Some symptoms of depression are much more central to the condition than others, a new study finds.
- Sad mood.
- Decreased interest in life or pleasure.
- Energy loss.
- Concentration problems.
Despite this, psychiatrists and psychologists sometimes use longer ‘checklists’ of symptoms to diagnose depression.
They then add them up, sometimes without regard to which symptoms are more important.
Dr Eiko Fried, who led the study, said:
“We need to stop thinking of depression as a disease that causes a number of interchangeable symptoms.
Depression is a complex, extremely heterogeneous system of interacting symptoms.
And some of these symptoms may be far more important than others.”
Researchers looked at 28 different symptoms of depression.
They examined them as a network, as Dr Fried explained:
“If you think of depression as a network of interacting symptoms, one symptom can cause another.
For instance, insomnia may lead to fatigue, which in turn may cause concentration problems that feed back into insomnia.
This example of a vicious circle shows that the specific symptoms patients report, and their interactions, can be of crucial clinical importance.
The researchers found that symptoms like weight change and agitation were less central to depression.
Dr Fried continued:
“Depression is not like, say, measles.
When you have measles, your symptoms help the doctor figure out what underlying disease you have.
But once you are diagnosed, it doesn’t really matter which of the possible symptoms you did or didn’t get.
Treating the disease itself makes all your symptoms disappear.
Depression is more complicated.
It is not an infection or a specific brain disease.
There is no easy cure, no drug that makes all symptoms go away.
Instead, we may want to focus treatment efforts on the symptoms driving a patient’s depression.”
The study was published in the Journal of Affective Disorders (Fried et al., 2015).
Depressed woman image from Shutterstock