Targeting emotional abuse in bipolar disorder

Children commonly experience trauma, such as physical, sexual and emotional abuse, and this exposure increases their future risk of developing several psychiatric disorders, including bipolar disorder. To offer tailored early intervention for bipolar disorder, one question is whether a specific type of childhood trauma is particularly important in people with bipolar disorder, and in what respect. The emerging picture here is that compared with other trauma subtypes, emotional abuse is greater among people with bipolar disorder compared with controls, and is the trauma subtype most strongly associated with a complex bipolar disorder illness course (i.e. earlier onset, rapid cycling, suicide attempts, increased mood episodes, comorbidity, psychotic features).^{Reference Etain, Henry, Bellivier, Mathieu and Leboyer4} The underlying biological mechanisms by which childhood trauma, and particularly emotional abuse, lead to an increased risk of developing bipolar disorder and a worsened bipolar disorder prognosis are far from resolved. Exposure to childhood trauma is associated with long-term changes in the hypothalamic-pituitary-adrenal axis response,^{Reference Quidé, Tozzi, Corcoran, Cannon and Dauvermann5} such as increased cortisol reactivity. Thus, individuals exposed to childhood trauma may have heightened responses to subsequent life stressors, rendering them vulnerable to developing mood disorders such as bipolar disorder.^{Reference Watson, Owen, Gallagher, Hearn, Young and Ferrier6}

The evidence suggest emotional abuse may be considered a disease modifier (i.e. explaining onset and course of the disorder), and could represent a therapeutic target for early intervention. Taken together, research suggests that, compared with other traumas, there may be a stronger association between emotional abuse and bipolar disorder. One possible explanation for this is that sexual and physical abuse will invariably involve emotional abuse, either predating it or being part of it. Thus, targeting the deleterious effects of emotional abuse in the first instance may be a fruitful first step in developing trauma-focused early interventions for bipolar disorder.

Affective instability as a potential psychological target

There is now a substantial body of evidence demonstrating that childhood trauma, and emotional abuse specifically, may be more strongly associated with high levels of affective instability.^{Reference Taylor, Ulrichsen, Young and Strawbridge7} Evidence indicates affective instability or similar difficulties, such as affective lability or emotional dysregulation, appear early and before the onset of bipolar disorder, and are connected to emotional abuse. Compared with controls, individuals with bipolar disorder report higher rates of affective instability and, more crucially, individuals with bipolar disorder who report childhood trauma also endorse higher rates of affective instability compared with those without trauma histories. Affective instability in bipolar disorder is a potential determinant of a worsened clinical trajectory for bipolar disorder. Path analyses of independent data-sets indicate that affective instability mediates the relationship between childhood trauma and several clinical features of bipolar disorder, such as suicide attempts, mixed episodes, anxiety disorders, earlier age of onset, and number of depressive and manic episodes.^{Reference Marwaha, Briley, Perry, Rankin, DiFlorio and Craddock8} Taken together, this research suggests that affective instability is a worthwhile therapeutic target for bipolar disorder and, because of its transdiagnostic nature, it would likely fit well within prevention frameworks targeting early clinical stages of bipolar disorder. There is ongoing debate about the nosological status and boundaries between bipolar disorder and borderline personality disorder (BPD). Given that childhood trauma is common among both disorders, and affective instability is also a core feature of BPD,^{Reference Bozzatello, Rocca, Baldassarri, Bosia and Bellino9} targeting of affective instability may also be part of early interventions for BPD.

Interventions to target emotional abuse and affective instability

Research shows that both emotional abuse and affective instability are prevalent, correlated and potential drivers to the deleterious outcomes found in bipolar disorder. Thus, we argue that both emotional abuse and affective instability should be: 1) routinely assessed by clinicians, and 2) key therapeutic targets for future interventions (e.g. secondary prevention). In terms of the assessment of emotional abuse and affective instability, there are brief, validated tools that could easily be implemented into routine clinical practice to assess for both. However, one limiting step for this to be seen as acceptable and clinically necessary is the action that might ensue. Presently, it remains unclear how to best target emotional abuse and/or affective instability within people at risk or those who already have a bipolar disorder diagnosis. We offer two key suggestions to help drive this area of research forward: interventions that target emotional abuse (mainly based on the post-traumatic stress disorder (PTSD) literature) and interventions that target emotional-abuse-related affective instability directly (mainly based on the BPD literature).