Day: July 17, 2022

Categories : Gender Mental HealthTags :

Why Depression Treatments May Have Different Efficacy for Women

On By ModernMedia
Woman with depression
Photo by Sydney Sims on Unsplash

It is not clear why women experience higher rates of depression than men, complicating treatments that are already prone to failure. Research exploring the reasons behind this found a difference in a part of the brain associated with motivation, social interactions and reward. The researchers’ findings were published in the journal Biological Psychiatry.

The study set out to understand how a specific part of the brain, the nucleus accumbens, is affected during depression. The nucleus accumbens is important for motivation, response to rewarding experiences and social interactions – all of which are affected by depression.

Brain drawing
The nucleus accumbens (represented in blue) is a part of the brain that controls motivation. Researchers from UC Davis compared samples of the nucleus accumbens in mice and humans to find clues to how this part of the brain is affected by stress and depression in males and females.

Previous analyses within the nucleus accumbens showed that different genes were turned on or off in women, but not in men diagnosed with depression. These changes could have caused symptoms of depression, or alternatively, the experience of being depressed could have changed the brain. To differentiate between these possibilities, the researchers studied mice that had experienced negative social interactions, which induce stronger depression-related behavior in females than males.

“These high-throughput analyses are very informative for understanding long-lasting effects of stress on the brain. In our rodent model, negative social interactions changed gene expression patterns in female mice that mirrored patterns observed in women with depression,” said study leader Alexia Williams, a doctoral researcher. “This is exciting because women are understudied in this field, and this finding allowed me to focus my attention on the relevance of these data for women’s health.”

After identifying similar molecular changes in the brains of mice and humans, researchers chose one gene, regulator of g protein signaling-2, or Rgs2, to manipulate. This gene controls the expression of a protein that regulates neurotransmitter receptors that are targeted by antidepressant medications such as Prozac and Zoloft. “In humans, less stable versions of the Rgs2 protein are associated with increased risk of depression, so we were curious to see whether increasing Rgs2 in the nucleus accumbens could reduce depression-related behaviorus,” said Professor Brian Trainor, senior author on the study.

When the researchers experimentally increased Rgs2 protein in the nucleus accumbens of the mice, they effectively reversed the effects of stress on these female mice, noting that social approach and preferences for preferred foods increased to levels observed in females that did not experience any stress.

“These results highlight a molecular mechanism contributing to the lack of motivation often observed in depressed patients. Reduced function of proteins like Rgs2 may contribute to symptoms that are difficult to treat in those struggling with mental illnesses,” Williams said.

Findings from basic science studies such as this one may guide the development of pharmacotherapies to effectively treat individuals suffering from depression, the researchers said.

“Our hope is that by doing studies such as these, which focus on elucidating mechanisms of specific symptoms of complex mental illnesses, we will bring science one step closer to developing new treatments for those in need,” said Williams.

Source: UC Davis

Categories : Mental Health Metabolic DisordersTags :

Migraine Drug Could be Beneficial for Weight Loss

On By ModernMedia
Obesity
Image source: Pixabay CC0

The commonly prescribed triptans, a class of migraine drugs, may be useful in treating obesity, a new study published in Journal of Experimental Medicine suggests. In studies on obese mice, a daily dose of a triptan caused them to eat less food and lose weight over the course of a month.

“We’ve shown that there is real potential to repurpose these drugs, which are already known to be safe, for appetite suppression and weight loss,” said study leader Chen Liu, PhD.

Serotonin has long been known to play a key role in appetite. However, there are 15 different serotonin receptors. Researchers have struggled to understand the role of each serotonin receptor in appetite, and previous drugs, including fen-phen and lorcaserin, that targeted certain individual receptors have been withdrawn from the market due to side effects.

Triptans, which are used to treat acute migraines and cluster headaches, work by targeting a different receptor — the serotonin 1B receptor (Htr1b) — that had not previously been well studied in the context of appetite and weight loss, said Dr Liu.

For the new study, the researchers tested six prescription triptans in obese mice that were fed a high-fat diet for seven weeks. Mice fed two of these drugs ate about the same amount, but mice fed the other four ate less. After 24 days, mice given a daily dose of the drug frovatriptan lost, on average, 3.6% of their body weight, while mice not given a triptan gained an average of 5.1% of their body weight. The researchers saw similar results when they implanted devices into the animals that gave them a steady dose of frovatriptan for 24 days.

“We found that these drugs, and one in particular, can lower body weight and improve glucose metabolism in less than a month, which is pretty impressive,” said Dr Liu.

Since triptans are generally prescribed for short-term use during migraines, Dr Liu suspects that patients would not have noticed the longer-term impacts on appetite and weight in the past.

To determine exactly how frovatriptan impacts food intake and weight, the researchers engineered mice to lack either Htr1b or Htr2c, the serotonin receptor targeted by fen-phen and lorcaserin. In mice without Htr1b, frovatriptan no longer could decrease appetite or cause weight loss, while cutting out Htr2c had no effect. This confirmed that the drug worked by targeting the serotonin 1B receptor.

