Most mental health problems manifest differently in different cultural contexts.
Westerners generally have a reasonable understanding of anxiety as a psychological problem and are comfortable talking about it as such and seeking treatment for it. In developing and middle-income countries, depression and anxiety more often present as physical symptoms like digestive problems, pain, fatigue and muscle weakness. These patients will typically meet the standard diagnostic criteria for depression or anxiety if they're asked, but that's not how they conceptualise their problem.
A raft of other things that would be diagnosed in the west as obvious psychiatric disorders are, in less psychologically-aware places and times, simply chalked up as personal problems or personality differences.
I can certainly think of older members of my family who have "trouble with their nerves", a "bad stomach" that only flares up at times of acute stress or "funny turns" that look very much like panic attacks. I can think of an eccentric aunt who lived alone and obsessively collected teapots and never quite got the hang of small talk or eye contact. I can think of many men who came back from the war with a violent temper and a crippling fear of loud noises. A lack of diagnosis does not necessarily reflect a lack of pathology.
It's certainly plausible that some western countries (and America in particular) might over-pathologise normal distress as psychiatric disorder, but it's clear that many people in less-developed countries often face avoidable suffering due to a lack of diagnosis and treatment, particularly people suffering from the most severe disorders such as schizophrenia and bipolar disorder.
https://www.cambridge.org/core/journals/advances-in-psychiat...
https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0...