Why is it that some people are happier than others? Our grandparents tell a story of endless cheeriness, despite the depression and the second world war. Meanwhile, despondent millennials flood the internet and social media with tales of genuine mental illness; many schools and workplaces now have their own psychologist to help with the tidal wave of mental health issues which are growing daily.
Between 15-30% of people today suffer from an active mental health condition. Without diving into the statistics, the rate of mental health issues is actually higher than ever recorded before.
The answer lies in our friends, the animals. When I travel, I make a point of going to the local zoo. In some countries, we see well fed, well cared for animals in open ranges. They interact with their friends, sleep under the stars, have the finest food and want not for nothing. In other countries I visit, I see animals well out of their climate, displaced, caged and lonely. They are haggard, with fur missing and have an unmistakable look of despair. You see them and feel their pain.
Like Elton John’s skyline pigeon, a trapped animal is always ‘dreaming of the open’ and ‘waiting for the day’. Many of us, even when mildly distressed, declare that we are ‘over it’ and reach for the vacation to Bali, the retreat, the new diet, the new lifestyle or even the new partner!
It is human intuition to seek a new environment when we are unwell. However, sometimes things get so bad that we cannot manage the effort. We ignore our instincts about our jobs, other people, our families; or perhaps lack the money or luck to change.
Mental health does not exist in a vacuum, in a state only of our minds. This is the mantra of much of pop psychology; but it simply is not true.
We are humans and we live in an ecosystem. That ecosystem is one of air, water, food and the people around us. All of it reaches into our body and directs a vast and complicated chemical traffic that impacts us.
This article discussed the basics of the brain chemistry, the gut, the hormones and how they related to the brain. As you read it, think of yourself and ask the question, ‘What is my zoo doing to me?’
Before we are born
From before we even leave the womb, we hear our mother’s voice. At the same time, we can sense her hormones and neural traffic. Is the blood reaching the uterus, and us, full of relaxing and happy signals or is it full of oxidising free radicals, distress chemicals, cortisol and other portents of harm?
The environment before we are born is termed the antenatal environment. Studies have shown that it has a long term impact on the baby if the mother experienced mental health issues whilst carrying the child. These include a lower birth weight, difficult temperament and different responses. Studies also show that depression is more likely in a person if their mother had depression whilst pregnant.
In addition, how about various chemicals, drugs, radiation, and noise pollution which enter the uterus? What long term effect do they have on the brain? In a world with over 80 000 new chemicals, we can only speculate that they must have an impact.
Early childhood
Early childhood is critical for long term development. This includes the formation of our attachment, personality, emotions, physical health, gut health and our intellectual abilities. Studies show very clearly that the environment after we were born, termed neonatal, has a huge impact on our long term likelihood of developing mental health issues.
Factors here are broad and include the household setting, use of drugs, poor diet, repeated antibiotics, exposures to chemicals. They also include how we are shaped to interact with the world.
Personality
Personality is the sum total of our beliefs about ourselves and how we relate to the world around us. The way our brains are shaped from the womb onwards, by both the physical and psychological environment, will shape how we respond to life’s events. This may lead us to anxiety, suspicion or paranoia or perhaps to a lack of self worth, guilt, shame and despondency. Our personalities come from our childhood environment and have a huge impact on our future mental health.
Psychological context
What messages are people hearing about today? Is it a story of happiness or of constant threat and risk? Those in high risk professions dealing with bad stories of harm (think ambulance drivers) have been shown to have higher rates of depression and mental distress. There are some studies showing higher rates of mental distress amongst those concerned about climate change.
Naturally, bad news is not new. However, our perception of bad news does matter; do we balance the troubles of this world or are they one catastrophe on another?
Recently there have been lots of studies on Doomscrolling; which is the act of people glued to their devices reading about bad news. Unsurprisingly, this brought on a lot of psychological distress.
In summary, do we have a culture of worrying endlessly about everything? Or do we keep calm and carry on? Are we Greta Thunberg or Steve Irwin? Sometimes, if you seek a problem, you will find it. The question is whether we have to take it deep enough to hurt our mental health.
