Tag Archives: symptoms

Psychedelic-like drug could fix the symptoms of stress without giving you hallucinations

Feeling stressed? New research might help, as we’ve identified a substance that can revert stress-induced behavioral deficits and restore neural circuits affected by stress in the brain — in mice, so far.

Image via Pixabay.

The compound tabernanthalog (TBG) is similar in structure to ibogaine, a psychedelic drug. However, it lacks its toxic and hallucinogenic effects and has been found to quickly reverse stress-related issues in mice. A single dose of TBG is enough for the job, the authors add, to address issues such as anxiety and cognitive inflexibility, regrow neuronal connections, and restore neural circuits — all possible effects of stress.


“It was very surprising that a single treatment with a low dose had such dramatic effects within a day,” said corresponding author Yi Zuo, professor of molecular, cell, and developmental biology at UC Santa Cruz.

“I had a hard time believing it even when I saw the initial data.”

TBG was developed in the lab of David Olson at UC Davis, a co-author on the current paper, and was first reported on in 2020. The study focused on its activity against the effects of stress, using a protocol in which lab mice were subjected to mild but unpredictable sources of stress over a period of a few days.

Stress, the team explains, especially sustained over longer periods of time, can lead to increased levels of anxiety, difficulty in processing sensory input, and reduced flexibility in decision-making. In the brain, it can lead to disruptions between neurons and changes in the structure of our neuronal circuitry — which, overall, impacts how well our brain can function on a day-to-day basis.

One dose of TBG, however, had reversed all of these effects in the mice used in this study. The team also performed imaging studies to assess changes in the brains of the mice at the neuronal level.

“This study provides significant insights into neural mechanisms underlying the therapeutic effects of psychedelic analogs on mental illnesses and paves the way for future investigations to understand their cellular and circuit mechanisms,” adds Zuo.

Psychedelic drugs have been receiving a lot of attention lately as they might be useful in treating addiction, depression, anxiety, and post traumatic stress disorder. However, their hallucinogenic effects can be quite impairing for some patients and remain a point of concern.

Ibogaine is one such compound that showed promise in the treatment of addiction. It does, however, also cause heart arrhythmia and is a very strong hallucinogenic substance. TBG is chemically and biochemically similar to Ibogaine, but seems to lack its toxic and hallucinogenic effects in mice. The compound has not yet been tested on humans, so we can’t be sure, but it doesn’t induce head-twitching behaviors in mice after administration, as known hallucinogens do.

Previous research on mice has shown that TBG can act as an antidepressant and can reduce addictive behavior. The current study was meant to expand on these initial findings by evaluating its potential in the treatment of stress and its symptoms.

Initial studies of TBG found that it had antidepressant effects and reduced addictive behaviors in rodents. The new study was initiated by co-first author Michelle Tjia, then a graduate student in Zuo’s lab studying the effects of stress. After Tjia left for a postdoctoral position, co-first author Ju Lu, a project scientist in the lab, led additional studies. The researchers conducted a range of tests to evaluate behavioral responses to stress and the effects of treatment with TBG.

The paper “An analog of psychedelics restores functional neural circuits disrupted by unpredictable stress” has been published in the journal Molecular Psychiatry.

Symptomatic and asymptomatic COVID-19 patients shed virus similarly

We are learning more about how COVID-19 affects people every day, and this new find confirms what we’ve been fearing: asymptomatic people can pass the virus with the same ease.

 We know that SARS-CoV-2, the virus causing COVID-19, is transmitted through direct contact with respiratory droplets of an infected person (generated through coughing and sneezing). Individuals can also be infected from and touching surfaces contaminated with the virus and touching their face (e.g., eyes, nose, mouth). The COVID-19 virus may survive on surfaces for several hours, but simple disinfectants can kill it.

Available evidence from contact tracing reported by countries suggests that asymptomatically infected individuals are much less likely to transmit the virus than those who develop symptoms. However, researchers from South Korea reported in JAMA Internal Medicine that patients with confirmed asymptomatic COVID-19 infections shed virus at similar levels to those who are experiencing symptoms. “Viral shedding” refers to the release of the virus from an infected host. The investigators concluded that “isolation of infected persons should be performed regardless of symptoms.”

Their cohort study involved 303 patients who were isolated at a community treatment center in Cheonan in March. Healthcare workers carefully tracked patients’ symptoms during isolation. Among the group, 193 (63.7%) had symptoms at the start of isolation and 21 (19.1%) of the asymptomatic patients went on the develop symptoms. Healthcare workers also conducted reverse transcription polymerase chain reaction (RT-PCR) tests on lower and upper respiratory tract samples on multiple days at doctor discretion. Cycle threshold values for SARS-CoV-2 were similar for both asymptomatic and symptomatic patients. Viral shedding lasted about 17 days in asymptomatic patients and 19.5 days for symptomatic and pre-symptomatic patients.

