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Therapeutic Application

Capturing the different health conditions that PAP may adress

Towards new mechanisms: an update on therapeutics for treatment-resistant major depressive disorder

July 7, 2015 / Depressive Disorders, Neuroscience, Papers, Psychology, Publications / By / ,

Abstract

Depression is a devastating disorder that places a significant burden on both the individual and society. As such, the discovery of novel therapeutics and innovative treatments—especially for treatment-resistant depression (TRD)—are essential. Research into antidepressant therapies for TRD has evolved from explorations of antidepressants with primary mechanisms of action on the monoaminergic neurotransmitter system to augmentation agents with primary mechanisms both within and outside of the serotonin/norepinephrine system. Now the field of antidepressant research has changed trajectories yet again; this time, compounds with primary mechanisms of action on the glutamatergic, cholinergic and opioid systems are in the forefront of antidepressant exploration. In this review, we will discuss the most recent research surrounding these novel compounds. In addition, we will discuss novel device-based therapeutics, with a particular focus on transcranial magnetic stimulation. In many cases of antidepressant drug discovery, the role of serendipity coupled with meticulous clinical observation in drug development in medicine was crucial. Moving forward, we must look toward the combination of innovation plus improvements on the remarkable discoveries thus far to advance the field of antidepressant research.

Papakostas, G. I., & Ionescu, D. F. (2015). Towards new mechanisms: an update on therapeutics for treatment-resistant major depressive disorder. Molecular psychiatry. https://dx.doi.org/10.1038/mp.2015.92
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Perceptual distortions and delusional thinking following ketamine administration are related to increased pharmacological MRI signal changes in the parietal lobe

July 6, 2015 / Ketamine, Neuroscience, Papers, Psychology, Psychotic Disorders, Publications / By / , , , , ,

Abstract

Ketamine produces effects in healthy humans that resemble the positive, negative and cognitive symptoms of schizophrenia. We investigated the effect of ketamine administration on brain activity as indexed by blood-oxygen-level-dependent (BOLD) signal change response, and its relationship to ketamine-induced subjective changes, including perceptual distortion. Thirteen healthy participants volunteered for the study. All underwent a 15-min functional MRI acquisition with a ketamine infusion commencing after 5 min (approx 0.26 mg/kg over 20s followed by an infusion of approx. 0.42 mg/kg/h). Following the scan, participants self-rated ketamine-induced effects using the Psychotomimetic States Inventory. Ketamine led to widespread cortical and subcortical increases in BOLD response (FWE-corrected p < 0.01). Self-rated perceptual distortions and delusional thoughts correlated with increased BOLD response in the paracentral lobule (FWE-corrected p < 0.01). The findings suggest that BOLD increases in parietal cortices reflect ketamine effects on circuits that contribute to its capacity to produce perceptual alterations and delusional interpretations.

Stone, J., Kotoula, V., Dietrich, C., De Simoni, S., Krystal, J. H., & Mehta, M. A. (2015). Perceptual distortions and delusional thinking following ketamine administration are related to increased pharmacological MRI signal changes in the parietal lobe. Journal of Psychopharmacology, 0269881115592337. https://dx.doi.org/10.1177/0269881115592337
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Ketamine and Other NMDA Antagonists: Early Clinical Trials and Possible Mechanisms in Depression

June 29, 2015 / Depressive Disorders, Ketamine, Papers, Psychology, Publications, Substance Use Disorder / By / , , , , ,

Abstract

Objective The authors conducted a systematic review and meta-analysis of ketamine and other N-methyl-d-aspartate (NMDA) receptor antagonists in the treatment of major depression.

Method Searches of MEDLINE, PsycINFO, and other databases were conducted for placebo-controlled, double-blind, randomized clinical trials of NMDA antagonists in the treatment of depression. Primary outcomes were rates of treatment response and transient remission of symptoms. Secondary outcomes included change in depression symptom severity and the frequency and severity of dissociative and psychotomimetic effects. Results for each NMDA antagonist were combined in meta-analyses, reporting odds ratios for dichotomous outcomes and standardized mean differences for continuous outcomes.

