Medical Bulletin 26/ June/ 2024

A new study by UCL researchers has found that the risk of developing Parkinson’s is at least twice as high in people with anxiety compared to those without the condition.

The research, published in the British Journal of General Practice, investigated whether there was a link between people over the age of 50 who had recently developed anxiety and a later diagnosis of Parkinson’s.

Parkinson’s disease is the world’s fastest-growing neurodegenerative disorder and currently affects nearly 10 million people across the globe. The condition is a progressive disorder that is caused by the death of nerve cells in the part of the brain called the substantia nigra, which controls movement. These nerve cells die or become impaired, losing the ability to produce an important chemical called dopamine, due to the build-up of a protein called alpha-synuclein.

For the study, the team utilized UK primary care data from 2008 to 2018, assessing 1,09,435 patients who developed anxiety after age 50 and comparing them to 8,78,256 matched controls without anxiety. They tracked the emergence of Parkinson’s features—such as sleep problems, depression, tremor, and balance impairment—from the point of anxiety diagnosis until one year before a Parkinson’s diagnosis. This approach helped them understand the risk of developing Parkinson’s over time and identify associated risk factors.

The researchers adjusted their results for factors including age, sex, social deprivation, lifestyle habits, severe mental illness, head trauma, and dementia, which could influence the likelihood of developing Parkinson’s in individuals with anxiety.

The study revealed that the risk of developing Parkinson’s doubled in people with anxiety compared to the control group. Additionally, they confirmed that symptoms like depression, sleep disturbances, fatigue, cognitive impairment, hypotension, tremor, rigidity, balance impairment, and constipation were significant risk factors for developing Parkinson’s in people with anxiety.

“Parkinson’s disease is the second most common neurodegenerative condition worldwide, and it is estimated that it will affect 14.2 million people by 2040.Anxiety is known to be a feature of the early stages of Parkinson’s disease, but prior to our study, the prospective risk of Parkinson’s in those over the age of 50 with new-onset anxiety was unknown. By understanding that anxiety and the mentioned features are linked to a higher risk of developing Parkinson’s disease over the age of 50, we hope that we may be able to detect the condition earlier and help patients get the treatment they need,” said the authors.

Reference: Juan Carlos Bazo-Alvarez, Danielle Nimmons, Kate Walters, Irene Petersen and Anette Schrag; Risk of Parkinson’s disease in people aged ≥50 years with new-onset anxiety: a retrospective cohort study in UK primary care; British Journal of General Practice 24 June 2024; BJGP.2023.0423. DOI: https://doi.org/10.3399/BJGP.2023.0423

A new tablet form of ketamine has shown promise in treating severe depression, offering a potential alternative to existing clinic-based treatments that can be expensive and lacking in convenience for some patients.

The study was published in the journal Nature Medicine.

Over the past twenty years, research has increasingly shown that ketamine can quickly relieve symptoms of depression in people who haven’t responded to other treatments. Most studies have looked at ketamine used in ways not originally approved by regulators, typically administered intravenously.

Recently, a nasal spray form of ketamine called esketamine has been approved for use. Both ketamine and esketamine can be given in different ways, and higher doses generally lead to greater improvements in depression than lower doses.

A study analysing different forms of ketamine found that those designed to be processed slowly by the liver and to reach peak levels in the blood more gradually were safer and better tolerated than those that don’t have these characteristics.

In the study, scientists conducted a randomized-controlled trial to test the effectiveness of ketamine tablets in treating depression compared to a placebo. They randomly assigned 168 patients with treatment-resistant depression into five groups: four received different doses of ketamine, and one received a placebo.

The researchers found that patients taking the highest dose of ketamine—180 mg, taken orally twice a week—experienced the most significant improvements compared to the placebo group. The effectiveness was measured using the MADRS score, which assesses depression symptoms, with higher scores indicating more severe depression.

In the group receiving 180 mg of ketamine, the average MADRS score dropped by 14 points from a starting score of 30. In contrast, the placebo group saw an average reduction of 8 points. The other ketamine doses (120 mg, 60 mg, and 30 mg) also showed slightly better outcomes than the placebo.

“First, administering ketamine tablets for depression is much more convenient than clinic visits for injections and two-hour monitoring sessions. Patients can take the tablets at home, making the treatment as easy as other antidepressants. Additionally, having multiple forms of treatment—tablets and injections—can help cater to different patient responses. Second, this tablet form challenges the belief that ketamine's effectiveness relies on causing altered reality perceptions. The tablet releases ketamine slowly, with only a tiny amount entering the bloodstream at a time, preventing dissociation while still improving depression symptoms. This suggests that the dissociative effects might not be necessary for ketamine to be effective,” said the researchers.

Reference: Glue, P., Loo, C., Fam, J. et al. Extended-release ketamine tablets for treatment-resistant depression: a randomized placebo-controlled phase 2 trial. Nat Med (2024). https://doi.org/10.1038/s41591-024-03063-x

In a pooled analysis of three clinical trials, published online in the peer-reviewed journal CANCER by Wiley, acupuncture was found to significantly reduce hot flashes and other hormonal side effects in women undergoing endocrine therapy for breast cancer.

Endocrine therapy, which blocks hormone signalling that drives some forms of breast cancer, can be a life-saving treatment, but up to 80% of patients who take it experience hot flashes—a sudden, temporary sensation of body warmth, flushing, and sweating—and other side effects. Many patients who experience these symptoms discontinue endocrine therapy, which can put them at an elevated risk of cancer progression and death.

Other medications can reduce hot flashes, but they come with unpleasant side effects. Studies have evaluated the impact of acupuncture on hot flashes in women with early breast cancer undergoing endocrine therapy.

In the study, researchers conducted three independent randomized controlled trials involving 158 women with stage 0–III breast cancer. The participants were divided into two groups: immediate acupuncture (IA) and delayed acupuncture control (DAC). Those in the IA group received acupuncture twice a week for 10 weeks, followed by 10 weeks without acupuncture. The DAC group received usual care for the first 10 weeks, then switched to once-weekly acupuncture for the next 10 weeks.

The researchers used standardised clinical questionnaires to assess hormonal symptoms such as hot flashes, night sweats, vaginal dryness, and joint pain, as well as quality of life aspects including physical, functional and emotional well-being.

After 10 weeks, the IA group showed a significant reduction in symptoms compared to the DAC group. Specifically, 64% of IA participants reported improvements in the number and severity of hot flashes, compared to only 18% in the DAC group. The IA group also experienced greater improvements in overall quality of life.

Between weeks 10 and 20, the IA group’s scores remained stable. However, the DAC group, which received weekly acupuncture during this period, showed significant improvements in symptoms compared to their scores at week 10. Notably, no participants reported any side effects from the acupuncture treatments.

“By managing side effects, our approach helps patients stick to their prescribed medication, potentially reducing cancer recurrence and improving long-term outcomes for breast cancer survivors. Patients can start with a short trial of acupuncture to see if it reduces hot flashes and other symptoms. If effective, they can continue with regular sessions throughout their anti-hormonal medication regimen,” said lead author Weidong of the Dana-Farber Cancer Institute.

Reference: Weidong Lu MB, MPH, PhD, Anita Giobbie-Hurder MS, Anna Tanasijevic MPH, Sylvia Baedorf Kassis MPH, Sung Hwan Park MD, PhD, Young Ju Jeong MD; Acupuncture for hot flashes in hormone receptor-positive breast cancer: A pooled analysis of individual patient data from parallel randomized trials; Cancer; https://doi.org/10.1002/cncr.35374