Educational reference
About this symptom
Low mood is more than passing sadness. It describes a mood state that persists for much of the day, on most days, over a sustained period, and that does not lift reliably in response to circumstances that would usually help.
People describe it in different ways: sadness, heaviness, flatness, emptiness, or a sense that colour has drained out of things. Some people do not feel sad so much as numb. In some people, particularly adolescents, it presents as irritability rather than sadness.
Persistently low mood is a recognised feature of depressive conditions, but it also occurs in bereavement, in other mental health conditions, in physical illness including thyroid and neurological conditions, as an effect of some medications, and in response to prolonged stress or difficult circumstances. Its presence does not establish a diagnosis, and its absence does not exclude one.
Assessment considers how long it has lasted, how much it affects daily life, what else is happening, and what else might explain it.