Why are some people asymptomatic while others are not? SARS-CoV-2 uses the angiotensin-converting enzyme 2 (ACE2) as a cell receptor to invade human cells. Using the spike-like protein on its surface, the SARS-CoV-2 virus binds to ACE2 – like a key being inserted into a lock – prior to entry and infection of cells. Hence, ACE2 acts as a cellular doorway.

The ACE2 receptors appear to be more prevalent in older people and those who are obese than in younger and healthier people. That may partly explain why so many young people have not been as badly affected by the virus as those older than 60. Previous exposure to other coronaviruses, which can give people “T-cell immunity” to similar viruses, receiving a lower viral load of COVID-19 and other lucky genetic variations may also contribute to why some people having less severe or not symptoms to infection.

Coronavirus main risk factor and symptoms ranked by new massive study

One of the most thorough studies of its kind, involving more than 20,000 patients in the UK across 208 hospitals, has ranked the main risk factors linked with the worst outcomes for COVID-19. Additionally, the study also ranked the main symptoms of coronavirus based on their frequency.

The British researchers, which are affiliated with universities from across the country, assessed the clinical features of patients admitted to hospitals with COVID-19 during the early growth phase of the first wave of the outbreak, between 6 February and 19 April 2020.

The median age of the 20,133 hospital inpatients with COVID-19 was 73 years while the median duration of symptoms before admission was required was 4 days (1-8 days).

According to the assessment, there are four main risk factors that are associated with developing the most dangerous coronavirus symptoms: age, sex, weight, and underlying illness.

Credit: BMJ.

Aside from old age, the researchers found that being male is an important factor, with 60% of coronavirus patients being male.

The vast majority of hospitalized coronavirus patients had at least one underlying chronic disease, with cardiac disease being the most prevalent among those who died, followed by asthmatic chronic pulmonary disease, chronic kidney disease, and liver disease.

Lastly, obesity was also found to be an important risk factor, although other studies have not linked obesity with in-hospital mortality after adjusting for other comorbidities, age, and sex.

Something should be said about smoking, too. Only 6% of the patients were current smokers and 30.8% were previous smokers. Although the study was not able to class smoking as a comorbidity, another recent study performed at Imperial College in London found that smokers were 14% more likely to end up in a hospital with coronavirus symptoms than non-smokers.

Credit: BMJ.

The study also tallied the most frequent coronavirus symptoms, such as cough, fever, shortness of breath, fatigue, and confusion, in this order.

These findings are very similar to other studies that reported on COVID-19 risk factors and symptoms. However, it’s valuable to see them confirmed by a massive study such as this, involving more than 20,000 hospitalized patients.

The findings were reported in The BMJ 

What are the symptoms of COVID-19? Here’s what the studies say so far

The most common symptoms of a coronavirus infection are fever (temperature above 37.8C or 100F), dry cough, difficulty breathing or shortness of breath, and fatigue.

Dry coughCommonMildCommonSometimes
Shortness of breathCommonNoNoCommon
Aches and
Sore throatSometimesCommonCommonNo
DiarrheaRareNoSometimes No
Runny noseRareCommonSometimesCommon
Loss of smell and tasteSometimesSometimesSometimesNo
Source: CDC, WHO.

There is significant overlap with fluids from the flu or the common cold, but other symptoms are almost unique to COVID-19, the respiratory illness caused by the SARS-CoV-2 coronavirus.

For instance, doctors have noticed that some cases experience anosmia — a complete loss of smell — as well as the loss of taste. These two symptoms, when they appear, tend to show in the early stage of infection. Some might not develop other symptoms of COVID-19 other than anosmia.

To make matters more confusing, many patients show no symptoms at all, despite producing viral loads in their respiratory tract which can spread to other people who may be much more vulnerable to developing life-threatening symptoms.

How long does it take to show symptoms?

According to scientists, it takes around 5 days on average for an individual who has just been infected in order to show symptoms. However, symptoms may take up to 14 days to surface in some cases, which is why many local authorities advise that people self-isolate for at least two weeks after returning home from abroad or from some region where the pandemic is evolving rapidly.

There is still a lot we don’t know about the virus, but public health experts believe that most people who get infected will go on to develop only mild symptoms of COVID-19.

However, the disease can prove to be life-threatening for some vulnerable groups, typically the elderly and those with preexisting medical conditions ( asthma, diabetes, heart disease, high blood pressure, autoimmune disease, cancer).

Scientists believe that infected individuals are the most contagious when they have obvious symptoms, such as fever and cough.

