What other methods of facilitation of mental illness could take place?

I assume that most people would consider it to be entirely plausible that there is likely to be a natural progression of mental illness following say offensive behaviour or criminal activity someone may reasonably be excluded and subject to a reduction in self esteem which then plausibly leads into depression reduced self care, disconnection from the same norms as others and become socially isolated etc. Then lacking the reinforcement and incentive through lack of appropriate social contact there will be a reduction biologically in various chemicals within an individual who may then require chemical support in order to normalise after this has manifested itself through anxiety, depression or other symptoms.
I assume again maybe rightly or wrongly there could be a great many alternate explanations bubbling under which may partially support this type of bio-psycho-social model of the development of mental illness which requires a medical intervention to rectify problems. I am really sceptical about this and have had no real joy in getting this type of matter addressed – mainstream political parties seem to disregard this as a matter of course and have a strong desire to marginalise anyone who may have experienced mental ill health and there seems total willingness to disregard the type of allegations that someone may make on the basis that they are paranoid and for example ‘look or appear mentally ill’. My own experience leads me to believe that there could be a great many problems linked together that would be difficult to separate and certainly this type of explanation should not be disregarded. If alternate explanations are dismissed as paranoid speculation then this could take place without investigation or concern from the authorities, who resemble something like the cast of Invasion of the Body Snatchers.
Whether it’s worth speculating on this or not I can’t say – I think it’s likely that there are various forms of medication that have been developed for ‘state’ purposes that could involve medication which has been specifically developed for degrading mental health. The CIA probably possesses drugs that can entirely melt your brains. They’re probably used in the USA for prisoners in Guantanamo Bay to ensure that they breakdown just a little bit and while the US government can deny they exist, as representatives of the British government would also do. The theory behind them is probably not that sophisticated. Depression lifts for the 50 million or so who are taking selective serotonin reuptake inhibitors (SSRIs) ensure that there is an increased level of serotonin around the neurons the brain – what could be simpler but to have a drug which could do the opposite of the SSRIs an unselective serotonin reuptake facilitator? You’d feel like death warmed up having the most impossible low that would be imaginable. What’s interesting about this is that there is the theory in place and technology to develop this, however, governments across the world would continue to deny their existence. Will anything give?