What are some of the medical factors that underpin our mental health?
Our brain uses multiple chemicals, called neurotransmitters, that help us see the world clearly and maintain a calm mood
- Dopamine is a neurotransmitter that helps alertness, concentration, mood and general ‘up and go’. It is also a reward neurotransmitter
- Serotonin is a calming and happiness neurotransmitter; it is mostly produced in the gut
- Noradrenaline is a concentration and mood neurotransmitter in the brain
- Acetylcholine is the main neurotransmitter of the ‘parasympathetic nervous system’ this helps us digest, relax and ‘slow down’ whilst the sympathetic nervous system is its opposite; for fight or flight responses.
- Histamine is a chemical often made in the gut. It is a major cause of allergies such as hives. In the brain, it promotes wakefulness but also a form of aggression or poor treatment of others and irritability.
- Endorphins are our happiness and pleasure molecules. They are released from pleasure, exercise and sex (Arnold Schwarzenegger once famously likened weightlifting to being like ‘I am coming’). Production of endorphins is lower in people with anxiety or depression.
- Oxytocin is a love molecule. It helps bonding between people and is released during sex and socialising. It is sometimes used as a medication for couples needing an aphrodisiac. It is a potent treatment for anxiety.
GABA and glutamate
Gamma Amino-butyric acid, or GABA, is one of the main inhibitory neurotransmitters. It slows things down. Alcohol and diazepam (or valium) release more GABA. Drugs that produce GABA are actually used as the emergency treatment for epileptic seizures which are caused when the neurotransmitters misfire dramatically leading to uncontrolled muscle activity.
Glutamate is the precursor molecule to GABA; it turns into GABA. However, glutamate itself is associated with anxiety.
Depression has been associated with lower levels of effective activity of both glutamate and GABA. GABA itself has been used to help with depression. This suggests that something wrong in the production of glutamate and GABA can have an impact on mental health overall.
It is also worth noting that prolonged anxiety can turn into depression; what is bad for the brain in one way is bad in all ways; including mood, memory and energy.
In order for glutamate to be made into sufficient amounts of GABA, the brain requires certain nutrients such as Vitamin B6 (Pyridoxal 5 Phosphate or P5P is the active form), Magnesium, Zinc and good levels of Vitamin B12 in order to make the conversion. People with deficiencies of these often have more anxiety and depression too. This is a part of the reason why magnesium is used to calm the mood and help with muscle cramps.
You can read about relevant health topics by clicking the short articles below:
- Neurotransmitters
- Neuroinflammation
- Dopamine
- GABA & Anxiety herbs
Inflammation
Inflammation is the chemical reaction that occurs when the cells are under threat. When there is an infection, trauma or injury, invasion of a bug into our gut or a lack of vitamins that the body needs to function, cells will get distressed. When this happens, they release special inflammatory chemicals. These chemicals also tend to cause more glutamate than GABA, diminish certain neurotransmitters and thus lead to anxiety and depression. As an example, just about every form of illicit drug addiction can lead to depression as can heavy metals toxicity.
You can read about relevant health topics by clicking the short article below:
- Neuroinflammation
Sleep
When we sleep, our brain releases a hormone called melatonin. Melatonin enhances how well GABA works. Furthermore, melatonin also promotes Brain Derived Neurotrophic Factor or BDNF. As this neat name suggests, BDNF helps our brain cells recover overnight, produce more neurotransmitters and also with memory.
When we wake up in the morning, melatonin is much less and cortisol is released from the adrenal gland. Cortisol is a stress hormone; it is typically at its highest at 5am in the morning when melatonin is at its lowest. By night, cortisol is lower and melatonin will be released.
Anything that disrupts our ‘diurnal rhythm’ (the day night rhythm in hormones) will cause poor sleep and poor brain health. This includes caffeine, late nights out, alcohol, certain drugs and jetlag.
Poor sleep is a major cause of anxiety and depression. We need good melatonin to be released so that our nerves can rest, be awash in BDNF and produce good neurotransmitters. Ideally, we go to bed with the sun and we are up with the sun; early morning sun exposure has been shown to help release cortisol, improve serotonin and enhance melatonin falling at the right time. Studies have also shown an improvement on mood.
