Prevalence of child sexual abuse among adults and youths with bipolar disorder: A systematic review

Highlights

• Studies on child sexual abuse and bipolar disorder are reviewed for the first time.

• The prevalence of child sexual abuse among subjects with bipolar disorder is 24%.

• Child sexual abuse is a common experience for both bipolar males and females.

• Bipolar subjects report higher rates of child sexual abuse than healthy individuals.

• Causality between child sexual abuse and bipolar disorder cannot be determined.

Abstract

To estimate the prevalence and social and demographic correlates of child sexual abuse among people with bipolar disorder, the findings of all the pertinent studies were qualitatively and semi-quantitatively analyzed. Five databases were searched. Blind assessments of study eligibility and quality were conducted by two independent researchers. Twenty studies, meeting minimum quality standards and including 3407 adults and youths with bipolar disorder across 10 countries and 3 continents, were examined. The prevalence of child sexual abuse was 24% (23% without outliers); however, such prevalence rate might be underestimated, because many studies restricted definitions to the most severe forms of abuse. Child sexual abuse was a common experience for both males and females, while it was more frequent for adults than for youths. Compared to healthy individuals, patients with bipolar disorder reported higher rates of child sexual abuse; compared to populations with other mental disorders, participants with bipolar disorder reported similar or lower rates of such abuse. Individuals with bipolar disorder are at risk of having a history of child sexual abuse, although such risk seems to be neither more specific to nor stronger for these individuals, compared to people with other psychiatric disorders.

Introduction

There is increasing awareness of the severe consequences of bipolar disorder on individuals and society, especially its economic costs associated with lost productivity and treatment and its adverse effects on a person's general health, well-being, quality of life, and social functioning. Such awareness is reflected in the increase in research aimed at highlighting the factors that promote the development and maintenance of bipolar disorder in order to develop appropriate prevention and treatment strategies.

Extensive research examining the etiology of bipolar disorder has focused on genetic influences, providing evidence for a strong genetic component (Barnett and Smoller, 2009, Craddock and Sklar, 2009, Escamilla and Zavala, 2008, Serretti and Mandelli, 2008). On the other hand, there is emerging evidence that bipolar disorder is also susceptible to certain environmental factors (Alloy et al., 2005, Johnson, 2005), especially early traumatic experiences (Alloy et al., 2006, Alloy et al., 2005, Daruy-Filho et al., 2011, Etain et al., 2008, Fisher and Hosang, 2010). In particular, it has been hypothesized that childhood sexual abuse might generate manic symptoms, especially hypersexuality, euphoria, or hyperactivity, that may be seen as emotionally avoidant coping activities, i.e. behavioral strategies employed to temporarily avoid or reduce painful abuse-related internal states (such as negative feelings, thoughts, memories, or affects) by providing more pleasurable experiences (Briere, 1992, Maniglio, 2011a). Furthermore, it has been suggested that child abuse can induce a cascade of neurobiological events that may produce persistent sensitization of central nervous system circuits and enduring changes in brain structure or function; these neurobiological effects, in turn, may provide the substrate through which child sexual abuse might increase the risk of developing bipolar disorder (Heim and Nemeroff, 2001, Teicher et al., 2002). It has been also hypothesized that another mechanism by which child sexual abuse might contribute to bipolar disorder is through the development of negative cognitive styles (Alloy et al., 2006).

These findings are not surprising, given that child sexual abuse is among the environmental factors potentially involved in the development of psychopathology that has received much empirical evidence (Maniglio, 2011a). A large amount of research has highlighted the role of child sexual abuse in the onset and maintenance of a large variety of psychological problems (Maniglio, 2009b). However, inadequate attention has been paid to the role of child sexual abuse in the etiology of bipolar disorder. In fact, only a few studies examining histories of child sexual abuse in participants with bipolar disorder have been published over the past twenty years, although they appear to be enough to be aggregated and analyzed together. Nevertheless, there are no systematic reviews focusing exclusively on the potential association between child sexual abuse and bipolar disorder. While a number of reviews have examined the potential relationship between bipolar disorder and child abuse in general (Alloy et al., 2005, Alloy et al., 2006, Daruy-Filho et al., 2011, Etain et al., 2008, Fisher and Hosang, 2010), they focused on the combination of different forms of child abuse. Thus, they did not provide adequate explanation of the specific role of child sexual abuse in the onset of bipolar disorder. Additionally, many of these reviews (Alloy et al., 2005, Alloy et al., 2006, Etain et al., 2008) did not systematically assess all the pertinent literature and lacked a formal quality assessment of studies. Therefore, they failed to aggregate and analyze all of the published articles having no important limitations that could invalidate their results.

Data coming from partial selection of literature and aggregation of findings from studies with important methodological limitations are vulnerable to several biases that may threaten the accuracy, reliability, and validity of the results obtained. Thus, it is important to provide a systematic review of all pertinent literature as well as a formal quality assessment of included studies. Importantly, it is essential to differentiate among specific types of child abuse, rather than investigating child abuse as a whole, because different forms of child abuse might have different paths to and effects on bipolar disorder. It is also possible that only some forms of child abuse might be associated with bipolar disorder. Most importantly, child sexual abuse has not only different effects in childhood and adulthood but also specific causes, dynamics, and effects that are different from those of other forms of child abuse (Maniglio, 2009b). Thus, it is important to focus only on child sexual abuse to understand its specific paths to and effects on bipolar disorder in both youths and adults.

In sum, very little is known about the relationship between child sexual abuse and bipolar disorder, since only a few empirical studies and no systematic reviews are currently available. Given the severity of bipolar disorder and with the high levels of public and scientific interests in child sexual abuse, the presence of such traumatic experience in bipolar individuals' lives needs careful consideration to implement research and health policy. Therefore, for the first time, this paper estimates the prevalence and important social and demographic correlates of child sexual abuse among youths and adults with bipolar disorder and attempts to elucidate the nature of the potential association between child sexual abuse and bipolar disorder. In doing so, the present systematic review provides a qualitative and semi-quantitative analysis of the findings of all the pertinent studies having no important methodological limitations that could invalidate their results.