Did I listen to pop music because I was miserable? Or was I miserable because I listened to pop music?

I'm glad you asked. Brian Primack at the University of Pittsburgh has been investigating teenage depression and music, and is starting to form an answer:

[He] says it's more likely that depressed teenagers are turning to music for solace, rather than music being the cause of the mental illness. "They don't feel like doing anything," Primack says. "They don't have a lot of energy, and this is a place where they can go and they don't have to perform."

How did Primarck study this, you might be wondering:

They called 106 teenagers on special cellphones as many as 60 times over eight weeks and asked what they were doing.

Yeah, I think I might be exhibiting signs of being a bit off my game if I was constantly getting calls on a "special" phone asking me what I was up to.

The teenagers listened to music 9 percent of the time on average. Those who listened to lots of music were 8 times more likely to be depressed than those who didn't listen very much.

By contrast, teenagers who read were far less likely to be diagnosed with depression.

Presumably, if you read books while listening to music, you'll be in some sort of mental balance.

[Full study results here]