of the original 11 items was identified. Measures of social comparison were found to be significantly negatively correlated with all measures of the Symptom Check List-90, suggesting that associations between negative social comparisons and psychopathology in ethnically Chinese participants are similar to those found in western populations. Hence, the Chinese version of the SCS (SCS-C) can be recommended for use within Chinese speaking populations. Study 2 employed the Chinese Social Comparison Scale (validated in Study 1), to examine the relationship between negative social comparisons and psychosis proneness, including moderators and familial associations. As expected, all measures of social comparison were found to predict both the negative and depressive dimensions of psychosis. Unexpectedly no measures of social comparison predicted the positive psychotic experiences. Use of more problem-focused coping styles, including seeking social support and active coping, was found to moderate the effects of negative social comparisons on psychosis proneness. Finally, the results of cross-twin, cross-trait analyses suggested a familial association between belonging and the negative dimension of psychosis. Together these findings highlight the potential importance of negative social comparisons as a risk factor for psychotic disorder, specifically the negative and depressive dimensions. Study 3 developed and validated a Chinese translation of a novel experimental task (Digi-Spee) designed to induce a minor social defeat experience through mimicking an online social networking interaction. The Chinese version of the Digi-Spee was found to be effective in inducing changes in affect and was able to differentiate amongst different levels of sensitivity according to sex and age, suggesting it as a valid measure of sensitivity to social defeat experiences for future research. Together this research represents an important step forward in our understanding of the association between social defeat and psychosis, particularly for ethnically Chinese individuals. Clinical and theoretical implications are discussed.