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Psychiatry

Ketamine-A Narrative Review of Its Uses in Medicine

April 24, 2015 / Anxiety disorders / PTSD, Ketamine, Medicine, Neuroscience, Papers, Psychiatry, Psychology, Psychopharmacology, Psychotherapy, Publications, Safety, Toxicology / By / , , , ,

Abstract

One of the most fascinating drugs in the anesthesiologist’s armament is ketamine, an N-methyl-D-aspartate receptor antagonist with a myriad of uses. The drug is a dissociative anesthetic and has been used more often as an analgesic in numerous hospital units, outpatient pain clinics, and in the prehospital realm. It has been used to treat postoperative pain, chronic pain, complex regional pain syndrome, phantom limb pain, and other neuropathic conditions requiring analgesia. Research has also demonstrated its efficacy as an adjunct in psychotherapy, as a treatment for both depression and posttraumatic stress disorder, as a procedural sedative, and as a treatment for respiratory and neurologic conditions. Ketamine is not without its adverse effects, some of which can be mitigated with certain efforts. Such effects make it necessary for the clinician to use the drug only in situations where it will provide the greatest benefit with the fewest adverse effects. To the best of our knowledge, none of the reviews regarding ketamine have taken a comprehensive look at the drug’s uses in all territories of medicine. This review will serve to touch on its chemical data, pharmacokinetics and pharmacodynamics, medical uses, and adverse effects while focusing specifically on the drugs usage in anesthesia and analgesia.

Radvansky, B. M., Puri, S., Sifonios, A. N., Eloy, J. D., & Le, V. (2015). Ketamine-A Narrative Review of Its Uses in Medicine. American journal of therapeutics. https://dx.doi.org/10.1097/MJT.0000000000000257
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Ketamine-induced modulation of the thalamo-cortical network in healthy volunteers as a model for schizophrenia

April 20, 2015 / Ketamine, Neuroscience, Papers, Psychiatry, Psychology, Psychopharmacology, Psychosis, Publications / By / , , , , , ,

Abstract

BACKGROUND:

Schizophrenia has been associated with disturbances of thalamic functioning. In the light of recent evidence suggesting a significant impact of the glutamatergic system on key symptoms of schizophrenia, we assessed whether the modulation of the glutamatergic system via blockage of the NMDA-receptor might lead to changes of thalamic functional connectivity.

METHODS:

Based on the “ketamine-model” of psychosis we investigated changes in cortico-thalamic functional connectivity by intravenous ketamine challenge during a 55 minutes resting-state scan. 30 healthy volunteers were measured with pharmacological functional magnetic resonance imaging (fMRI) using a double-blind, randomized, placebo-controlled, crossover design.

RESULTS:

Functional connectivity analysis revealed significant ketamine-specific changes within the “thalamus hub network”, more precisely an increase of cortico-thalamic connectivity of the somatosensory and temporal cortex.

CONCLUSIONS:

Our results indicate that changes of thalamic functioning as described for schizophrenia can be partly mimicked by NMDA-receptor blockage. This adds substantial knowledge about the neurobiological mechanisms underlying the profound changes of perception and behaviour during the application of NMDA-receptor antagonists.

Höflich, A., Hahn, A., Küblböck, M., Kranz, G. S., Vanicek, T., Windischberger, C., … & Guertel, W. (2015). Ketamine-induced modulation of the thalamo-cortical network in healthy volunteers as a model for schizophrenia. The international journal of neuropsychopharmacology. http://dx.doi.org/10.1093/ijnp/pyv040
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Mania following use of ibogaine: A case series

April 14, 2015 / Depression, Iboga / Ibogaine, Papers, Psychiatry, Psychology, Psychopharmacology, Publications, Safety, Substance Use Disorder / By / , , ,

Abstract

BACKGROUND:

Ibogaine is a naturally occurring hallucinogen with postulated anti-addictive qualities. While illegal domestically, a growing number of individuals have sought it out for treatment of opiate dependence, primarily in poorly regulated overseas clinics. Existing serious adverse events include cardiac and vestibular toxicity, though ours is the first report of mania stemming from its use.

OBJECTIVES:

To report on a case series of psychiatric emergency room patients whose unregulated use of ibogaine resulted in mania in three patients with no prior diagnosis of bipolar illness.

