Mood

7 Ways to Successfully Navigate Holiday Stress

The holiday season is supposed to be a time of joy, happiness and goodwill. However, the often unrealistic demands that accompany it can make it tough to keep the holiday spirit alive, fostering stress — and even depression — instead. Holiday stress can become overwhelming; when you feel it creeping in, it’s a good idea to stop, regroup and reset. Follow these effective tips to minimize (and even prevent) the stress that comes with the season.

Preparation Eases Frustration

One reason people feel frustrated and tense over the holidays is that they respond to things as they come up without really developing a plan of action. Taking a more proactive approach can alleviate the holiday pressure by helping you adhere to a set schedule. Mark down your obligations and tasks on a calendar, so you can see what needs to be done on each day. This will help you organize your time better. As you schedule your tasks, such as shopping or the office holiday party, remember that traffic will be heavier and department stores will be busier.

Take Time for Self Care

The holiday season is a hectic time, but that’s all the more reason to make sure to spend time on yourself. Don’t forget that prolonged stress can weaken the immune system and open us up to illness. If you ordinarily engage in relaxation techniques or hobbies, don’t let those activities go just because the holidays are upon us. If you don’t normally meditate, perform yoga or exercise, this may be a good time to start. Even taking up a hobby or activity that interests you can relax your mind and body. You’ll be surprised by how well you’re able to handle holiday pressure once you begin taking time for yourself.

Give Your Body a Natural Boost

Often, people forget to take care of their health during the holiday season. They eat on the go more frequently and that means they’re not getting all of the vitamins and nutrients their bodies need to stay mentally and physically healthy. Taking a natural supplement like Mitochron that provides vitamins, enzymes and amino acids that support the body and cells during times of stress can help limit the risk of holiday burnout. In addition to boosting energy, the amino acids L-carnitine and L-arginine also help the body eliminate toxins from the body. This is especially helpful in reducing the physical toll of holiday stress, because the unhealthier diets and lifestyles we adopt during the season cause our bodies to collect and store more toxins that negatively impact our health.

Dealing with Family

Spending time with family is one of the most common causes of stress during the holidays. People often feel pressured to see as many of their relatives as possible, which can cause them to spend more time traveling than actually visiting loved ones. To avoid this, don’t try to see everyone every year. Choose one destination each year, so you don’t overburden yourself with too much traveling. You can always spend time with other relatives in the spring for Easter or the fall for Labor Day.

Work Out a Budget

For many people, the stress of the holidays doesn’t end after the first of the year, because that’s when those post-holiday credit card bills start rolling in. You can avoid that by developing a holiday budget and sticking to it. Decide in advance how much you’ll contribute to holiday parties and don’t go over that for the total number of parties you’re involved in planning. Office parties, family get-togethers, and parties with friends can become a huge financial burden, if you let yourself get carried away. Similarly, limit how much you’ll be spending on gifts and realize that you don’t have to buy everyone a special gift. Use cash or your debit card, but keep those credit cards set aside for real emergencies.

Get Enough Sleep to Limit Holiday Stress

Getting seven to eight hours of quality sleep is essential for a variety of reasons. In addition to helping the body physically recuperate, it also gives the mind a chance to regenerate. This is why insufficient sleep leads to symptoms like irritability, mood swings, anxiety and depression. A lack of sleep can have a worse effect on the mind and body throughout the holiday season because people usually expend more energy than usual. Getting enough sleep will give your mind the time it needs to ease stress and recharge energy levels.

Accept What Can’t Be Changed

When it comes down to it, people often take on more than they can handle without realizing it. One way to avoid doing this is to accept that some things are beyond your control. For instance, if a relative is coming to your home for dinner and doesn’t like what you’re serving, don’t take it upon yourself to make a separate meal for that person. Instead, recommend the relative bring one of her favorite dishes to add to the dinner. Similarly, don’t be afraid to ask others to contribute to meal preparations, shopping, and other tasks. Delegating your responsibilities will help everyone have a less stressful holiday.

