Some people can change to some degree, some can’t. Some people for example can recover from PTSD with time and talk therapy, and if you insist on others doing that they’ll end up killing themselves. Not taking medication is just as much of a fallacious “one-size-fits-all” solution as insisting that everyone take medication.
Parent was originally dismissing the complexity of the situation mentally and emotionally by insisting that there's just a simple biochemical thing that needs to be changed, like adding more gasoline or oil to a car engine to make it run longer. The reality is way more complex than that.
Change is really fucking hard and there's no silver bullet solution.