METHODS:

Review and summarize charts of three cases. Relevant literature was also reviewed for discussion.

RESULTS:

Two cases of reported ibogaine ingestion for self-treatment of addictions, and one for psycho-spiritual experimentation resulted in symptoms consistent with mania. No prior reports of mania were found in the literature, and the literature suggests growing popularity of ibogaine’s use.

CONCLUSIONS:

The three cases presented demonstrate a temporal association between ibogaine ingestion and subsequent development of mania.

SCIENTIFIC SIGNIFICANCE:

In light of these cases, clinicians faced with a new onset mania may benefit from careful substance use and treatment history, specifically regarding opiates. In the vulnerable and often desperate addiction population, in particular, the number of patients seeking this treatment appears to be growing. We advise clinicians to be prepared for discussing the safety, efficacy, and paucity of good data regarding ibogaine with patients who may be considering its use.

Marta, C. J., Ryan, W. C., Kopelowicz, A., & Koek, R. J. (2015). Mania following use of ibogaine: A case series. The American Journal on Addictions. https://dx.doi.org/10.1111/ajad.12209
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Ketamine and other N-methyl-D-aspartate receptor antagonists in the treatment of depression: a perspective review

April 13, 2015 / Depression, Ketamine, Other substances, Papers, Psychiatry, Psychology, Psychopharmacology, Publications / By / , , , , , ,

Abstract

Current pharmacotherapies for major depressive disorder (MDD) and bipolar depression (BDep) have a distinct lag of onset that can generate great distress and impairment in patients. Furthermore, as demonstrated by several real-world effectiveness trials, their efficacy is limited. All approved antidepressant medications for MDD primarily act through monoaminergic mechanisms, agonists or antagonists with varying affinities for serotonin, norepinephrine and dopamine. The glutamate system has received much attention in recent years as an avenue for developing novel therapeutics. A single subanesthetic dose infusion of the noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist ketamine has been shown to have rapid and potent antidepressant effects in treatment-resistant MDD and BDep. In a reverse translational framework, ketamine’s clinical efficacy has inspired many preclinical studies to explore glutamatergic mechanisms of antidepressant action. These studies have revealed enhanced synaptic plasticity/synaptogenesis via numerous molecular and cellular mechanisms: release of local translational inhibition of brain-derived neurotrophic factor and secretion from dendritic spines, mammalian target of rapamycin activation and glycogen synthase kinase-3 inhibition. Current efforts are focused on extending ketamine’s antidepressant efficacy, uncovering the neurobiological mechanisms responsible for ketamine’s antidepressant activity in biologically enriched subgroups, and identifying treatment response biomarkers to personalize antidepressant selection. Other NMDA receptor antagonists have been studied both preclinically and clinically, which have revealed relatively modest antidepressant effects compared with ketamine but potentially other favorable characteristics, for example, decreased dissociative or psychotomimetic effects; therefore, there is great interest in developing novel glutamatergic antidepressants with greater target specificity and/or decreased adverse effects.

Iadarola, N. D., Niciu, M. J., Richards, E. M., Voort, J. L. V., Ballard, E. D., Lundin, N. B., … & Zarate, C. A. (2015). Ketamine and other N-methyl-D-aspartate receptor antagonists in the treatment of depression: a perspective review. Therapeutic Advances in Chronic Disease. https://dx.doi.org/10.1177/2040622315579059
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The use of ketamine as an antidepressant: a systematic review and meta-analysis

April 7, 2015 / Depression, Ketamine, Papers, Psychiatry, Psychology, Psychopharmacology, Publications / By / ,

Abstract

Objective

The current meta-analysis examines the effects of ketamine infusion on depressive symptoms over time in major depressive disorder (MDD) and bipolar disorder (BD).

Methods

Following a systematic review of the literature, data were extracted from 21 studies (n  = 437 receiving ketamine) and analysed at four post-infusion time points (4 h, 24 h, 7 days and 12–14 days). The moderating effects of several factors were assessed including: repeat/single infusion, diagnosis, open-label/participant-blind infusion, pre–post/placebo-controlled design and the sex of patients.

Results

Effect sizes were significantly larger for repeat than single infusion at 4 h, 24 h and 7 days. For single infusion studies, effect sizes were large and significant at 4 h, 24 h and 7 days. The percentage of males was a predictor of antidepressant response at 7 days. Effect sizes for open-label and participant-blind infusions were not significantly different at any time point.