Depression is more common through the holiday season partly because people experience heightened stress levels. During this time, it becomes that much more important to take proper care of your mental well-being. This means taking the time to engage in enjoyable activities and finding ways to limit the pressures placed upon your shoulders. This may include asking others to lend a hand, organizing your plans more efficiently, and practicing relaxation techniques. The holidays only last a short time, but unrelieved stress can affect you for much longer if you let it.

Tryptophan and Sleep: Does Eating Thanksgiving Turkey Really Make You Sleepy?

Nov 22 by Ewcopywriting

Thanksgiving is a time of giving thanks, of family and, most of all, of tradition. Although every American family has a unique way of celebrating this fall festival, most traditions have two things in common: turkey and rest. This has led to a widespread belief that turkey, or more precisely, tryptophan, an amino acid that turkey contains in large proportions, makes you sleepy. Is turkey really what makes you feel so tired on Thanksgiving afternoon? The research on tryptophan and sleep has borne mixed results.

Tryptophan and Turkey: Fact or Myth?

Much of the belief that turkey causes sleep is based on the purported effects of the amino acid tryptophan. Like many essential amino acids, tryptophan is converted to different molecules that are crucial to human health. It is an important building block in several proteins, but it also is important because it is converted to a molecule called 5-HTP. 5-HTP is a precursor to serotonin and melatonin, both of which play an essential role in sleep and mood.

Serotonin is best known as the happiness hormone. It is the molecule that is the target of many popular antidepressants. In addition, it plays an important role in digestion. One of the “side effects” of increased serotonin is more energy. Melatonin, on the other hand, is a hormone associated with sleep. Its effects on the human body are many, as it acts as a potent antioxidant and also triggers DNA repair. However, most people who take melatonin will simply notice that it makes them sleepy.

Tryptophan’s role as a precursor to melatonin is the reason that it is so often associated with sleep. For many people, the tryptophan that they eat is converted to both serotonin and melatonin, giving them that happy and sleepy feeling that so many associate with their post-turkey nap. However, the relationship between turkey and sleep may not be so simple.

Links Between Tryptophan and Sleep

Tryptophan has been linked to sleep in several studies. People who take a tryptophan supplement before bed generally wake up better-rested and more alert. They perform better on tests that require concentration and also display less aggression. This change in behavior can even be seen in lab animals. Because tryptophan has to be converted to melatonin in order to induce sleepiness, this effect tends to be more gentle than that seen by taking a sleeping pill or even from taking melatonin.

The problem with linking turkey and sleep is that turkey is not actually the best place to get tryptophan. In fact, chicken has more of this amino acid. Many foods have ample amounts of tryptophan yet are not associated with sleep. This is due to the fact that tryptophan takes a significant amount of time to be converted to melatonin.

First, tryptophan must be transported across the blood-brain barrier, which can take significant time because it basically has to wait in line with other amino acids. Once there, it is converted to serotonin in several different areas of the brain, and then to melatonin in the pineal gland. Eating turkey is not a fast way to fall asleep. On the contrary, your post-turkey dip in energy is likely due to eating a large amount of carbohydrates.

Could a Tryptophan Supplement Help You Sleep?

To keep it simple, tryptophan may not provide a quick way to fall asleep, but it indeed can contribute to your sleeping well. Tryptophan supplements have been shown to encourage higher-quality sleep. However, they may not be the answer to insomnia for some people. In elderly people, for example, this amino acid may have the opposite effect. Older people have a less-functional pineal gland due to age-related changes in blood flow to this gland. As a result, excess tryptophan is converted to serotonin rather than to melatonin, leaving elderly people even more energetic.

People who suffer from insomnia similarly tend to have problems with producing melatonin. As a result, many insomniacs may get the opposite effect as well, getting a boost of energy from the serotonin that is made in lieu of the melatonin they seek.

