Depression: Symptoms, Prevalence and Causes

by | May 7, 2021 | Depression and Faith

Late in 2020 I produced a 26.5 page, single-spaced document on depression for a strategic parachurch ministry. It wasn’t a document they would ever use “as is,” but it contained research as well as my own reflections, rooted in my study of the topic as well as personal experience. That particular ministry hoisted some sections from the document, and adapted others, for use on their top-notch website.* Here is the first of several posts in which I share with you pertinent excerpts that I’ve adapted from that document.


Definition and Symptoms of Depression

Depression is a dip in mood that causes a persistent feeling of sadness and loss of interest in life and normal activities. It is more than a bout of the blues or temporary discouragement. To be diagnosed with a major depressive disorder (clinical depression), a person must experience at least five of the following symptoms for a period of at least two weeks. A  number of different organizations and mental health websites display this list:

  • Feelings of sadness, tearfulness, emptiness or hopelessness
  • Angry outbursts, irritability or frustration, even over small matters
  • Loss of interest or pleasure in most or all normal activities, such as sex, hobbies or sports
  • Sleep disturbances, including insomnia or sleeping too much
  • Tiredness and lack of energy, so even small tasks take extra effort
  • Reduced appetite and weight loss or increased cravings for food and weight gain
  • Anxiety, agitation or restlessness
  • Slowed thinking, speaking or body movements
  • Feelings of worthlessness or guilt, fixating on past failures or self-blame
  • Trouble thinking, concentrating, making decisions and remembering things
  • Frequent or recurrent thoughts of death, suicidal thoughts, or suicide attempts
  • Unexplained physical problems, such as back pain or headaches


Prevalence of Major Depression

Statistics are based on research through 2017 (National Institute of Mental Health)

  • Approximately 17.3 million people 18 and older (7.1% of the adult U.S. population) have at least one episode of depression in any given year.
  • More adult females (8.7%) than males (5.3%) experience major depression.
  • 8% of adults diagnosed with major depression report severe impairment.
  • On the adult population spectrum, prevalence of major depression is highest among young adults 18-25 years old (11.3%).
  • Among adults diagnosed with major depression, close to 80% will have episodes off and on for the remainder of their lives.
  • Among adolescents in the United States (ages 12-17), about 3.2 million (13.3%) have a major depressive episode in any given year.
  • Depression is the leading cause of disability in the world.


Causes of Depression

Physicians and psychologists who write about depression differ in how they categorize its causes. Identifying causes is complicated by the fact that what one perceives as a cause may also be viewed as a symptom, or consequence, of depression. Perhaps the best approach to a complex issue consists of three core causes.


Bodily or Physical Causes

Bodily disorders such as diabetes, thyroid disease and vitamin deficiencies may cause a descent into depression. (The first time I sought medical intervention for my depression in 1989, my doctor ordered a complete blood panel, including a check of thyroid and blood sugar levels. Years later, I had a married student who spiraled into deep depression and failed several classes in one semester. I suggested that he have this lab work, which exposed his diabetes, a condition that may cause a dip in mood. His depression improved dramatically after treatment for his diabetes.)  Also, many physicians and psychological experts believe that about 40% of persons diagnosed with major depression have a genetic predisposition to it. Neurotransmitters in the brain that control mood include serotonin, dopamine, and norepinephrine. When one or more of these are depleted, depression may result. Evidence of this physical cause is seen in research data. An individual is 3-5 times more likely to experience clinical depression if a close blood relative has suffered from it.


Circumstantial or Reactionary Causes

Reactive depression episodes are typically traced to an external trigger, such as severe personal loss or unsettling life events. Such external stressors may work in tandem with the body to cause depression, since stressful situations may result in changes in brain chemistry. Some people do not respond as well to external stressors as others do. Variables such as one’s basic temperament and personal history affect the inherent capacity to cope with setbacks.

 A prime example of a circumstantial cause is the Covid-19 pandemic. By the late summer of 2020, long before the pandemic began diminishing, the JAMA Network (Journal of the American Medical Association) reported more than a 300% increase in depression in the U.S. Depression rates rose from almost 8.5% of the U.S. population (pre-Covid) to 28% within six months. Factors such as social isolation, unemployment and psychological distress prompted the escalation.


Spiritual Causes

Though most depression is not the direct result of a person’s sin, certain spiritual factors affect one’s susceptibility to and experience of depression. A person without the hope and resources that a relationship with God offers may be more vulnerable. Or a Christian who does not avail himself of the means of God’s grace and strength, such as Bible study, prayer, worship and fellowship with other believers, has less ability to cope with the inevitable trials of life. A believer who persists in a pattern of sin may experience depression-like symptoms because he is under the Holy Spirit’s conviction. A Christian also has an enemy, Satan, who strives to take advantage of his or her dark moods. Christians are more vulnerable to certain temptations during a depressive episode, especially “sins of the flesh.” The numbness or lethargy of mind, body and spirit that accompanies depression makes them more susceptible to anything that titillates the senses.

Well known Bible teacher and author John Piper believes that no matter what initially causes depression, a Christ-follower still faces a spiritual battle, and the battleground is the mind:

Wherever despondency might come from, Satan paints it with a lie. The lie says, “This is it. You will never be happy again. You will never be strong again. You will never have vigor and determination again. Your life will never again be purposeful. There is no morning after this night. No joy after weeping. All is gathering gloom, darker and darker.” This is the color that Satan paints on our despondency. But God has woven His Word with strands of truth directly opposed to that lie. The law of God does revive (Psalm 19:7). God does lead us to springs of water (Psalm 23:3). God does show us the path of life (Psalm 16:11). Joy does come in the morning (Psalm 30:5). Unbelief is the root of yielding to despondency, but faith takes the promises of God and throws them against despondency. – From Future Grace, Chapter titled, “Future Grace and Despondency.”


Questions To Ponder

What is the most helpful information that you gleaned from this material?

As you perused the symptoms, did you see yourself or a loved one in at least five of the bullet points? (Ouch: I’ve consistently exhibited 10 of the 12 symptoms in 2021!) If so, yet neither you nor your loved one has received medical intervention, I strongly urge you to see a physician and ask for a complete blood panel.

What is your personal take on the causes of major depression? On how the spiritual realm intersects with physical and circumstantial causes?  I’d love to hear from you.

Soon I will post a section from that document titled, “Misconceptions About Depression.”  You’ll discover that some misconceptions are rooted in false beliefs about the cause of depression.

Keep on living and serving strong for Jesus Christ!

“But You, O Lord, are a shield about me, my glory, and the One who lifts my head” (Psalm 3:3).


*The organization for which I prepared the depression document is Chronic Joy Ministry. Their excellent website covers physical illnesses and disabilities, mental illnesses, as well as the needs of caregivers.




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