Results Ketamine (seven trials encompassing 147 ketamine-treated participants) produced a rapid, yet transient, antidepressant effect, with odds ratios for response and transient remission of symptoms at 24 hours equaling 9.87 (4.37–22.29) and 14.47 (2.67–78.49), respectively, accompanied by brief psychotomimetic and dissociative effects. Ketamine augmentation of ECT (five trials encompassing 89 ketamine-treated participants) significantly reduced depressive symptoms following an initial treatment (Hedges’ g=0.933) but not at the conclusion of the ECT course. Other NMDA antagonists failed to consistently demonstrate efficacy; however, two partial agonists at the NMDA coagonist site, d-cycloserine and rapastinel, significantly reduced depressive symptoms without psychotomimetic or dissociative effects.

Conclusions The antidepressant efficacy of ketamine, and perhaps D-cycloserine and rapastinel, holds promise for future glutamate-modulating strategies; however, the ineffectiveness of other NMDA antagonists suggests that any forthcoming advances will depend on improving our understanding of ketamine’s mechanism of action. The fleeting nature of ketamine’s therapeutic benefit, coupled with its potential for abuse and neurotoxicity, suggest that its use in the clinical setting warrants caution.

Newport, D. J., Carpenter, L. L., McDonald, W. M., Potash, J. B., Tohen, M., & Nemeroff, C. B. (2015). Ketamine and Other NMDA Antagonists: Early Clinical Trials and Possible Mechanisms in Depression. American Journal of Psychiatry, 172(10), 950-966. http://dx.doi.org/10.1176/appi.ajp.2015.15040465

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Assessing measures of suicidal ideation in clinical trials with a rapid-acting antidepressant

June 16, 2015 / Depressive Disorders, Ketamine, Papers, Psychology, Publications / By / , , , , , ,

Abstract

Rapid reduction of suicidal thoughts is critical for treating suicidal patients. Clinical trials evaluating these treatments require appropriate measurement. Key methodological issues include: 1) the use of single or multi-item assessments, and 2) evaluating whether suicidal ideation measures can track rapid change over time. The current study presents data from two randomized, placebo-controlled, crossover clinical trials evaluating ketamine in individuals with treatment-resistant depression (n = 60). Participants were assessed for suicidal thoughts using the Hamilton Depression Rating Scale (HAM-D), Montgomery-Asberg Depression Rating Scale (MADRS), Beck Depression Inventory (BDI), and Scale for Suicidal Ideation (SSI) at eight time points over three days. Assessments were compared using correlational analyses and effect sizes at 230 min and three days after ketamine infusion. Linear mixed models evaluated change in ideation across all time points. The HAM-D and MADRS suicide items demonstrated correlations of r > .80 with the first five items of the SSI (SSI5). On linear mixed models, an effect for ketamine was found for the HAM-D, MADRS, BDI items, and SSI5 (p < .001), but not for the full SSI (p = .88), which suggests a limited ability to assess change over time in patients with low levels of suicidal thoughts. Taken together, the results suggest that repeated suicidal assessments over minutes to days appear to detect improvement in suicidal thoughts after ketamine infusion compared to placebo. The MADRS suicide item, BDI suicide item, and SSI5 may be particularly sensitive to rapid changes in suicidal thoughts.

Ballard, E. D., Luckenbaugh, D. A., Richards, E. M., Walls, T. L., Brutsché, N. E., Ameli, R., … & Zarate, C. A. (2015). Assessing measures of suicidal ideation in clinical trials with a rapid-acting antidepressant. Journal of psychiatric research, 68, 68-73. dx.doi.org/10.1016/j.jpsychires.2015.06.003
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Antidepressant drug action – From rapid changes on network function to network rewiring

June 9, 2015 / Depressive Disorders, Ketamine, Neuroscience, Papers, Psychology, Publications / By / ,