Getting to Sleep the Natural Way

If you are hoping to sleep better, it may be best to “skip the middle man” and simply take a high-quality melatonin supplement rather than a tryptophan supplement. The effects of melatonin, after all, are what most people seek when they take tryptophan. In addition, behavioral changes such as better sleep hygiene have been found in multiple studies to have the most dramatic effects. Ultimately, there is no guaranteed way to get the sleep you need without the hard work of keeping your circadian rhythm on track. Melatonin can help, but a heaping helping of turkey likely will not.

Increasing Prebiotics in Your Diet Improves Digestive Health, Sleep and More

Oct 22 by Ewcopywriting

Confused about the difference between probiotics and prebiotics and how they work together? Here, we will take a brief look at what probiotics and prebiotics are, break down the differences between these important digestive helpers and learn how increasing the prebiotics in your diet not only improves digestion but also supports immune function, promotes sleep, lowers stress and provides many other benefits.

What Are Prebiotics?

Prebiotics are types of nondigestible fibers and sugars found in certain foods. Because your body can’t break them down completely, these substances pass undigested through the upper parts of the gastrointestinal tract. Once the prebiotic compounds reach the colon, they’re fermented by the bacteria residing in the gut. There, they feed the communities of bacteria that make up the gut’s microbiota.

So, what exactly is the difference then between prebiotics and probiotics? The term “probiotics” typically refers to foods and supplements that contain live microorganisms known to be beneficial to gut health. Conversely, “prebiotics” are compounds that serve as food for the microorganisms that live in the gut. The also-related but less well-known “postbiotics” are the byproduct that occurs as a result of gut bacteria fermenting the prebiotic compounds. Individually, each of these components possesses a number of health benefits while also working together to improve digestive health and overall well-being.

Why Are Prebiotics Important?

The human body is a host to trillions of bacteria, the vast majority of which live within our large intestines. Many of these bacteria are critical to bodily functions. The bacteria in our guts not only aid in the digestion of food and absorption of nutrients but also help to regulate hormone production and neurotransmitter release, with a direct effect on the immune system and the body’s ability to cope with stress.

Because our guts are so integral to many bodily functions, the abundance and diversity of the good bacteria in our guts is important to our overall health. Prebiotics act as a food source for these bacterial colonies that reside within our GI tracts. Working together, prebiotics and probiotics have been shown to significantly improve health outcomes.

What Are the Benefits of Prebiotics?

Prebiotics improve digestion and promote a healthy gut. Acting as food for good bacteria, prebiotics encourage the growth of the beneficial microbes residing in our guts. When these otherwise nondigestible fibers are metabolized by friendly gut bacteria, the byproduct is another group of beneficial compounds known as short-chain fatty acids (SCFAs). SCFAs strengthen the intestinal lining, aid digestion, improve the symptoms of inflammatory bowel conditions and may even lower the chances of developing colorectal cancer.

Prebiotics reduce your risk for cardiovascular disease. Studies have shown that combining prebiotics and probiotics helps to regulate insulin signaling, lower “bad” cholesterol, balance electrolyte levels and reduce blood pressure, all factors that greatly reduce the risk of developing cardiovascular problems.

Prebiotics aid weight loss and the chances of obesity. Numerous studies have indicated that gut dysbiosis can be a contributing factor to weight gain and obesity-related disorders. Increased fiber intake is known to help curb weight gain. Researchers have found that prebiotic fiber regulates the stimulation and suppression of gastrointestinal hormones that control the feelings of hunger and satiation and is associated with a lowered BMI.

Prebiotics can help to reduce inflammation. Inflammation is believed to be a contributing factor for chronic conditions such as heart disease, diabetes and even some cancers. Studies have demonstrated that increased intake of prebiotic fiber lowers systemic inflammation. Research indicates that this association may be due to the production of SCFAs that occurs during prebiotic fermentation.

Prebiotics improve the body’s immune system response. A healthy gut is key to a strong immune system.Recent findings have shown that adding more prebiotics into your diet elevates SCFA levels and increases the expression of antibodies and antioxiants, important for helping the body to fight off illness and disease.

Prebiotics promote healthier, stronger bones. Imbalances to the gut microbiota have been tied to cases of disease and loss of density within bones. According to research, upping intake of prebiotics improves bone strength by increasing calcium absorption and bone density.