Conclusions

Single ketamine infusions elicit a significant antidepressant effect from 4 h to 7 days; the small number of studies at 12–14 days post infusion failed to reach significance. Results suggest a discrepancy in peak response time depending upon primary diagnosis — 24 h for MDD and 7 days for BD. The majority of published studies have used pre–post comparison; further placebo-controlled studies would help to clarify the effect of ketamine over time.

Coyle, C. M., & Laws, K. R. (2015). The use of ketamine as an antidepressant: a systematic review and meta‐analysis. Human Psychopharmacology: Clinical and Experimental, 30(3), 152-163. https://dx.doi.org/10.1002/hup.2475
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Protecting the human rights of people who use psychedelics

April 1, 2015 / LSD, Mushrooms / Psilocybin, Other disciplines, Other subjects, Papers, Psychiatry, Psychology, Psychopharmacology, Publications / By /

Summary

In a recent Comment Ben Sessa1 explained how the War on the Drugs worldwide has impeded development of psychiatric treatment with psychedelics such as LSD (lysergic acid diethylamide) and psilocybin (found in magic mushrooms). Prohibition also had negative outcomes for the millions of individuals who find it worthwhile to use psychedelics in various cultural settings outside of those in the clinic.

Krebs, T. S. (2015). Protecting the human rights of people who use psychedelics. The Lancet, 2(4), 294.295. http://dx.doi.org/10.1016/S2215-0366(15)00084-X
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Current knowledge on the neurobiology of classical hallucinogens and their relevance for the treatment of mood and anxiety disorders

March 28, 2015 / Anxiety disorders / PTSD, Depression, Mushrooms / Psilocybin, Papers, Psychiatry, Psychology, Psychopharmacology, Publications / By /

Abstract

Hallucinogenic substances have been used for millenia. Still, the scientific investigation into the effects and mechanisms of classical hallucinogens in humans has only commenced with the discovery of LSD by Albert Hofmann in 1943. In the 1960’s, there were more than a thousand clinical studies that reported promising therapeutic effects of LSD and psilocybin in psychiatric patients. Only recently, however, the neuropharmacological and neurobiological underpinnings of hallucinogenic drugs have undergone systematic investigations. Despite having different chemical structures, classical hallucinogens produce striking similar subjective and behavioral effects in both animals and humans. Activation of the serotonin 2A (5-HT2A) receptor is a core feature in hallucinogenic pharmacology. Recent neuroimaging studies have begun to elucidate the brain mechanisms underlying hallucinogen-induced changes of thought, perception, and mood. Among the many networks involved in hallucinogen-related states of consciousness, the prefrontal cortex and the limbic regions appear to be especially relevant to the putative antidepressant effects of classical hallucinogens. Furthermore, hallucinogens may foster neuroplastic adaptations within cortico-subcortical brain networks. This appears to be a promising mechanism with regard to future clinical studies into the effects of classical hallucinogens in depression and anxiety.

Kraehenmann, R. (2015). The Effect of Serotonin Receptor Manipulation On Brain Networks and Its Impact On Emotion Regulation. European Psychiatry, 30, 21. http://dx.doi.org/10.1016/S0924-9338(15)30016-X
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5HT2a Receptors – a New Target for Depression?

March 28, 2015 / Depression, LSD, Mushrooms / Psilocybin, Papers, Psychiatry, Psychology, Psychopharmacology, Publications / By /

Abstract

Cortical 5HT2A receptors are largely expressed in layer 5 pyramidal neurons and appear to play a pivotal role in brain function in that they gate top-down descending inputs to local cortical microcircuits. There is evidence that they may play a role in depression in that the number of these receptors is increased in some people with depression and the augmenting action of atypical antipsychotics in depression is thought to be – at least in part – due to blockade of these receptors. We have explored this possibility by studying the effects of agonists at these receptors – the psychedelic drugs psilocybin and LSD. We found they had profound effects to reduce brain activity particularly in regions that higly express the 5HT2A receptor such as the default mode network [DMN]. As this region is overactive in depression this may explain the improvements in mood that users of psychedelic often report. Based on these findings a study of psilocybin in resistant depression has been funded by the UK MRC and will start in early 2015.

