Beyond “No Reason”: A Systems Approach to Understanding and Healing Persistent Sadness

For years, I lived under a gray cloud.

It wasn’t the dramatic, crashing storm of major depression you see in movies.

It was more like a persistent, drizzling fog that settled deep in my bones.

I was a high-functioning professional, successful by every outward measure, but inside, I carried what felt like an ocean of sadness.¹

There was a constant, low-grade ache, a fatigue that no amount of sleep could touch, and a muted quality to life, as if the volume on joy had been turned all the way down.

The most maddening part? There was no reason.

I would rack my brain, searching for a cause for the hollowness, the pit of emptiness that felt so physical it was as if it lived inside me.¹

My life was, by all accounts, good.

Yet, I felt like a stranger looking in, unable to connect with the happiness that should have been mine.

Friends and family, with the best intentions, would offer advice that only deepened my isolation.

“Snap out of it,” they’d say.

“Just be positive.” “You have so much to be grateful for.”.²

Each piece of advice felt like a small paper cut on an already aching wound, a confirmation of my own secret fear: that I was fundamentally broken, a failure at the simple act of being happy.

This chronic, low-grade sadness has a name: Persistent Depressive Disorder (PDD), also known as dysthymia.⁴

It’s a continuous, long-term form of depression where symptoms may ebb and flow in intensity but rarely disappear for more than two months at a time.⁴

A core feature of this experience is often anhedonia—a “markedly diminished interest or pleasure in all, or almost all, activities”.⁶

It’s not just sadness; it’s the absence of joy, the inability to feel pleasure from things you once loved, which can affect up to 70% of people with depression.⁶

I wasn’t just sad; the world had lost its color.

My journey through this fog was long and frustrating, filled with failed attempts to follow the standard advice.

I tried to exercise more, eat better, and think positively, but the changes were fleeting, the gray cloud always rolling back in.

I felt like a mechanic trying to fix a sputtering engine by polishing the hood.

It was only when I stumbled upon a concept from a completely unrelated field that the fog finally began to lift.

I realized I had been asking the wrong question all along.

In a Nutshell: The Shift from “Why?” to “How?”

For anyone wrestling with this invisible weight, here is the essential shift in perspective that changed everything for me.

• The Old Question (and its trap): “Why am I sad for no reason?” This question sends you on a fruitless hunt for a single, linear cause. It assumes that a specific event or thought is the sole culprit. When you can’t find one, you’re left with confusion, frustration, and self-blame. You conclude the problem must be you.
• The New Question (and its power): “How is my system functioning that it produces sadness as an output?” This question reframes the entire problem. It moves you from blame to curiosity. It suggests that your emotional state isn’t a mysterious flaw but a predictable outcome of a complex, interconnected system.
• The Core Idea: Persistent sadness is often a signal—like a “check engine” light—that the entire system of your well-being is out of balance. The solution isn’t to find and fix one broken gear but to understand and gently tune the entire engine. This report is your guide to becoming the chief engineer of your own well-being.

The Epiphany: Discovering the Blueprint of You

The Day I Stopped Trying to Fix a Gear and Started Looking at the Engine

My turning point didn’t come from a self-help book or a therapy session.

It came from reading about Systems Thinking, a way of understanding the world used in fields like engineering and ecology.⁷

The core idea is simple but profound: you can’t understand a system by just looking at its individual parts.

You have to understand how the parts

interact with each other.⁸

A car, for example, is a system.

It has an engine, wheels, a transmission, and an electrical system.

If you take all those parts and lay them on a garage floor, you don’t have a car anymore.

You have a pile of junk.

It is the dynamic interaction of those parts that creates the emergent property of “transportation”.¹⁰

If the car is sputtering, a good mechanic doesn’t just check the spark plugs.

They consider how the fuel system, electrical system, and engine are all working together.

I realized I had been treating my sadness like a single, faulty spark plug.

I was trying to fix one part—my thoughts, my diet, my exercise—in isolation, without understanding how it connected to everything else.

