A new UK study has found that staying in sync with natural circadian rhythms – our daily sleep-wake and light-dark cycles – is linked to improvements in mood and cognitive functioning as well as a decreased likelihood of developing major depression and bipolar disorder.

Our internal body clock regulates multiple functions including body temperature and eating habits. Disruption of this clock, for instance through long-term night-shift work, has previously been associated with an increased risk of cancer, heart disease and obesity.

The observational study of over 91,000 people, aged 37 to 73, was conducted at the University of Glasgow and published in The Lancet Psychiatry.  It measured disruptions in sleep-wake cycles using a device called an accelerometer that is worn on the wrist and measures a person’s daily activity levels. Moods and mental well-being were measured using a standardised questionnaire.

Disruption leads to depression

Those with more circadian rhythm disruptions – defined as increased activity at night, decreased activity during the day or both – were significantly more likely to have symptoms consistent with bipolar disorder or major depression. They were also more likely to have decreased feelings of well-being and to have reduced cognitive functioning, based on a computer-generated reaction time test.

Lead researcher Professor Daniel Smith, professor of psychiatry at the university, noted: “It’s widely known that a good night’s sleep is a good thing for well-being and health. That’s not a big surprise. But I think what’s less well-known and what comes out of this work is that not only is a good night’s sleep important, but having a regular rhythm of being active in daylight and inactive in darkness over time is important for mental well-being.”

Aim for better sleep hygiene

Smith also says that it is still not certain whether an out-of-kilter body clock causes mental health problems, or if the mental health problems are causing disturbances to people’s daytime and night-time cycles.

However, findings from this study – the largest of its kind so far – are consistent with research indicating a link between sleep disruptions and mood disorders. Another British study in, for example, showed that men who worked night shifts for four years or more were more likely to have anxiety and depression than those who work during the day.

There is also evidence that the body clocks of people who suffer from depression are ‘out of sync’.

He adds that better sleep hygiene is key. ‘There are a lot of things people can do, especially during the winter, such as getting out of the house in the morning to get exposed to light and take exercise, so that by evening they are tired.

‘You can also turn off your mobile phone around 10pm because the light in it is telling your brain it’s daytime. But it is hard for some people, such as shift workers, because of their job or because of their family circumstances.’

Again this advice links to recent findings that taking a more mindful approach to using our phones, computers and tablets can make us happier.

• For more on circadian rhythms see our article The ancient clock that rules our lives – and determines our health

The international team of researchers from Brazil, Belgium, Australia, USA, UK and Sweden say their report is the first global meta-analysis to demonstrate that physical activity helps protect against depression.

The researchers began their study by collecting any past studies which looked at physical activity and depression. This yielded more than 13,000 papers from which they took the best 49, which involved 266,939 people from across Asia, Europe, North America, and Oceania. The average follow up time across these studies was 7.4 years.

“The evidence is clear that people that are more active have a lesser risk of developing depression,” said lead author Felipe Barreto Schuch, an exercise scientist at Universidade La Salle in Brazil. “We have looked at whether these effects happen at different age groups and across different continents and the results are clear. Regardless your age or where you live, physical activity can reduce the risk of having depression later in life.”

The findings, which were published in the  American Journal of Psychiatry, did not look at specific types of activity, but did take into account important factors like physical health conditions, smoking and body mass index. Even so they showed the value of engaging people in physical activity in a variety of settings, according to co-author Joseph Firth.

“The compelling evidence presented here provides an even stronger case for engaging all people in regular physical activity; through schools, workplaces, leisure programs and elsewhere, in order to reduce the risk of depression across the lifespan,” said Firth, a research fellow at the National Institute of Complementary Medicine at Australia’s Western Sydney University.

Physiological effects

The authors note that people with major depressive disorder are 50% less likely to be meeting the recommended physical activity levels (e.g., performing 150 minutes of moderate-intensity physical activity each week) compared with people without major depression.