Prebiotics may improve sleep quality. Every cell in the human body responds to circadian rhythms, and this includes the microbial life within us. Under normal circumstances, subjects with a higher intake of prebiotics tend to spend more time in the restorative sleep phase, except for after stressful events, which observed longer periods of REM sleep, the phase of sleep thought to help recover from stress. This suggests that prebiotics encourage better, more restful sleep and help to ease stress. Prebiotics also alter the release of hormones such as melatonin and serotonin that are known to play a role in or have an effect on sleep and sleep quality.

Prebiotics help to regulate moods and hormone levels. As our knowledge of the gut-brain connection grows, it’s becoming more and more clear that many conditions, including mental health issues, are affected by gut health. Not only does our gut flora affect bodily function, but studies suggest that our gut’s microbial makeup may even be responsible for how bodily systems, such as our stress response system, are actually developed. Increased consumption of prebiotics has been shown to improve stress responses, reduce cortisol levels and alleviate feelings of depression and anxiety.

How to Incorporate More Prebiotics Into Your Diet

Want to know how you can increase your daily intake of prebiotics? There are a handful of prebiotic-rich foods that you can add to your diet. Remember that, as with most foods, cooking changes the nutritional makeup. For the most benefit, try to consume foods that are raw and unprocessed. Here are a few food choices that are packed with health-promoting prebiotics:

asparagus
chicory root
dandelion greens
garlic
jicama
leeks
onions
under-ripened bananas

Dietary supplements are also available for those unable to fit enough prebiotics into their diet. Look for supplements that combine both prebiotics and probiotics for the greatest impact.

Study Investigates Using Unique Formulation of 5-HTP and Tryptophan for Depression

Oct 08 by Ewcopywriting

Treating depression is one of the biggest challenges facing the field of modern primary care. Although we have treatments that can help, a cure remains elusive for millions of people suffering from this health disorder. According to new research on 5-HTP and tryptophan for depression, a unique formulation combining fast-release 5-HTP and timed-release L-tryptophan may help more people to get the relief that they need.

Depression in the Western World

Depression is an all too common health problem in the modern world. Studies have found that around 6.7 percent of people will suffer from this mental illness in any given year. More than just sadness, this disorder can involve changes in sleeping and eating patterns as well as a general loss of pleasure and motivation. Without effective treatment, depression often leads to negative long term changes such as an inability to work or the breakdown of formerly close relationships.

The current first-line medication is a class of drugs called SSRIs. While these drugs are the most effective choice for antidepressant medications, they successfully treat depression less than half the time. In addition, these medications can have devastating side effects such as fuzzy thinking, weight gain and a loss of sex drive. Although they increase blood levels of serotonin, the neurotransmitter responsible for feelings of happiness, the benefits of this class of medication sometimes are just not worth the side effects. While SSRIs remain the best treatment on the market, a growing number of people need a new solution. Could there be a natural alternative?

Research on 5-HTP and Tryptophan for Depression

5-HTP and tryptophan are both components of serotonin, the so-called happiness hormone. Increasing blood levels of these two building blocks appears to increase levels of serotonin. In fact, when taken orally, 5-HTP can cross the blood-brain barrier while orally administered serotonin cannot, allowing serotonin to be synthesized where it is most needed to improve mood. This suggests that both tryptophan and 5-HTP could potentially be effective for treating depression.

Although these natural substances have grown in popularity over the past several years, the research regarding 5-HTP and tryptophan as a depression treatment is mixed. The aforementioned study found that patients only saw a temporary lift in mood, but no change in depression as a whole. This is due to the fast metabolism of 5-HTP, which is used up in just two hours. The most complete meta-analysis on the subject compared both supplements to a placebo and found there was simply not enough evidence to determine if they were as effective as SSRIs.

New Formulations of 5-HTP and Tryptophan: Could Natural Remedies Be the Answer?

