Peer recognition of prodromal signs of psychosis : a signal detection analysis : a thesis presented in partial fulfilment of the requirements for the degree in Master of Arts in Psychology at Massey University, Palmerston North, New Zealand
Using signal detection analysis, this study investigated young peoples' sensitivity to prodromal signs or psychotic symptoms compared to more everyday signs of distress in their friends. In a questionnaire format, 117 high school students (aged 13 to 16 years) were asked to report the level of concern they would have if one of their friends exhibited certain characteristics. Half of the latter were neutral, everyday phenomena (no signal), and the remainder were either DSM-IV symptoms of psychosis or empirically-derived prodromal signs of early onset psychosis (signal). Each possible sign was modified (made more serious) by descriptors used in psychological models to define pathology behaviorally: rare in youth, high in frequency, recent change, and lack of obvious (rational) environmental cause. High frequency was the modifier leading to the greatest degree of concern. Accurate and sensitive detection, based on d' values, was adequate for psychotic symptoms, especially by females rather than by males, although depressed mood (a prodromal sign in this context) was most readily detected as a worrisome feature. The study has implications for analyzing how youth judge indices of distress in their friends and for their general ability to recognize that certain characteristics are more troublesome than others. Telling a responsible adult of their concerns was the most frequently suggested response, followed by attempting to help and talking to the peer about their concerns. If rapid detection of early onset psychosis is to be a goal of preventative mental health services, youth who are sensitive to classic symptoms of psychosis may still need educating in recognizing the difference between behavioral characteristics that are part of everyday distress and those that are indicative of more serious adjustment difficulties that might be emerging.