Sleep deprivation is an ancient form of torture. Depriving somebody of sleep has been known to cause memory issues, depression, anxiety and even hallucinations. It is a standalone risk for crashing your car and there are now road safety campaigns all around Australia reminding people to pull over if they are tired. Long haul truck drivers are particularly at risk of depression from sleep deprivation; this would apply to any job facing shift work or sleep interruption.
Unfortunately, this is far too common in all workplaces in the age of email and should be addressed as a priority Work Health and Safety Issue.
In summary, our brain needs good sleep to function.
Vitamins and Minerals
As mentioned before, our nerves need vitamins to fuel their recovery and produce neurotransmitters. Key vitamins matter in the production of neurotransmitters and the balance of glutamate/GABA. They include…
- Magnesium
- P5P or Vitamin B6
- Methylation (A process using all the B vitamins for cell function)
- Vitamin B12
- Zinc
Vitamins are not just about what we eat but also the total health of our gut. In order to have good nutrition we need to consider the foods we eat, how natural and whole they are, the function of our gut and also whether we live in a part of the world with low minerals in the soil. A major risk factor for malnutrition linked depression is chronic alcohol ingestion, which strips the body of B vitamins. Iron deficiency is common in women and is also a known risk factor for depression.
We will touch on nutrition later in this article.
You can read about relevant health topics by clicking the short articles below:
- B12
- Vitamin (whole section)
- Zinc
What about our hormones?
Many of our hormones have a major impact on Glutamate/GABA, neurotransmitter production, brain function, melatonin and BDNF to name a few
- Testosterone is generally good for anxiety; testosterone deficiency is associated with anxiety
- High estrogen or ‘estrogen dominance’ is associated with anxiety; especially before menopause
- Low progesterone is associated with lower GABA
- High levels of thyroid hormone can cause anxiety
- Low levels of thyroid can also cause anxiety as they lower GABA
- Synthetic or ‘fake’ hormones from chemicals in the environment can lead to higher anxiety
Low estrogen and progesterone in menopause and low testosterone are both known risk factors for depression. This can occur in any age and not just a condition of older people.
You can read about relevant health topics by clicking the articles below:
- Thyroid
- Estrogen Dominance
- Testosterone deficiency
Heavy metals and poisons
For those who have read Alice in Wonderland, we are all familiar with the mad hatter. In the old days, Mercury was used in the production of hats. This is a toxic metal and would produce mental health symptoms.
Mercury, Cadmium, Lead, Arsenic and to a lesser degree, Copper excess can all be associated with anxiety and depression.
There are a few specific disorders where people will accumulate copper in the body. One is called Wilson’s disease, due to a genetic defect. Another is called Pyrrole disorder; where zinc is lost and copper is retained. We also have to think about industrial exposures such as those working in factories or in plumbing.
You can read about relevant health topics by clicking the short articles below:
- Heavy metals
- Pyrrole disorder
- Wilson’s Disease (Copper)
Environmental Toxicity
We live in a world of chemicals. Compared with our ancestors, we are faced with literally thousands of man-made chemicals that our body was never able, nor had to, break down. These chemicals can accumulate in the body and disrupt how well our nerves function and repair themselves.
Some of these chemicals are industrial such as fumes, building materials, paints, solvents, insecticides, pesticides, fragrances etc. whilst some are used in the household. Household chemicals include food preservatives and colourings, artificial flavours as well as chemicals in beauty products, cleaning products etc.
As an example, aspartame is a sweetener that has been linked to anxiety symptoms.
Eating a healthy diet, fasting, exercise, good sleep, sweating and sauna all help clear toxins and are associated with lower anxiety. The use of a sauna has been studied extensively in multiple studies and is worth reading more on.
