Mildly Interesting

Orange you glad you’re not depressed?

I would love to see a clinical trial done to definitively show that eating citrus can lower the risk of depression,

Ie, there are no clinical trials, this is just the result of running statistical analysis on large datasets that rely on self-reported data, along with a proposed causitive mechanism.

My guess at an alternative explaination: people who eat healthy diets and generally take care of themselves have a lower risk of depression. One significant factor in this is eating fruit. People on answering questions on a survey, even an anonymous survey, are embarassed to admit that they've only eaten McDonalds this week, and so imagine/justify eating some fruit, and the imaginary fruit that they are eating is apples and bananas, since that is the most stereotypical fruit to think of. People who actually live a healthy lifestyle are thinking of actual instances where they ate specific fruits, and are thus far more likely to report eating oranges. Oranges are a very common fruit to eat, since they are generally palatable, convenient, and cheap. Compare to mangos (messy, inconvenient) or blackberries (expensive), oranges are common enough that they can actually produce some sort of signal in the data. Then tack on maybe some accidental p-hacking (some fruit somewhere in the data was bound to indicate that eating fruit is good for your health), and you get this result.

Watch out for your 50 year old Aunt to tell you that drinking margaritas cures depression after she sees it on The View a month from now.

https://pubmed.ncbi.nlm.nih.gov/38932560/

Scurvy is depressing so this checks out.