Psychology of music literature also suggests that Richard Wagner himself may have experienced symptoms of bipolar disorder. Music historians document how Wagner's music was blamed for nervousness, heart palpitations and melancholy. It would be fascinating, let alone scientifically sound(!), to explore the connection between types of music and negative emotional states in the same way that previous scientific literature has explored the connection between songs we choose and dopaminergic brain activity.
Here's Richard Wagner's "Tristan und Isolde", Prelude.