Pazdernik, Vanessa K

Background: Ketamine and esketamine are increasingly used for treatment-resistant depression (TRD), yet their hepatic safety profile with repeated or long-term use remains poorly characterized. Chronic recreational ketamine abuse has been linked to cholestasis and cholangiopathy, raising concern that therapeutic use may carry similar risks. No systematic data exist on liver enzyme trajectories or biliary injury at subanesthetic doses used for depression. Methods: This historical cohort study included adults with TRD receiving IV ketamine or intranasal (IN) esketamine at the Mayo Clinic Ketamine Clinic (2017 to 2024). Patients were eligible if they had at least one liver enzyme value (AST, ALT, ALP, or bilirubin) within 12 months before through 3 months after treatment. Longitudinal enzyme trajectories were modeled using generalized linear-mixed models with a Gamma distribution. Clinically significant elevation was defined as ≥2× the upper limit of normal (ULN). Wilcoxon signed-rank tests compared pretreatment and post-treatment paired values. Results: Of 104 enrolled patients, 74 had liver enzyme data available; 51 had post-initiation data. Median age was 51.5 years; 72% were female. Most (78.4%) received IV ketamine. No clinically meaningful changes in enzyme trajectories were observed. Three patients (5.9%) had elevations ≥2× ULN, all attributable to alcohol use, myalgias, or pre-existing hepatic steatosis rather than (es)ketamine. Conclusions: Subanesthetic IV ketamine (0.5 mg/kg) and FDA-approved IN esketamine doses were not associated with clinically significant liver enzyme elevations in this real-world TRD cohort. Current evidence does not support routine hepatic monitoring for asymptomatic patients, although prospective, larger-scale studies are needed to confirm these findings.

ABSTRACT Background Despite the classic Kraepelinian dichotomy between bipolar disorder (BD) and schizophrenia (SZ), contemporary evidence suggests shared antecedent risk factors and similarities in the early course. This study aimed to identify distinct trajectories leading to first‐episode mania (FEM) and first‐episode psychosis (FEP) by examining antecedent psychopathology, including psychiatric diagnoses, symptoms, substance use, and psychotropic medication exposure. Methods Individuals born after 1985 who resided in Olmsted County, Minnesota, USA, and had FEM/FEP were identified through the Rochester Epidemiology Project. Latent class analysis (LCA) was used to identify subgroups based on antecedent psychopathology incorporating 57 dichotomous antecedent measures before FEM/FEP. Results A total of 202 individuals ( BD n = 73, SZ n = 129; 26.7% female, mean age 20.8 ± 3.7 years) were included. A 3‐class LCA model optimally fits the data. Class 1 (Neurodevelopmental, 29.7%) had a high prevalence of neurodevelopmental disorders, behavioral symptoms, and ADHD medication use. Class 2 (Depressive‐Anxious, 31.2%) included depressive and anxiety disorders, mood‐related symptoms, and SSRI / SNRI use. Class 3 (Minimal Psychiatric Morbidity, 39.1%) had a low prevalence of antecedent diagnoses and symptoms, with comparable substance use to other classes. There were significant diagnostic differences, with SZ being more common in the Neurodevelopmental (71.7%) and Minimal Psychiatric Morbidity (70.9%) classes, while BD was more common in the Depressive‐Anxious class ( p = 0.007). Neurodevelopmental and Minimal Psychiatric Morbidity classes had higher proportions of males (85.0% and 82.3%, respectively) compared to the Depressive‐Anxious class (50.8%, p < 0.001). The Neurodevelopmental class showed an earlier age at first mental health visit (9.5 ± 5.5 years) and a longer antecedent illness duration (10.8 ± 6.1 years) than the other classes ( p < 0.001). Conclusion This study identified three distinct pathways to FEM and FEP, offering a transdiagnostic perspective on the antecedent illness trajectories of BD and SZ. Future research should validate these categories that are more inclusive than the classic BD versus SZ dichotomy and explore their potential for predicting illness course and guiding personalized early interventions.