diagnosing

“In general, a motivated GP in an urban setting (where the rate of depression is 20%) would correctly diagnose ten out of 20 cases, missing ten true positives. The GP would correctly reassure 65 out of 80 non-depressed individuals, falsely diagnosing 15 people as depressed”?

Now is this a bad thing? I don’t think so.

• The diagnoses of depression has a large overlap with adjustment disorders. An adjustment disorder will subside within weeks all by itself.
• Most mild depressions which exist shorter than 3 months subside within weeks to months (50%). Moreover, more-severe cases of depression are diagnosed more reliably than less-severe forms by the General Practitioner.
• The failure to diagnose depression accurately were mostly found in patients close to the threshold of diagnoses. In other words, the apparent failure to identify depression accurately in primary care might have been overstated.
• The fact that depression is not diagnosed doesn’t always mean some form of treatment is not started.
• Most of the “golden standards” used in the trials included in this meta-analysis deliver false positive diagnoses of depression especially when used by other than experienced clinicians. From most publications used in this meta-analysis it’s not cleat who preformed the diagnostic screening.

Practical as well as methodological factors explain why I am not so worried. Peter Tyrer, who wrote an editorial about this meta-analysis in The Lancet even had a better suggestion:

Rather than concentrate on attaining the chimera of perfect agreement with an entity that is provisional at best or quite simply wrong, it would be better to enhance the treatments available for common mental disorders in primary care.

GP’s are usually very practical doctors who are able to indicate treatment on more dimensional ground than categorical entities. I would certainly welcome treatment of low mood and/or anxiety with problem solving therapy compared to no treatment. What do you think?

Related post on this blog:

Depression in General Practice, psychological treatment

Tyrer, P. (2009). Are general practitioners really unable to diagnose depression? The Lancet DOI: 10.1016/S0140-6736(09)61156-9
Mitchell, A., Vaze, A., & Rao, S. (2009). Clinical diagnosis of depression in primary care: a meta-analysis The Lancet DOI: 10.1016/S0140-6736(09)60879-5