Ketamine treatment safety and tolerability in treatment-resistant depression with somatic comorbidities: focus on dissociation and psychotic symptomatology.

Abstract Background and objectives: There is evidence for ketamine use in treatment-resistant depression (TRD). Several safety and tolerability concerns arise regarding adverse drug reactions and specific subpopulations. The aim of this paper is to investigate the relationship between dissociative and psychometric measures in course of intravenous ketamine treatment in TRD inpatients with Major Depressive Disorder and Bipolar depression.Methods: The study population of 49 inpatients comprises of MDD and BP subjects treated with ketamine registered in the naturalistic observational protocol of the tertiary reference unit for mood disorders (NCT04226963). The study may be underpowered due to the small sample size. The observations apply to inhomogeneous TRD population in a single-site with no blinding and are limited to the acute administration. Results: The epilepsy was significantly associated with changes in BPRS over time (p=0.008). Psychotic symptomatology with BPRS scores for comorbid somatic conditions excluding epilepsy turned out to be insignificant (p = 0.198) regardless the diagnosis. Conclusions: In ketamine use, careful consideration of comorbidities and concomitant medication is needed. In ketamine administration close-clinical supervision is necessary at every visit. Psychotic symptoms must be taken into consideration in planning treatment with TRD patients with epilepsy. Somatic comorbidity may impact dissociative symptomatology. Trial Registration: Study registered: 04DEC2019, clinicaltrials.com no. NCT04226963 https://clinicaltrials.gov/ct2/show/NCT04226963