Well, the article and the research it discusses is exclusively focussed on language.

Of course, there are more factors to depression beyond just language. Your body's internal chemistry is also going to factor in.

You say cutting carbs and fibers from your diet helped you. It might help some other people as well. For yet another group of people with depression, such a change might not help at all.

There's no magic solution and there are many, many possible causes for why a person is suffering from depression.