The Connections Between Alexithymia, Childhood Maltreatment, Impulsivity and Extreme Sensory Processing Patterns in Relation to Bipolar Symptoms in Inpatients With Bipolar Disorder

Childhood maltreatment, alexithymia and impulsivity are related to bipolar disorder (BD), but the role of potential underlying mechanisms of this link, such as extreme sensory processing, in BD are unclear. This study compared sensory processing patterns between individuals with BD-I or BD-II and between those with and without alexithymia and childhood maltreatment. Additionally, the study aimed to examine the role of extreme sensory processing in the relationship between childhood trauma, alexithymia and impulsivity with both depression and mania in a sample of hospitalized individuals with BD (n = 300). Participants completed self-report and clinician-rated scales. Patients with BD-II exceeded those with BD-I in low registration, sensory sensitivity and sensation avoidance, whereas patients with BD-I exhibited a more heightened sensation-seeking pattern. Patients with BD who had alexithymia and a history of childhood maltreatment exhibited more heightened sensory processing patterns, apart from sensory seeking, compared to those without alexithymia and childhood maltreatment. Additionally, the same pattern was more pronounced in individuals with BD who had both alexithymia and childhood maltreatment compared to those with either condition or neither of these conditions. The pathways from childhood maltreatment and alexithymia to depressive symptoms were mediated by low registration and sensation avoidance. Sensory seeking indirectly affected the link between alexithymia and manic symptoms. Childhood maltreatment and challenges in effectively processing emotional information, along with their related hypo- and hypersensitivity, may characterize BD individuals and its manifestation of depressive and manic symptoms.