They hypothesize that improving levels of physical activity reduces inflammation, increases neurogenesis, the process by which nervous system cells, known as neurons, are produced. This is important because increasingly research is suggesting that nerve cell connections, nerve cell growth, and the healthy functioning of nerve circuits have a major impact on depression. Exercise may also activate the endocannabinoid system, which has in the past been linked to exercise-induced euphoria, sometimes called ‘runner’s high’.

The study further suggests that physical activity may directly increase psychological factors such as self-esteem or perceptions of physical competence.

“Given the multitude of other health benefits of physical activity, our data add to the pressing calls to prioritize physical activity across the lifespan,” said co-author Brendon Stubbs, a postdoctoral research physiotherapist at King’s College London.

But you’ve got to commit

The findings come not long after another study from the University of Adelaide, published in the Journal of Affective Disorders, found that stopping exercise can result in increased depressive symptoms. The authors acknowledge that starting and maintaining exercise can have benefits on mental health – what they wanted to know was what happened if a person suddenly dropped their exercise regimen.

It’s not a questions that has had much focus but the research team found and reviewed studies that investigated the cessation of exercise in 152 adults. They had each undertaken at least 30 minutes of exercise, three times a week, for a minimum of three months.

“In some cases, ceasing this amount of exercise induced significant increases in depressive symptoms after just three days,” says Professor Bernhard Baune, Head of Psychiatry at the University of Adelaide and senior author on the paper.

Taken together these studies show the importance of not just starting but maintaining regular programme of physical activity in order to support good mental health.

• For other suggestions for addressing depression see our article: Depression – feeling your way out of the darkness

According to the UK’s NICE (National institute of Clinical Excellence) people who are diagnosed with a chronic physical health problem such as diabetes are 3 times more likely to be diagnosed with depression than people without it.

People with diabetes who are also suffering from depression are at greater risk of suffering from an episode of ‘diabetic burnout’ – a state of disillusionment and frustration around their disease and a consequent disregard for their blood sugar levels, which can seriously threaten their health.

Past research suggests that vitamin D supplementation has been shown to help improve both type-2 diabetes and some forms of depression, independent of one another. However, until now, there has been no data looking at women, who are statistically more likely to experience depression, and whether vitamin D could help.

In a recent study funded by the National Institute of Health (NIH), and published in the Journal of Diabetes Research, scientists tried to determine whether vitamin D supplementation could improve mental health status among women with type-2 diabetes.

Raising blood levels of the sunshine vitamin

A total of 50 women with type-2 diabetes and symptoms of depression were included in the study. All received weekly high-dose supplementation of 50,000 IU vitamin D2 per week for a total of 6 months (a dose that he been studied previously in obese individuals). Vitamin D2 is the form found in plant-based foods, as opposed to D3 which is found in meat and fish and which is synthesised by the body in the presence of sunlight.

The researchers used several standard tools to evaluate the participants’ mental and physical health status. Among their findings were:

• Compliance with the study was high; a total of 92% attended all of the required visits for the study.
• Blood levels of vitamin D (25(OH)D) increased significantly; from an average of 19 ng/ml (47.5 nmol/l) at the beginning, to 34.29 ng/ml (85.73 nmol/l) after 3 months and 37.6 ng/ml (94 nmol/l)
• The participants experienced a significant improvement in depression and anxiety symptoms, as well as mental health status.

Even after adjusting for several variables, including participants’ weight, their race and the season, the relationship between vitamin D supplementation and depression remained significant. Though not statistically significant, those who were not taking mood stabilising medications also experienced an improved response from vitamin D supplementation.

More data needed

The researcher’s chose to supplement the participants with large weekly doses of vitamin D2 instead of daily doses of D3, which has been proven to be more efficient in raising and maintaining healthy vitamin D levels. While the supplement regimen did increase blood levels of vitamin D, even after 6 months participants levels were still not within optimal range (40-60 ng/ml). Nevertheless the researchers believe that this initial research is promising.

