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.
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