We have known for a long time that exercise is good for mental health. The evidence on this is not new or contested. Study after study, across decades of research, points to the same conclusion: people who move regularly feel better, think more clearly, and show lower rates of depression and anxiety than people who do not. What has been less understood, until relatively recently, is why. The standard explanation has leaned heavily on endorphins, that familiar post-workout moo

There's a question that doesn't get asked often enough in mental health conversations: what is the brain actually running on? We talk about neurotransmitters constantly, serotonin, dopamine, norepinephrine. These are the chemical messengers that carry signals between neurons, and they're the primary target of most psychiatric medications. That framing has dominated mental health treatment for decades. But there's another layer underneath the neurotransmitter story that most