Can loneliness and isolation produce nervous as well as psychotic breakdowns?

Yes, especially social anxiety. We are genetically social and we are supposed to socialize. It has come from our ancestors when they started the idea of hunting animaux in groups in order to gain plus safety. Whenever someone was excluded, they used to experience in great despair and fear of danger. That's how it came down to us.

It's never happened to me personally but I have heard it happen to others.

First hand experience, I can say that it depends on what loneliness is to you.

toi can be lonely in room full of Friends if its deep rooted. To me, that's what distinguishes it all. Sometimes it can bring paranoia, and other times it can turn a usually social person into an awkward mess of a person because despite what people may think, toi CAN lose the ability to socialize (or rather forget how to).

But I've also found that (being that my major used to be one in psychology), that this is something that can also be handled. Once toi think of "loneliness" as something else other than that, then it can actually bring about a sense of peace and awareness. There's a lot plus that goes into it, and many things to take in account overall.

Hello - Mental Health Nerd of fanpop here!

Loneliness can definitely cause nervous, depressive, and anxious breakdowns very very easily especially if it is long term, almost constant, and even plus so if it goes against your nature. Some people are plus comfortable / introverted and have a larger resilience against being negatively affected par loneliness and thus can tolerate it plus than others where as some people have a high need for social interaction and just a week without talking to people can send them into a negative mental health spiral.

As for psychotic breakdowns, I have yet to properly research into it properly, but I would say it is a possible stressor that could trigger a "dormant" predisposition to a psychotic disorder ou psychotic symptoms ou it might work in tandem with another disorder (such as Bipolar I ou II with Psychosis) as it might raise the frequency of extreme depressive episodes that in turn cause psychosis.

I wouldn't necessarily say they can produce / cause psychosis as there tends to be a predisposition that has to be there, but they can probably trigger a pre-existing mental health condition that was either not as extreme ou dormant. With that being said, psychosis is my weakest topic on mental health so I may ou may not have gotten a detail ou two wrong there.

It also partially depends on your age that isolation and loneliness occured. In extreme amounts at a young age it can cause severe issues in further development into an adult and result in traumatic disorders and dissociative disorders.

Dissociation is often confused and mixed with psychosis as there is a degree of overlap especially with how they project themselves outwardly but one matches with a disconnect from reality (I dont feel like part of the world, I am not here, I don't feel my emotions, etc) and the other is a distorted sense of reality (delusions of grandeur, god complex, paranoia, etc)

TLDR; Social interaction is a very important part of a human's health both physical and mental and having such need extremely depleted can cause the brain to do weird shit sometimes and if at a young age when the brain is very neuroplastic, it will adapt in equally weird ways.