Depression: A Deeper Dive

Mood is defined as a pervasive and sustained feeling or tone that is endured internally, and that impacts nearly all aspects of a person’s behavior in the external world. Mood disorders or affective disorders are described by marked disruptions in emotions (severe lows called depression or highs called hypomania or mania). Mood disorders have been broadly categorized as bipolar disorders and depressive disorders.1 According to the National Institute of Mental Health:

  • An estimated 9.7% of U.S. adults had any mood disorder in the past year.
  • Past year prevalence of any mood disorder among adults was higher for females (11.6%) than for males (7.7%).
  • An estimated 21.4% of U.S. adults experience a mood disorder at some time in their lives.2

Depression is a common illness worldwide, with an estimated 3.8% of the population affected, including 5.0% among adults and 5.7% among adults older than 60 years (1). Approximately 280 million people in the world have depression (1). 3 According to the Centers for Disease Control (CDC), in 2019, 2.8% of US adults experienced severe symptoms of depression, 4.2% experienced moderate symptoms, and 11.5% experienced mild symptoms in the past 2 weeks. The percentage of adults who experienced any symptoms of depression was highest among those aged 18–29 (21.0%), followed by those aged 45–64 (18.4%) and 65 and over (18.4%), and lastly, by those aged 30–44 (16.8%). Women were more likely than men to experience mild, moderate, or severe symptoms of depression.4

Theories of Depression

  • The Monoamine Theory
  • Stress as a Cause of Depressive Disorders
  • Disturbance of Neurogenesis and Neuroplasticity
  • The Cytokine Theory
  • The Circadian Rhythm Theory
  • Mitochondrial Dysfunction
  • Genetic Factors

The combination of medication and psychotherapy is generally used as the first-line treatment for depression. Selective serotonin reuptake inhibitors (SSRIs) are the most widely-prescribed psychiatric drugs for the treatment of depression and are considered first-line treatment for depressive disorders.  However, the efficacy has been shown to be variable and incomplete: the majority (60%) of depressed patients do not benefit from their first antidepressant5and 60%-70% of the patients do not experience remission, while 30%-40% do not show a significant response.6

Depression as a Multifactorial Syndrome

According to Robert Hedaya, MD, Clinical Professor of Psychiatry at Georgetown University Medical Center, depression is a multifactorial syndrome, co-morbid with many chronic illnesses, by virtue of shared biological mechanisms. Dr. Hedaya states that our molecular environment has changed over the decades since the monoamine hypothesis was proposed, citing mechanisms such as endocrine disrupting chemicals, food supply alterations, dietary factors, and gut microbiome changes.  He describes depression as a syndrome whose underlying causes have expanded to include a number of disorders.7

Potential Causes of Mood Disorders8-99

  • Chronic Inflammation
  • Microbiome Imbalance
  • Lack of Brain Stimulation
  • Autoimmunity
  • Mitochondrial Dysfunction
  • Traumatic Brain Injury
  • Chemical & Metal Toxicity
  • Metabolic Imbalance (hormonal, nutritional, blood sugar, HPA axis)
  • Circadian Mismatch
  • Epigenetic Changes
  • Infection

Rather than focusing on a single cause, a functional health approach to mood disorders takes into account multiple contributors. Considered in the broadest sense, targets for this therapeutic lifestyle approach include the following major modifiable factors:

  • Food intake and nutritional status;
  • Digestive system dysfunction, infection and imbalanced gut bacteria;
  • Imbalance in immune cells that promote versus dampen inflammation;
  • Dysfunctional mitochondria, the “power plants” in every cell responsible for manufacturing ATP (the body’s energy compound);
  • Psycho-emotional and physical stressors;
  • Hormonal imbalances; and
  • Exposure to and accumulation of toxins and dysfunction in the body’s detoxification system.

References and Citations

For more information about our program and to explore whether our lifestyle-based approach for supporting mood is right for you, please click here, or use the scheduling widget to schedule a free discovery consultation with Dr. Ward.


If your device is having issues with the above calendar app, click here to visit Dr. Ward’s calendar in our practice management system.

Disclaimer