It would be interesting to see the same study repeated with vitamin D3 and in particular see if those not on mood stabilising drugs had a bigger response, and indeed the researchers say they are already planning this as their next study. Watch this space.

Arginine is an amino acid which the body uses to produce nitric oxide which, among other things supports a healthy vascular and nervous system.

The study carried out by the University of Eastern Finland and Kuopio University Hospital compared 99 adults with diagnosed major depressive disorder to 253 non-depressed individuals. The concentrations of three amino acids, namely arginine, citrulline and ornithine, were analysed from their fasting glucose samples, and this data was used to calculate their global arginine bioavailability ratio (GABR) – an indicator of the body’s arginine levels.

The study also analysed whether these concentrations changed in people with depression during a follow-up of eight months, and whether remission of depression had an effect on the concentrations.

A role for inflammation?

People with depression had weaker arginine bioavailability than their non-depressed counterparts. The use of anti-depressants or anti-psychotics did not affect the concentrations, either. There were also no clear differences in the concentrations measured from people who had recovered from depression and people who remained depressed.

Toni Ali-Sisto, the lead author of the study, comments: “It is possible that depression-induced inflammatory responses lead to reduced arginine levels. This may result in insufficient production of nitric oxide for the needs of the nervous system and circulation. However, we don’t know yet what exactly causes reduced arginine bioavailability in people with depression,”

Although the results showed that people with depression have reduced arginine bioavailability, the researchers say this doesn’t mean that taking an arginine supplement would protect against depression. “That’s an area for further research,” Ali-Sisto says

About arginine

Arginine is considered a semi-essential amino acid because while it is needed for children’s growth, it has long been considered nonessential for healthy adults. The body can also make arginine in addition to getting it from food sources, so deficiencies are generally considered rare. However, a person can become deficient in arginine if the body’s production does not meet the body’s requirements or if, as this study suggests, something is interfering with the body’s ability to absorb it.

Adequate arginine can aid the production of nitric oxide, which widens and relaxes arteries and blood vessels, improving blood flow, help heal injuries, aid the kidneys in removing waste and boost immune system function.

Arginine can be taken as a supplement but too much can have side effects such as upset stomach and diarrhoea. Larger doses may also carry risks for people who take other medications or have certain health conditions.

A varied diet should help ensure you get adequate arginine and the best food sources of arginine are:

• Turkey
• Pork loin
• Chicken
• Pumpkin and squash seeds
• Sesame seeds, and tahini paste
• Soybeans
• Nuts, including peanuts, Brazils, pistachios, almonds, walnuts and cashews
• Spirulina
• Chick peas (garbanzo beans)
• Lentils
• Dairy foods

Researchers from Binghamton University in New York surveyed 463 people who were either under 30s (young adults) and over 30s (mature adults). Standard questionnaires were used to assess diet and exercise habits, as well as mental states. In particular, they looked at consumption of food groups containing constituents known to be associated with neurochemistry and neurobiology.

Published in the journal Nutritional Neuroscience ​the results suggest that the mood and healthy behaviour of young adults appears to be driven by diet and lifestyle elements that increase concentration and availability of neurotransmitter precursors in the brain. A higher meat intake and regular exercise may be the best choice, say the scientists.

In mature adults the critical determinants of mood and healthy behaviour were the availability of dietary antioxidants  and the avoidance of foods and dietary practices that activate the sympathetic nervous system. These include coffee, high-carbohydrate intake (particularly high glycaemic index carbs) and skipping breakfast.

Different ages, different needs

According to leading author Lina Begdache, assistant professor of health and wellness studies: “Regular consumption of meat leads to build-up of two brain chemicals (serotonin and dopamine) known to promote mood. Regular exercise leads to build-up of these and other neurotransmitters as well.​”

In this study, young adults who ate meat (red or white) less than three times a week and exercised less than three times week showed a significant mental distress, she said.

