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  • Linnette Johnson

What is depression?

Major depressive disorder (MDD) is a severe mood disorder characterized by symptoms that interfere with an individual’s feelings, thoughts, actions, and daily functioning. According to the World Health Organization, depression is the leading cause of disability worldwide, affecting more than 300 million individuals globally.

Remember, fluctuations in mood are typical and expected; however, prolonged, disruptive patterns can present themselves at various times. One of the most common mood conditions is depression or depressive symptoms, with an overall pooled prevalence cited at 27%.

Specific populations may be more susceptible to these symptoms. Factors such as gender and age play a role in risk factors associated with depressed moods. Depressed moods may be present in conjunction with other cognitive dysfunction such as anxiety, memory problems, and sleep disorders. Depending on the individual patient’s needs, various options exist to address their symptoms. Pharmaceutical interventions such as antidepressants are typically used to address prolonged periods of low mood or diagnosed depression.

Types of Depression:

  • Bipolar disorder is characterized by experiencing alternating periods of extremely high moods and extremely low moods

  • Persistent depressive disorder, characterized by a depressed mood lasting over two years

  • Postpartum depression is characterized by experiencing major depression during pregnancy and/or the postpartum period (directly following childbirth)

  • Psychotic depression is characterized by severe depression with some form of psychosis (e.g., delusions, hallucinations)

  • Seasonal affective disorder (SAD) is characterized by a cyclical onset of depression associated with less sunlight exposure in the winter months.

Signs, symptoms, and complications

The severity, frequency, and duration of symptoms will vary depending on the individual. To be classified as MDD, some of the following symptoms must be present almost every day for a minimum of two weeks. The signs and symptoms of depression include:

  • Feeling hopeless, guilty, worthless, or helpless

  • Disturbed sleep

  • Low or depressed mood

  • Change in appetite and/or weight

  • Suicidal thoughts or suicide attempts

  • Decreased energy or fatigue (without significant exertion)

  • Difficulty concentrating or remembering

  • Loss of pleasure in usual hobbies or activities

Causes and risk factors

Having one episode of major depression is a strong predictor of future episodes. Mood disorders and depression are not associated with a single cause. Still, they have a variety of genetic, biological, environmental, and psychological risk factors, including

  • Genetic predisposition or family history of mood disorders

  • Gender: more frequent among females

  • Significant stress, trauma, or life events

  • Socio-economic factors: poverty, housing difficulties, prejudice

  • Certain chronic medical conditions (e.g., dementia, Alzheimer’s disease, epilepsy, Parkinson’s disease, stroke, obesity, cancer, arthritis)

  • Certain medications (e.g., PPIs, antihypertensives, analgesics)

  • Family history/genetic predisposition

Preventing and addressing depression

While depression is typically addressed using a combination of medication, psychotherapy, and electroconvulsive therapy (in treatment-resistant cases), specific dietary and lifestyle interventions may also be beneficial.

Lifestyle interventions

While depression is typically addressed using a combination of medication, psychotherapy, and electroconvulsive therapy in treatment-resistant cases, specific dietary and lifestyle interventions may be beneficial.


Regular aerobic exercise at moderate or high intensity has been shown to have antidepressant effects. More significant improvements are seen with physical activity led by trained professionals, such as personal training, trainer-led running groups, spin classes, circuit training, and aerobic classes.


Mindfulness-based practices may help prevent the relapse of depressive episodes. Mindfulness interventions involve practicing awareness of the present moment. Meditation or mindfulness apps can help to introduce you to mindfulness practice and include apps such as Calm, Insight Timer, 10% Happier, and Stop, Breathe & Think.


Research has shown that an overall dietary pattern focusing on whole foods while reducing processed or fast foods may reduce the risk of depression. The table below summarizes foods to limit and favor in your diet.

Consume more of-

  • Antioxidants (e.g., dark chocolate, nuts, berries, leafy greens, herbs, spices)

  • Extra-virgin olive oil

  • Fish (e.g., salmon, trout, mackerel)

  • Fruit

  • Dairy (e.g., yogurt, kefir, milk)

  • Vegetables

  • Whole grains (e.g., rice, oats, buckwheat, barley)

Consume less of-

  • High-fat dairy products (e.g., butter, heavy cream)

  • Potatoes

  • Processed meat (e.g., hot dogs, cured meats, canned meat, sausages)

  • Red meat (e.g., beef, pork, veal)

  • Refined grains (e.g., bread, pasta, crackers, baked goods, cereals)

  • Sweets/Sugar (e.g., desserts, candy, soda)

  • Caffeine

Lastly, always put food first, but if you are looking at supplements, some may help- St. John’s Wort (Hypericum perforatum) and 5-HTP have shown potential promising effects on mood symptoms. Omega-3 fatty acids are another option that might also benefit memory and sleep symptoms. Moderating stress with an adaptogen such as Rhodiola can also assist with mood function.

However, like with anything else-- there is not a one-size-fits-all, and make sure supplements are needed and won't interact with other medications.


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