The different types of mood disorders The Black Dog Institute believes there are 3 broadly different types of depression: • Non‐melancholic depression • Melancholic depression & • Psychotic depression And there are 2 types of bipolar disorder: Type 1 & Type 2 Depression can be a ‘normal’ mood state (like feeling sad), a severe reaction to a difficult or stressful situation, or a disease state (such as melancholic, psychotic or bipolar depression).

Let’s look at melancholic depression first. This is often known as biological depression as its causes are primarily physiological – caused by biochemical imbalances in the brain. Its defining features are: • a severe depressed mood state; & • psychomotor disturbance – usually showing as: slowed speech, agitated physical movements & slowed cognitive abilities or thought processes.   Melancholic depression is a relatively uncommon type of depression.

Melancholic depression is often hereditary & can run in the family.

Psychotic depression is the least common type of depression. The defining features of psychotic depression are: an even more severely depressed mood state more severe psychomotor disturbance, & psychotic symptoms – either delusions (false beliefs) or hallucinations (false sensations), with delusions being more common; & strong feelings of guilt.

Non‐melancholic depression is the most common of the 3 types of depression. Non‐melancholic essentially means that the depression is not primarily biological. Instead, it has to do with psycho-social causes, very often linked to stressful life events &/or the individual’s personality styles. It can be hard to accurately diagnose because it lacks the defining characteristics of the other two depressive types (namely psychomotor disturbance or psychotic features), & People with non‐melancholic depression can usually be cheered up to some degree.