Beneath the psychological blows lie a biological landscape that can quietly set the stage for low mood, anxiety, irritability and exhaustion

By Dina Gavarieva

A new study has added an important piece to the puzzle of depression – and why women may be more vulnerable to it.

Researchers at the QIMR Berghofer Medical Research Institute in Queensland, Australia, have discovered that women carry almost twice as many genetic variants linked to major depressive disorder as men.

In the largest study of its kind, these genetic ‘flags’ also appear to overlap with metabolic traits such as weight fluctuation and fatigue, which may explain why depression often manifests differently in women.

The findings reinforce what many have long suspected – depression and anxiety aren’t purely psychological conditions, but the result of a complex mix of genetics, biology and environment.

Yet in most clinics, treatment still focuses on the mind while the body’s role is largely ignored.

That’s not to downplay the importance of trauma, grief or chronic stress, which are powerful triggers for mental illness, but beneath those emotional blows lies a biological landscape that can quietly set the stage for low mood, anxiety, irritability and exhaustion. It’s time we began investigating those underlying layers with the same seriousness we apply to psychological causes.

Take nutrition, for example. Certain vitamins and minerals are indispensable to brain chemistry, and their absence can quite literally alter mood, motivation and clarity of thought.

A deficiency in vitamin B12 can cause fatigue, irritability, brain fog and even neuropathy.

Folate, or vitamin B9, is another example whereby low levels have long been linked to depression. Its active form, L-methylfolate, is sometimes prescribed alongside antidepressants to improve their effectiveness.

Low vitamin D is now widely known to affect mood, especially in people who get little sunlight, while even a mild iron deficiency can leave you tired, foggy and flat.

Thyroid function, too, sits at the crossroads of mood and metabolism. When thyroid hormones dip, depression and sluggishness often follow. When they surge, anxiety and restlessness tend to appear.

The thyroid’s health depends partly on nutrients such as iodine and selenium – deficiencies that are rarely discussed in mental health consultations.

Other nutrients also play a big part in keeping mood and energy on an even keel.
Vitamin B6, for instance, helps the brain make serotonin and GABA – the chemicals that steady our emotions and quiet anxious thoughts. A lack of thiamine (vitamin B1) can leave you tired and irritable, while too little niacin (B3) or riboflavin (B2) can drain vitality and darken mood.
Magnesium, another often-overlooked mineral, helps the nervous system relax and promotes deep sleep; when levels drop, restlessness and anxiety tend to rise.

Low zinc can blunt both mood and mental sharpness, and omega-3 fats, particularly the EPA found in fish oils, are well known for supporting emotional wellbeing.

Even protein intake plays a part in how we feel because it isn’t solely about building muscle – it also feeds the brain.

The amino acids in protein help make the chemicals that control mood and focus, like serotonin and dopamine.

If you’re not eating enough protein, or your body isn’t absorbing it properly, your brain may struggle to stay balanced.

Another key nutrient, choline, helps with memory and clear thinking, and too little of it can leave you feeling foggy or low.

While nutritional deficiencies can subtly undermine mental health, toxic exposures can erode it more dramatically.

Heavy metals such as lead, mercury, arsenic, cadmium, manganese and copper are known to affect the nervous system, sometimes with devastating psychological consequences. Lead exposure has been linked to depression, irritability and cognitive decline; mercury toxicity can cause anxiety, insomnia and tremors; arsenic and cadmium, often found in contaminated water, rice or cigarettes, have both been associated with fatigue and low mood.

Even an imbalance between copper and zinc has been tied to agitation and irritability.

Then there are the modern industrial and agricultural chemicals that quietly infiltrate our lives.

Organic solvents such as toluene and benzene, used in paints and fuels, can damage the brain and alter mood.

Pesticides, particularly organophosphates and carbamates, have been linked to higher rates of depression and anxiety among agricultural workers.

Chemicals found in everyday plastics and household products, such as BPA, phthalates and PFAS, are now being studied for how they might affect our hormones and mood.

And perhaps the most frustrating truth behind all of this is that many psychiatrists are not trained to look for these triggers.

Patients aren’t routinely tested for nutrient deficiencies, thyroid dysfunction or heavy metal exposure – despite a growing body of evidence suggesting that these biological factors can be just as significant as trauma or genetics and, in many cases, they interact.

 A woman who already carries a higher genetic predisposition for depression, as the Australian study indicates, may find that low iron, sub-optimal thyroid function or long-term exposure to pollutants pushes her further towards illness.

In short, her genes load the gun and her biology and environment pull the trigger.

In the modern world we live in, our psychological health cannot be separated from our physical health.

A nutrient-starved brain cannot think clearly or feel joy; a toxic body cannot rest easily; a dysregulated thyroid cannot sustain calm.

If we truly want to tackle depression and anxiety, we need to think systemically. That means looking beyond antidepressants and counselling alone, and towards comprehensive investigations that include blood tests for B-vitamins, vitamin D, iron stores, zinc, magnesium and thyroid function; assessments of omega-3 status and protein intake; and, where relevant, screens for toxic exposures or hormonal disruptors.

It also means recognising that every patient is biochemically unique. What works for one may not work for another, particularly across the sexes.

The findings from Queensland are not a reason for despair; they are a call for precision.

If women are indeed genetically more susceptible to depression, then their treatment plans should reflect that reality.

We need a model of care that connects psychiatry with hormone health, nutrition, and environmental medicine – one that sees the person as a whole, not just a collection of symptoms.

Dina Gavarieva is a qualified naturopath practising at Neomed Institute and Medical Centre, Limassol