Bullying and psychosis: The impact of chronic traumatic stress on psychosis risk in 22q11.2 deletion syndrome - a uniquely vulnerable population

Abstract

Bullying is an adverse childhood experience that is more common among youth with special needs and is associated with increased psychopathology throughout the lifespan. Individuals with chromosome 22q11.2 deletion syndrome (22q) represent one group of special needs youth who are at increased risk for bullying due to co-occurring genetically-mediated developmental, physical, and learning difficulties. Furthermore, individuals with 22q are at increased risk for developing psychotic disorders such as schizophrenia. However, there is a paucity of research exploring the impact of bullying on individuals with 22q and the possible impact this has on risk for psychosis in this population. To explore this relationship using existing research the goals of the review are: (i) to explore the nature of bullying among youth with special needs, and (ii) to discuss its potential role as a specific risk factor in the development of adverse outcomes, including psychosis symptoms. We reviewed the relationship between bullying and its short and long-term effects on the cognitive, social, and developmental functioning of typically developing individuals and those with special needs. We propose an interactive relationship between trauma, stress, and increased psychosis risk among youth with 22q with a history of bullying. The early childhood experience of trauma in the form of bullying promotes an altered developmental trajectory that may elevate the risk for maladaptive functioning and subsequent psychotic disorders, particularly in youth with genetic vulnerabilities. Therefore, we conclude the experience of bullying among individuals with 22q should be more closely examined.

Introduction

The vulnerability-stress model for psychosis risk posits that interactions between endogenous and exogenous factors contribute to the development of psychosis spectrum disorders. This model hypothesizes that certain biological vulnerabilities (e.g., genetic predisposition, neurophysiological dysregulation, etc.) interact with environmental stressors (e.g., perinatal issues, adverse experiences, substance misuse, etc.) and lead to the emergence of psychosis symptoms (Nuechterlein and Dawson, 1984). When individuals possess a genetic or biological vulnerability to psychosis, they can only withstand a certain amount of environmental stressors; once this threshold of stress is surpassed, there is higher risk for the development of psychosis (Zubin and Spring 1977). From this perspective, the experience of trauma increases one's subjective stress and, therefore, leaves an individual with greater susceptibility to developing psychopathology.

One population has demonstrated unique genetic vulnerability to the development of psychosis: individuals with 22q11.2 deletion syndrome (22q; Stoddard et al., 2010). Chromosome 22q11.2 deletion syndrome (22q) results from the most common de novo microdeletion and occurs in approximately 1 in 2000–4000 live births (Botto et al., 2003; Grati et al., 2015; Shprintzen, 2008). The chromosome 22q11.2 deletion syndrome is typically associated with a variety of complex medical (e.g., cleft palate, congenital heart defects, facial anomalies, immune function, velopharyngeal dysfunction), developmental (e.g., speech difficulties, learning/developmental disorders, poor motor/balance and coordination, social deficits), and psychiatric issues (e.g., psychosis, anxiety, ASD, attention-deficit/hyperactivity disorder; Goldenberg et al., 2012; Gothelf, 2014; Stoddard et al., 2010; Tang et al., 2014). Individuals with 22q not only demonstrate a genetic vulnerability for psychiatric disorders, but are also more likely to endorse the presence of a variety of stressors. Additionally, these individuals are more likely to experience repeated or chronic stress than their typically developing counterparts. One such form of chronic stress is bullying. Although currently limited, emerging research on bullying among youth with disabilities report that they are 1.5 times more likely to be victimized (Blake et al., 2012) and become involved in bullying through various roles (McLaughlin et al., 2010; Rose et al., 2015; Rose et al., 2011).

Exposure to chronic stress, like bullying, in conjunction with increased genetic risk may have a significant impact on the development of psychosis in this population. To date, there has not been an in-depth investigation into the effect of bullying in individuals with 22q in general, let alone the possible relationship this form of chronic stress has on risk for psychosis specifically. We propose that bullying may have an even greater impact on individuals with 22q11.2 deletion syndrome due to the increased risk associated with multiple physical, developmental, intellectual, and psychiatric vulnerabilities. In this review, we first present 1) an overview of the impact of stress on psychological and functional outcomes in 22q, 2) the impact of bullying for individuals with and without special needs, and 3) the potential role of bullying as a chronic stressor leading to expression of psychosis risk in 22q.