If the short life of 5-HTP and tryptophan are the reason these naturally occurring neurotransmitters are less effective, would an extended-release version be more effective? This was the question posed by researchers in a study from the University of Milan in Italy that was published in the journal NUTRAfoods. A team of biochemists and pharmacists developed a tablet with a novel formulation of the two popular natural remedies: The outer layer contained a fast-release version of 5-HTP while the internal portion had tryptophan and 5-HTP formulated to be released slowly throughout the day.

The new formulation was found in its first clinical trial to be effective for both mild and moderate cases of depression. In addition, it had relatively few side effects. It performed significantly better than placebo, which suggests that this treatment may present hope for people struggling to get control of a debilitating mood disorder. In addition, both 5-HTP and tryptophan are natural ingredients made by the human body as well as a variety of plants.

Could this be the natural and effective option so many are seeking? Although more study will be needed, the data is certainly promising.

Fighting Depression Naturally

Although this new formulation of 5-HTP and tryptophan is promising as a future alternative remedy, it is not the only natural way to deal with depression. Whether you use antidepressants or not, the following natural methods can help to fight the blues:

the popular herb St. John’s Wort
SAM-e, an amino acid naturally found in the human body
saffron, the popular spice found in Spanish and Indian cuisines
sleep, which has been found in multiple studies to reduce severity of mood disorders
exercise, especially vigorous outdoor exercise
omega-3 fatty acids, especially those found in fish oils

Doctors note that these natural remedies are most effective when used in combination with prescribed antidepressants and high-quality therapies. As with all supplements, it is important to discuss any natural remedies with your physician so you can find out if they are right for you. There is no cure for depression, but there is also no need to suffer alone. There are a huge range of medications and natural remedies that can help alleviate the symptoms of this destructive disorder.

Researchers Discover a Novel and Effective Treatment for Burnout Syndrome

Sep 27 by Ewcopywriting

While amazingly resilient to the effects of short-term stress, the human body simply can’t endure the constant assault produced by chronic stress for long periods of time. Long-term, unresolvable stress, whether it be job-related or otherwise, can eventually produce feelings of exhaustion, listlessness, inability to cope and even depression — a condition dubbed “burnout” in the 1970s by psychologist Herbert Freudenberger. Technically, there is no clinical definition or diagnostic criteria for “burnout.” Increasingly, however, health care professionals are recognizing burnout to be a serious mental health concern, impacted by both biological and lifestyle factors, which can have dire consequences if left unchecked.

To date, the most common approach to treating severe burnout is the prescription of antidepressant medications. While effective at managing burnout symptoms, these medications tend to be accompanied by adverse side effects such as weight gain and increased blood pressure. In a study published in the journal NUTRAfoods, researchers have identified a specific composition of amino acids that could be used to safely treat burnout without the negative side effects of antidepressants.

Stress and Mental Health

Mental health is an ever-growing area of concern. According to the National Institute of Mental Health, mental illness affects nearly 45 million adults in the U.S. That means that just about one in every five adults in America are living with some form of mental illness. Accounting for about 20 percent of all claims, mental health conditions are the second most common disability diagnosis in the U.S. and are estimated to cost the country roughly $193 billion in lost earnings each year.

Stress is necessary for survival. It is our natural defense mechanism against perceived danger. When we’re faced with a challenging situation, our bodies respond physically by releasing hormones to prepare for either confrontation or evasion. This “fight-or-flight” response mechanism helps us to know when and how to react in times of danger, but if triggered constantly, it has the power to deteriorate both mental and physical health.

5-HTP and L-Tryptophan in Mental Health and the Treatment of Burnout

There is an undeniable overlap between burnout and depressive symptoms. Previous research found that the amino acids 5-hydroxytryptophan (5-HTP) and l-tryptophan, both chemical precursors of serotonin, are effective treatments for mental health conditions such as depression, anxiety, and insomnia without many of the adverse effects that are generally associated with the use of antidepressants. Now, scientists analyzing the effectiveness of long-term use of a particular formulation of the two amino acids have determined that 5-HTP and l-tryptophan are also effective at treating the symptoms of burnout without the adverse effects of antidepressants.

