Abstract Background Ketamine has been showing high efficacy and rapid antidepressant effect. However, studies of ketamine infusion wash subjects out from prior antidepressants, which may be ...impractical in routine practice. In this study, we determined antidepressant response and remission to six consecutive ketamine infusions while maintaining stable doses of antidepressant regimen. We also examined the trajectory of response and remission, and the time to relapse among responders. Methods TRD subjects had at least 2-month period of stable dose of antidepressants. Subjects completed six IV infusions of 0.5 mg/kg ketamine over 40 min on a Monday–Wednesday–Friday schedule during a 12-day period participants meeting response criteria were monitored for relapse for 4 weeks. Results Fourteen subjects were enrolled. Out of twelve subjects who completed all six infusions, eleven (91.6%) achieved response criterion while eight (66.6%) remitted. After the first infusion, only three and one out of twelve subjects responded and remitted, respectively. Four achieved response and six remitted after 3 or more infusions. Five out of eleven subjects remain in response status throughout the 4 weeks of follow-up. The mean time for six subjects who relapsed was 16 days. Limitations Small sample and lack of a placebo group limits the interpretation of efficacy. Conclusions Safety and efficacy of repeated ketamine infusions were attained without medication-free state in patients with TRD. Repeated infusions achieved superior antidepressant outcomes as compared to a single infusion with different trajectories of response and remission. Future studies are needed to elucidate neural circuits involved in treatment response to ketamine.
The strategy of repeated ketamine in open-label and saline-control studies of treatment-resistant depression suggested greater antidepressant response beyond a single ketamine. However, consensus ...guideline stated the lack of evidence to support frequent ketamine administration. We compared the efficacy and safety of single vs. six repeated ketamine using midazolam as active placebo. Subjects received either six ketamine or five midazolam followed by a single ketamine during 12 days followed by up to 6-month post-treatment period. The primary end point was the change from baseline in the Montgomery-Åsberg Depression Rating Scale (MADRS) score at 24 h after the last infusion. Fifty-four subjects completed all six infusions. For the primary outcome measure, there was no significant difference in change of MADRS scores between six ketamine group and single ketamine group at 24 h post-last infusion. Repeated ketamine showed greater antidepressant efficacy compared to midazolam after five infusions before receiving single ketamine infusion. Remission and response favored the six ketamine after infusion 4 and 5, respectively, compared to midazolam before receiving single ketamine infusion. For those who responded, the median time-to-relapse was nominally but not statistically different (2 and 6 weeks for the single and six ketamine group, respectively). Repeated infusions were relatively well-tolerated. Repeated ketamine showed greater antidepressant efficacy to midazolam after five infusions but fell short of significance when compared to add-on single ketamine to midazolam at the end of 2 weeks. Increasing knowledge on the mechanism of ketamine should drive future studies on the optimal balance of dosing ketamine for maximum antidepressant efficacy with minimum exposure.
The glutamate N-methyl-d-aspartate (NMDA) receptor antagonist ketamine rapidly ameliorates posttraumatic stress disorder (PTSD) and depression symptoms in individuals with comorbid PTSD and major ...depressive disorder (MDD). However, concerns over ketamine's potential neurocognitive side effects have yet to be assessed in this population. The current study investigated 1) changes in neurocognitive performance after a repeated ketamine dosing regimen and 2) baseline neurocognitive performance as a predictor of ketamine treatment effect.
Veterans with comorbid PTSD and MDD (N = 15) received six infusions of 0.5 mg/kg ketamine over a 12-day period. Neurocognitive and clinical outcomes assessments occurred at baseline and within 7 days of infusion-series completion using the CogState battery.
Repeated ketamine infusions did not significantly worsen any measures of cognition. Rather, significant improvement was observed in working memory following completion of the infusion series. In addition, greater improvements in PTSD and MDD symptoms were associated with lower working memory, slower processing speed and faster set shifting at baseline. Lower verbal learning was also predictive of improvement in depression.
This study applied an open-label design without a placebo control. As such, it is not known to what extent the correlations or improvement in neurocognitive performance may have occurred under placebo conditions.
This is the first study to examine the neurocognitive effects of repeated ketamine in participants with comorbid PTSD and MDD. Our findings suggest potential baseline neurocognitive predictors of ketamine response for comorbid PTSD and MDD symptoms.
•This is the first study reporting neurocognitive outcomes to IV ketamine for PTSD.•Repeated IV ketamine did not significantly worsen any measures of cognition.•Working memory was significantly improved following repeated ketamine infusions.•Baseline working memory, processing speed and set shifting predicted PTSD and MDD improvement.
•Baseline working memory is a predictor of antidepressant response to repeated ketamine.•Most neurocognitive performance at the end of treatment remain stable or improved to repeated or single ...ketamine.•Speed of processing, set shifting, and spatial working memory improved in the six ketamine group.•These cognitive improvements from baseline to the end of treatment was independent of changes in depression.
Ketamine demonstrated rapid antidepressant effects in treatment-resistant depression (TRD). However, evaluation of ketamine's neurocognitive effect in TRD is unclear. We aim to (1) characterize baseline neurocognitive performance as a predictor of the change in severity of depressive symptoms over time, and (2) investigate the association of six versus single intravenous (IV) ketamine and neurocognitive changes from baseline to the end of treatment.