“This finding could be important for drug development,” said Dr Liu. “We not only shed light on the potential to repurpose existing triptans but also brought attention to Htr1b as a candidate to treat obesity and regulate food intake.”

Source: UT Southwestern Medical Center

Categories : COVID Obstetrics & GynaecologyTags :

Menstrual Changes after COVID Vaccine

On By ModernMedia
Photo by Natracare on Unsplash

A new analysis of offers the most comprehensive assessment so far of menstrual changes experienced by pre- and post-menopausal individuals in the first two weeks after being vaccinated against COVID. Published in the journal Science Advances, the study adds to the growing body of evidence that significant numbers of people experience this unexpected side effect.

“Menstruating and formerly menstruating people began sharing that they experienced unexpected bleeding after being administered a COVID vaccine in early 2021,” the scientists who led the study wrote. Because vaccine trials typically do not ask about menstrual cycles or bleeding, this side effect was largely ignored or dismissed.

Early reports about post-vaccination menstrual changes were largely brushed aside, said Kathryn Clancy, a professor of anthropology who led the research with Katharine Lee, another anthropology professor. Some clinicians said it was unclear how a vaccine could trigger such changes.

However, it is known that other vaccines – including those for typhoid, Hepatitis B and HPV – are sometimes associated with changes in menstruation, Prof Clancy said. The changes are more likely to be associated with an increase in immune-related inflammatory pathways, as opposed to any hormonal changes.

“We suspect that for most people the changes associated with COVID vaccination are short-term, and we encourage anyone who is worried to contact their doctor for further care,” Lee said. “We want to reiterate that getting the vaccine is one of the best ways to prevent getting very sick with COVID, and we know that having COVID itself can lead not only to changes in periods, but also hospitalisation, long COVID and death.”

The researchers used a survey to query people about their experiences after vaccination. Launched in April 2021, the survey asked for demographic and other information but focused on respondents’ reproductive history and experiences regarding menstrual bleeding. The team downloaded the data from the surveys on June 29, 2021. Only those who had not been diagnosed with COVID were included in the analysis, as COVID itself is sometimes associated with menstrual changes. Data from people aged 45–55 years was excluded to avoid the confounding of effect menstrual changes associated with perimenopause.

“We focused our analysis on those who regularly menstruate and those who do not currently menstruate but have in the past,” Prof Clancy said. “The latter group included postmenopausal individuals and those on hormonal therapies that suppress menstruation, for whom bleeding is especially surprising.”

A statistical analysis revealed that 42.1% of menstruating survey respondents reported a heavier menstrual flow after receiving the COVID-19 vaccine. Some experienced this in the first seven days but many others saw changes 8–14 days after vaccination. Roughly the same proportion, 43.6%, reported no alteration of their menstrual flow after the vaccine, and a smaller percentage, 14.3%, saw a mix of no change or lighter flow, the researchers report.

Because the study relied on self-reported experiences logged more than 14 days after vaccination, it cannot establish causality or be seen as predictive of people in the general population, Lee said. But it can point to potential associations between a person’s reproductive history, hormonal status, demographics and changes in menstruation following COVID vaccination.

For example, the analysis revealed that respondents who had experienced a pregnancy were most likely to report heavier bleeding after vaccination, with a slight increase among those who had not given birth. A majority of non-menstruating premenopausal respondents on hormonal treatment experienced breakthrough bleeding after receiving the vaccine. This side effect was common in respondents using long-acting reversible contraception and 38.5% of those undergoing gender-affirming hormone treatments reported this side effect.

Those who were older, and those who experienced fever or fatigue as a side effect of vaccination were also more likely than other groups to report heavier menstrual flow after vaccination. White respondents were slightly less likely to report heavier menstrual flow.

Those who had experienced endometriosis, menorrhagia, fibroids or other reproductive problems also were more likely to report a heavier menstrual flow post-vaccination, the team found. The largest single increase was in those who have been pregnant without a delivery.

While the uptick in menstrual flow for some people may be transitory and quickly resolve, unexpected changes in menstruation can still cause concern, Prof Lee said.

“Unexpected breakthrough bleeding is one of the early signs of some cancers in post-menopausal people and in those who use gender-affirming hormones, so experiencing it can make people worry and require expensive and invasive cancer-screening procedures,” Prof Lee said.

“This screening is very important so we can catch cancers early,” Prof Clancy said. “For diagnostic purposes, it would be helpful to know whether there are other causes for the bleeding.”

“We’d love to see future vaccine testing protocols incorporate questions about menstruation that go beyond screening for pregnancy,” Prof Lee said. “Menstruation is a regular process that responds to all kinds of immune and energetic stressors, and people notice changes to their bleeding patterns, yet we don’t tend to talk about it publicly.”

Source: University of Illinois at Urbana-Champaign