What is Major Depression?

Major depression, also known as unipolar or major depressive disorder (MDD), is characterized by a persistent feeling of sadness or a lack of interest in outside stimuli. The unipolar connotes a difference between major depression and bipolar depression, which refers to an oscillating state between depression and mania. Instead, unipolar depression is solely focused on the “lows,” or the negative emotions and symptoms that you may have experienced.

Fortunately, major depression is well understood in the medical community and is often easily treatable through a combination of medication and talk therapy. Below is a guide to everything from the symptoms and causes of major depression, to statistics and treatment that you can seek from a medical professional if you feel that you need assistance.

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Patient Statistics

According to the Journal of the American Medical Association, the lifetime incidence of depression in the United States is more than 20-26% for women and 8-12% for men. Although that is not a vast majority, it represents a significant section of the population, many of whom do not seek recurring treatment for their depression. While these men and women do have lifetime occurrences, the median age for the onset of major depression is age 32, as reported by the U.S. Census Bureau Population Estimates by Demographic Characteristics in 2005. With that in mind, it’s important to note that women are disproportionately affected by major depression in comparison to men, as reflected in the significant percent different cited above.

There are several reasons why women find themselves more commonly afflicted by major depression disorder, but it mainly stems from depression’s tendency to co-occur with other illnesses and mental conditions. It can result in collation with anything from pregnancy to more chronic or recurring problems. The National Institute of Mental Health has noted that 25% of cancer patients, one third of HIV patients, and one third of heart attack survivors suffer from major depression.

While those particular conditions are more prevalent in men, Psychology Today has stated that a commonly cited physiological reason for women experiencing major depression more than men is due to fluctuating hormones and genetic predisposition, particularity around the times of puberty, childbirth, and menopause.

However, major depression is a serious issue for both genders, and if left untreated, can have fatal results. Fortunately, there is good news. The National Institute of Health has noted that approximately 80% of patients who seek treatment for major depression show improvement within four to six weeks, from “beginning medication, psychotherapy, attending support groups or a combination of these treatments.


While the prevalence of major depression is widespread, the causes of major depression are equally as numerous and have their origins in a variety of places. Medical journal Neuron cites genetics as a prevailing cause of major depressive disorder, with “an approximately 3-fold increased risk for MDD [Major Depressive Disorder] in the first-degree relatives (parents, siblings, offspring) of individuals with MDD versus the general population.” This means that the single biggest determining factor of your depression can be found in your family tree, but there also is a significant physiological and anatomical basis.

Co-occurring illness and medical conditions can be a serious risk factor in having a major depressive episode. Also, symptoms of the disorder itself can cause depression. For example:

  • Changing your appetite, overeating, or undereating
  • Deregulating your sleep schedule or offsetting your circadian rhythms

Adjusting these patterns and habits often won’t treat your depression, but they can be a great step in relieving your other symptoms in conjunction with professional treatment.

The extent that anatomical and physiological factors have on major depression is unknown, but it is thought to be significant. Along with socioeconomic factors (the loss of a job and a feeling of economic disenfranchisement, for example), the above are considered the major reasons why you would suffer from major depressive disorder.


You might be surprised to learn that there are many different types of major depressive disorder that can affect you can make living your daily life difficult. Each type often has different causes, but they typically involve the same feeling of disinterest in activities that you once loved and an overall feeling of melancholy. These are divided into subtypes called specifiers that determine how long the diagnosis of depression lasts and the defining characteristic of each type.

  • Seasonal affective disorder or SAD is categorized as a disease directly caused by the time of the year. It occurs most often in the winter months when sunlight is not as readily available. The National Institute of Mental health states that SAD can be “effectively treated with light therapy, but nearly half of those with SAD do not get better with light therapy alone.” Counseling and medication is also recommended.
  • Psychotic depression often develops if you have been hallucinating or you believe in delusions that are not cohesive with reality. This can be caused by a traumatic event or if you have already had a form of depression in the past.
  • Postpartum depression is a common occurrence among new mothers experiencing hormonal changes following childbirth. The stress of raising a new child and changes in and to your body can greatly affect your mood. Additionally, the Canadian Mental Health Association states that parents who adopt can also suffer some of the symptoms of postpartum depression.
  • Those with melancholic depression often exhibit the most typical signs of depression including weight loss and decreased interest in activities they once loved. You might experience a depressed mood similar to losing someone you love or intense grief. Atypical depression is often directly related to your mood and your interactions with others. Symptoms include hypersomnia, heaviness in the limbs, and social anxiety.
  • If you suffer from catatonic depression, you are most likely experiencing motor problems and behavioral issues. You might be immobilized or have involuntary movements. According to the US National Library of Medicine National Institute of Health, it is a “psychotic disorder presents significant risk to the patient’s well-being, as well as an additional barrier to treating the underlying disorder. The signs and symptoms of catatonia interfere severely with essential activities of daily living.”

Other Types

In addition, to those listed above, the fifth edition of the Diagnostic and Statistical Manual of Mental Health Disorders separates out bipolar and related disorders and includes these other distinct types:

  • Persistent depressive disorder (dysthymia)
  • Premenstrual dysphoric disorder
  • Disruptive mood dysregulation disorder
  • Substance/medication-induced depressive disorder
  • Depressive disorder due to another medical condition
  • Other specified depressive disorder and unspecified depressive disorder (such as situational)

Signs and Symptoms

There can be a number of contributing factors related to the cause of your depression. These typically manifest themselves in coping behaviors and reactions to how you feel. Depending on which type of depression you have, you may experience various symptoms.

  • Negative thinking with inability to see positive solutions
  • Agitation
  • Restlessness
  • Inability to focus
  • Lashing out at loved ones
  • Irritability
  • Withdrawing from loved ones and regular activities
  • Increase in sleeping
  • Exhaustion and lethargy
  • Morbid, suicidal thoughts
  • Weight loss or gain


There are several treatment methods for major depression disorder. These approaches include psychotherapy, antidepressant medications, electroconvulsive treatment (ECT), and other somatic therapies. However, ECT is generally avoided, except in extreme circumstances, in favor of both psychotherapy and antidepressants. A medical psychiatrist can provide both psychotherapy services and prescribe antidepressants, which differ for each person based on individual needs.

If you find yourself experiencing any of the symptoms or relating in any way to major depression disorder, you should seek assistance from a medical professional. Thankfully, major depressive disorder has become much less stigmatized in recent years. There is plenty of in-depth information available about depression, and your chosen medical professional is often likely to go through it with you so you can choose the best treatment for your lifestyle.

You should feel as though you have options. You most likely will not have to be burdened by this disease and the negativity that often comes with symptoms of depression. Talking to a counselor and a medical professional is the first step to living a happier, more fulfilling life.

Last Updated: Jun 4, 2021