This doesn’t say much. In fact, the study says the association is not causal. There are a few directions one can go with this:
-is this true on a larger population based study?
-are people prone to depression more likely to adopt vegan diets?
-are people who choose vegan diets have other lifestyle factors that make them more prone to depression ?
-do vegan diet nutritional deficiencies adversely affect mental health?
-do vegan lifestyles lead to social ostracism, contributing to depression?
A lot of these sound plausible. However, no causal reason can be identified.
You make some valid points and pose some interesting questions/outside factors.
I myself did pescatarian for most of last year trying to address some health issues and I think many vegetarian men who also workout have a much better understanding of supplementation and overall diet like yourself. However, most that I know who became vegan/vegetarian haven't a clue how to maintain proper nutrition. From a dietary perspective omega 3, b12 and iron are commonly low in vegans/vegetarians and those greatly contribute to symptoms of depression.
The potential factors you list above can and should be considered and I have seen other sites attempting to combat these studies in a similar vein, but the grounds by which to measure these things are difficult. I believe empiricism is important in shaping an opinion on a matter alongside personal experience and observations.
In my experience most vegetarians are a bit 'off'
and I don't mean that in a bad way. More So they are atypical and deviate from the norm. With that in mind they are commonly neurodivergent and more likely to have mental health issues.
Is the diet contributing to the increase of mental illness? Or is it the outside factors you list prior? No one can say for sure, but there certainly are quite a few studies that showcase there is indeed an abundance of mental health related issues with those that practice vegetarianism.
An aside, one of the most important things I learned when writing a dissertation with the supervision of a professor was to come to terms with "studies just being studies".
The way you interpret the data and how you respond to it is more important. You also have to keep in mind sample size, bias and recreating things in a controlled environment among others. That and studies come out and completly change past results and views all the time. Studies, statistics and datasets are important,
but they don't paint the whole picture, they do get ink on the canvas though.
Here is a few more worth looking at.
Several studies have suggested an association between vegetarian diet and higher depression scores. However, some studies have also shown an effect in…
www.sciencedirect.com
(larger sample size)
How does the health and well-being of young Australian vegetarian and semi-vegetarian women compare with non-vegetarians? - Volume 10 Issue 5
www.cambridge.org
Recent evidence suggests that vegetarian and vegan diets may increase the risk and symptoms of depression, a mental health condition affecting 350 million people globally. We aimed to systematically review the literature on the associations between vegetarian and/or vegan diets and the risk or...
pubmed.ncbi.nlm.nih.gov
A cross sectional study of over 23 studies.
There was conflicting evidence, yet
nearly half of the total of studies still indicate a high prevalence of depression in vegetarians.
