Q. I’m confused over when to use the article the in expressions like “the British psychiatrist Michael Rutter’s study.” Although readers will know it might not be the case, to me, using the makes that person the only one in that field.
A. It’s just a matter of how you read it. When you see that the name Michael Rutter is a restrictive appositive defining which British psychiatrist we’re talking about, the does not make him the only British psychiatrist—quite the contrary. See CMOS 5.23.