Conversely, says Begdache, as we age there is an increase in free radical (oxidant) formation, so our need for antioxidants increases.​ Not getting a steady supply of these in the diet can trigger our innate fight-or-flight response (commonly known as the stress response).​

“Free radicals cause disturbances in the brain, which increases the risk for mental distress. Also, our ability to regulate stress decreases, so if we consume food that activates the stress response (such as coffee and too much carbohydrates), we are more likely to experience mental distress.”​

The reason for the age-dependent response to different types of diet may be explained by brain maturity, she suggests, which may not bw complete until after the age of 30, and which may explain the different responses to food in otherwise healthy people.

The researchers note that, as this was an observational study, more information would be needed to draw firm conclusions. Even so, these preliminary results open the door to potential new insights into how our dietary needs, as they relate to overall wellbeing, change over time and how a one-size fits all approach to nutrition can let (some of) us down.

That’s the takeaway from a new US study that measured the neurological and behavioural impacts the placebo effect had on a group of recently broken-hearted volunteers.

“Breaking up with a partner is one of the most emotionally negative experiences a person can have, and it can be an important trigger for developing psychological problems,” said first author and postdoctoral research associate Leonie Koban, noting that such social pain is associated with a 20-fold higher risk of developing depression in the coming year. “In our study, we found a placebo can have quite strong effects on reducing the intensity of social pain.”

For decades, research has shown that placebos – sham treatments with no active ingredients – can measurably ease pain, Parkinson’s disease and other physical ailments.

Emotional responses

But this new study, published in the Journal of Neuroscience, is the first to measure their impact on emotional pain from romantic rejection.

Researchers recruited 40 volunteers who had experienced an “unwanted romantic breakup” in the past six months. They were asked to bring a photo of their ex and a photo of a same-gendered good friend to a brain-imaging lab.

The researchers used a magnetic resonance imaging (fMRI) machine, to measure brain responses to pictures of their ex, a supportive friend of the same gender and to physical pain. This provided a baseline against which the scientists could measure the effect of the placebo.  White the fMRI machine tracked their brain activity, participants were also asked to give a subjective rating to how they felt about these things on a scale of 1 (very bad) to 5 (very good).

While not identical, the regions that lit up during physical and emotional pain were similar.

This finding alone sends an important message to the heartbroken, said senior author Tor Wager, a professor of psychology and neuroscience at CU Boulder: “Know that your pain is real — neuro-chemically real.”

Brain changes

The subjects were then taken out of the machine and given a nasal spray. Half were told it was a “powerful analgesic effective in reducing emotional pain.” Half were told it was a simple saline solution.

Using the fMRI again, the subjects were again shown images of their ex and subjected to pain. The placebo group not only felt less physical pain and felt better emotionally, but their brain responded differently when shown the ex.

Brain imaging showed that activity in the brain’s dorsolateral prefrontal cortex – an area involved with modulating emotions – increased sharply. Across the brain, areas associated with rejection quieted. Notably, after the placebo, when participants felt the best they also showed increased activity in an area of the midbrain called the periaqueductal grey (PAG). The PAG plays a key role in modulating levels of painkilling brain chemicals, or opioids, and feel-good neurotransmitters like dopamine.

While the study did not look specifically at whether the placebo prompted the release of such chemicals, the authors suspect this could be what’s happening.

“The current view is that you have positive expectations and they influence activity in your prefrontal cortex, which in turn influences systems in your midbrain to generate neurochemical opioid or dopamine responses,” said Wager.

Do anything

Previous studies have shown that the placebo effect alone not only eases depression, but may actually make antidepressants work better.

“Just the fact that you are doing something for yourself and engaging in something that gives you hope may have an impact,” said Wager.

Bottom line, if you’ve been dumped recently: “Doing anything that you believe will help you feel better will probably help you feel better,” Said Koban

In the first researchers from the University of Reading, UK, looked at the effect of the daily consumption of a blueberry beverage (over a period of approximately one week) in 50 children and 21 young people.

