How can the society be more constructive in helping people with mental needs

The "chemical imbalance" story — that depression is caused by low serotonin, correctable by SSRIs — has been substantially debunked. A widely discussed 2022 umbrella review found no consistent evidence that lowered serotonin activity causes depression, and its authors have argued publicly that the theory was never well-supported even at the time it became public-facing shorthand. It's also true that SSRIs' mechanism of action was identified before any theory of why raising serotonin should relieve depression existed — the drug came first, the story came after. And there's a serious strand of thinking, including from evolutionary psychiatrists, that overmedicalizing what may be adaptive, context-driven distress leads to reaching for a prescription pad when a lifestyle or environmental fix — sleep, isolation, sedentary living — would be the more logical first move.

What you're describing has a name: evolutionary mismatch theory (sometimes "evolutionary psychiatry"). Randolph Nesse, who essentially founded the field, argues directly that natural selection is too slow to keep up with rapid social and environmental change, and that many modern "disorders" are evolved responses — anxiety, low mood, even substance vulnerability — firing in an environment radically unlike the one they were shaped for. This isn't fringe; it's published in mainstream venues like World Psychiatry. That said, it's worth knowing the field has an internal critique too: some philosophers of science argue the mismatch hypothesis is hard to test rigorously, because proving a modern psychological mechanism really is the "same" mechanism our ancestors had, for the reason it evolved, is a tall empirical order. So treat it as a compelling, well-populated research program — not a settled fact.