Effect of Ketamine on Rumination in Treatment-Resistant Depressive Patients.

BACKGROUND: A rapid antidepressant effect of ketamine has repeatedly been documented in the literature, and identifying clinical features associated with a better response to this treatment is currently an essential question. Considering the relationship between rumination and depression and the need to identify potential predictors of response to ketamine, we analyzed the effect of a single injection of ketamine 0.5 mg/kg on rumination in treatment-resistant depressive (TRD) patients and explored whether baseline ruminative style and early improvements of rumination would predict a greater antidepressant effect of ketamine. METHODS: Ten TRD outpatients who participated in a 4-week open study on the antidepressant effect of ketamine also completed the Ruminative Response Scale the day before, the day after, and a week after ketamine administration. RESULTS: We found that in our patients, a single rapid 1-minute intravenous injection of ketamine 0.5 mg/kg was efficacious in reducing rumination, but neither severity of rumination at baseline nor early improvements of rumination after ketamine injection predicted antidepressant response. CONCLUSIONS: Our preliminary data suggest that a single injection of ketamine 0.5 mg/kg can be efficacious in reducing rumination in TRD patients but rumination does not seem to be a useful clinical predictor of response to ketamine. Larger studies are necessary to confirm these results.

Levetiracetam efficacy on frontal lobe dysfunctions and anger rumination in patients with epilepsy.

This study compared the frontal lobe functioning and anger rumination between patients with epilepsy and healthy individuals. The second objective was to examine the efficacy of levetiracetam therapy on frontal lobe dysfunctions and anger rumination in patients with epilepsy. Participants (50 patients with epilepsy and 50 healthy individuals) completed the Frontal Assessment Battery (FAB) and Anger Rumination Scale (ARS). The patients had two testing sessions: pre- and post-levetiracetam therapies. The results showed that patients with epilepsy had frontal lobe dysfunctions in contrast with healthy individuals. Patients with epilepsy had higher anger rumination than healthy individuals. Compared with baseline performance, frontal lobe dysfunctions and anger rumination were significantly reduced after three months of levetiracetam therapy in patients with epilepsy. It is concluded that levetiracetam therapy may be beneficial in improving frontal lobe functioning and anger rumination thought pattern in patients with epilepsy. However, further studies are required to confirm this evidence.

Effects of alcohol, rumination, and gender on the time course of negative affect.

This study modelled associations between gender, ruminative cognitive style, alcohol use, and the time course of negative affect over the course of 43,111 random assessments in the natural environment. Participants (N = 263) completed 49 days of experience sampling over 1.3 years. The data indicated that rumination at baseline was positively associated with alcohol dependence symptoms at baseline as well as higher negative affect over the course of the study. Consistent with negative reinforcement models, drinking served to decrease the persistence of negative affect from moment to moment. However, this ameliorative effect of drinking was evident only among women, suggesting an increased risk for negative reinforcement driven drinking behaviour. In addition, rumination appeared to counteract the desired effects of alcohol on mood among women. This suggests that women who ruminate more may be motivated to consume larger amounts of alcohol to achieve the desired effects. Overall, the results indicate that ruminative cognitive style and the persistence of negative affect from moment to moment may reflect an individual vulnerability for the development of alcohol use disorder especially among women.