According to Dalrymple, what is the fundamental difference between "depression" and "unhappiness"? Are you persuaded by his argument? Why or why not?

According to Dalrymple, people who are unhappy often mistakenly self-diagnose themselves as depressed and say that they are "depressed" rather than "unhappy". Dalrymple claimed that unhappiness commonly results from poor life choices, whereas, depression is considered to be a medically diagnosable condition that is separate and external to people. He further claimed that a healthy diet, regular exercise, adequate sleep and regular socialization will get rid of people's so called "depression".

While Dalrymple's perspective has some merits, I am not entirely persuaded and in favor of his argument. While I agree that people tend to mistaken their unhappiness as depression, I believe that there is a fundamental difference between the two. This is because, scientific research provides adequate evidence suggesting that depressed individuals have differences in brain functioning compared to non-depressed individuals.