Abstract

There has been significant recent progress in understanding the neurobiological mechanisms of antidepressant treatments. The delayed-onset of action of monoamine-based antidepressant drugs have been linked to their ability to slowly increase synaptic plasticity and neuronal excitability via altering neurotrophic signaling (synthesis of BDNF and activation of its receptor TrkB), dematuration of GABAergic interneurons and inhibition of “breaks of plasticity”. On the other hand, antidepressants rapidly regulate emotional processing that – with the help of heightened plasticity and appropriate rehabilitation – gradually lead to significant changes on functional neuronal connectivity and clinical recovery. Moreover, the discovery of rapid-acting antidepressants, most notably ketamine, has inspired renewed interest for novel antidepressant developments with better efficacy and faster onset of action. Therapeutic effects of rapid-acting antidepressants have been linked with their ability to rapidly regulate neuronal excitability and thereby increase synaptic translation and release of BDNF, activation of the TrkB-mTOR-p70S6k signaling pathway and increased synaptogenesis within the prefrontal cortex. Thus, alterations in TrkB signaling, synaptic plasticity and neuronal excitability are shared neurobiological phenomena implicated in antidepressant responses produced by both gradually and rapid acting antidepressants. However, regardless of antidepressant, their therapeutic effects are not permanent which suggests that their effects on neuronal connectivity and network function remain unstable and vulnerable for psychosocial challenges.

Rantamäki, T., & Yalcin, I. (2015). Antidepressant drug action–from rapid changes on network function to network rewiring. Progress in Neuro-Psychopharmacology and Biological Psychiatry. https://dx.doi.org/10.1016/j.pnpbp.2015.06.001
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In vivo effects of ketamine on glutamate-glutamine and gamma-aminobutyric acid in obsessive-compulsive disorder: Proof of concept

June 6, 2015 / Anxiety Disorders / PTSD, Ketamine, Neuroscience, Papers, Psychology, Publications / By / , , , , ,

Abstract

We previously reported the rapid and robust clinical effects of ketamine versus saline infusions in a proof-of-concept crossover trial in unmedicated adults with obsessive-compulsive disorder (OCD). This study examined the concurrent neurochemical effects of ketamine versus saline infusions using proton magnetic resonance spectroscopy (H MRS) during the clinical proof-of-concept crossover trial. Levels of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) and the excitatory neurochemicals glutamate+glutamine (Glx) were acquired in the medial prefrontal cortex (MPFC), a region implicated in OCD pathology. Seventeen unmedicated OCD adults received two intravenous infusions at least 1 week apart, one of saline and one of ketamine, while lying supine in a 3.0 T GE MR scanner. The order of each infusion pair was randomized. Levels of GABA and Glx were measured in the MPFC before, during, and after each infusion and normalized to water (W). A mixed effects model found that MPFC GABA/W significantly increased over time in the ketamine compared with the saline infusion. In contrast, there were no significant differences in Glx/W between the ketamine and saline infusions. Together with earlier evidence of low cortical GABA in OCD, our findings suggest that models of OCD pathology should consider the role of GABAergic abnormalities in OCD symptomatology.

Rodriguez, C. I., Kegeles, L. S., Levinson, A., Ogden, R. T., Mao, X., Milak, M. S., … & Simpson, H. B. (2015). In vivo effects of ketamine on glutamate-glutamine and gamma-aminobutyric acid in obsessive-compulsive disorder: Proof of concept. Psychiatry Research: Neuroimaging. http://dx.doi.org/10.1016/j.pscychresns.2015.06.001
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The use of ketamine for the treatment of depression in the context of psychotic symptoms

June 4, 2015 / Depressive Disorders, Ketamine, Papers, Psychology, Psychotic Disorders, Publications / By / , , ,

Abstract

Mounting evidence from a series of small clinical trials and case series suggests ketamine can have rapid and robust antidepressant(1), and possibly anti-suicidal effects(2) in patients who had not responded to standard treatment options. However, due to ketamine’s variable psychotomimetic effects in healthy volunteers and exacerbation of previously experienced positive symptoms in schizophrenic volunteers(3,4), patients previously experiencing psychotic features have been excluded from the reported studies and trials.

da Frota Ribeiro, C. M., Sanacora, G., Hoffman, R., & Ostroff, R. (2015). The use of ketamine for the treatment of depression in the context of psychotic symptoms. Biological Psychiatry. http://dx.doi.org/10.1016/j.biopsych.2015.05.016
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MDMA for the treatment of mood disorder: all talk no substance?

