A few articles have popped up regarding a recent paper that aimed to assess the effectiveness of lifestyle changes (dietary and activity) against CBT therapy on depression. They suggest that the lifestyle intervention was as effective as the therapy. And reading the paper that does seem to be the case.

Though there were a couple of issues that weren't flagged in any of the articles.  One being that there was no 'control group'. In this case a similar group that was given neither treatment. You may think of it as a formality, the authors probably assumed the same. Given they had no intervention, they would have stayed the same is a reasonable assumption. But depression fluctuates and often people seek out help at the lowest point so a 'regression to the mean' would make an improvement with time perfectly reasonable too.

Though the main thing, that wasn't flagged elsewhere, is that the participants in the lifestyle group were only given advice on diet that advised moving them towards a Mediterranean style diet.  As well as advice of how to become more active, movement snacks and similar. The actual reported changes were minimal, worse in some cases.

So really we're assessing the effectiveness of talking about lifestyle changes on depression. And it does seem to be as effective as CBT. Which raises the question: How effective is actual diet and activity change on depression? And, is CBT as much about attention and social bond as theory? We're definitely not going there, it's well outside our remit, but it is an interesting thought.

There are papers on diet and depression, and though small, the conclusions seem to suggest that changes in diet can effect depression. One meta study, linked below, suggested a 33% decrease in depression from switching to a Mediterranean diet. 

There are papers and meta papers on actual activity and, though they are mixed, the general direction is that activity lowers depression. It seems to be most effective at lower doses so going from sedentary to moderately active has the biggest change. Being highly active doesn't make you proportionally less depressed. So it's a 'zero to one' issue, as your local VC would probably say.

As ever, it's health and humans so it's complicated but making sure you get enough movement and eat well are going to pay dividends. Though you probably didn't need a stack of papers to tell you that. 

Lifestyle and CBT study

Diet and depression study

Activity and Depression study


Note:
We are not medical professionals and none of this is personal medical advice.