diagnostic criteria for depression

Last reviewed 09/2020

Diagnostic criteria for depression

NICE adopted the DSM-IV criteria rather than the ICD-10 criteria for diagnosis of depression:

DSM versus ICD-10 classification

  • DSM-IV is used in nearly all clinical trials and it provides definitions for atypical symptoms and seasonal depression
    • its definition of severity also makes it less likely that a diagnosis of depression will be based solely on symptom counting
    • NICE though favouring DSM-IV note that clinicians are not expected to switch to DSM-IV but should be aware that the threshold for mild depression is higher than ICD-10 (five symptoms instead of four) and that degree of functional impairment should be routinely assessed before making a diagnosis

Assessment of depression is based on the criteria in DSM-IV. Assessment should include the number and severity of symptoms, duration of the current episode, and course of illness. Key symptoms:

      • persistent sadness or low mood; and/or
      • marked loss of interests or pleasure
    • at least one of these, most days, most of the time for at least 2 weeks

  • if any of above present, ask about associated symptoms:
    • disturbed sleep (decreased or increased compared to usual)
    • decreased or increased appetite and/or weight
    • fatigue or loss of energy
    • agitation or slowing of movements
    • poor concentration or indecisiveness
    • feelings of worthlessness or excessive or inappropriate guilt
    • suicidal thoughts or acts

  • the duration and associated disability, past and family history of mood disorders, and availability of social support should also be asked about:

    • 1. factors that favour general advice and active monitoring:
      • four or fewer of the above symptoms with little associated disability
      • symptoms intermittent, or less than 2 weeks' duration
      • recent onset with identified stressor
      • no past or family history of depression
      • social support available
      • lack of suicidal thoughts
    • 2. factors that favour more active treatment in primary care:
      • five or more symptoms with associated disability
      • persistent or long-standing symptoms
      • personal or family history of depression
      • low social support
      • occasional suicidal thoughts
    • 3. factors that favour referral to mental health professionals:
      • inadequate or incomplete response to two or more interventions
      • recurrent episode within 1 year of last one
      • history suggestive of bipolar disorder
      • the person with depression or relatives request referral
      • more persistent suicidal thoughts
      • self-neglect
    • 4. factors that favour urgent referral to specialist mental health services
      • actively suicidal ideas or plans
      • psychotic symptoms
      • severe agitation accompanying severe symptoms
      • severe self-neglect.

DSM-IV severities of depression

  • subthreshold depressive symptoms: Fewer than 5 symptoms
  • Mild depression: few, if any, symptoms in excess of the 5 required to make the diagnosis, and symptoms result in only minor functional impairment
  • Moderate depression: symptoms or functional impairment are between 'mild' and 'severe'
  • Severe depression: most symptoms, and the symptoms markedly interfere with functioning. Can occur with or without psychotic symptoms.