Anti-psychotic medication has a range of really unpleasant side effects. Weight gain is one. It's not just that the illness makes it hard to exercise and eat right, or that the meds are sedating. There's a weird mechanism on top of that which increases weight sometimes dramatically. This has all the other problems of weight (social stigma, ill health, cost, etc etc.)
Anti psychotics are not just prescribed for people with a psychotic illness either. Sometimes they're used for people with personality disorder (often against best current practice guidance) or similar.
See the example of the anti-epileptic drug, given a tweak and re-released as a mood stabiliser. This drug was later found to increase risk of PCOS. Thus, a bunch of women given a med against BCP guidance (because it probably wasn't that useful for them) had all the side effects of that med, and little benefit from it, and were then told that they were at higher risk of Poly Cystic Ovarian Syndrome. You don't have to hear too many stories from people on meds like that before you wonder just what this handful of drugs you've been given are.
In the past many people were sedated beyond the point of useful life, because we had asylums to keep these people warehoused for many years. Obviously that's bad. But now we (at least, the UK) don't really have decent enough community support, or better meds, and in-patient stays are rightfully kept for people who are a risk to themselves or others.
There is great work happening with FEP - first episode of psychosis. Early intervention can make a significant difference.
And we've stopped saying that psychosis is invented by the family of the relative too.