In the study, a total of 64 volunteers from varied backgrounds who were between the ages of 25 and 55 were administered “a combination of fast-release 5-HTP and timed-release L-Tryptophan” over the course of a month. The nutraceutical formulation was designed to make the 5-HTP immediately bioavailable, while continuously releasing the l-tryptophan over a six-hour period. The mental state, burnout severity and general well-being of each participant was assessed daily, with any adverse side effects also documented in the case report. The blood pressure rate, body mass index and heart rate of each participant was recorded from the beginning of the study until 21 days after the study ended.

An analysis of the resulting data showed that burnout severity improved continuously over the course of treatment with an absence of adverse effects on heart rate, blood pressure or BMI. Evidence suggests that long-term treatments would see even more significant improvements over time.

The team believes the effectiveness of serotonin precursors in treatment to substantiate the theory that burnout may be in part due to “an underlying serotonergic mechanism”. The authors state within their findings, “the results of this study confirm the involvement of serotonin in burnout and indicate that continuous and repeated stress could exhaust the pool of serotonin and/or interfere with the CNS availability of this neurotransmitter.”

Their results showed 5-HTP and l-tryptophan to be effective at improving the mental and physical well-being of those with the early signs of burnout. The authors conclude, “treatment with controlled release serotonin precursors clearly demonstrated promising results in slowing the progression of early burnout syndrome by alleviating symptoms as shown by improved MBI and motivational index scores.”

The Consequences of Burnout: Impacts on the Brain and Body

Addressing the cause and treating the symptoms of burnout is critical to curbing the long-term effects that constant stress can have on the body. When our stress response is triggered, the body revs up production of chemicals such as adrenaline and cortisol, which are meant to increase energy, alertness and preparedness by upping blood pressure, heart rate, and blood glucose levels. Consistently high levels of these hormones hinder normal bodily functions like digestion, immune response and sleep-wake cycles.

Chronic stress is known to have a lasting impact on the physical structure of the brain and key systems of the body. Constant over-stimulation leads to premature aging and dysfunction in the nervous system, the HPA axis, the serotonergic system as well as emotion- and stress-regulating regions of the brain like the amygdala. Long-term stimulation of stress mechanisms can eventually lead to cortisol dysfunction and adrenal insufficiency, at which point, the symptoms of burnout are likely to become disruptive to both mental and physical health.

Signs of Burnout: Indications You Could Be Suffering From Too Much Stress

If not addressed, constant stress leads to the development of mental and physical health problems such as depression, obesity, heart disease, digestive problems and increased vulnerability to illness. Knowing what to look out for is important to be able to recognize the earliest signs of burnout. Here are some of the most common tells that the body is encountering too much stress:

feelings of fatigue and exhaustion
gastrointestinal difficulties
difficulty maintaining focus, concentration and attention
fixation on work or stressors during leisure time
increased negativity and feelings of frustration
a general lack of interest, drive and motivation
decreased job performance
lowered work and life satisfaction
sexual dysfunction
an increase in interpersonal troubles and social withdrawal
poor impulse control with regard to eating, sleeping and consumption of alcohol or stimulants

Prevention and Remedy: Things You Can Do About Burnout

Outside of pharmaceutical treatments and natural supplements, the generally accepted antidote for burnout is much the same as the preventative measures one may use to avoid it. A combination of lifestyle changes and behavioral interventions can help to curb the symptoms of burnout:

Be sure to get plenty of good quality sleep.
Manage time effectively by staying organized and setting goals and priorities.
Make ample time for relaxation and play.
Devote time to learning and personal growth.
Develop your support network of friends and family.
Delegate tasks to others when things are too much.
Find rewarding passions, challenges and hobbies unrelated to work.
Known when to turn off your phone and email.
Always pay attention to what your body is telling you.