Systems thinking gave me a new analogy: the iceberg.⁷

The sadness I felt, the “reasonless” depression, was just the tip of the iceberg—the part that was visible above the water.

All the conventional advice was focused on chipping away at that visible tip.

A systems approach demanded that I look beneath the surface, to understand the massive, unseen structure of interconnected factors that was creating and supporting that tip.

My sadness wasn’t the problem; it was a

symptom of a dysregulated system.

Introducing Your Personal Ecosystem: A New Map for Well-Being

This realization allowed me to create a new map for my own well-being, one that I call the “Personal Ecosystem.” It views our health not as a collection of separate issues, but as a holistic system composed of three major, interconnected subsystems.

When one is out of balance, it creates ripple effects throughout the others, and the feeling of “being sad for no reason” is often the result.

• System 1: The Control Center (Your Brain, Mind & Nervous System): This is the hardware and software that governs your experience of the world. It includes your brain’s physical structure and chemistry, your ingrained thought patterns, and the state of your nervous system.
• System 2: The Power Plant (Your Physical Body): This is the biological foundation that provides the fuel and raw materials for the Control Center. It encompasses your gut health, the food you eat, and the quality of your sleep. It’s the engine room of your entire being.
• System 3: The Climate (Your External World): This is the environment in which your internal systems operate. It includes your relationships, social connections, work environment, and life stressors.

For the first time, I had a framework that could hold all the complexity of my experience.

The sadness wasn’t “reasonless.” Its reasons were just distributed across a system I had never been taught to see.

Tuning the System: A Guided Tour of Your Inner World

Understanding this map is the first step.

The next is learning how to read it and make adjustments.

Let’s take a deep dive into each subsystem, exploring the hidden connections that produce the persistent fog of dysthymia.

The Control Center: Your Brain, Mind & Nervous System

This is the command hub of your ecosystem.

When it’s not functioning optimally, the entire system suffers.

This dysfunction isn’t a matter of willpower; it’s rooted in biology and experience.

The Hardware: Brain Chemistry & Genetics

It is crucial to understand that persistent depression is a real, biological illness.

People with PDD may have physical changes in their brains and differences in naturally occurring brain chemicals called neurotransmitters, such as serotonin, dopamine, and norepinephrine.⁴

This is not a personal failing.

Furthermore, depression has a significant genetic component.

Research on twins suggests that the heritability of major depression is likely 40-50%.¹³

This means that if you have a parent or sibling with major depression, your own risk is two to three times higher than average.¹³

Accepting this biological reality is the first step toward self-compassion.

You didn’t choose this, any more than someone chooses a genetic predisposition for heart disease.

It simply means your system may be more vulnerable to dysregulation.

This knowledge frees you from the burden of guilt and allows you to approach your well-being like a responsible steward rather than a failed optimist.

The Ghost in the Machine: How the Body Keeps the Score

One of the most profound insights into the “reasonless” nature of chronic sadness comes from understanding how past experiences, especially trauma, are stored in the body.

Many people with persistent low mood have a history of difficult childhoods, traumatic events, or chronic stress.⁴

As psychiatrist Bessel van der Kolk details in his seminal work,

The Body Keeps the Score, trauma is not just a bad memory.

It is an experience that fundamentally reshapes the brain and body, creating a hyperactive alarm system that gets stuck in a state of fight, flight, or freeze.¹⁵

The body literally holds onto the raw emotions and survival instincts of the event, even when the conscious mind has tried to move on.¹⁶

This creates a devastating feedback loop that directly fuels anhedonia and persistent sadness.

