No shit Sherlock

Saw this paper today:

Occurrence of depressive disorder was best predicted by a combination of a history of depression and subthreshold symptoms, followed by either one alone. Occurrence of anxiety disorder was best predicted by both a combination of a history of anxiety disorder and subthreshold symptoms and a combination of a history of depression and subthreshold symptoms, followed by any subthreshold symptoms or a history of any disorder alone.

Now I realise that they were trying to make the point that:

Past episodes of depressive or anxiety disorders and subthreshold symptoms have both been reported to predict the occurrence of depressive or anxiety disorders. It is unclear to what extent the two factors interact or predict these disorders independently.

But it did just make me ask whether it was really worth the effort to show that, when all is said and done, people who have had a common mental disorder in the past, and are showing symptoms of it now, are more likely to be diagnosed with it in the future.