Due to unmet clinical needs for efficient drugs with a rapid onset of antidepressant effects, we aimed to evaluate the efficacy of single-dose ketamine in different subgroups of patients with major depression and establish whether repeated ketamine administration could be a viable strategy to maintain treatment gains.
As interest has grown in the potential psychiatric applications of ketamine, the number of registered clinical trials has grown substantially. Herein, we summarize and analyze clinical trials registered with ClinicalTrials.gov that assess the treatment of any psychiatric disorder with ketamine or ketamine enantiomers (e.g., S-ketamine, R-ketamine), with a focus on ongoing clinical trials. A ClinicalTrials.gov search on February 2020 returned 140 registered trials. Frequency data was analyzed to determine the distribution of study designs. The majority of trials (70%) investigated the therapeutic effect of ketamine in mood disorders (unipolar: 60%, bipolar: 0.7%, both:5.7%). Suicidal ideation (13.1%), post-traumatic stress disorder (5.4%), and obsessive-compulsive disorder (3.6%) were also investigated. Intravenous (IV) administration was the most common route with 87% of the studies using IV ketamine. Single-dose studies represented 50% of IV ketamine studies. Few studies were assessing maintenance treatment. Most studies were phase I or II with few definitive phase III trials registered. Given the large number of ongoing studies assessing psychiatric application of ketamine, researchers and relevant stakeholders should consider not only completed, published studies, but also ongoing registered studies in adjudicating the most relevant research questions. More definitive phase III trials and maintenance studies of IV ketamine for mood disorders are required, as numerous completed and ongoing studies have already assessed and demonstrated the proof-of-concept of acute antidepressant effects in phase I and II trials.
After a legally mandated, decades-long global arrest of research on psychedelic drugs, investigation of psychedelics in the context of psychiatric disorders is yielding exciting results. Outcomes of neuroscience and clinical research into 5-Hydroxytryptamine 2A (5-HT2A) receptor agonists, such as psilocybin, show promise for addressing a range of serious disorders, including depression and addiction.
Maladaptive reward memories (MRMs) are involved in the development and maintenance of acquired overconsumption disorders, such as harmful alcohol and drug use. The process of memory reconsolidation - where stored memories become briefly labile upon retrieval - may offer a means to disrupt MRMs and prevent relapse. However, reliable means for pharmacologically weakening MRMs in humans remain elusive. Here we demonstrate that the N-methyl D-aspartate (NMDA) antagonist ketamine is able to disrupt MRMs in hazardous drinkers when administered immediately after their retrieval. MRM retrieval + ketamine (RET + KET) effectively reduced the reinforcing effects of alcohol and long-term drinking levels, compared to ketamine or retrieval alone. Blood concentrations of ketamine and its metabolites during the critical ‘reconsolidation window’ predicted beneficial changes only following MRM reactivation. Pharmacological reconsolidation interference may provide a means to rapidly rewrite maladaptive memory and should be further pursued in alcohol and drug use disorders.
In major depression, remission rate in response to monoaminergic antidepressant is around 50%. The lack of strong synergies between classical antidepressants and psychotherapy may be due to the molecular effects of classical antidepressants. They modulate synapses but they do not substantially influence synaptogenesis. They also increase brain-derived neurotrophic factor (BDNF). However, for activity-dependent plasticity, BDNF release has to work in concert with activation of synaptogenesis. There has been considerable excitement about ketamine’s antidepressant effect. Ketamine leads to fast changes in synaptic function and plasticity that go well beyond effects of classical antidepressants. As a result, ketamine may turn out to have the capacity to considerably enhance the effects of psychotherapy. Such enhancing effects may become an important clinical indication for ketamine since its purely pharmacological effect is transient. This editorial outlines some mechanistic hypotheses, how Behavioral Activation, Trauma-Focused Psychotherapies and Humanistic Psychotherapy may specifically prolong ketamine’s antidepressant effects.
Currently, ketamine is the only legal psychedelic medicine available to mental health providers for the treatment of emotional suffering. Over the past several years, ketamine has come into psychiatric use as an intervention for treatment resistant depression (TRD), administered intravenously without a psychotherapeutic component. In these settings, ketamine’s psychedelic effects are viewed as undesirable “side effects.” In contrast, we believe ketamine can benefit patients with a wide variety of diagnoses when administered with psychotherapy and using its psychedelic properties without need for intravenous (IV) access. Its proven safety over decades of use makes it ideal for office and supervised at-home use. The unique experience that ketamine facilitates with its biological, experiential, and psychological impacts has been tailored to optimize office-based treatment evolving into a method that we call Ketamine Assisted Psychotherapy (KAP). This article is the first to explore KAP within an analytical framework examining three distinct practices that use similar methods. Here, we present demographic and outcome data from 235 patients. Our findings suggest that KAP is an effective method for decreasing depression and anxiety in a private practice setting, especially for older patients and those with severe symptom burden.
By now, everyone knows that medication development for mental disorders has hit a wall, pharmaceutical companies have abandoned the search for new medications, and there are no promising new medications on the horizon.1 So it is important to take a moment to consider ketamine, an anesthetic that has been around for decades. Intravenous ketamine was the anesthetic of choice for outpatient procedures in children when I was in medical training nearly 40 years ago. Twenty years ago ketamine achieved notoriety as a recreational drug under the moniker “Special K.” But in the past decade, ketamine has emerged as a potential antidepressant.