Ketamine and depression: a narrative review.
Abstract
Corriger, A., & Pickering, G. (2019). Ketamine and depression: a narrative review. Drug design, development and therapy, 13, 3051., https://doi.org/10.2147/DDDT.S221437
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Background: Posttraumatic stress disorder (PTSD) is a common psychiatric condition that can develop following a traumatic experience. PTSD is associated with significant disability, a large economic burden, and despite the range of therapies to treat PTSD, response to antidepressants is limited. A growing body of clinical research suggests the efficacy of 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy in individuals with treatment-refractory PTSD.
Aim: To assess the effectiveness and safety of MDMA-assisted psychotherapy for reducing symptoms of PTSD, a systematic review and meta-analysis was undertaken.
Methods: Six online databases were searched from inception to December 2018. Reference lists of relevant articles were manually searched as well as electronic sources of ongoing trials and conference proceedings. Researchers active in the subject were also contacted. Eligible studies included randomized and quasi-randomized clinical trials using MDMA-assisted psychotherapy for PTSD in comparison with other medications, placebo or no medication (supportive care). We used standard methodological procedures expected by the Cochrane Collaboration. Two authors assessed studies for inclusion and extracted data. Using random-effects meta-analysis with Cochrane’s Review Manager 5.3, we obtained standardized mean differences [SMD] and rate ratios [RR] for reduction in PTSD symptomatology.
Results: A total of 5 trials met inclusion criteria, totaling 106 participants (average age: 35-40 years, 70% female). Studies were rated as moderate in quality. MDMA-assisted psychotherapy demonstrated a high rate of clinical response (RR = 3.47, 95% CI: 1.70, 7.06), remission (RR = 2.63, 95% CI: 1.37, 5.02), with a large effect size at reducing the symptoms of PTSD (SMD = 1.30, 95% CI: 0.66, 1.94). Available evidence indicates that MDMA was well-tolerated, with few serious adverse events reported across studies.
Conclusions: MDMA-assisted psychotherapy appears to be a potentially safe, effective, and durable treatment for individuals with chronic, treatment-refractory PTSD. However, future studies involving larger samples and longer durations of treatment and follow-up are warranted-and underway.
Bahji, A., Forsyth, A., Groll, D., & Hawken, E. R. (2020). Efficacy of 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy for posttraumatic stress disorder: A systematic review and meta-analysis. Progress in neuro-psychopharmacology & biological psychiatry, 96, 109735. https://doi.org/10.1016/j.pnpbp.2019.109735
Both psychedelics and meditation exert profound modulatory effects on consciousness, perception and cognition, but their combined, possibly synergistic effects on neurobiology are unknown. Accordingly, we conducted a randomized, double-blind, placebo-controlled study with 38 participants following a single administration of the psychedelic psilocybin (315 μg/kg p.o.) during a 5-day mindfulness retreat. Brain dynamics were quantified directly pre- and post-intervention by functional magnetic resonance imaging during the resting state and two meditation forms. The analysis of functional connectivity identified psilocybin-related and mental state–dependent alterations in self-referential processing regions of the default mode network (DMN). Notably, decoupling of medial prefrontal and posterior cingulate cortices, which is thought to mediate sense of self, was associated with the subjective ego dissolution effect during the psilocybin-assisted mindfulness session. The extent of ego dissolution and brain connectivity predicted positive changes in psycho-social functioning of participants 4 months later. Psilocybin, combined with meditation, facilitated neurodynamic modulations in self-referential networks, subserving the process of meditation by acting along the anterior–posterior DMN connection. The study highlights the link between altered self-experience and subsequent behavioral changes. Understanding how interventions facilitate transformative experiences may open novel therapeutic perspectives. Insights into the biology of discrete mental states foster our understanding of non-ordinary forms of human self-consciousness and their concomitant brain substrate.
Smigielski, L., Scheidegger, M., Kometer, M., & Vollenweider, F. X. (2019). Psilocybin-assisted mindfulness training modulates self-consciousness and brain default mode network connectivity with lasting effects. NeuroImage, 196, 207-215., https://doi.org/10.1016/j.neuroimage.2019.04.009
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Pérez‐Esparza, R., Kobayashi‐Romero, L. F., García‐Mendoza, A. M., Lamas‐Aguilar, R. M., & Fonseca‐Perezamador, A. (2019). Promises and concerns regarding the use of ketamine and esketamine in the treatment of depression. Acta Psychiatrica Scandinavica, 140(2), 182-183., https://doi.org/10.1111/acps.13063
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Muttoni, S., Ardissino, M., & John, C. (2019). Classical psychedelics for the treatment of depression and anxiety: a systematic review. Journal of affective disorders., https://doi.org/10.1016/j.jad.2019.07.076
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Background: The rapid-acting clinical effects of ketamine as a novel treatment for depression along with its complex pharmacology have made it a growing research area. One of the key mechanistic hypotheses for how ketamine works to alleviate depression is by enhancing long-term potentiation (LTP)-mediated neural plasticity.
Methods: The objective of this study was to investigate the plasticity hypothesis in 30 patients with depression noninvasively using visual LTP as an index of neural plasticity. In a double-blind, active placebo-controlled crossover trial, electroencephalography-based LTP was recorded approximately 3 to 4 hours following a single 0.44-mg/kg intravenous dose of ketamine or active placebo (1.7 ng/mL remifentanil) in 30 patients. Montgomery-Åsberg Depression Rating Scale scores were used to measure clinical symptoms. Visual LTP was measured as a change in the visually evoked potential following high-frequency visual stimulation. Dynamic causal modeling investigated the underlying neural architecture of visual LTP and the contribution of ketamine.
Results: Montgomery-Åsberg Depression Rating Scale scores revealed that 70% of participants experienced 50% or greater reduction in their depression symptoms within 1 day of receiving ketamine. LTP was demonstrated in the N1 (p = .00002) and P2 (p = 2.31 × 10-11) visually evoked components. Ketamine specifically enhanced P2 potentiation compared with placebo (p = .017). Dynamic causal modeling replicated the recruitment of forward and intrinsic connections for visual LTP and showed complementary effects of ketamine indicative of downstream and proplasticity modulation.
Conclusions: This study provides evidence that LTP-based neural plasticity increases within the time frame of the antidepressant effects of ketamine in humans and supports the hypothesis that changes to neural plasticity may be key to the antidepressant properties of ketamine.
Sumner, R. L., McMillan, R., Spriggs, M. J., Campbell, D., Malpas, G., Maxwell, E., Deng, C., Hay, J., Ponton, R., Kirk, I. J., Sundram, F., & Muthukumaraswamy, S. D. (2020). Ketamine Enhances Visual Sensory Evoked Potential Long-term Potentiation in Patients With Major Depressive Disorder. Biological psychiatry. Cognitive neuroscience and neuroimaging, 5(1), 45–55. https://doi.org/10.1016/j.bpsc.2019.07.002