Here is how the system connects:

1. Trauma Creates a Hypervigilant Nervous System: A history of trauma or chronic stress calibrates your nervous system to be on constant high alert. Your body is perpetually braced for a threat that is no longer present, secreting stress hormones that wreak havoc on your immune system and organs.¹⁵
2. Hypervigilance Destroys Restorative Sleep: This state of constant alarm is physiologically incompatible with deep, restorative sleep. Sleep is not just a period of rest; it is a critical time for brain maintenance.¹⁷ Brain activity fluctuates through different stages, allowing for the processing of memories and emotions.¹⁸ A hyper-aroused nervous system prevents the brain from fully entering these restorative states.
3. Poor Sleep Impairs Positive Emotion Processing: Research from the Sleep Foundation highlights a critical link: a lack of sufficient sleep, especially REM sleep, is particularly harmful to the brain’s ability to consolidate positive emotional content.¹⁸ Your brain literally loses its capacity to process and store experiences of joy, connection, and pleasure.
4. Impaired Processing Leads to Anhedonia: This neurological impairment manifests as anhedonia—the core dysthymic experience of life feeling flat, gray, and joyless. The world feels less vibrant because the very brain machinery required to perceive its vibrancy is offline, starved of the restorative maintenance that sleep provides.
5. Anhedonia Reinforces the Trauma Response: This anhedonic state, this feeling of hopelessness and disconnection, is interpreted by your nervous system as further evidence that the world is an unsafe, unrewarding place. This reinforces the original state of hypervigilance, which in turn further disrupts sleep, locking you into a vicious, self-perpetuating cycle.

The sadness feels “reasonless” because its source isn’t a current event or a conscious thought.

It is a physiological echo of the past, amplified by the downstream cascade of a dysregulated nervous system and sleep-deprived brain.

The reason isn’t in the now, which is precisely why looking for it there is so confusing and frustrating.

The Software: Defragmenting Your Thoughts

While you can’t simply will your brain chemistry to change, you can absolutely learn to manage the “software”—the patterns of thinking and behavior that run on that hardware.

This is where evidence-based psychotherapies become powerful tools for system regulation.

• Cognitive Behavioral Therapy (CBT): CBT is a structured form of therapy that helps you identify, challenge, and change the unhelpful thoughts and beliefs that are hallmarks of depression.¹⁹ For example, a common depressive thought pattern is “overgeneralization,” where one negative event (e.g., “I made a mistake on that report”) is generalized into a global negative belief (“I’m a complete failure”). CBT provides practical tools to catch these automatic negative thoughts and reframe them into more realistic and balanced ones.²⁰ It’s like running a defragmentation program for your mental hard drive.
• Behavioral Activation (BA): This is a particularly powerful approach for combating the inertia of anhedonia.²² When you feel no joy or motivation, the natural tendency is to withdraw and do less, which only deepens the depression. BA works to reverse this cycle by helping you gradually decrease avoidance and isolation and increase your engagement in activities—even if you don’t “feel like it”.²⁰ The goal isn’t to force yourself to have fun, but to schedule activities that were once rewarding or that align with your values. This provides your system with new data. By engaging in the behavior, you create the
  possibility of a positive experience, which can slowly begin to reactivate the brain’s dormant reward circuits. It’s about acting your way into feeling better, not waiting to feel better before you act.

The Power Plant: Your Physical Body

For decades, we treated the mind as if it were separate from the body.

We now know this is profoundly wrong.

Your brain does not float in a void; it is a physical organ housed within a larger biological system.

The health of that system—your Power Plant—is arguably the most overlooked and most critical factor in persistent sadness.

The Second Brain: The Gut-Brain Axis

This is perhaps the most revolutionary insight for anyone who feels sad for “no reason.” There is a massive, bidirectional communication network connecting your gut and your brain, known as the Gut-Brain Axis (GBA).²³

This isn’t a fringe theory; it’s a well-established field of neuroscience.

This axis consists of neural, hormonal, and immune pathways that allow your gut to constantly “talk” to your brain, and vice-versa.²⁶

In fact, the network of neurons in the gut is so extensive it’s often called the “second brain”.²⁷

The key players in this communication are the trillions of microbes living in your gut—your microbiome.

These microbes are not passive passengers; they are a veritable chemical factory, producing and influencing a vast array of compounds that directly affect your mood.