Nutt, D. (2015). 5HT2a Receptors–a New Target for Depression? European Psychiatry, 30, 35. http://dx.doi.org/10.1016/S0924-9338(15)30027-4
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The Effect of 5-HT2A/1a Agonist Treatment On Social Cognition, Empathy, and Social Decision-making

March 28, 2015 / Anxiety disorders / PTSD, Depression, Mushrooms / Psilocybin, Papers, Psychiatry, Psychology, Psychopharmacology, Publications / By / , , , , ,

Abstract

Social cognition is a crucial factor influencing development, progress, and treatment of psychiatric disorders. However, social cognition skills are insufficiently targeted by current treatment approaches. In particular, patients suffering from depression show an increased negative reaction to social exclusion and deficits in empathy. The 5HT-1A/2A receptor agonist psilocybin has previously been shown to reduce the neural response to negative emotional stimuli. However, it is not known if this extends to negative social interaction and whether 5HT-1A/2A receptor stimulation induces changes in empathy. Given the clear need for improved treatment of socio-cognitive functioning in psychiatric disorders, it is important to better understand the neuronal and neuromodulatory substrates of social cognition.

In a double-blind, randomized, cross-over design we therefore investigated the neural response to ostracism after the acute administration of psilocybin (0.215mg/kg) and placebo in healthy volunteers using fMRI. Furthermore, we assessed cognitive and emotional empathy using the Multifaceted Empathy Test.

The neural response to social exclusion in the ACC – a brain region associated with ‘social pain”- was reduced after psilocybin administration compared to placebo. Furthermore, emotional empathy was enhanced after treatment with psilocybin while no significant differences were found in cognitive empathy.

These results show that the 5HT-1A/2A receptor subtypes play an important role in the modulation of socio-cognitive functioning and therefore may be relevant for the treatment of social cognition deficits in psychiatric disorders. In particular, they may be important for the normalization of empathy deficits and increased negative reaction to social exclusion in depressed patients.

Preller, K. H., Pokorny, T., Krähenmann, R., Dziobek, I., Stämpfli, P., & Vollenweider, F. X. (2015). The Effect of 5-HT2A/1a Agonist Treatment On Social Cognition, Empathy, and Social Decision-making. European Psychiatry, 30, 22. http://dx.doi.org/10.1016/S0924-9338(15)30017-1
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MDMA-assisted therapy: A new treatment model for social anxiety in autistic adults

March 25, 2015 / Anxiety disorders / PTSD, MDMA, Papers, Psychiatry, Psychology, Psychopharmacology, Psychotherapy, Publications, Safety / By / , , ,

Abstract

The first study of 3,4-methylenedioxymethamphetamine (MDMA)-assisted therapy for the treatment of social anxiety in autistic adults commenced in the spring of 2014. The search for psychotherapeutic options for autistic individuals is imperative considering the lack of effective conventional treatments for mental health diagnoses that are common in this population. Serious Adverse Events (SAEs) involving the administration of MDMA in clinical trials have been rare and non-life threatening. To date, MDMA has been administered to over 1133 individuals for research purposes without the occurrence of unexpected drug-related SAEs that require expedited reporting per FDA regulations. Now that safety parameters for limited use of MDMA in clinical settings have been established, a case can be made to further develop MDMA-assisted therapeutic interventions that could support autistic adults in increasing social adaptability among the typically developing population. As in the case with classic hallucinogens and other psychedelic drugs, MDMA catalyzes shifts toward openness and introspection that do not require ongoing administration to achieve lasting benefits. This infrequent dosing mitigates adverse event frequency and improves the risk/benefit ratio of MDMA, which may provide a significant advantage over medications that require daily dosing. Consequently, clinicians could employ new treatment models for social anxiety or similar types of distress administering MDMA on one to several occasions within the context of a supportive and integrative psychotherapy protocol.

Danforth, A. L., Struble, C. M., Yazar-Klosinski, B., & Grob, C. S. (2015). MDMA-Assisted Therapy: A New Treatment Paradigm for Autistic Adults with Social Anxiety. Progress in Neuro-Psychopharmacology and Biological Psychiatry. http://dx.doi.org/10.1016/j.pnpbp.2015.03.011
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