Appendix: Assessing depression and its severity

Guidance

In this guideline, the 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 the course of the 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.

Then ask about duration and associated disability, past and family history of mood disorders, and availability of social support

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 2 or more interventions
recurrent episode within 1 year of last one
history suggestive of bipolar disorder
patient 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.

Depression definitions

Subthreshold depressive symptoms: Fewer than 5 symptoms of depression.

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 features.