An exploration of actigraphy in the context of ketamine and treatment-resistant depression.

OBJECTIVES: This study explored the potential of non-parametric and complexity analysis metrics to detect changes in activity post-ketamine and their association with depressive symptomatology. METHODS: Individuals with treatment-resistant depression (TRD: n = 27, 16F, 35.9 ± 10.8 years) and healthy volunteers (HVs: n = 9, 4F, 36.4 ± 9.59 years) had their activity monitored during an inpatient, double-blind, crossover study where they received an infusion of ketamine or saline placebo. All participants were 18-65 years old, medication-free, and had a MADRS score ≥20. Non-parametric metrics averaged over each study day, metrics derived from complexity analysis, and traditionally calculated non-parametric metrics averaged over two weeks were calculated from the actigraphy time series. A separate analysis was conducted for a subsample (n = 17) to assess the utility of these metrics in a hospital setting. RESULTS: In HVs, lower intradaily variability was observed within daily rest/activity patterns post-ketamine versus post-placebo (F = 5.16(1,15), p = 0.04). No other significant effects of drug or drug-by-time or correlations between depressive symptomatology and activity were detected. CONCLUSIONS: Weak associations between non-parametric variables and ketamine were found but were not consistent across actigraphy measures. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT00088699.

Characteristics, Methods, And Functions Of Non-Suicidal Self-Injury Among Highly Dissociative Individuals.

Upto 86% of dissociative individuals engage in non-suicidal self-injury (NSSI). Research suggests that people who dissociate utilize NSSI to regulate posttraumatic and dissociative experiences, as well asrelated emotions. Despite high rates of NSSI, no quantitative study has examined the characteristics, methods, and functions of NSSIwithin a dissociative population. The present study examined thesedimensions of NSSI among dissociative individuals, as well aspotential predictors of intrapersonal functions of NSSI. The sample included 295 participants who indicated experiencing one or more dissociative symptoms and/or having been diagnosed with a trauma- or dissociation-related disorder. Participants were recruited through online trauma- and dissociation- related forums. Approximately 92% of participants endorsed a history of NSSI. The most common methods of NSSI were interfering with wound healing (67%), hitting oneself (66%), and cutting (63%). After controlling for age and gender, dissociation was uniquely associated with cutting, burning, carving, interfering with wound healing, rubbing skin against rough surfaces, swallowing dangerous substances, and other forms of NSSI. Dissociation was correlated with affect regulation, self-punishment,anti-dissociation, anti-suicide, and self-care functions of NSSI;however, after controlling for age, gender, depressive symptoms, emotion dysregulation, and PTSD symptoms, dissociation was no longer associated with any function of NSSI. Instead, only emotion dysregulation was associated with the self-punishment function ofNSSI and only PTSD symptoms were associated with the anti-dissociation function of NSSI. Understanding the unique properties of NSSI among dissociative individuals may improve the treatment of people who dissociate and engage in NSSI.