1. Your Gut as a Neurotransmitter Factory: An astonishing 90% of your body’s serotonin—the “feel-good” neurotransmitter targeted by many antidepressants—is produced in your gut, a process heavily influenced by your gut bacteria.²³ Gut microbes also produce or influence other critical mood-regulators like dopamine (related to motivation and reward) and GABA (the primary calming neurotransmitter).²³
2. Dysbiosis: An Imbalance in the Factory: When the community of gut microbes is unhealthy and out of balance—a state called “dysbiosis”—the production of these vital mood-regulating chemicals can plummet.²³ This can be caused by factors like a poor diet, chronic stress, or courses of antibiotics.²⁸
3. Leaky Gut and Neuroinflammation: An unhealthy microbiome often leads to increased intestinal permeability, or “leaky gut.” This allows inflammatory molecules from bacteria, such as lipopolysaccharide (LPS), to escape the gut and enter the bloodstream.²⁹ Even small amounts of LPS in the blood are known to trigger significant symptoms of anxiety and depression, as they provoke an inflammatory response in the brain itself (neuroinflammation).²⁹

This chain of events is a game-changer.

It means you can be experiencing all the classic neurological symptoms of depression—low mood, crushing fatigue, anhedonia, brain fog—not because of a negative thought or a life event, but because your internal Power Plant is malfunctioning.

Your gut is sending constant signals of distress, inflammation, and chemical deficiency up to your brain via the vagus nerve and other pathways.²⁶

The sadness feels “reasonless” because its origin is invisible to your conscious mind.

You can’t “think” your way out of it because the problem isn’t a thought.

It’s a physiological state originating in your gut.

This is profoundly empowering because it moves the problem from the realm of the abstract and intractable to the realm of the tangible and actionable.

It means what you eat matters.

The Fuel: Nutritional Psychiatry

If your gut is a garden, then the food you eat is the soil and fertilizer.

Nutritional psychiatry is an emerging field that studies the direct link between diet and mental health.³¹

The connection is no longer theoretical; it’s grounded in the science of the GBA.

• The Pro-Inflammatory Diet: A diet high in ultra-processed foods (UPFs)—packaged snacks, sugary drinks, frozen meals—is strongly linked to an increased risk of depression.³² One large study found that women eating nine or more servings of UPFs per day had a 50% higher risk of developing depression.³² These foods fuel the growth of inflammatory gut bacteria, promote dysbiosis, and contribute to the neuroinflammation that drives depressive symptoms.³⁵ Artificial sweeteners, common in many UPFs, have also been independently linked to a higher risk of depression.³²
• The Anti-Inflammatory Diet: Conversely, traditional whole-food diets like the Mediterranean diet are associated with a lower risk of depression.³⁰ These diets are rich in fiber, which is indigestible by humans but serves as the primary food for our beneficial gut microbes. When these microbes ferment fiber, they produce incredibly beneficial compounds called Short-Chain Fatty Acids (SCFAs), such as butyrate, acetate, and propionate.²³ These SCFAs are anti-inflammatory, help maintain a healthy gut barrier (preventing “leaky gut”), and have neuroprotective effects on the brain.²³

To fuel your Power Plant for optimal mental health, focus on incorporating foods rich in these key nutrients ³⁵:

• Omega-3 Fatty Acids: Found in oily fish like salmon and mackerel, as well as walnuts and flax seeds. They are vital for brain health and have anti-inflammatory properties.
• B Vitamins (especially Folate/B9 and B12): Found in leafy greens, legumes, and eggs. They are essential for producing the neurotransmitters that regulate mood.
• Magnesium: Found in leafy greens, nuts, seeds, and dark chocolate. It is vital for the body’s stress response and promotes relaxation.
• Zinc: Found in organ meats, shellfish, and legumes. It can help ease symptoms of stress and anxiety.
• Vitamin D: Often called the “sunshine vitamin,” it plays a role in mood, sleep, and digestion.
• Fiber: Found in fruits, vegetables, whole grains, and legumes. It’s the essential fuel for your beneficial gut bacteria.

