A simplified 6-Item clinician administered dissociative symptom scale (CADSS-6) for monitoring dissociative effects of sub-anesthetic ketamine infusions.
Nelson B Rodrigues, R. Mcintyre, Orly Lipsitz, Yena Lee, D. Cha, Margarita Shekotikhina, M. Vinberg, H. Gill, M. Subramaniapillai, Kevin Kratiuk, Kangguang Lin, R. Ho, R. Mansur, J. Rosenblat
Journal of Affective Disorders December 29, 2020 DOI: 10.1016/j.jad.2020.12.119 via Semantic Scholar
Summary
A 6-item short form of the Clinician-Administered Dissociative States Scale (CADSS-6) strongly correlates with the full 23-item version in patients with treatment-resistant depression receiving IV ketamine. Using retrospective data from 260 patients split into two groups, the CADSS-6 was derived from items most sensitive to ketamine-induced dissociation. Correlations between the short and full scale ranged from 0.91 to 0.95 across four infusions. The CADSS-6 offers a brief clinical assessment for dissociation, though it remains unvalidated in this population and requires prospective validation.
Study at a glance
| Characteristics | Retrospective analysis Peer reviewed |
|---|---|
| Sample size | 260 |
| Population | Patients with treatment-resistant depression receiving IV ketamine |
| Keywords | Medicine |
| Key finding | 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.