Results showed that the flavonoid-rich blueberry drink, supplying  253 mg of anthocyanins, improved mood (or positive affect, PA) in both children and young adults. There was no effect on anxiety (or negative affect, NA)

“Although preliminary, these results are intriguing and warrant focused investigation of the relationship between flavonoids and mood, as well as with mental health more generally,” wrote the researchers in Nutrients.

“A low PA is more highly linked to depression, and high NA is more closely related to anxiety. Thus, these data suggest that the effect of flavonoid consumption on mood may be specific to depressive disorders, rather than pervasive across different mood states.”

How does it work?

While the study was not deigned to show how blueberries influenced mood, the researchers proposed two possibilities: The first involves a potential indirect effect on blood flow in the brain, which would enhance executive functioning, and “thus helping to inhibit cognitive features (i.e., rumination) that maintain depression”.

Another possibility is direct inhibition of the enzyme monoamine oxidase (MAO) by blueberry anthocyanins.

“MAO is involved in the oxidation of monoamines, some of which are neurotransmitters involved in the regulation of mood (e.g., serotonin, dopamine, and noradrenaline),” they explained. “MAO inhibitors have been used to treat mood disorders. Thus, the consumption of fruits high in flavonoids, such as blackcurrants, may significantly reduce MAO activity, thereby increasing circulating monoamines, and elevating mood,” they write.

The researchers concluded: “Given the potential implications of these findings for preventing depression, a disabling and common mental health problem in adolescents and adults, it is important to replicate the study and assess the potential to translate these findings to practical, cost-effective and acceptable interventions.”

And better memory in older adults

A separate study from researchers at Exeter University, UK, added to the potential cognitive effects of blueberries.

Scientists there report that blueberry concentrate may increase activity in select regions of the brain, and boost working memory in older adults (approximately 68 years of age).

For the study, published in Applied Physiology, Nutrition, and Metabolism, participants were given either a placebo drink or 30 ml of blueberry concentrate per day (providing 387 mg anthocyanidins) for 12 weeks. Results showed “significant increases in brain activity … in response to blueberry supplementation relative to the placebo”.

The scientists also found that compared to placebo, working memory improved in the blueberry group.

“Supplementation with an anthocyanin rich blueberry concentrate improved brain perfusion and activation in brain areas associated with cognitive function in healthy older adults,” they concluded.

These findings are similar to those of a 2010 study which found that a daily drink of about 500 mL of blueberry juice was associated with improved learning and word list recall, as well as a suggestion of reduced depressive symptoms in older people with early memory problems.

US researchers wanted to examine the “acute effects of brewed cocoa consumption on attention, motivation to perform cognitive work and feelings of anxiety, energy and fatigue.”

In a nearly year-long small double-blind study, two dozen university aged student were split into groups that consumed either brewed cocoa, cocoa with caffeine, caffeine without cocoa, or a placebo with neither caffeine nor cocoa prior to performing a series of cognitive tests. None of the test drinks included milk, but they were sweetened with stevia.

The study had a crossover design, which meant that the groups was given each of the drinks in the four test periods over the course of the year.

Results of the study, which was sponsored by the chocolate manufacturers Hershey, were published in the journal BMC Nutrition.

Who says science can’t be fun?

The coffee and or cocoa drink were made in a regular (Mr Coffee)  coffee maker.

After drinking their brewed drinks, the participants were asked to do tests to evaluate both cognitive tasks and mood.

Results showed quicker response rates from those who drank cocoa, but those drinking the caffeine-cocoa concoction had higher accuracy than those with the cocoa drink alone.

The study found another interesting statistic in that the caffeine had a negative effect on people’s moods: when compared to the placebo group, those who had only caffeine in their drink were angrier. Consuming cocoa along with the caffeine lessened those feelings of anger along with anxiety.

“It was a really fun study,” said lead researcher Ali Boolani a professor at Clarkson University, New York.

