A simplified 6-Item clinician administered dissociative symptom scale (CADSS-6) for monitoring dissociative effects of sub-anesthetic ketamine infusions.
Nelson B Rodrigues, Roger S McIntyre, Orly Lipsitz, Yena Lee, Danielle S. Cha, Margarita Shekotikhina, Maj Vinberg, Hartej Gill, Mehala Subramaniapillai, Kevin Kratiuk, Kangguang Lin, R. Ho, Rodrigo B. Mansur, Joshua D. Rosenblat
Journal of Affective Disorders December 29, 2020 DOI: 10.1016/j.jad.2020.12.119 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Retrospective analysis Peer reviewed |
|---|---|
| Sample size | 260 |
| Population | Patients with treatment-resistant depression receiving IV ketamine |
| Intervention | IV ketamine |
| Topics | Esketamine Ketamine |
| Key points | A 6-item short form of the CADSS shows strong correlation (0.91–0.95) with the full-length CADSS across four ketamine infusions in patients with treatment-resistant depression. |
Abstract
Background: Dissociation is a treatment-emergent adverse event commonly associated with IV ketamine, often measured using the 23-item Clinician-Administered Dissociative States Scale (CADSS). The objective of this study was to develop a short form version of the CADSS for easier clinical use.
Methods: Retrospective data of 260 patients with treatment-resistant depression (TRD) receiving IV ketamine were randomly divided into two datasets. The first dataset (n = 130) was leveraged to develop a brief 6-item version of the CADSS (CADSS-6) based on items most sensitive to ketamine-induced dissociation. The CADSS-6 questions were then applied to the second dataset (n = 130) and the Spearman's correlation between the full-length CADSS and the CADSS-6 were assessed.
Results: The CADSS-6 was developed from questions 1, 2, 6, 7, 15, and 22 from the full length CADSS. There was a strong significant correlation between the CADSS-6 total score and the CADSS total score at infusions 1 (rs(106) = 0.92, p < 0.001), 2 (rs(100) = 0.91, p < 0.001), 3(rs(99) = 0.95, p < 0.001) and 4 (rs(102) = 0.94, p < 0.001).
Limitations: The CADSS-6 was developed using a retrospective data; therefore, the scale remains unvalidated in this population.
Conclusions: The CADSS-6 presented herein was sensitive to dissociation experienced by patients receiving IV ketamine. Overall, the CADSS-6 was strongly correlated at each infusion with the full-length CADSS. While future studies should look to validate the CADSS-6 in a TRD sample, this scale offers clinicians a brief assessment that can be used to characterize symptoms of dissociation.