This is quoted from article Moderate exercise not only treats, but prevents depression:
Physical activity is being increasingly recognized as an effective tool to treat depression. PhD candidate George Mammen’s review published in the October issue of the American Journal of Preventive Medicine has taken the connection one step further, finding that moderate exercise can actually prevent episodes of depression in the long term.
What does recognize said above mean? I've looked up OALD and there are several definitions that could fit this context, but I'm unsure which is the most appropriate, they are:
to admit or to be aware that something exists or is true
SYNONYM acknowledge -They recognized the need to take the problem seriously. -Drugs were not recognized as a problem then. -Nobody recognized how urgent the situation was. -We recognized that the task was not straightforward. -It was recognized that this solution could only be temporary. -Drugs were not recognized to be a problem then.
to accept and approve of somebody/something officially
-recognized qualifications -The UK has refused to recognize the new regime. -He is recognized to be their natural leader.
to be thought of as very good or important by people in general
-The book is now recognized as a classic. -She's a recognized authority on the subject.