Mood-Boosting Neurotransmitter Serotonin Enhances Learning Speed

Jul 12 by Ewcopywriting Leave a Comment

According to new data from the Champalimaud Centre for the Unknown (CCU) and University College London (UCL), the neurotransmitter serotonin plays a vital role in the learning process, helping to speed learning. Researchers believe this explains why selective serotonin reuptake inhibitor (SSRI) antidepressants are more effective when combined with cognitive behavioral therapy (CBT). Their findings were recently published in the journal Nature Communications.

The Different Roles of Serotonin

Serotonin, also known as 5-hydroxytryptamine (5-HT), is one of the major chemicals that nerves use for communication. It impacts every part of our bodies, but there is still much about the neurotransmitter and its many roles that is relatively unknown. Neuroscientists have long pursued an integrated theory as to exactly what serotonin does within the body and brain, but pinning down all of serotonin’s functions is a challenge.

Most commonly associated with mood regulation, we know that serotonin plays a variety of other key roles throughout the body. Around 90 percent of the body’s serotonin is actually located within the gastrointestinal tract, where it helps to regulate intestinal motility. Serotonin is also stored within blood platelets, acting as a vasoconstrictor during the clotting process. The rest of the body’s serotonin is synthesized by the central nervous system, where it aids in the regulation of appetite, behavior, mood, and sleep.

Previous research has linked serotonin with memory and neuroplasticity. This newest study supports those findings and provides further insight into serotonin’s effect on cognitive function.

Serotonin Enhances Learning Speed

In this latest study on the well-known neurotransmitter, researchers conducted a series of mice trials in which they observed that when serotonin neurons were artificially activated via light, an emerging technique referred to as optogenetics, the mice were quicker to adapt their behavior.

According to Zach Mainen, one of the study’s lead authors, “the study found that serotonin enhances the speed of learning. When serotonin neurons were activated artificially, using light, it made mice quicker to adapt their behavior in a situation that required such flexibility. That is, they gave more weight to new information and therefore changed their minds more rapidly when these neurons were active.”

To arrive at this conclusion, the researchers observed how mice reacted in a basic learning task where the goal was for the mice to get water from one of two sources. According to study co-author Madalena Fonseca of the CCU, “animals were placed in a chamber where they had to poke either a water-dispenser on their left side or one on their right, which, with a certain probability, would then dispense water, or not.”

The amount of water released and which dispenser it was released from was randomized so that the mice would need to continually adapt their strategy. In some of the trials, the researchers used the optogenetics technique to artificially boost serotonin release. Analyzing the data using a computational model developed by study co-author Kiyohito Iigaya of UCL, the team observed that the mice seemed to exhibit two distinct approaches to decision making depending on how quickly they made their choice.

Working Memory and Long-Term Memory: Two Different Learning Strategies

According to Iigaya, “To our surprise, we found that animals’ choice behavior was generated from two distinctive decision systems. On most trials, choice was driven by a ‘fast system’, where the animals followed a win-stay-lose-switch strategy. But on a small number of the trials, we found that this simple strategy didn’t explain the animals’ choices at all.”

It was this smaller subset of trials that revealed serotonin’s effect on the decision-making process. “Serotonin is always enhancing learning from reward, but this effect is only apparent on a subset of the animals’ choices,” said CCU co-author Masayoshi Murakami.

In the faster system, the mice relied on their working or short-term memory. However, when the interval between trials was longer, the mice utilized their long-term memory of all previous trials. According to their data, serotonin boosted learning from the history of all past rewards, but only affected the choices that were made during these longer intervals.

Iigaya explains, “on these trials, we instead found that animals followed their ‘slow system,’ in which it was the reward history over many trials, and not only the most recent trials, that affected their choices. Moreover, serotonin affected only these latter choices, in which the animal was following the slow system.”

The team believes that their findings may explain why SSRIs, which is a type of antidepressant that increases serotonin levels, is significantly more effective when combined with cognitive behavioral therapy, which is a form of therapy. The authors state, “our results suggest that serotonin boosts [brain] plasticity by influencing the rate of learning. This resonates, for instance, with the fact that treatment with an SSRI can be more effective when combined with so-called cognitive behavioral therapy, which encourages the breaking of habits in patients.