This thesis has been prepared in paper based format. The thesis focusses of the use of experimental manipulations in the investigation of paranoia and extends the use of these to an empirical investigation of the role of attachment theory in paranoia. Papers 1 and 2 have been prepared for submission to Clinical Psychology Review and Schizophrenia Bulletin respectively. Paper 1 provides a comprehensive overview of experimental paradigms that aim to induce or manipulate paranoid thinking in both clinical and analogue samples. Twenty-seven studies were identified that satisfied inclusion criteria for the review. The strengths, limitations, effectiveness of individual paradigms, as well as of the literature as a whole, are considered throughout the review and recommendations for future research are made. Theoretical and clinical implications are also discussed.Paper 2 reports an experimental analogue in which participants (N=60) were randomised to a secure attachment prime (or neutral/positive affect control) condition before being exposed to a paranoia induction paradigm. Dispositional levels of insecure attachment were associated with both trait and state paranoid thinking. Contrary to predictions, the secure attachment prime did not appear to buffer paranoid thinking. The secure attachment prime was indicated to have a negative impact for people with high levels of attachment anxiety, who experienced higher levels of paranoia following the paranoia induction. Paper 3 is a critical reflection of the submitted papers and research process as a whole. The strengths and limitations of the presented research, methodological considerations and implications for clinical practice and theory are discussed and directions for future research are highlighted.