Subjects with TRD were randomized to receive either five IV midazolam followed by a single IV ketamine or six IV ketamine during a 12-day period. Depression symptom assessments occurred prior and 24 h after infusion days using the Montgomery–Åsberg Depression Rating Scale. Neurocognitive tasks were designed to test attention, memory, speed of processing, and set shifting using the CogState battery at baseline and at the end of treatment.
Better complex working memory at baseline predicted improvement in MADRS scores of ketamine (vs midazolam) after 5 infusions. Most, but not all, neurocognitive functions remained stable or improved after repeated or single ketamine. There was a greater differential effect of treatment on speed of processing, set shifting, and spatial working memory that favors subjects in the six ketamine group. These cognitive improvements from baseline to the end of treatment were robust when controlling for age and changes in depression severity.
The study suggests that six IV ketamine compared to single IV ketamine has a mood independent procognitive effect among TRD patients. Large scale studies are needed to confirm whether ketamine enhances cognitive function in TRD.
The present study examined the efficacy, safety, and durability of repeated ketamine infusions for the treatment of comorbid posttraumatic stress disorder (PTSD) and treatment-resistant depression ...(TRD) in a sample of veterans.
Individuals with comorbid DSM-5-defined PTSD and DSM-IV-defined major depressive disorder (N = 15) received 6 intravenous ketamine infusions (0.5 mg/kg) on a Monday-Wednesday-Friday schedule over a 12-day period from May 2015 to June 2016. Data from outcome measures were collected before and 24 hours after each infusion and weekly for 8 weeks following the final infusion.
Continuous measures of symptom change were significant for both disorders and were associated with large effect sizes (mean decrease in PTSD Checklist for DSM-5 score = 33.3 points 95% CI, 23.0-43.5 points, P < .0005, sample size-adjusted Cohen d d' = 2.17; mean decrease in Montgomery-Asberg Depression Rating Scale score = 26.6 points 95% CI, 23.0-30.2 points, P < .0005, d' = 4.64). The remission rate for PTSD was 80.0%, and the response rate for TRD was 93.3%. Participants in remission from PTSD after the infusion series (n = 12) had a median time to relapse of 41 days. Similarly, participants whose depression symptoms responded to the infusion series (n = 14) had a median time to relapse of 20 days. Repeated ketamine infusions were associated with transient increases in dissociative symptoms. No participant reported worsening of PTSD symptoms over the study duration.
This study, the first open-label study of repeated ketamine infusions in a comorbid population, found rapid and sustained improvement in PTSD and depression symptoms. This report suggests that repeated ketamine treatments are safe and may represent an efficacious treatment for individuals with comorbid PTSD and TRD.
ClinicalTrials.gov identifier: NCT02577250.
The N-methyl-D-aspartate glutamate receptor antagonist ketamine has demonstrated rapid antidepressant effects in treatment-resistant depression (TRD). However, evaluation of ketamine's neurocognitive ...aspects in TRD has started to be explored. This study aims to (1) examine baseline neurocognitive performance and change in severity of depressive symptoms through six ketamine infusions, (2) examine the neurocognitive effects after completion of serial infusions and whether changes were associated to relapse to depression. Six IV infusions of 0.5 mg/Kg ketamine over 40 min were conducted on a Monday–Wednesday–Friday schedule during a 12-d period on 15 patients with TRD followed by a 4-wk observational period. Neurocognitive functioning was assessed using the CogState battery at baseline and at each follow-up visit. Tasks were designed to test attention, memory (working, visual, and verbal), speed of processing, and set shifting. The likelihood of response through six infusions was greater among depressed subjects with lower attention at baseline (F(1,13) = 5.59, p = 0.034). Significant improvement was found in scores of visual memory (F(4,33.82) = 5.12, p = 0.002), simple working memory (F(4, 24.85) = 3.29, p = 0.027) and complex working memory (F(4, 32.76) = 4.18, p = 0.008) after the last ketamine infusion. However, neurocognitive changes were accounted for by improvement in the severity of depressive symptom. The acute neurocognitive effect after completion of repeated infusions was not associated with the likelihood of subsequent relapse during follow-up. Our findings suggest a potential baseline neurocognitive predictor of ketamine response and the apparently lack of short-term neurocognitive impairment after completion of six ketamine infusions in TRD.
Transcranial magnetic stimulation (TMS) is an intervention for treatment-resistant depression (TRD) that modulates neural activity. Deep TMS (dTMS) can target not only cortical but also deeper limbic ...structures implicated in depression. Although TMS has demonstrated safety in adolescents, dTMS has yet to be applied to adolescent TRD.
This pilot study evaluated the safety, tolerability, and clinical effects of dTMS in adolescents with TRD. We hypothesized dTMS would be safe, tolerable, and efficacious for adolescent TRD.