The System Reboot: The Foundational Role of Sleep

Sleep is the master regulator of your entire ecosystem.

It is during sleep that your body and brain perform essential repair and maintenance.

As discussed, there is a clear bidirectional relationship: depression disrupts sleep, and sleep deficiency makes depression worse.¹⁷

Ongoing sleep deficiency doesn’t just make you tired; it fundamentally impairs the functioning of your Control Center.

It leads to problems with decision-making, emotional regulation, memory, and coping with change.¹⁷

After just a few nights of losing even one or two hours of sleep, your cognitive function can be as impaired as if you hadn’t slept at all for a full day or two.¹⁷

Improving sleep hygiene is not a “cure” for depression, but it is a non-negotiable prerequisite for healing.

No other intervention—therapy, medication, or diet—can be fully effective if the system is not getting the fundamental reboot it needs each night.

Key practices include ¹⁸:

• Consistency: Go to bed and wake up at the same time every day, even on weekends. This helps regulate your body’s internal clock.
• Create a Wind-Down Routine: Signal to your body that it’s time to sleep. Dim the lights, put away electronic devices an hour before bed, read a book, or take a warm bath.
• Optimize Your Environment: Make your bedroom as dark, quiet, and cool as possible.
• Get Morning Sunlight: Exposure to natural light shortly after waking helps to set your circadian rhythm for the day.
• Avoid Evening Stimulants: Limit caffeine and alcohol, especially in the hours before bed.

The Climate: Your External World

No ecosystem exists in a vacuum.

The health of your internal world is profoundly influenced by the climate of your external world—your connections, your environment, and your stressors.

You Are Not an Island: The Biology of Connection

Humans are a social species.

Social connection is not a luxury; it is a biological necessity.

Loneliness and isolation are significant risk factors for depression.¹

When you feel depressed, the instinct is often to retreat into your shell, but this only deepens the problem.⁴⁰

Reaching out and talking to a trusted person—a friend, family member, or therapist—is a powerful intervention.

The person you talk to doesn’t need to “fix” you or offer solutions.

The healing power lies in the act of connection itself.⁴⁰

Being heard and validated by someone who cares is deeply regulating for a nervous system stuck in a state of alarm.

It sends a powerful signal to the Control Center that you are safe and not alone.

Weathering the Storms: Systemic Stress

Just as a plant struggles to thrive in a harsh climate, your internal ecosystem will struggle under the weight of chronic stress.

Traumatic events, financial problems, work overload, or unsupportive relationships can all trigger or sustain P.D.⁴

A systemic approach to mental health recognizes that an individual’s distress often makes sense within the context of their relationships and environment.⁴¹

Sometimes, the most effective way to reduce personal stress is to address unhealthy dynamics in the larger systems you are a part of, whether that’s your family, your workplace, or your social circle.

This can involve setting boundaries, improving communication skills, or making difficult decisions about which environments are no longer healthy for you.

Tending the Garden: Cultivating a Supportive Environment

While you can’t always control the weather, you can tend your own garden.

This means actively cultivating an environment that supports your well-being.

This is not about grand gestures but small, consistent actions that provide your system with positive, regulating inputs.

Consider developing a “wellness toolbox” of activities that you can turn to for a quick mood boost, even when you don’t feel like it.⁴⁰

This might include:

• Spending Time in Nature: Walking in a park or hiking can ease stress and improve mood.³⁹
• Caring for a Pet: The unconditional affection and responsibility of caring for an animal can be incredibly therapeutic.⁴⁰
• Engaging in a Hobby: Pick up a former hobby or try something new. Creative expression through music, art, or writing can be a powerful outlet.³⁹
• Mindfulness and Meditation: These practices teach you to observe your thoughts and feelings without judgment, reducing their power over you. Mindfulness has been shown to provide as much relief from some depression symptoms as antidepressants.³⁶
• Movement: Regular exercise is one of the most effective ways to alleviate depressive symptoms. It releases mood-boosting endorphins and stimulates the growth of new nerve cells in the brain.³⁶

The Integrated Path Forward: Becoming the Architect of Your Own Well-Being

The feeling of being “sad for no reason” is one of the most disempowering experiences a person can have.