You can read about relevant health topics by clicking the short articles below:
- Environmental toxicity
- Sauna and sweating
Exercise and Detoxification
Detoxification means getting the toxins out of your body. This starts with not putting them in! Consider smoking, alcohol and clean eating the foundation point for this. In addition, when we sweat and when we exercise we are able to get rid of a lot of toxins. This is a part of the reason why exercise is very good for mental health
Exercise has many other benefits; light exposure, social connection, good hormones, sleep improvement. The health benefits of exercise are well known and there is very little that cannot be improved in your health from exercise.
Gut and Liver
Our gut contains 100 trillion bacteria, about three times as many cells as we have in our bodies.
These bacteria are critical for life. They are a biochemical factory; they produce significant amounts of vitamins, neurotransmitters, hormones and other chemicals that are essential for good health.
Sometimes, in the context of so many chemicals and synthetic foods in our world, our digestive system cannot cope. It is overwhelmed and instead of good bacteria getting into our gut (commensals) we get a nest of bad bacteria (this is called Dysbiosis).
When this happens, our health can suffer dramatically. These bacteria will eat our food, produce toxins, rob us of key vitamins that the good bacteria should make and shower our body in toxic inflammatory chemicals. Overall, they will make it harder for our liver to process toxins and harder for our nerves to function.
There is an incredible association between gut health and mental health. Probiotics have repeatedly been shown to be modestly effective in anxiety, depression and ADD/ADHD (Attention Deficit Disorder). Imbalances in gut bacteria have been shown to be associated with anxiety. A higher amount of lactobacillus (a common good bacteria) is associated with lower rates of depression.
Dysbiosis, which means the wrong kind of bacteria living in our gut in the wrong balance with the good ones, is associated with mental health problems. In fact, dysbiosis is increasingly being recognised as the root of many illnesses including diabetes, fatty liver, high blood pressure and so on. Just because you do not have gut symptoms does not mean you do not have dysbiosis!
The liver, digestive system and gut should be thought about as one big ecosystem. Considering the function of your gut, the presence of irritable bowel syndrome symptoms and your diet should be a major consideration in treating anxiety.
You can read about relevant health topics by clicking the short articles below:
- Gut microbiome and dysbiosis
- Endotoxin
- Glucuronidation
Diet
Food is a major contributor to our health. As already mentioned, our brain cells require significant key nutrients to function well. Our gut is a major driver of good mental health with the bacterial balance being substantially influenced by the kinds of food we eat.
A highly processed food diet has been linked to depression whilst the mediterranean diet has been shown to have a lower rate of depression. The mediterranean diet is notable for its high levels of good fats, B vitamins and roughage; which is basically dietary fiber that acts as a probiotic to feed our good bacteria in the gut.
Finally, toxic chemicals get in the way of our brain cells functioning well. These do not just come from factories, cars and man made chemicals but also as the waste products of bacteria we do not want living in our gut in high numbers.
You can read about relevant health topics by clicking the short articles below:
- Omega 3 and 6
- Big Four Dietary Mistakes
- Bile
- Children’s nutrition
- Cow’s milk & other milks
Tips
- Consume organic foods rich in fiber and nutrients.
- Vegetables are better for our gut bacteria; they help lower inflammation, provide higher nutrients and are associated with less anxiety.
- The Mediterranean diet is associated with a lower chance of anxiety, depression and dementia. This diet involves a lot of variety of salads and vegetables with a generous use of Extra Virgin Olive Oil
- Foods which are high in saturated fats (french fries) are associated with more inflammation and more mental health symptoms; we should eat less of them
- Non-healthy diet patterns are associated with ADHD in children demonstrating the toxicity to the brain
- Chronic alcohol consumption is a clear cause of anxiety; it significantly lowers Vitamin B12 levels.
Dementia and Cognitive Decline
The dark underbelly of anxiety and depression is neuroinflammation; damage and hardship to the cells in our brain. All the factors we have discussed in this article that combine to cause mental health problems can also cause other cognitive and mental diseases.
For example, whilst some people may end up with anxiety, almost exactly the same bundle of factors can cause depression, memory issues, aggression, ADD and even psychosis. They are a variation on a theme.