June 1, 2015 / Depressive Disorders, MDMA, Papers, Psychology, Publications / By / ,

Abstract

BACKGROUND:

Unipolar depression is the third highest contributor to the global burden of disease, yet current pharmacotherapies typically take about 6 weeks to have an effect. A rapid-onset agent is an attractive prospect, not only to alleviate symptoms before first-line antidepressants display therapeutic action, but as a further treatment option in nonresponsive cases. It has been suggested that 3,4-methylene-dioxymethamphetamine (MDMA) could play a part in the treatment of depression, either as a rapid-onset pharmacological agent or as an adjunct to psychotherapy. Whilst these hypotheses are in keeping with the monoamine theory of depression and the principles surrounding psychotherapy, explicit experimental evidence of an antidepressant effect of MDMA has rarely been established.

AIMS:

To address the hypothesis surrounding MDMA as a rapid-onset antidepressant by examining pharmacological, psychological and behavioural studies. We consider whether this therapy could be safe by looking at the translation of neurotoxicity data from animals to humans.

METHOD:

A literature review of the evidence supporting this hypothesis was performed.

CONCLUSIONS:

The pharmacology of MDMA offers a promising target as a rapid-onset agent and MDMA is currently being investigated for use in psychotherapy in anxiety disorders; translation from these studies for use in depression may be possible. However, experimental evidence and safety analysis are insufficient to confirm or reject this theory at present.

Patel, R., & Titheradge, D. (2015). MDMA for the treatment of mood disorder: all talk no substance?. Therapeutic Advances in Psychopharmacology, 2045125315583786. https://dx.doi.org/10.1177/2045125315583786
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Single-Dose ketamine followed by daily D-Cycloserine in treatment-resistant bipolar depression

June 1, 2015 / Depressive Disorders, Ketamine, Neuroscience, Papers, Psychology, Publications / By / , ,

Abstract

Bipolar depression is a leading cause of disability in the United States. Recently, N-methyl-D-asparate glutamate-receptor (NMDAR) antagonists, such as ketamine, have been shown to induce remission in bipolar depression. Nevertheless, ketamine use is limited by transient effects and psychogenic potential during repeated administration.

Kantrowitz, J. T., Halberstam, B., & Gangwisch, J. (2015). Single-Dose ketamine followed by daily D-Cycloserine in treatment-resistant bipolar depression. The Journal of clinical psychiatry, 76(6), 737-738. https://dx.doi.org/10.4088/JCP.14l09527
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The positive effect on ketamine as a priming adjuvant in antidepressant treatment.

May 26, 2015 / Depressive Disorders, Ketamine, Papers, Psychology, Publications / By / , , , , , ,

Abstract

Ketamine is an anesthetic with antidepressant properties. The rapid and lasting effect of ketamine observed in preclinical and clinical research makes it a promising therapeutic to improve current major depression (MD) treatment. Our work intended to evaluate whether the combined use of classic antidepressants (imipramine or fluoxetine) and ketamine would improve the antidepressant response. Using an animal model of depressive-like behavior, we show that the addition of ketamine to antidepressants anticipates the behavioral response and accelerates the neuroplastic events when compared with the use of antidepressants alone. In conclusion, our results suggest the need for a reappraisal of the current pharmacological treatment of MD.

Melo, A., Kokras, N., Dalla, C., Ferreira, C., Ventura-Silva, A. P., Sousa, N., & Pêgo, J. M. (2015). The positive effect on ketamine as a priming adjuvant in antidepressant treatment. Translational Psychiatry, 5(5), e573. https://dx.doi.org/10.1038/tp.2015.66
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