Autistic and Catatonic Spectrum Symptoms in Patients with Borderline Personality Disorder

Background: Recent literature has shown that a considerable percentage of patients with severe mental disorders can develop, over time, full-blown or subthreshold catatonia. Some studies corroborate the model of an illness trajectory in which different mental disorders would be arranged along a continuum of severity until the development of catatonia. In such an illness pathway, autistic traits (AT) and borderline personality disorder (BPD) may represent important steps. In order to further explore the association between AT, BPD, and catatonia, the aim of this study was to compare catatonic spectrum symptoms and AT among patients with major depressive disorder (MDD), BPD, and healthy controls (CTL), also evaluating possible predictive dimensions of the different diagnoses. Methods: A total of 90 adults affected by BPD, 90 adults with a diagnosis of MDD, and 90 CTL, homogeneous in terms of gender and age, were recruited from six Italian university departments of psychiatry and assessed with the SCID-5-RV, the Catatonia Spectrum (CS), and the Adult Autism Subthreshold Autism Spectrum (AdAS Spectrum). Results: The total CS score was significantly higher in the BPD and MDD groups than in the CTL group, while the majority of CS domain scores were significantly higher in the BPD group than in the MDD group, which scored significantly higher than the CTL group. The total AdAS Spectrum score and the AdAS Spectrum domain scores were significantly higher in the BPD group than in the MDD group, which in turn scored significantly higher than the CTL group. The CS domains "psychomotor activity" and "impulsivity", and AdAS Spectrum domains "verbal communication", "empathy", and "hyper-/hyporeactivity to sensory input" were associated with the risk of presenting a diagnosis of BPD.