A Functional medicine Approach to Anxiety, Depression & Related Mood Disorders
Mental illness and Brain Based disorders have become increasingly common in our modern world.
Especially in a COVID19 and likely Post-Covid pandemic, robust mental health may be challenging to care for and maintain.
During the current pandemic, effects from social distancing and isolation combined with increases in stress and anxiety result in short and long-term mental health consequences. 
According to the National Alliance on Mental Illness, one in five American adults currently experiences mental illness, and 17 percent of U.S. adolescents have a mental illness. 
Before diving into an in-depth discussion on the Functional Medicine approach to mood & brain based disorders, let’s briefly discuss some of the most common mental illnesses experienced.
Common Mental Health Disorders
- Changes in sleep habits
- Changes in appetite
- Lack of energy
- Lack of interest in activities
- Hopelessness or guilty thoughts
- Physical aches and pains
Left untreated, depression begins to significantly impact our physical health, functionality, and relationships. While some people may experience just one depressive episode in their lives, more often than not, depression recurs.
Women are twice as likely as men to experience major depression.
Women also experience types of depression related to fertility hormones including: 
- Premenstrual dysphoric disorder
- Postpartum depression
- Postmenopausal depression
The conventional treatment for depression includes the prescription drugs known as selective serotonin reuptake inhibitors (SSRIs).
However, research indicates that the clinical response to SSRIs is inadequate at best, with only 40 to 60 percent of people experiencing symptomatic relief and a mere 30 to 45 percent experiencing remission. 
- Weight gain
- Sexual dysfunction
- Depletion of beneficial gut bacteria
- Withdrawal symptoms upon discontinuation
More concerning is the fact that 25 percent of people on SSRIs, have taken them for over a decade and there are no SSRI safety studies have lasted for more than two years. 
Anxiety disorders are the most common mental illness in the U.S. impacting more than 40 million adults ages 18 and older.
People with an anxiety disorder are three to five times more likely to go to the doctor and six times more likely to be hospitalized for psychiatric disorders than those who do not suffer from anxiety disorders. 
The vast majority of people diagnosed with an anxiety disorder will be prescribed SSRIs. In addition, another common prescription includes benzodiazepines which in turn have their own side effects including cognitive dysfunction, sexual dysfunction and increased anxiety and depression.   
Bipolar disorder, also known as manic-depressive disorder, is characterized by dramatic highs and lows in mood, energy and activity levels that go on to influence an individuals ability to function. It's estimated that 2.8 percent of American adults have experienced bipolar disorder in the past year, and 89 percent of people with bipolar disorder are seriously impaired, unable to carry out the activities of daily living. 
Post-Traumatic Stress Disorder
Post-Traumatic Stress Disorder (PTSD) affects people from all walks of life, including former soldiers, victims of sexual abuse, and people who were bullied as children.
PTSD is generally the result of acute trauma (combat trauma, witnessing death, natural disasters and severe car crashes or accidents).
Complex PTSD on the other hand is the result of repetitive and prolonged trauma including ongoing physical (sexual) abuse, neglect, domestic violence and exploitation. 
Eating disorders encompass an array of food- and body-image-related disorders, including:
- Anorexia nervosa
- Atypical anorexia nervosa (severe food restriction and other anorexic behaviors without low body weight)
- Binge eating disorder
- Purging disorder
- Night eating syndrome
Mental Illness Theories
When it comes to asking WHY mental health issues occur, there are 2 leading theories:
- The evolutionary mismatch theory
- The pathogen-host theory
Underlying Causes of Anxiety, Depression and Mood Disorders
Taking into account both theories of mental illness, we can begin to create a clinical hierarchy of underlying causes in mental illness.
The major underlying causes of anxiety, depression and mood disorders include:
- Infection and Immune Dysregulation
- The standard American diet
- Blood Sugar Dysregulation
- Sedentary Lifestyle
- Impaired neurogenesis
- Gut-Brain Communication
- Circadian Rhythm Disruption
- Environmental triggers
- HPA Dysfunction (cortisol imbalances)
- Low production of neurotrophic factors (BDNF)
- Chronic Inflammation
- Changes in the Microbiome
- Traumatic Brain Injuries
As discussed in this article, there's obviously more to mental health and mood disturbance than chemical imbalances such as low serotonin or dopamine.
Although this doesn’t mean that chemical imbalance is not a factor in depression or mental health disorders, it does suggest that it’s not the only one.
An increasing body of evidence suggests that inflammation may be the underlying issue in many cases of mood disturbance.
People who suffer from mental health disorders all have the cardinal features of inflammation, including reduced levels of anti-inflammatory chemicals and higher levels of pro-inflammatory chemicals in their blood.
When inflammatory cytokines are administered to healthy people over time, they develop symptoms of depression and respond to antidepressant therapy.
Finally, major depression is associated with a range of changes in the brain that promote inflammation. So assessing for the cause of inflammation, nutrient imbalances and even gut health should be considered.
Contrary to what the conventional medical paradigm has led us to believe, mental illness is not a life sentence. With the identification of critical underlying causes and the implementation of Functional Medicine-based interventions, it is entirely possible to improve your mental health and overall quality of life.