It leaves you feeling broken, flawed, and a victim of a mysterious ailment.

The systems approach offers a radical and liberating alternative.

Your sadness is not a mystery, and you are not broken.

It is a valid and understandable signal from a complex, interconnected system that is out of balance.

The “reason” is not a single event but a cascade of interactions between your brain and body, your past and present, your internal state and your external world.

By learning to see yourself as a Personal Ecosystem, you shift from being a victim to being a steward.

You are the architect of your own well-being.

You now have a map and a set of tools.

You understand that tuning your Power Plant with nourishing food and restorative sleep provides the necessary foundation for your Control Center to function.

You know that calming your nervous system through mindfulness and connection makes it possible to change your thought patterns.

You recognize that cultivating a supportive external Climate reduces the load on your entire internal system.

This is not a one-time fix.

It is a lifelong practice of curiosity, compassion, and gentle, consistent action.

There will still be cloudy days.

But you will no longer be lost in the fog.

You will have a compass, a map, and the knowledge that you have the power to navigate your way back to the light.

Your Systems-Thinking Toolkit

To help you put this framework into practice, the table below contrasts the old, ineffective way of thinking about these issues with the new, integrated systems approach.

Use it as a reference to guide your actions as you begin to tune your own personal ecosystem.

Table 1: The Personal Ecosystem – A Systems-Based Action Plan

System & Component	The Old Way (Single-Point Failure)	The Systems Approach (Integrated Action)
CONTROL CENTER: Thought Patterns	Trying to force “positive thinking” or “just snap out of it” while the brain is under-fueled and inflamed. This often leads to more guilt and frustration when it fails.2	Support brain function from the ground up. Combine an anti-inflammatory, nutrient-dense diet (to fuel the brain) with mindfulness (to calm the nervous system) and Behavioral Activation (to create new positive feedback loops).20
CONTROL CENTER: Nervous System State	Ignoring the physical sensations of stress and anxiety, or treating past trauma as “just in your head” and something you should be “over by now”.2	Recognize that “the body keeps the score”.15 Use body-based practices like yoga, deep breathing, or somatic exercises to help regulate the nervous system and release stored trauma, creating a state of safety that allows for psychological healing.37
POWER PLANT: Gut Microbiome	Treating gut issues (like bloating or IBS) as a separate, unrelated problem from mood, or ignoring them altogether.28	View the gut as your “second brain.” Actively cultivate a healthy microbiome with a diet rich in fiber (vegetables, fruits, legumes) and fermented foods, while minimizing ultra-processed foods that cause inflammation and dysbiosis.23
POWER PLANT: Nutrition	Relying on willpower to eat “healthy” without understanding the biochemical reasons. Viewing food as calories rather than as information that instructs your genes and gut bacteria.35	Practice nutritional psychiatry. Prioritize key mood-supporting nutrients like Omega-3s, B vitamins, and magnesium. Understand that a whole-foods diet directly reduces neuroinflammation and provides the building blocks for neurotransmitters.35
POWER PLANT: Sleep	Treating sleep as a luxury or something to “catch up on.” Trying to function through chronic sleep deficiency and accepting fatigue as a personality trait.17	Treat sleep as non-negotiable system maintenance. Establish rigorous sleep hygiene as the foundation for all other mental health efforts, recognizing its critical role in emotional processing and brain repair.18
CLIMATE: Social Connection	Isolating yourself when you feel down, believing you are a burden to others and that you should handle it alone.40	Make connection a proactive strategy. Schedule time with trusted, supportive people. The act of sharing and being heard is a biological regulator for the nervous system, even if the conversation doesn’t “solve” anything.40
CLIMATE: Environment & Stress	Enduring chronic stressors (at work or home) and blaming yourself for not being “resilient” enough to handle them.47	View your environment as part of your health system. Actively curate a supportive climate by setting boundaries, reducing exposure to toxic situations or media, and scheduling time for restorative activities like being in nature or engaging in creative hobbies.39

