Depression IS a reaction to what has happened. While depression and anxiety are different, they're also related. This suggests a common chemical in-balance may underlie anxiety and depression. Words such as I feel worried, or nervous, or irritable, or fearful, or afraid, or uncertain, or insecure, or terrified, or stressed, or tense, or panicked are used to describe anxiety. Half signal the anxiety's neither agreeable or disagreeable.
Half signal the anxiety's disagreeable.
Depression, in turn, results in more isolation. For the sad old earth must borrow its mirth, But has trouble enough of its own. Sing, and the hills will answer, Sigh, it's lost on the air. And it also accounts for why some people who are depressed are mistakenly thought to have Parkinson disease. I feel flushed.