Notes for researchers: are your measurement tools incomplete?

In drug trials, the instruments to measure depression, like the Hamilton Depression Rating Scale (HAM-D), clump together a broad constellation of symptoms, such as insomnia, feelings of guilt, physical retardation, etc. These symptoms are measured and combined to make a depression super-score. For example, a study participant might be given a HAM-D score of 18 (moderate depression) at the start and 10 (mild depression) at the end of the trial. The study would then report that the antidepressant caused a -8 change in the HAM-D score.

A single super-score ignores the fact that there are different types of depression that require different types of treatment. Some people have melancholic depression, they want to feel less, while others have anhedonic depression, they want to feel more. A drug might make a patient’s feelings less intense, which would reduce their HAM-D score, but this would harm someone whose main problem is anhedonia. Therefore, in addition to the super-score, studies should report two separate measures of progress: reduction of melancholy and improvement of anhedonia.

To measure how a drug affects general cognitive ability, there should be a baseline measurement of IQ at the outset, and a measurement of IQ at the end of the study, and, ideally, at a long-term follow up a few years later.

Imagine a drug lowered IQ by ten points over the course of three years. Would this erosion of IQ be noticed by researchers or clinicians? Not if they don’t measure it. Yet this would be a big enough hit to stop someone from getting into med school or law school.

Are all antidepressants appropriate to treat anhedonia?

No. In general, SSRIs are not effective at treating anhedonia. Some patients report that SSRIs make their anhedonia worse.

If a patient’s main complaint is emotional numbness, SSRIs should not be the first treatment given.

Is something else going on with my anhedonic patient? Are they autistic?

That is unlikely. Clinicians and non-clinicians are often too quick to apply a label to a person they don’t quite understand. This is why anhedonia should be a stand-alone diagnosis in the DSM-5.

When someone is incapable of feeling pleasure, including pleasure during social interactions, they may not be as warm, friendly, or outgoing as a normal person.

Take a moment to think about it from their perspective. If you feel that socializing is “weary, stale, flat, and unprofitable”, and you felt this way for years, would you be motivated to smile and speak with an upbeat voice?