The National Institute of Mental Health Highlights Ketamine for Depression

The National Institute of Mental Health (NIMH) issued a highlight on ketamine for treating depression.

The most commonly used antidepressants are largely variations on a theme; they increase the supply within synapses of a class of neurotransmitters believed to play a role in depression. While these drugs relieve depression for some, there is a weeks-long delay before they take effect, and some people with “treatment-resistant” depression do not respond at all.

The delay in effectiveness has suggested to scientists that the medication-induced changes in neurotransmitters are several steps away from processes more central to the root cause of depression. One possibility for a more proximal mechanism is glutamate, the primary excitatory, or activating, neurotransmitter in the brain. Preliminary studies suggested that inhibitors of glutamate could have antidepressant-like effects, and in a seminal clinical trial, the drug ketamine—which dampens glutamate signaling—lifted depression in as little as 2 hours in people with treatment-resistant depression.34

The discovery of rapidly acting antidepressants has transformed our expectations—we now look for treatments that will work in 6 hours rather than 6 weeks. But ketamine has some disadvantages; it has to be administered intravenously, the effects are transient, and it has side effects that require careful monitoring. However, results from clinical studies have confirmed the potential of the glutamate pathway as a target for the development of new antidepressants. Continuing research with ketamine has provided information on biomarkers that could be used to predict who will respond to treatment.35 Clinical studies are also testing analogs of ketamine in an effort to develop glutamate inhibitors without ketamine’s side effects that can then be used in the clinic.36 Ketamine may also have potential for treating other mental illnesses; for example, a preliminary clinical trial reported that ketamine reduced the severity of symptoms in patients with PTSD. 37  Investigation of the role of glutamate signaling in other illnesses may provide the impetus to develop novel therapies based on this pathway.

Left: Change in the 21-item Hamilton Depression Rating Scale (HDRS) following ketamine or placebo treatment.
Right: Proportion of responders showing a 50 percent improvement on the HDRS following ketamine or placebo treatment.34

Source: Carlos Zarate, M.D., Experimental Therapeutics and Pathophysiology Branch, NIMH

One of the imperatives of clinical research going forward will be to demonstrate whether the ability of a compound to interact with a specific brain target is related to some measurable change in brain or behavioral activity that, in turn, can be associated with relief of symptoms. In a study of ketamine’s effects in patients in the depressive phase of bipolar disorder, ketamine restored pleasure-seeking behavior independent from and ahead of its other antidepressant effects. Within 40 minutes after a single infusion of ketamine, treatment-resistant depressed bipolar disorder patients experienced a reversal of a key symptom—loss of interest in pleasurable activities—which lasted up to 14 days.38 Brain scans traced the agent’s action to boosted activity in areas at the front and deep in the right hemisphere of the brain. This approach is consistent with the NIMH’s RDoC project, which calls for the study of functions—such as the ability to seek out and experience rewards—and their related brain systems that may identify subgroups of patients with common underlying dysfunctions that cut across traditional diagnostic categories.

The ketamine story shows that in some instances, a strong and repeatable clinical outcome stemming from a hypothesis about a specific molecular target (e.g., a glutamate receptor) can open up new arenas for basic research to explain the mechanisms of treatment response; basic studies can, in turn, provide data leading to improved treatments directed at that mechanism. A continuing focus on specific mechanisms will not only provide information on the potential of test compounds as depression medications, but will also help us understand which targets in the brain are worth aiming at in the quest for new therapies.

If you or someone you know is depressed, please make an appointment to see if you are a good candidate for ketamine.  Dr. Ashraf Hanna is located in Clearwater, FL and is one of the leading experts in IV ketamine therapy.  Dr. Hanna is a licensed anesthesiologist and Director of Pain Management at the Florida Spine Institute.  He has performed thousands of infusions and patients travel from all over the world to benefit from his expertise. If you want to learn more, visit his website and listen to his patient testimonies. You won’t be disappointed!  What are you waiting for?  Make an appointment today!

