Abstract
Introduction : Bipolar Disorder (BD) is a severe, persistent disorder that causes functional impairment. Besides heritability, environmental factors, such as traumatic experience, impact the development of BD. Little is known about the early developmental signs of this disorder; therefore, this study aims to look at the impact of interpersonal trauma on the early developmental signs of BD. Specifically, differences in psychopathological behaviors were investigated between (1) at-risk children to controls and (2) at-risk children who experienced an interpersonal traumatic event to those who did not.
Methods :  Using the Adolescent Brain Cognitive Development (ABCD) dataset, participants with a first-degree relative with BD were identified (Nat-risk=625) and matched on sex and age to a control group (Ncontrol=625). The Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS) was used to assess interpersonal trauma and psychopathological symptoms. The trauma (Ntrauma=198) and no trauma subgroups (Nno trauma=428) were built from the at-risk population. Group comparison was conducted on depressive, manic, and anxiety symptoms.
Results: Compared to controls, at-risk children exhibited a significantly greater number of manic symptoms at baseline, and depression and anxiety symptoms at two-year follow-up. No significant differences were found between the trauma and no-trauma groups at either baseline or follow-up.
Discussion: These results confirm the presence of early symptoms in at-risk children, in line with the staging model of BD. Extended longitudinal research is needed to further investigate the potential specific role of trauma on its early behavioral patterns.
Keywords: adverse childhood experience, anxiety, bipolar disorder, children, depression, mania, mental disorders, risk factor
Bipolar disorders (BD) are severe, persistent mental disorders characterized by fluctuations in mood, energy, and activity levels (Nierenberg et al., 2023) and are marked by substantially reduced psychosocial functioning (Akers et al., 2019) and premature mortality (Kessing et al., 2015). The onset of BD typically occurs in adolescence and early adulthood (Faedda et al., 2019; McGrath et al., 2023). BD impairs people’s lives, families, work, and general functioning (American Psychiatric Association, 2013). Its burden becomes substantially larger with unrecognized or misdiagnosed individuals (McIntyre et al., 2022). Misdiagnosis rates are high in BD leading to inappropriate treatment and negative outcomes (Fritz et al., 2017; Wolkenstein et al., 2011). For instance, when misdiagnosed as unipolar depression, administering antidepressants to those with bipolar disorder tends to trigger manic episodes and lead to poorer prognosis (Awad et al., 2007; Goldman et al., 2022; McIntyre et al., 2022). Delayed diagnoses and treatment also lead to increased mortality (Duffy et al., 2019) and health care cost (Singh & Rajput, 2006)
BD runs in families, as shown by its high heritability estimates (Algorta et al., 2015; Bienvenu et al., 2011; Birmaher et al., 2009). Concordance rates are higher in monozygotic than dizygotic twins, showing that BD is strongly dependent on genetics (Edvardsen et al., 2008; O’Connell & Coombes, 2021). Further twin studies showed heritable estimates of 0.85 to 0.93 (Kieseppa et al., 2004; McGuffin et al., 2003). Therefore, children with a first-degree relative with BD are considered at extremely elevated risk of developing BD themselves.
Moreover, BD has recently been suggested to develop through progressive stages, suggesting that symptoms slowly develop before reaching the full-blown manifestation of the disorder (Vieta et al., 2018). Duffy et al. (2019) mapped out a potential trajectory of BD’s emerging course: children with a familial risk of developing BD might first experience sleep and anxiety symptoms, then minor mood symptoms, before presenting a major depressive disorder, and eventually develop a first full-blown BD episode (Duffy et al., 2019). Moreover, a review by Vieta and colleagues also endorsed sleep problems, anxiety, and mood disorders as vulnerability markers of the development of bipolar disorder in the offspring of parents with BD (Vieta et al., 2018).
Environmental factors, such as the experience of traumatic stressful events in youth, are also implicated in the development of psychopathology (Gur et al., 2019). Though many studies emphasize the importance of considering familial and developmental factors when diagnosing children at risk for BD, some have specifically investigated the impact of traumatic experience on the clinical course of this disorder. Traumatic experiences can be differentiated into interpersonal (i.e., consequences of other people’s direct actions) and non-interpersonal (i.e., other life-threatening events, such as severe accidents or illness) (Hughesdon et al., 2021). Interpersonal traumatic experiences, such as abuse and neglect, are particularly correlated with the development of BD (T. Li et al., 2023a). These traumatic events are more likely to occur in individuals diagnosed with BD compared to control groups (T. Li et al., 2023a; Palmier-Claus et al., 2016; Yang et al., 2024). Additionally, the frequency of childhood adversity among individuals with BD is relatively high, ranging from 45% to 68% (Daruy‐Filho et al., 2011; T. Li et al., 2023a). Therefore, examining the impact of interpersonal traumatic events on the early stages of development of BD, rather than only its course, may be crucial for recognizing it early and potentially preventing its onset.
Therefore, the aim of this study was to observe the development of early psychopathological behaviors (e.g. mood disorders and anxiety) that are considered to illustrate the emergent course of BD, in children at risk of developing BD and more specifically those who experienced an interpersonal traumatic event. The Adolescent Brain Cognitive Development (ABCD) longitudinal dataset was used to compare, at both baseline and two-year follow-up, the psychopathological behaviors between (1) at-risk children and controls and between (2) at-risk children who experienced an interpersonal traumatic event and those who did not. The hypotheses were that (1) at-risk children would present more anxiety and mood symptoms than the control group and (2) that these symptoms would be more frequent in children at risk who have experienced a traumatic event when compared to those who did not.