Revisiting the concept of severe mental illness: severity indicators and healthcare spending in psychotic, depressive and dissociative disorders.

Background: The concept of severe mental illness (SMI) has been related to bipolar or psychotic diagnosis, or to some cases of depressive disorders. Other mental health problems such as personality disorders or posttraumatic dissociative conditions, which can sometimes lead to relevant functional impairments, remain separate from the SMI construct.Aims: This study aimed to evaluate the clinical severity as well as healthcare spending on dissociative disorders (DDs). This diagnostic group was compared with two other groups usually considered as causing severe impairment and high healthcare spending: bipolar and psychotic disorders, and unipolar depression.Methods: From a random sample of 200 psychiatric outpatients, 108 with unipolar depression (N = 45), psychotic/bipolar (N = 31) or DDs (N = 32) were selected for this study. The three groups were compared by the severity of their disorder and healthcare indicators.Results: Of the three groups, those with a DD were more prone to and showed higher indices of suicide, self-injury, emergency consultations, as well as psychotropic drug use. This group ranked just below psychotic/bipolar patients in the amount of psychiatric hospitalisations.Conclusions: Despite a certain intra-professional stigma regarding DDs, these data supported the severity of these posttraumatic conditions, and their inclusion in the construct of SMI.