IV Ketamine Shows Promise in Clinical Trial with Depressed Teens

Researchers from the University of Minnesota and The Mayo Clinic found that ketamine caused an average decrease of 42% on the Children’s Depression Rating Scale(CDRS)—the most widely used rating scale in research trials for assessing the severity of depression and change in depressive symptoms among adolescents. The study recruited adolescents, 12-18 years of age, with treatment-resistant depression (TRD; failure to respond to two previous antidepressant trials). The teens were administered intravenous ketamine (0.5 mg/kg) by infusion six times over two weeks.

The study reported that the average decrease in CDRS-R was 42.5% (p = 0.0004). Five (38%) adolescents met criteria for clinical response (defined as >50% reduction in CDRS-R). Three responders showed sustained remission at 6-week follow-up; relapse occurred within 2 weeks for the other two responders. The ketamine infusions were generally well tolerated; dissociative symptoms and hemodynamic symptoms were transient. Interestingly, higher dose was a significant predictor of treatment response.

“Adolescence is a key time period for emergence of depression and represents an opportune and critical developmental window for intervention to prevent negative outcomes,” the authors wrote in the study.

“Unfortunately, about 40% of adolescents do not respond to their first intervention and only half of non-responders respond to the second treatment,” they said. “Because standard interventions require prolonged periods (e.g., weeks to months) to assess efficacy, serial treatment failures allow illness progression, which in turn worsens the outcome. Hence, novel treatment strategies to address treatment-resistant depression in adolescents are urgently needed.”

The authors concluded that their results demonstrate the potential role for ketamine in treating adolescents with TRD. Additionally, evidence suggested a dose–response relationship; future studies are needed to optimize dose.

If you or someone you know is depressed, please make an appointment to see if you are a good candidate for ketamine.  Dr. Ashraf Hanna is located in Clearwater, FL and is one of the leading experts in IV ketamine therapy.  Dr. Hanna is a licensed anesthesiologist and Director of Pain Management at the Florida Spine Institute.  He has performed thousands of infusions and patients travel from all over the world to benefit from his expertise. If you want to learn more, visit his website and listen to his patient testimonies. You won’t be disappointed!  What are you waiting for?  Make an appointment today!

Yale study found no safety issues with long-term ketamine treatment

Researchers at Yale published a new study titled “Acute and Longer-Term Outcomes Using Ketamine as a Clinical Treatment at the Yale Psychiatric Hospital” in Clinical Psychiatry.  In late 2014, Yale began providing ketamine as an off-label therapy on a case-by-case basis for patients who could not participate in research protocols.  The authors observed 54 patients that received IV ketamine infusion for the treatment of severe and treatment-resistant mood disorders such as depression.

“Ketamine is being used as an off-label treatment for depression by an increasing number of providers, yet there is very little long-term data on patients who have received ketamine for more than just a few weeks,” Samuel T. Wilkinson, MD,from the department of psychiatry, Yale School of Medicine and Yale Psychiatric Hospital, told Healio Psychiatry.

The Yale researchers studied the acute and longer-term outcomes in this patient population. Importantly, a subset of patients (n=14) received ketamine on a long-term basis, ranging from 12 to 45 total treatments, over a course of 14 to 126 weeks.  The researchers found no evidence of cognitive decline, increased proclivity to delusions, or emergence of symptoms consistent with cystitis in this subset of long-term ketamine patients.  They also reported that the infusions were generally well-tolerated.

Although this study population was relatively small, limiting the conclusions that can be drawn, this is still an important first step in establishing the long-term safety of ketamine for the treatment of a myriad of diseases that it’s being used to treat.

If you or someone you know is depressed, please make an appointment to see if you are a good candidate for ketamine.  Dr. Ashraf Hanna is located in Clearwater, FL and is one of the leading experts in IV ketamine therapy.  Dr. Hanna is a licensed anesthesiologist and Director of Pain Management at the Florida Spine Institute.  He has performed thousands of infusions and patients travel from all over the world to benefit from his expertise. If you want to learn more, visit his website and listen to his patient testimonies. You won’t be disappointed!  What are you waiting for?  Make an appointment today!

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