Surprising Result: Ketamine No More Effective Than Placebo in Treating Depression


Intravenous ketamine, administered during surgical anesthesia, has shown no significant advantage over a placebo in reducing the severity of depression among patients with major depressive disorder.

The research, led by Dr. Theresa R. Lii from the Stanford University School of Medicine in California, focused on a group of 40 adult patients diagnosed with major depressive disorder, all scheduled for routine surgery.

These individuals were randomly divided into two groups, with one receiving a single infusion of ketamine during their usual anesthesia, while the other received a placebo.

The primary outcome measure was the assessment of depression severity, quantified using the Montgomery-Åsberg Depression Rating Scale. The evaluations took place at one, two, and three days after the infusion. After all follow-up visits, participants were asked to guess which intervention they had received.

The study’s findings failed to provide any evidence of significant differences in the primary outcome when analyzed using a mixed-effects model (-5.82; 95 percent confidence interval, -13.3 to 1.64; P = 0.13). Approximately 36.8 percent of participants correctly guessed their treatment assignments, with similar proportions in both the ketamine and placebo groups.

Analyzing Sedentary Behavior and Dementia Risk

In a separate endeavor, researchers delved into the realm of sedentary behavior and its potential impact on dementia risk. This study drew from a vast dataset of accelerometer readings, in which over 100,000 adults agreed to wear wrist-worn accelerometers that tracked their movement around the clock for one week.

This initiative was part of a U.K. Biobank sub-study. The researchers zeroed in on a sample of approximately 50,000 adults aged 60 and older who, at the study’s outset, had no dementia diagnosis.

Sophisticated machine-learning algorithms were applied to the extensive dataset, enabling the classification of behaviors based on various levels of physical activity.

These algorithms successfully distinguished between different activities, such as sedentary behavior versus sleeping. Crucially, the researchers scrutinized the amount of time individuals spent engaged in various sedentary behaviors.

After a follow-up period averaging six years, the research team identified 414 cases of dementia using inpatient hospital records and death registry data. Statistical analyses were conducted, adjusting for demographics, lifestyle characteristics, and chronic conditions that could influence brain health, such as heart disease or diabetes.

The study’s findings revealed a significant increase in dementia risk for individuals who spent more than 10 hours a day engaged in sedentary activities, regardless of how that time accumulated. However, sedentary behaviors totaling around 10 hours or less exhibited no elevated risk of dementia.

This discovery offers a sense of reassurance, particularly for those in office jobs that necessitate prolonged periods of sitting. Nevertheless, individuals may still reduce their risk of dementia by making efforts to limit their daily sedentary time as much as possible.

The research surrounding the effectiveness of ketamine in treating depression highlights the complexity of this mental health condition. While ketamine has shown promise in some cases, this study emphasizes that it may not be universally effective for all individuals with major depressive disorder.

As research in the field of mental health continues to advance, the search for more personalized and effective treatments remains a priority.

The study on sedentary behavior and dementia risk underscores the importance of maintaining an active lifestyle, even as individuals age. Prolonged periods of sedentary behavior, beyond 10 hours a day, were associated with a significantly higher risk of developing dementia.

This knowledge reinforces the importance of encouraging physical activity and reducing sedentary time for overall brain health.

These two studies offer valuable insights into mental health and brain function. The ketamine study reminds us that treatment for depression remains a complex puzzle, and personalized approaches may be necessary.

Meanwhile, the research on sedentary behavior and dementia underscores the critical role of physical activity in promoting cognitive well-being.

As the scientific community delves deeper into these areas, the quest for effective treatments and lifestyle adjustments continues, with the ultimate goal of enhancing mental health and preserving cognitive function.

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  • Surprising Result: Ketamine No More Effective Than Placebo in Treating Depression