“Cocoa increases cerebral blood flow, which increases cognition and attention. Caffeine alone can increase anxiety. This particular project found that cocoa lessens caffeine’s anxiety-producing effects – a good reason to drink mocha lattes!”

“The results of the tests are definitely promising and show that cocoa and caffeine are good choices for students and anyone else who needs to improve sustained attention,” he adds.

Brewed cocoa?

Cocoa beans can be roasted, ground and brewed just like coffee and some people do use them in this way as a healthier alternative to coffee.

Cocoa contains only a small amount of caffeine (approximately 5-fold and 20-fold less caffeine per ounce than cola and coffee, respectively). But even small amounts of caffeine can influence attention and mood and cocoa, of course, has other constituents such as antioxidant flavonols and the stimulant theobromine which have been shown to improve alertness and choline and tryptophan (which have been shown to influence mood, motivation or cognitive performance.

“We’ve known for some time that there is a clear association between the quality of people’s diets and their risk for depression,” said lead author Professor Felice Jacka Director of Deakin University’s Food and Mood Centre.

“This is the case across countries, cultures and age groups, with healthy diets associated with reduced risk, and unhealthy diets associated with increased risk for depression.

Her team’s findings, she said, offer up a possible new treatment approach to depression, one of the world’s most prevalent – and costly – medical disorders.

Focus on nutrition

The 12-week study, involving 67 adults with major depressive disorder, claims to be the first randomised controlled trial to directly test whether improving diet quality can actually treat clinical depression.

Participants were recruited and randomly assigned to receive either social support, which is known to be helpful for people with depression, or support from a clinical dietitian, over a three-month period.

The dietary group received information and assistance to improve the quality of their current diets.

For this groups the main focus was on increasing diet quality by supporting the consumption of the following 12 key food groups:

• whole grains (5–8 servings per day)
• vegetables (6 per day); fruit (3 per day)
• legumes (3–4 per week)
• low-fat and unsweetened dairy foods (2–3 per day)
• raw and unsalted nuts (1 per day)
• fish (at least 2 per week)
• lean red meats (3–4 per week)
• chicken (2–3 per week)
• eggs (up to 6 per week)
• olive oil (3 tablespoons per day)

The programme also included limits on certain ‘extra’ foods, such as sweets, refined cereals, fried food, fast-food, processed meats and sugary drinks (no more than 3 per week).

Red or white wine consumption beyond 2 standard drinks per day and all other alcohol (e.g. spirits, beer) were included within the ‘extras’ food group.

From depression to remission

Results, published in the international journal BMC Medicine, showed that participants in the dietary intervention group had a much greater reduction in their depressive symptoms over the three-month period, compared to those in the social support group.

At the end of the trial, a third of those in the dietary support group met criteria for remission of major depression, compared to 8 percent of those in the social support group.

“These results were not explained by changes in physical activity or body weight, but were closely related to the extent of dietary change,” Professor Jacka said.

“Those who adhered more closely to the dietary program experienced the greatest benefit to their depression symptoms.”

Professor Jacka, who is president of the International Society for Nutritional Psychiatry Research, said the findings offered an important new strategy for the treatment of depression.

“Mental disorders account for the leading cause of disability worldwide, with depression accounting for the large proportion of that burden,” she said.

“While approximately half of sufferers are helped by currently available medical and psychological therapies, new treatment options for depression are urgently needed.

Wider protection

“Importantly, depression also increases the risk of and, in turn, is also increased by common physical illnesses such as obesity, type 2 diabetes and heart disease. Successfully improving the quality of patients’ diets would also benefit these illnesses.”

The study suggests the new possibility of adding clinical dieticians to mental health care teams and making dietitian support available to those experiencing depression.

“It also supports the previous extensive research from human population studies and animal research suggesting that diet is a key determinant of mental and brain health,” Professor Jacka said.

Indeed a Mediterranean diet – strongly associated with the food components emphasised in this study – has been linked with a 30% reduced risk for depression as well as chronic disease.