Depression: Assessment and diagnosis​

Key points

• Depression should be assessed as mild, moderate or severe, depending on the extent and impact of symptoms and the level of functional impairment or disability it causes. This assessment will determine what level of treatment to initiate.
• The Diagnostic and Statistical Manual of Mental Disorders (DSM IV-TR or DSM-5) criteria are used to make a formal diagnosis.

Assessment

Depression should be assessed as mild, moderate or severe, depending on the extent and impact of symptoms and the level of functional impairment or disability it causes.

Watch a video of a depression assessment interview.

A depression assessment should:

• include a full history and examination, including a mental status examination(Download a pdf of the Mental Status Examination.)
• explore functional, interpersonal and social issues
• take a psychiatric history that documents past episodes of depression or mood elevation, response to previous treatment and the existence of comorbid mental health conditions
• assess client safety and risk to others. Suicidal intent should be assessed regularly.
• obtain third-party history from family members or other caregivers if the client consents and it is appropriate.

Diagnosis

DSM-IV-TR criteria for major depressive episode

A. 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 due to a general medical condition, or mood-incongruent delusions or hallucinations.

1. depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feels sad or empty) 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 made by others)
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 gains
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.

B. The symptoms do not meet criteria for a mixed episode.

C. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.

D. The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition (e.g., hypothyroidism).

E. The symptoms are not better accounted for by bereavement, i.e., after the loss of a loved one, the symptoms persist for longer than 2 months or are characterized by marked functional impairment, morbid preoccupation with worthlessness, suicidal ideation, psychotic symptoms, or psychomotor retardation.

Reprinted with permission from the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.). Copyright 2000 American Psychiatric Association.

Evidence summary

American Psychiatric Association. (2000). Diagnostic and Statistical Manual of Mental Disorders (4th ed., tex rev.). Washington, DC: Author.

American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Washington, DC: Author.

Kennedy, S.H., Lam, R.W., Parikh, S.V., Patten, S.B. & Ravindran, A.V. (2009). Canadian Network for Mood and Anxiety Treatments (CANMAT) Clinical Guidelines for the Management of Major Depressive Disorder in Adults. Journal of Affective Disorders, 117(Suppl. 1). S44–53.

Lam, R.W. (2011). In D. Goldbloom & J. Davine (Eds.), Psychiatry in Primary Care: A Concise Canadian Pocket Guide (pp. 13–26). Toronto, ON: Centre for Addiction and Mental Health.

National Institute for Health and Care Excellence. (2009). Depression in Adults: The Treatment and Management of Depression in Adults (Clinical Guideline 90). London, UK: Author.