Childhood adversities and psychosis: evidence, challenges, implications

Abstract

There is a substantial body of research reporting evidence of associations between various forms of childhood adversity and psychosis, across the spectrum from experiences to disorder. This has been extended, more recently, to include studies of cumulative effects, of interactions with other factors, of specific effects, and of putative biological and psychological mechanisms. In this paper we evaluate this research and highlight the remaining methodological issues and gaps that temper, but do not dismiss, conclusions about the causal role of childhood adversity. We also consider the emerging work on cumulative, synergistic, and specific effects and on mechanisms; and discuss the broader implications of this line of research for our understanding of psychosis. We conclude that the current balance of evidence is that childhood adversities -particularly exposure to multiple adversities involving hostility and threat -do, in some people, contribute to the onset of psychotic experiences and psychotic disorders. There has been a flurry of research on the relationship between childhood adversity and psychosis over the past ten years. This has extended, more recently, to studies that have sought to elaborate on the nature of the relationship, by examining cumulative effects, interactions with other risk factors (e.g., genes), specificity of effects, and putative mechanisms.For some authors, the accumulated evidence unequivocally establishes that difficult and unpleasant experiences in childhood contribute to the development of psychoses 1 . For others, the evidence is not so clear cut 2 . At issue, in part at least, are fundamental questions about the nature and aetiology of psychosis. Much, then, is at stake and a further appraisal of the evidence is warranted. In this paper, we first summarize and critically evaluate research on the association between childhood adversities and psychosis (including low-level experiences, at risk states, and disorders). In doing this, we focus particularly on remaining methodological issues and gaps in the literature, and on research that has further investigated the nature of the association. We then reflect on the broader implications of this work for our understanding of psychosis. CHILDHOOD ADVERSITYChildhood adversity is a broad term that denotes exposure to a range of difficult or unpleasant situations or experiences, usually before the age of 16. The adversities typically considered in studies of psychoses include household poverty, separation from a parent (i.e., family breakdown), death of a parent, neglect, abuse (including emotional, psychological, physical, and sexual), and peer bullying.Estimates suggest that large numbers of children are exposed to such situations and experiences. In the UK, for example, according to estimates, over 3 million children (28%) live in poverty (defined as less than 60% of the average household income) 3 , over 3 million children (23% of those living in families) live in lone parent households 4 , around 6% of those aged 0-10 years and around...

The association between childhood adversities and subsequent first onset of psychotic experiences: a cross-national analysis of 23 998 respondents from 17 countries

“…Our findings suggest that Other CAs might increase the risk for PEs through mechanisms that have proximal consequences (Bentall et al , 2014, Morgan and Gayer-Anderson, 2016). In contrast, maladaptive family functioning CAs appear to create a generalized diathesis for PEs that persists across the life-course.…”

“…This diathesis could involve a variety of emotional, neurobiological, and cognitive processes that are influenced by CAs, including heightened vulnerability to stress (McLaughlin et al , 2010c), elevated emotional reactivity and poor emotion regulation skills (McLaughlin et al , 2010a, McCrory et al , 2011, McLaughlin et al , 2015, Heleniak et al , 2016), and deficits in cognitive control (DePrince et al , 2009). Each of these domains, in turn, has been proposed as mechanisms that may underlie PEs (Freeman et al , 2007, Bentall et al , 2009, Bentall et al , 2014, Morgan and Gayer-Anderson, 2016). CAs related to maladaptive family functioning may differentially lead to social deafferentation and social defeat (at the individual and/or family level), which has been linked to risk of PEs (Morgan and Gayer-Anderson, 2016).…”

“…Recent evidence indicates that exposure to childhood adversities (CAs) is associated with elevated risk of later PEs (Varese et al , 2012, Trotta et al , 2015, Morgan and Gayer-Anderson, 2016), with a meta-analysis reporting that CAs are associated with a 76% increased risk of PEs (Trotta et al , 2015). …”

Cannabis Use, Polysubstance Use, and Psychosis Spectrum Symptoms in a Community-Based Sample of U.S. Youth

“…Given evidence that adverse experiences characterized by hostility, threat, and intent to harm may be particularly strong risk factors for psychosis [30], we created a three-level variable reflecting assaultive trauma exposure, non-assaultive trauma exposure, and no trauma exposure.…”

The role of cognitive functioning in the relationship between childhood trauma and a mixed phenotype of affective-anxious-psychotic symptoms in psychotic disorders

“…It has also been shown that psychotic patients who have experienced childhood trauma (CT), an environmental risk factor for psychosis (Morgan and Gayer-Anderson, 2016;Rössler et al, 2016;Varese et al, 2012), score lower on a range of cognitive domains than those without CT (Aas et al, 2013). Cross-sectional studies on psychotic spectrum disorder found lower processing speed, and working and episodic memory deficits in patients with CT compared to patients without CT, after adjusting for premorbid intelligent quotient (IQ) (Lysaker et al, 2001) and depressive symptoms (Shannon et al, 2011).…”