This "study" isn't a study at all. One week provides factually meaningless data. You'd need a minimum of 3 months just to register a new baseline, and another 6-12 months to see if those participants who originally found a higher baseline at 3 months maintain it or fall back to previous levels as the novelty of the situation wears off.
You want to know why people reported feeling better? Because they changed a habit. When you change anything in your life for a single week, you will feel better because you have pulled yourself out of your everyday routine and are experiencing something NEW. This is the result of a change; what changed - Facebook in this case - does not matter.
The novelty of a change in habit for a single week does not even begin to offer evidence of anything. This isn't even a case of "not enough evidence", but rather "no evidence whatsoever". This novelty is similar to the kind of high you get from buying a new expensive toy/gadget. A temporary boost of "happiness" that quickly fades as the new item just becomes another object in your day-to-day life.
You want to know why people reported feeling better? Because they changed a habit. When you change anything in your life for a single week, you will feel better because you have pulled yourself out of your everyday routine and are experiencing something NEW. This is the result of a change; what changed - Facebook in this case - does not matter.
The novelty of a change in habit for a single week does not even begin to offer evidence of anything. This isn't even a case of "not enough evidence", but rather "no evidence whatsoever". This novelty is similar to the kind of high you get from buying a new expensive toy/gadget. A temporary boost of "happiness" that quickly fades as the new item just becomes another object in your day-to-day life.