Depression: An Overview

Depression is a mood disorder associated with low mood and/or difficulty to experience pleasure, which impacts the person’s daily functioning. Depression is considered the leading cause of disability worldwide. (12). The global economic cost associated with depression is expected to rise and double by 2030 (13), however,  analyses predicted a return of $4 for every $1 spent on treatment for depression (14). In the United States, prevalence ranges from 5%–10% but can be as high as 40%–50% in some specific settings (15). Unfortunately, only half of the people dealing with depression receive proper treatment. (16)

Diagnostic Criteria for Major Depressive Disorder, Based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition

Major depressive disorder represents the classic condition in this group of disorders. It is characterized by discrete episodes of at least 2 weeks’ duration (although most episodes last considerably longer) involving clear-cut changes in effect, cognition, and neurovegetative functions, and inter-episode remissions. A diagnosis based on a single episode is possible, although the disorder is a recurrent one in the majority of cases. Careful consideration is given to the delineation of normal sadness and grief from a major depressive episode. Bereavement may induce great suffering, but it does not typically induce an episode of major depressive disorder. When they do occur together, the depressive symptoms and functional impairment tend to be more severe and the prognosis is worse compared with the bereavement that is not accompanied by major depressive disorder. Bereavement-related depression tends to occur in persons with other vulnerabilities to depressive disorders, and recovery may be facilitated by antidepressant treatment. (19)

Diagnostic Criteria for Major Depression:

  1. Five (or more) of the following symptoms have been present during the same 2-week period and represent a change from previous functioning; at least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure.
    • Note: Do not include symptoms that are clearly attributable to another medical condition.
  1. Depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feels sad, empty, hopeless) or observation made by others (e.g., appears tearful). (Note: In children and adolescents, can be irritable mood.)
  2. Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day (as indicated by either subjective account or observation).
  3. Significant weight loss when not dieting or weight gain (e.g., a change of more than 5% of body weight in a month), or decrease or increase in appetite nearly every day. (Note: In children, consider failure to make expected weight gain.)
  4. Insomnia or hypersomnia nearly every day.
  5. Psychomotor agitation or retardation nearly every day (observable by others, not merely subjective feelings of restlessness or being slowed down).
  6. Fatigue or loss of energy nearly every day.
  7. Feelings of worthlessness or excessive or inappropriate guilt (which may be delusional) nearly every day (not merely self-reproach or guilt about being sick).
  8. Diminished ability to think or concentrate, or indecisiveness, nearly every day (either by subjective account or as observed by others).
  9. Recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide.
  1. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
  2. The episode is not attributable to the physiological effects of a substance or another medical condition.

Note: Criteria A–C represent a major depressive episode.

Note: Responses to a significant loss (e.g., bereavement, financial ruin, losses from a natural disaster, a serious medical illness or disability) may include the feelings of intense sadness, rumination about the loss, insomnia, poor appetite, and weight loss noted in Criterion A, which may resemble a depressive episode. Although such symptoms may be understandable or considered appropriate to the loss, the presence of a major depressive episode in addition to the normal response to a significant loss should also be carefully considered. This decision inevitably requires the exercise of clinical judgment based on the individual’s history and the cultural norms for the expression of distress in the context of loss. (19)

Most effective treatments for Depression:

The American College of Physicians recommend CBT or second-generation antidepressants as initial treatment of mild to severe MDD.(18)

Both psychotherapy and pharmacotherapy are efficacious treatments for GAD (see Bandelow et al., 2015; Newman, Llera, Erickson, Przeworski, & Castonguay, 2013). Cognitive‐behavioral therapy (CBT) has received the most extensive empirical support for GAD, several meta‐analyses have supported its effectiveness (Carpenter et al., 2018; Covin, Ouimet, Seeds, & Dozois, 2008; Cuijpers et al., 2014). CBT is considered the most effective treatment for GAD, according to the definition of Chambless and Hollon (1998). CBT is the only treatment listed by the American Psychological Association’s (APA) Division 12 as having strong empirical support (i.e., for GAD).


1. Dozois, David J. AMental Health Research Canada.Canadian Psychology/Psychologie canadienne Vol. 62, Iss. 1,  (Feb 2021): 136-142. DOI:10.1037/cap0000251

 2. Penninx, B. W., Pine, D. S., Holmes, E. A., & Reif, A. (2021). Anxiety disorders. Lancet (London, England), 397(10277), 914–927.

12. Gore FM, Bloem PJ, Patton GC, et al. Global burden of disease in young people aged 10–24 years: a systematic analysis. Lancet. 2011;377:2093-102. [PMID: 21652063] 

13. Bloom DE, Cafiero ET, JaneLlopis E, et al. The Global Economic Burden of Noncommunicable Diseases. World Economic Forum; 2012. 

14. Chisholm D, Sweeny K, Sheehan P, et al. Scaling-up treatment of depression and anxiety: a global return on investment analysis. Lancet Psychiatry. 2016;3:415-24. [PMID: 27083119]

 15. Wang J, Wu X, Lai W, et al. Prevalence of depression and depressive symptoms among outpatients: a systematic review and meta-analysis. BMJ Open. 2017;7:e017173. [PMID: 28838903] 

16. González HM, Vega WA, Williams DR, et al. Depression care in the United States: too little for too few. Arch Gen Psychiatry. 2010;67:37-46. [PMID: 20048221]

18. Qaseem A, Barry MJ, Kansagara D; Clinical Guidelines Committee of the American College of Physicians. Nonpharmacologic versus pharmacologic treatment of adult patients with major depressive disorder: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2016;164:350-9

19. DSM 5

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Parivash Kalantari
Articles: 7

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