Sadness or being sad is an emotion, and depression is a mood disorder. So, we have to think about what is the difference between an emotion, and a mood.
An emotion is a short lived experience in our body that will have a physiological component, it will have a thinking component, and it will often have a behavioural component. But they tend not to last very long, and our emotions will be contingent on the environment. Something scary happens, you feel frightened, something dreadful happens – you feel sad. So, we respond to that. But typically, the emotion then passes.
Whereas for a mood, what we’re looking at is an enduring experience of something affective, referring to the emotional component, but it is something that’s lasting much longer. So, straight away, we’re looking at depression as something that’s lasting longer than sadness. When we think about depression, we’re really talking about a clinical diagnosis for someone who is experiencing these enduring feelings of sadness, that will be accompanied by a host of other experiences, or symptoms. So, that might look like changes in their sleeping habits, changing in their dietary habits, there could be thoughts of self harm or suicidality, there’ll be a sense of helplessness, and reduced mood or apathy.
I think for diagnosis, you have to have had these experiences for at least two weeks, and they have to be impacting on your ability to function in the world. They have to be distressing to you, and they have to be what we would call – deviant from the norm, which just means that you’re having an experience that’s not part of most people’s everyday experience.
Whereas sadness is not like that. Sadness is in fact part of the everyday experience. We all have it when something upsetting happens in life. We respond to the sadness, and the sadness emotion will shift as the environment shifts, and updates itself and we no longer need to be sad.
