Understanding the risk factors involved in the development of psychosis is important and may lead to developing treatments and even prevention. Recent research has led to a method which identifies those individuals at greatest risk of developing psychosis. These individuals are considered to be at ‘clinical high-risk’ for psychosis. Being at clinical high risk for psychosis is a major risk factor for developing clinically significant psychosis. Another risk factor for developing psychosis is exposure to stress. Individuals at-risk for psychosis have greater exposure to stress. Recent, mainly pre-clinical work has highlighted the intimate relationship of the endocannabinoid system and stress. Endocannabinoid alterations have also been reported in psychosis. However, the links between stress and the endocannabinoid system remain woefully under investigated in psychosis. This thesis describes a series of studies aiming to examine the role of stress, both remote and current in the development of psychotic symptoms and psychosis and how the endocannabinoid system may be involved. To achieve this aim, I investigated childhood trauma, core schemas and endocannabinoid levels in healthy individuals and those at-risk for psychosis to examine how these might be related to psychosis. In order to examine the acute effect of stress, I conducted the Trier Social Stress Test in healthy volunteers and examined the effect on anxiety, paranoia and cortisol. Secondly, individuals at clinical high-risk for psychosis were split in a randomised double blind manner into two groups; one who had received cannabidiol daily for 8 days and one who had received placebo and were submitted to the Trier Social Stress Test. I found that exposure to childhood trauma was related to core schemas, being at-risk for psychosis and endocannabinoid levels. I also found that acute stress induces paranoia in 13 healthy individuals and that cannabidiol may be a viable option to mitigate the harmful effects of stress in those at clinical high-risk of psychosis, although more research is needed to confirm this.
Psychosis, stress and cannabinoids
Appiah-Kusi, E. M. (Author). 1 Apr 2019
Student thesis: Doctoral Thesis › Doctor of Philosophy