Affect dysregulation and dissociation in borderline personality disorder and somatoform disorder: differentiating inhibitory and excitatory experiencing states.

Affect dysregulation and dissociation may be associated with borderline personality disorder (BPD) and somatoform disorder (SoD). In this study, both under-regulation and over-regulation of affect and positive and negative somatoform and psychoform dissociative experiences were assessed. BPD and SoD diagnoses were confirmed or ruled out in 472 psychiatric inpatients using clinical interviews and clinical multidisciplinary consensus. Affect dysregulation and dissociation were measured using self-reports. Under-regulation (but not over-regulation) of affect was moderately related to positive and negative psychoform and somatoform dissociative experiences. Although both BPD and SoD can involve dissociation, there is a wide range of intensity of both somatoform and psychoform dissociative phenomena in patients with these diagnoses. Compared with other groups, SoD patients more often reported low levels of dissociative experiences and reported fewer psychoform (with or without somatoform) dissociative experiences. Compared with the other groups, patients with both BPD and SoD reported more psychoform (with or without somatoform) dissociative experiences. Evidence was found for the existence of 3 qualitatively different forms of experiencing states. Over-regulation of affect and negative psychoform dissociation, commonly occurring in SoD, can be understood as inhibitory experiencing states. Under-regulation of affect and positive psychoform dissociation, commonly occurring in BPD, can be understood as excitatory experiencing states. The combination of inhibitory and excitatory experiencing states commonly occurred in comorbid BPD + SoD. Distinguishing inhibitory versus excitatory states of experiencing may help to clarify differences in dissociation and affect dysregulation between and within BPD and SoD patients.