Over the long term, neuroinflammation is a risk factor for dementia. Our cells will not live forever. Over time, all cells do not reproduce as well and we lose cells via programmed cell death. This is called ageing.
The more poorly we treat our cells, the faster they age. I often like to tell my patients to imagine two people; one is a person under a bridge drinking cheap wine every single day and smoking 40 cigarettes whilst the other is a farmer in the sun, non-smoker, eating organic food and exercising every day. Which one is more likely to get dementia?
All factors that underlie anxiety and depression are a risk factor for dementia. Anxiety is known to be a risk for dementia. This highlights how critical it is to treat the underlying factors of anxiety early and hard.
You can read about relevant health topics by clicking the articles below:
- Mitochondrial Function and Aging
- Nutritional and Environmental Medicine
- ADD and ADHD
- Cognitive Decline
Society and other people
So far, we have discussed the chemistry of good mental health. However, our environment is more than just the sum of the chemicals that enter and play around in our body; it also includes the people in our lives. Going back to our zoo story, what other animals are in your cage or enclosure? Are you an otter with lions or with otters?
In general, strong and warm relationships with people are essential to diminish fear and anxiety. When we feel that we can trust the people around us and have no reason to be in competition with them, we are more at ease with the world and will have lower anxiety.
Loneliness is the mother of all problems; an environment of retribution and fear will rub off on our psychology and lead to higher anxiety.
What to do to look after our mental health?
There is no easy answer here. Once I had a patient sit in my office for 40 minutes describing genuine despair about his whole life. He was cripplied with anxiety and depression and did not know what to do. After a while, I told him he needed to go on a long holiday and not go back. He needed fresh air, sunshine, new friends. We had tried every other treatment including psychology, antidepressants, vitamins to no avail.
Sometimes a change in environment is key. However, there are a range of places to start and that includes all the factors above.
The suggestions are broadly the same for depression and anxiety:
The goal of treatment is:
- to improve brain rest and repair,
- support the vitamins,
- improve the neurotransmitter production
- Support a healthy gut
- support the liver in detoxifying neuroactive compounds.
Lifestyle changes
- Minimise alcohol
- Optimise sleep; REM is an important hormonal cycle phase of sleep where many neurotransmitters are made
- Minimise stress as best you can; if necessary, change your work, home or environment
- Experience early morning sunshine
- Diet; consider regular fasting, it reduces inflammation from the gut
- A Keto diet has been used to assist with neurotoxic disorders; it has been shown to increase dopamine production
- Ketones also promote higher GABA to glutamate ratio, calming nerves down; consider the keto diet and minimising carbohydrates
- Foods: high vegetable intake, soups, cut out saturated fats (fries, burgers) and consume fresh food and vegetables.
- Take up cooking
- Get rid of soft drinks in your fridge and juice (they have too much sugar)
- Eat with others at the dinner table; this is more social and better for your digestion
- Take up a new hobby; this can be very social and helps to distract the mind and reward your brain with dopamine
- Exercise: group exercise is often easier and more motivating
- Form key relationships with supportive people
- Consider buying a dog or spending time with one; they are good friends for the price of a bit of food
- If friends pressure you to go out and get drunk, start forming friendships over lunch or informal house parties; it is less anxiety provoking and confronting
- Take up reading; it is a great distraction
Supplements and nutrition
Supplements are best taken with the advice of your doctor, ideally based on blood tests. Nonetheless, there are some key starting points for most people. These treatments are based on adults and should not be done for children <50kg.
Disclaimer: Treatments for anxiety should always be done in conjunction with your healthcare professional.
The following are the supplements I prescribe most often for anxiety:
- Vitamin B6 or P5P (the activated version) 40mg taken once in the morning
- Magnesium, such as Magnesium citrate 500mg twice per day; although I find that powdered magnesium is more effective in water
- Zinc Picolinate 15mg twice per day (be careful not to take too much over time)
- Lactulose 5-10mL twice per day is a useful prebiotic; it boosts the number of good bacteria in the gut and can help reduce inflammation
- Saccharomyces Boulardii taken once per day is a yeast probiotic that helps
- Fish Oil (supports brain health)
- Phosphatidyl Choline (supports nerve cell walls)
- Liquid melatonin at night time (easy to take)
- NAC 600mg twice per day for 3 months can help the liver detoxify; it is best not to take it more than 3 months
- SAMe is a supplement used to support ‘methylation’, this is the pathway that involves folate and B12 helping cells reproduce. It is especially helpful for some patients
- Folate 400mcg or 0.4mg once per day
- CBD and this is illegal in many jurisdictions but when used appropriately it has a role to play.