Works cited

1. Soul sadness : r/CPTSD – Reddit, accessed August 10, 2025, https://www.reddit.com/r/CPTSD/comments/13tue9d/soul_sadness/
2. What Not to Say to Someone Who Is Depressed – Verywell Mind, accessed August 10, 2025, https://www.verywellmind.com/worst-things-to-say-to-someone-who-is-depressed-1066982
3. What NOT to Say to Someone with Depression – Teva Pharmaceuticals, accessed August 10, 2025, https://www.tevapharm.com/patients-and-caregivers/all-stories/what-not-to-say-to-someone-with-depression/
4. Persistent depressive disorder – Symptoms and causes – Mayo Clinic, accessed August 10, 2025, https://www.mayoclinic.org/diseases-conditions/persistent-depressive-disorder/symptoms-causes/syc-20350929
5. Dysthymia | Johns Hopkins Medicine, accessed August 10, 2025, https://www.hopkinsmedicine.org/health/conditions-and-diseases/dysthymia
6. Anhedonia and Depressive Disorders – PMC, accessed August 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC10335915/
7. What is Systems Thinking? | SNHU, accessed August 10, 2025, https://www.snhu.edu/about-us/newsroom/business/what-is-systems-thinking
8. What is systems thinking? – APM, accessed August 10, 2025, https://www.apm.org.uk/resources/find-a-resource/what-is-systems-thinking/
9. What Is Systems Thinking? | University of Phoenix, accessed August 10, 2025, https://www.phoenix.edu/articles/business/what-is-systems-thinking.html
10. Systems Thinking examples: Learn how to apply by Catalyst Consulting, accessed August 10, 2025, https://www.catalystconsulting.co.uk/systems-thinking-examples/
11. www.catalystconsulting.co.uk, accessed August 10, 2025, https://www.catalystconsulting.co.uk/systems-thinking-examples/#:~:text=Systems%20Thinking%20examples%20include%20ecosystems,has%20lost%20its%20essential%20functions.
12. What Is Depression? – American Psychiatric Association, accessed August 10, 2025, https://www.psychiatry.org/patients-families/depression/what-is-depression
13. Major Depression and Genetics | Genetics of Brain Function – Stanford Medicine, accessed August 10, 2025, https://med.stanford.edu/depressiongenetics/mddandgenes.html
14. Causes of depression | Types of mental health problems – Mind, accessed August 10, 2025, https://www.mind.org.uk/information-support/types-of-mental-health-problems/depression/causes/
15. The Body Keeps The Score | Bessel van der Kolk, MD., accessed August 10, 2025, https://www.besselvanderkolk.com/resources/the-body-keeps-the-score
16. Body Keeps The Score Summary – Simply Psychology, accessed August 10, 2025, https://www.simplypsychology.org/the-body-keeps-the-score-summary.html
17. Sleep Deprivation and Deficiency – How Sleep Affects Your Health | NHLBI, NIH, accessed August 10, 2025, https://www.nhlbi.nih.gov/health/sleep-deprivation/health-effects
18. Mental Health and Sleep – Sleep Foundation, accessed August 10, 2025, https://www.sleepfoundation.org/mental-health
19. Depression – National Institute of Mental Health (NIMH), accessed August 10, 2025, https://www.nimh.nih.gov/health/publications/depression
20. Treatment-resistant depression – Mayo Clinic, accessed August 10, 2025, https://www.mayoclinic.org/diseases-conditions/depression/in-depth/treatment-resistant-depression/art-20044324
21. 22 Ways to Cope With Your Depression – Healthline, accessed August 10, 2025, https://www.healthline.com/health/depression/how-to-fight-depression
22. Psychotherapy of Mood Disorders – PMC – PubMed Central, accessed August 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC4258697/
23. The Bidirectional Relationship Between the Gut Microbiome and …, accessed August 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC12007925/
24. Understanding the Gut–Brain Axis and Its Therapeutic Implications for Neurodegenerative Disorders – PubMed Central, accessed August 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC10648099/
25. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems – PMC – PubMed Central, accessed August 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC4367209/
26. Gut Microbiota and Mental Health: A Comprehensive Review of Gut-Brain Interactions in Mood Disorders – PMC – PubMed Central, accessed August 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC12038870/
27. What Is the Gut-Brain Connection? – Cleveland Clinic, accessed August 10, 2025, https://my.clevelandclinic.org/health/body/the-gut-brain-connection
28. Gut-Brain Axis | Psychology Today, accessed August 10, 2025, https://www.psychologytoday.com/us/basics/gut-brain-axis
29. Gut–Brain Axis and Mood Disorder – PMC – PubMed Central, accessed August 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC5987167/
30. Healthy diet, depression and quality of life: A narrative review of biological mechanisms and primary prevention opportunities – PubMed Central, accessed August 10, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC8613751/
31. Introduction to Nutritional Psychiatry Basic Principles | MGH Academy, accessed August 10, 2025, https://lms.mghcme.org/content/introduction-nutritional-psychiatry-basic-principles
32. Ultra-processed foods may increase risk of depression, accessed August 10, 2025, https://hsph.harvard.edu/news/ultra-processed-foods-may-increase-risk-of-depression/
33. Researcher explains connection between ultra-processed foods and depression – YouTube, accessed August 10, 2025, https://www.youtube.com/watch?v=mWRgB2Rhq34
34. Ultra-processed foods may increase risk of depression | Harvard …, accessed August 10, 2025, https://www.hsph.harvard.edu/news/ultra-processed-foods-may-increase-risk-of-depression/
35. The Link Between Nutrition and Mental Health – BENEFITS, accessed August 10, 2025, https://www.tamus.edu/benefits/the-link-between-nutrition-and-mental-health/
36. Natural Approaches to Depression | Psychology Today, accessed August 10, 2025, https://www.psychologytoday.com/us/basics/depression/natural-approaches-depression
37. Holistic Treatments for Depression | Neuro Wellness Spa, accessed August 10, 2025, https://neurowellnessspa.com/holistic-treatments-for-depression/
38. What Are Sleep Deprivation and Deficiency? | NHLBI, NIH, accessed August 10, 2025, https://www.nhlbi.nih.gov/health/sleep-deprivation
39. Self-care for depression | Mind, accessed August 10, 2025, https://www.mind.org.uk/information-support/types-of-mental-health-problems/depression/self-care/
40. How to Deal with Depression – HelpGuide.org, accessed August 10, 2025, https://www.helpguide.org/mental-health/depression/coping-with-depression
41. The Evidence Base of Family Therapy and Systemic Practice, accessed August 10, 2025, https://cdn.ymaws.com/www.aft.org.uk/resource/resmgr/research/final_evidence_base.pdf
42. Natural Relief for Depression | Johns Hopkins Medicine, accessed August 10, 2025, https://www.hopkinsmedicine.org/health/wellness-and-prevention/natural-relief-for-depression
43. Alternative Treatment for Depression: Options & Remedies – Cleveland Clinic, accessed August 10, 2025, https://my.clevelandclinic.org/health/treatments/9303-depression-alternative-therapies
44. Debugging Dysthymia: Overcoming Chronic Fatigue – Josh Kaufman, accessed August 10, 2025, https://joshkaufman.net/debugging-dysthymia/
45. r/depression_help – Reddit, accessed August 10, 2025, https://www.reddit.com/r/depression_help/
46. Feeling depressed and don’t know how to cope – Discussion – 7 Cups, accessed August 10, 2025, https://www.7cups.com/forum/depression/General_2427/Feelingdepressedanddontknowhowtocope_316476/
47. Jean-François’s Story of Battling Dysthymia | HeadsUpGuys, accessed August 10, 2025, https://headsupguys.org/dysthymia-jean-francois/