Mass psychogenic illness (MPI), also known as mass/epidemic hysteria, mass sociogenic illness, mass conversion disorder, and epidemic of medically unexplained illness, is a globally occurring dissociative phenomenon. In contemporary Nepal, MPI is widespread and a large number of young children and adolescents in schools as well as adult women in some communities are affected in clusters by unintentional trance and possession episodes, known as chhopne/chhopuwā in the Nepali language. In recent years, there has been a burgeoning recognition of and interest in MPI in Nepal. For example, the Ministry of Health (MoH) Nepal has included MPI in the training curriculum for primary health workers and some nonprofit organizations in Nepal have published psychoeducational materials on MPI and guidelines on how to manage MPI outbreaks. However, the possible causes and correlates of these epidemics are not well understood and have not been widely studied in Nepal. As a result, existing guidelines are largely based on generic information on MPI in the western psychiatric literature. The dearth of studies on the potential causes and correlates of MPI in Nepal represents a significant knowledge gap with implications for intervention.
This thesis was driven by the premise that effective management of MPI requires a comprehensive understanding of its causes and correlates. Three studies were conducted to examine the social and psychological correlates of mass psychogenic illness involving a cluster of adult women in a community and adolescent children in schools in Nepal. The aim of these studies was to test existing hypotheses about the etiology of MPI by comparing afflicted and control populations with regard to (a) prior exposure to trauma, (b) underlying mental health problems, (c) personality traits, and (d) level of dissociative experiences
To achieve this aim, first, we conducted a case study following a mixed-methods case-control design in a village in central Nepal with a cluster of women experiencing unintentional spirit possession episodes. This study assessed sociocultural context, prior exposure to trauma, and prevalence of symptoms of common mental disorders in women who had (n=22) and had not (n=16) experienced possession (N=38). Quantitative results indicated that possessed women had higher rates of traumatic exposure and higher levels of symptoms of mental disorder compared to non-possessed women. However, qualitative interviews with possessed individuals and their non- possessed friends, family members, and traditional healers painted a different picture. Spirit possession was viewed as an affliction that provided a unique mode of communication between humans and spirits. Thus, it was concluded that possession was better understood not as a specific form of psychopathology but as an idiom of distress, that is, an avenue to communicate and cope with distress associated with existing psychosocial problems.
Secondly, we conducted a cross-sectional survey of adolescents (N=314) from five schools in three districts of Nepal. Using a path analysis model, this study evaluated the applicability of three existing theoretical models to explain dissociative experiences and behaviors (DEBs), namely: (1) childhood trauma; (2) cognitive and personality traits (i.e., cognitive failures, fantasy proneness, emotional contagion); and (3) current distress (i.e., quality of life, depression, posttraumatic stress). Results confirmed that the factors associated with all three models were correlates of DEBs, however, only cognitive failures (lapses in day-to-day memory) and posttraumatic stress emerged as significant predictors of DEBs in the path analysis. Simple mediation analysis using posttraumatic stress and cognitive failures as mediators in separate mediation models confirmed the full mediation of the effect of childhood trauma on dissociation. This suggests that childhood trauma along with all of the other personality and distress variables assessed are important correlates of DEBs; however, they are not always present and are neither necessary nor sufficient to produce dissociation. Various socioecological factors, cognitive and personality traits, and other contextual factors not measured in this study may play an important role in determining the occurrence of dissociative experiences and behaviors.
Thirdly, we conducted a case-control study with adolescent children affected (cases) by MPI that involved dissociative trance and possession episodes (chhopne) and their friends who had never experienced chhopne (N=379). This study aimed to evaluate if DEBs and their correlates identified in the previous study could predict epidemics of episodes of chhopne among children in schools in Nepal affected by MPI episodes. Bivariate logistic regression models showed that family type (i.e., nuclear family), childhood trauma, a higher tendency to dissociative experiences, prior experience of peritraumatic dissociation, depression, and hypnotizability were significant predictors of caseness, that is, the odds of being a case (being affected in MPI) among those who lived in the nuclear family, traumatic experience in childhood, current depressive symptoms, a higher tendency to dissociative experiences, prior experience of peritraumatic dissociation, and higher hypnotizability was greater than the odds of being a case among those without such experiences and characteristics. However, in terms of DEBs and their correlates predicting caseness in MPI episodes, results were mixed. Multiple logistic regression showed that only a few variables, physical abuse, peritraumatic dissociation, and hypnotizability significantly differentiated affected from not affected. Further, family type, which was not a significant predictor of DEBs in the previous study turned out to be a significant predictor of caseness in MPI. Taken together, the results suggest that adolescents with higher susceptibility to suggestion, living in nuclear families, who have experienced physical abuse and peritraumatic dissociation are more likely to be affected by MPI episodes.
The findings from these studies have important implications for understanding the possible causes and correlates of MPI phenomena and may guide the development of appropriate prevention and intervention strategies for MPI in Nepal and beyond.