Depression: Definition, Prevalence, Etiology, Treatment and everything in between.

Depression is an affective disorder that consists of persistent feelings of sadness and worthlessness (First & American Psychiatric Association, 2014). Individuals suffering from depression often lack the desire to engage in activities previously enjoyed. The disorder normally interferes with the person’s normal functioning, and not only affects the person with the disorder but those who care about him/her as well.

The symptoms of Depression according to DSM-V include:-

  • Loss of interest in almost all activities (Anhedonia).
  • Motor retardation (sluggish behavior.)
  • Sleep disturbances.
  • Feelings of worthlessness.
  • Suicidal ideations.
  • Diminished ability to concentrate and make decisions.
  • Significant loss of appetite and or weight.

Additional criteria for diagnosis include:-

  • Last at least 2 weeks since the onset of the symptoms.
  • Cause considerable distress or severely impact important life areas.
  • Not meet the criteria of other disorders like schizophrenia or bipolar.
  • Not be triggered by drug use.
  • Not be better explained by grief resulting from bereavement.

There are various forms of depression including:

  • Major depression:- manifests through a combination of symptoms that inhibit normal functioning, occurring once or several times in a lifetime.
  • Chronic Depression/Dysthymia:- long-standing depressive mood that lasts longer than 2 years (symptoms are often less inhibitive than those of major depression).

Other forms of depression that occur under unique circumstances and whose characteristics are slightly different from those described above:-

  • Post-partum depression:- occurs in new mothers who develop depressive episodes within a month after childbirth. It’s estimated that around 10-15% of women experience this form of depression soon after birth.
  • Psychotic depression:- depression is accompanied by psychotic symptoms like delusions and hallucinations.
  • Seasonal Affective Disorder:- Characterized by the onset of depressive mood during particular seasons, mostly winter when there’s less natural light. It often resolves with the passing of the season.


Depression has an incidence rate of 20-26% for women and 8-12% for men (DeRubeis & Strunk, 2017). It is asserted that approximately 3-5% of adults suffer from major depression at any point and around 2 out of 100 young children and 8 out of 100 teens may experience serious depression. The median age for the onset of major depression is 32. With this in mind, it’s important to note that women are more vulnerable to depression with double the odds of men. This may be linked to factors unique to women like genetic disposition, life cycle, hormonal fluctuations, among others. Clinical evidence also reveals that while both men and women can develop the standard symptoms of depression, they experience it differently and may have dissimilar ways of coping with the symptoms. However, regardless of the gender, major depression is a serious illness that can have catastrophic effects if left untreated.


DeRubeis, R. J., & Strunk, D. R. (2017). The Oxford handbook of mood disorders. Oxford: Oxford University Press.
First, M. B., & American Psychiatric Association. (2014). DSM-5 handbook of differential diagnosis. Washington, DC: American Psychiatric Publishing.