For really keen:
- L Theanine 100mg Taken before bed
- Taurine 250mg
- GABA itself (150mg) best taken before bed
- Inositol (antiinflammatory and insulin sensitising)
- L Tyrosine (a precursor amino acid to Dopamine),
- Rhodiola and curcumin are anti-inflammatory.
- Probiotics: Aim for high doses >250 billion colony forming units including L casei, L rhamnosus
- Aim for good Vitamin D levels (best to have blood tests)
- Herbal: Ashwagandha, Chamomile, Lemon balm, Valerian
Some tips
- Supplements are best taken in discussion with your healthcare provider
- Consider starting supplements a short while after eating, it softens the blow on the stomach
- Start one supplement at a time and wait a few days; your stomach won’t like it if you swallow 20 capsules at once!
- If a new supplements causes stomach problems or an unwanted reaction, stop it immediately, discuss with your healthcare provider and wait a while before trying to take it again
The bottom line
Supplements will not help if they are not addressing a problem that actually exists in you. You will always get more out of supplements if they are targeted and rational.
Medications
For severe cases, the first line medication therapy for both anxiety and depression would be a class of antidepressants known as SSRIs or SNRIs, followed by more advanced medications.
It is important to remember that depression and anxiety medications do not produce more neurotransmitters, they only redistribute them. They are very valuable and rightly used medications, however a nutritional and lifestyle focus is also important to heal the underlying issues
Finally, the use of benzodiazepines for ‘short term’ panic attacks can be considered in patients without a history of drug abuse; but as a last resort. Further treatments exist for more significant cases and referral to a Psychiatrist may be considered.
Disclaimer
As always, you should seek help from your actual doctor before taking any therapy. Vitamins and supplements are generally safe however there are some conditions that these will make worse. You should read this as a guide only and not a substitute for formal, supervised care.
You can read about all the relevant health topics by clicking the articles below:
- Mitochondrial Function and Aging
- Nutritional and Environmental Medicine
- ADD and ADHD
- Cognitive Decline
- Omega 3 and 6
- Big Four Dietary Mistakes
- Bile
- Children’s nutrition
- Cow’s milk & other milks
- Gut microbiome and dysbiosis
- Endotoxin
- Glucuronidation
- Environmental toxicity
- Sauna and sweating
- Heavy metals
- Pyrrole disorder
- Wilson’s Disease (Copper)
- Thyroid
- Estrogen Dominance
- Testosterone deficiency
- B12
- Vitamin (whole section)
- Zinc
- Neuroinflammation
- Neurotransmitters
- Neuroinflammation
- Dopamine
- GABA & Anxiety herbs
References
Cakal E. (2019). “Befogging reason, undermining will: Understanding the prohibition of sleep deprivation as torture and ill-treatment in international law. Torture : quarterly journal on rehabilitation of torture victims and prevention of torture, 29(2), 11–22. https://doi.org/10.7146/torture.v29i2.109620
Choudhary, A. K., & Lee, Y. Y. (2018). Neurophysiological symptoms and aspartame: What is the connection?. Nutritional neuroscience, 21(5), 306–316. https://doi.org/10.1080/1028415X.2017.1288340
Chao, L., Liu, C., Sutthawongwadee, S., Li, Y., Lv, W., Chen, W., Yu, L., Zhou, J., Guo, A., Li, Z., & Guo, S. (2020). Effects of Probiotics on Depressive or Anxiety Variables in Healthy Participants Under Stress Conditions or With a Depressive or Anxiety Diagnosis: A Meta-Analysis of Randomized Controlled Trials. Frontiers in neurology, 11, 421. https://doi.org/10.3389/fneur.2020.00421
