Classification of Depressive Illness

There are several different methods of classifying depressive illness. The most relevant factors for AA/DLA are severity and course.

Severity:

• Mild
• Moderate
• Severe
• Severe with psychotic [hallucinations or delusions] and/or somatic features [physical symptoms such as severe weight loss].

or

• Mild
• Moderate
• Major
• Major with psychotic features

Course:

Single or recurrent episodes.

Other terms frequently encountered when describing depressive illness include:

• Unipolar [depressive illness alone] or bipolar [associated with mania]. This guidance refers to unipolar depressive illness only, which make up 90 % of all depressive disorders.
• Primary or secondary [associated with or caused by another medical condition, for example hypothyroidism or dementia].
• Endogenous [not triggered by life events] or reactive [triggered by life events]. Note that this term is not now used by Health Care Professionals.