How to tell apart COVID-19 symptoms from the flu or allergies?

COVID-19 and the common cold have some overlapping symptoms. These include a sore throat, fatigue, and a cough.

One of the most reported differences between a common cold and coronavirus is a runny nose. This is common for a cold but rare for COVID-19. Similarly, a fever is possible with a cold but is rare. A fever is common with coronavirus.

Shortness of breath is common with coronavirus but rare for a common cold. The allergy symptoms that overlap with COVID-19 are nasal congestion, cough, runny nose, and sore throat.

“The main difference that people should remember is with fevers,” said Dr. Alex Thomas, an asthma and allergy specialist at the Center for Asthma and Allergy in Illinois. “That is something you would only really see with a viral infection such as COVID-19. Even though the term is ‘hay fever,’ you would not get a fever with environmental allergies.”

However, the only to tell for certain if you have COVID-19 is to take a test.

How many cases show no symptoms?

SARS-CoV-2 is particularly contagious due to its considerably high incubation period, lasting 5.1 days (median) but which can be up to 14-16 days. During this time, the infected person can transmit the virus to other people oblivious to the fact that she is actually sick.

A study performed by researchers at Hasselt University in Belgium found that 48% of the transmission in Singapore and 62% in Tianjin, China, was enabled by people who had yet to develop symptoms.

It has become increasingly clear that a large part of COVID-19 cases never shows any symptoms, but it is what is the rate of asymptomatic cases. Such estimates are difficult to ascertain while an epidemic (or pandemic in this case) is still in progress.

Two new studies offer some hints, though. The first was published in the journal Eurosurveillance by an international team of scientists from Japan, the U.S., and the UK, who analyzed COVID-19 cases aboard the Diamond Princess, which was docked in Yokohama, Kanagawa Prefecture in Japan.

The cruise ship had 3,711 onboard, which were immediately put under quarantine (they weren’t allowed to set foot ashore) after one of the guests was tested positive. Eventually, 696 passengers and crew members tested positive and six died of the illness.

Using a statistical model that filled some of the gaps in the reported data because not all passengers had been tested, the authors of the new study estimated that 17.9% of those infected were asymptomatic.

This asymptomatic rate is similar to that of the flu virus, the authors wrote in their study. I’ll take this opportunity to note that while the two types of viruses might share a similar asymptomatic rate, that’s not to say that the novel coronavirus is like influenza. SARS-CoV-2 is both different and a lot more dangerous than the virus for the flu.

A second study published in the International Journal of Infectious Diseases analyzed the rate at which symptoms showed in 565 Japanese nationals who had been evacuated from Wuhan. A third of those who had tested positive for SARS-CoV-2 (13 people in total) were asymptomatic cases — a much higher rate than found among Diamond Princess passengers and crew, but the confidence interval is much wider (7.7% to 53.8%). There were only 9 symptomatic cases and 4 asymptomatic cases.

Both studies have their limitations. The study on the Japanese nationals included a very small sample size of confirmed cases while the one that monitored individuals from the Diamond Princess is not very representative of a wider demographic. However, these preliminary results are still helpful in establishing a rough estimate for the transmissibility of SARS-CoV-2.

Perhaps the most reliable study of COVID-19 asymptomatic involved a country-wide experiment: the situation in Iceland. The island state has a population of only 364,000 people and is extremely isolated. It also tests a lot per capita compared to other countries.

Of the 10,000 tests or so carried out in Iceland so far, which yielded 473 positive cases. Of these, half were non-symptomatic. Similarly, a survey carried out in the Italian town of Vo, which has a population of 3,300, reported similar results showing that about 50% of all confirmed cases of infection were non-symptomatic.

Similar studies carried on Chinese patients report similar things: the virus is spreading far more than we are anticipating. For every known case, there are five or ten people whose symptoms go undetected.

“Covid-19 is proving to be a “stealth virus” in that we now know a significant amount of transmission is through people who don’t have symptoms. The exact % will depend on setting, but is high enough to make testing and surveillance key tools,” said Dr. Jonathan Quick in a Reddit AMA.

On top of those showing no symptoms of disease despite being infected and capable of spreading the virus, there are also many mild cases that can be easily dismissed as a common cold or flu.

When to see a doctor

If you have COVID-19 symptoms or you’ve been in contact with someone diagnosed with COVID-19, contact your doctor or clinic right away for medical advice on how to proceed further with testing. Be careful not to leave anything out when contacting healthcare providers, such as when symptoms first started to appear or who you’ve been in contact with recently.

If you have emergency COVID-19 signs and symptoms, seek care immediately. Emergency signs and symptoms can include:

  • Trouble breathing
  • Persistent chest pain or pressure
  • Confusion
  • Blue lips or face