15 adolescents with TRD (Age, years: M = 16.4, SD = 1.42) completed a six-week daily dTMS protocol targeting the left dorsolateral prefrontal cortex (BrainsWay H1 coil, 30 sessions, 10 Hz, 3.6 s train duration, 20s inter-train interval, 55 trains; 1980 total pulses per session, 80 % to 120 % of motor threshold). Participants completed clinical, safety, and neurocognitive assessments before and after treatment. The primary outcome was depression symptom severity measured by the Children's Depression Rating Scale-Revised (CDRS-R).
14 out of 15 participants completed the dTMS treatments. One participant experienced a convulsive syncope; the other participants only experienced mild side effects (e.g., headaches). There were no serious adverse events and minimal to no change in cognitive performance. Depression symptom severity significantly improved pre- to post-treatment and decreased to a clinically significant degree after 10 treatment sessions. Six participants met criteria for treatment response.
Main limitations include a small sample size and open-label design.
These findings provide preliminary evidence that dTMS may be tolerable and associated with clinical improvement in adolescent TRD.
•dTMS may be helpful for some adolescents with treatment resistant depression (TRD).•dTMS was tolerable for most adolescents with TRD in this sample.•Clinical improvements were observable within two weeks of treatment.•Additional research to test efficacy and to inform parameter selection is needed.
Treatment-resistant depression (TRD) is a serious problem in adolescents. Development and optimization of novel interventions for these youth will require a deeper knowledge of the neurobiology of ...depression. A well-established phenomenon of depression is an attention bias toward negativity and away from positivity that is evidenced behaviorally and neurally, but it is unclear how symptom reduction is related to changes to this bias. Neurobiological research using a treatment probe has promise to help discover the neural changes that accompany symptom improvement. Ketamine has utility for such research because of its known rapid and strong antidepressant effects in the context of TRD. Our previous study of six open-label ketamine infusions in 11 adolescents with TRD showed variable response, ranging from full remission, partial response, non-response, or clinical worsening. In this study, we examined the performance of these participants on Word Face Stroop (WFS) fMRI task where they indicated the valence of affective words superimposed onto either congruent or incongruent emotional faces before and after the ketamine infusions. Participants also completed a clinical assessment (including measurement of depression symptomology and anhedonia/pleasure) before and after the ketamine infusions. Following ketamine treatment, better WFS performance correlated with self-reported decreased depressive symptoms and increased pleasure. Analyses of corticolimbic, corticostriatal and default mode (DMN) networks showed that across networks, decreased activation during all conditions (congruent negative, congruent positive, incongruent negative, and incongruent positive) correlated with decreases in depressive symptoms and with increases in pleasure. These findings suggest that in adolescents with TRD, clinical improvement may require an attenuation of the negativity bias and re-tuning of these three critical neural networks to attenuate DMN and limbic regions activation and allow more efficient recruitment of the reward network. Lower activation across conditions may facilitate shifting across different salient emotional stimuli rather than getting trapped in downward negative spirals.
Multivariable comorbidity research indicates that childhood adversity increases the risk for the development of common mental disorders. This risk is explained by underlying internalizing and ...externalizing transdiagnostic constructs that are amplified by environmental stressors. The differential susceptibility model suggests that this interaction of risk and environment is bidirectional: at-risk individuals will have worse outcomes in high-stress environments but better outcomes in in low-stress environments.
To test the differential susceptibility model by examining how a history of adverse childhood experiences moderates the association between life stress and transdiagnostic psychopathology.
Data came from the US National Epidemiological Survey on Alcohol and Related Conditions (NESARC), a population-based observational longitudinal survey administered to adults (≥18 years of age). Participants completed the survey at wave 1 (from 2001 through 2002) and wave 2 (from 2004 through 2005). Responses from 34 458 participants were used for the analyses from March 3, 2017, through October 8, 2018.
Latent variables for internalizing-fear, internalizing-distress, externalizing, and general psychopathology were created to represent continuous levels of psychopathology in each wave. Latent variables were also created to represent continuous levels of life stress at each wave. Level of childhood adversity was characterized based on the number of types of childhood adversity experienced (no 0 types, low 1-2 types, and high ≥3 types exposure). Analyses examined how the interaction between level of childhood adversity and adult life stress was associated with change in adult transdiagnostic psychopathology factors.
Of the 34 458 participants included in the analysis (58.0% women and 42.0% men; mean SD age, 46.0 17.4 years at wave 1 and 49.0 17.3 years at wave 2), 40.5% had no adverse childhood experiences, 34.6% had 1 to 2, and 24.9% had 3 or more. At wave 1, 61.5% of the sample endorsed at least 1 stressful life event and 27.2% met criteria for at least 1 mental disorder; at wave 2, these figures were 64.7% and 29.7%, respectively. Childhood adversity moderated the association between changes in adult life stress and changes in all transdiagnostic psychopathology factors. Specifically, higher levels of childhood adversity had a stronger association between adult life stress and adult transdiagnostic psychopathology factors. Further, significant differences between childhood adversity groups occurred in the mean scores of all transdiagnostic psychopathology factors for both increases and decreases in life stress, providing preliminary evidence of differential susceptibility.
Results provide empirical support for childhood adversity as a differential susceptibility factor engendering heightened functional and dysfunctional reactivity to later stress.
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