Clapp, M., Aurora, N., Herrera, L., Bhatia, M., Wilen, E., & Wakefield, S. (2017). Gut microbiota’s effect on mental health: The gut-brain axis. Clinics and practice, 7(4), 987. https://doi.org/10.4081/cp.2017.987
Crizzle, A. M., McLean, M., & Malkin, J. (2020). Risk Factors for Depressive Symptoms in Long-Haul Truck Drivers. International journal of environmental research and public health, 17(11), 3764. https://doi.org/10.3390/ijerph17113764
Field T. (2011). Prenatal depression effects on early development: a review. Infant behavior & development, 34(1), 1–14. https://doi.org/10.1016/j.infbeh.2010.09.008
Kalenik, A., Kardaś, K., Rahnama, A., Sirojć, K., & Wolańczyk, T. (2021). Gut microbiota and probiotic therapy in ADHD: A review of current knowledge. Progress in neuro-psychopharmacology & biological psychiatry, 110, 110277. https://doi.org/10.1016/j.pnpbp.2021.110277
Khera M. (2013). Patients with testosterone deficit syndrome and depression. Archivos espanoles de urologia, 66(7), 729–736.
Liu, Y., Heron, J., Hickman, M., Zammit, S., & Wolke, D. (2022). Prenatal stress and offspring depression in adulthood: The mediating role of childhood trauma. Journal of affective disorders, 297, 45–52. https://doi.org/10.1016/j.jad.2021.10.019
Luscher, B., Shen, Q., & Sahir, N. (2011). The GABAergic deficit hypothesis of major depressive disorder. Molecular psychiatry, 16(4), 383–406. https://doi.org/10.1038/mp.2010.120
Pinto, S., Correia-de-Sá, T., Sampaio-Maia, B., Vasconcelos, C., Moreira, P., & Ferreira-Gomes, J. (2022). Eating Patterns and Dietary Interventions in ADHD: A Narrative Review. Nutrients, 14(20), 4332. https://doi.org/10.3390/nu14204332
Nguyen, E., Meadley, B., Harris, R., Rajaratnam, S. M. W., Williams, B., Smith, K., Bowles, K. A., Dobbie, M. L., Drummond, S. P. A., & Wolkow, A. P. (2023). Sleep and mental health in recruit paramedics: A 6-month longitudinal study. Sleep, zsad050. Advance online publication. https://doi.org/10.1093/sleep/zsad050
Satici, S. A., Gocet Tekin, E., Deniz, M. E., & Satici, B. (2023). Doomscrolling Scale: its Association with Personality Traits, Psychological Distress, Social Media Use, and Wellbeing. Applied research in quality of life, 18(2), 833–847. https://doi.org/10.1007/s11482-022-10110-7
Schaub, AC., Schneider, E., Vazquez-Castellanos, J.F. et al. Clinical, gut microbial and neural effects of a probiotic add-on therapy in depressed patients: a randomized controlled trial. Transl Psychiatry 12, 227 (2022). https://doi.org/10.1038/s41398-022-01977-z
Schwaab, L., Gebhardt, N., Friederich, H. C., & Nikendei, C. (2022). Climate Change Related Depression, Anxiety and Stress Symptoms Perceived by Medical Students. International journal of environmental research and public health, 19(15), 9142. https://doi.org/10.3390/ijerph19159142
Ventriglio, A., Sancassiani, F., Contu, M. P., Latorre, M., Di Slavatore, M., Fornaro, M., & Bhugra, D. (2020). Mediterranean Diet and its Benefits on Health and Mental Health: A Literature Review. Clinical practice and epidemiology in mental health : CP & EMH, 16(Suppl-1), 156–164. https://doi.org/10.2174/1745017902016010156
Zheng, L., Sun, J., Yu, X., & Zhang, D. (2020). Ultra-Processed Food Is Positively Associated With Depressive Symptoms Among United States Adults. Frontiers in nutrition, 7, 600449. https://doi.org/10.3389/fnut.2020.600449
