Is it possible for a "mental illness" to be "contagious"?

Can a mental illness be contagious?

Yes it's rare, but worrisome I feel for you & those around you. This is why they lock up the crazies.	17.4%	[ 12 ]
No, you're just screwed up from love hormones & mental abuse from your mom who was probably a ticking time-bomb	72.5%	[ 50 ]
I don't know, but your all crazy & I don't wanna be around any of you!	10.1%	[ 7 ]
Total Votes:			[ 69 ]

[Villain Vanilla]

Depression is. Because misery loves company.

[crimsin eyes]

Show me your friends and I will show you your future.

[PanDah K]

No, any other answer is illogical. Mental illness are isolated to one brain, and are not contagious because they are related to chemical imbalances in the brain which cannot be transferred to any other human being.

[crimsin eyes]

Villain Vanilla

Depression is. Because misery loves company.

Where does misery find her roots?

[maggoty tacos]

I think your behavior can be influenced by people with mental disorders. But seeing those behaviors may have triggered one she already had?

[elijah would]

mental illness can be passed through genes but not like a virus would be. i'm not sure if that's what you meant, or what. this stuff is carried from one family member to the next, and sticks with whoever is unfortunate enough.

if that was the case i'd be locked away right now, lol

[itzapizzaghost]

Saying you can catch a mental disorder is like saying you can catch someones sexual preference. It's not possible. People can put ideas into your head, and some people can influence your desicions in life...but they cannot physically infect you with any kind of mental disorder. Genetically it can be passed down...but just catching a mental illness like you catch the common cold? That seems sort of impossible!

[WiseInsanity]

Contagious? I don't think so..
But often times mental illness can be something that genetics passes along.

ie: I come from a family where a line of about four of us all have depression, often times just paired up with other additions..
for example, one has severe seasonal depression/anxiety.. the next has massively brutal bipolar disorder, depression, OCD,..the next in line having schizophrenia.. and myself with depression/anxiety/OCD combo. '
In that wonderful way that genetics works.. I suppose you could call it "contagious" but clearly under a different context than what you're asking.

[Mein Frankenmind]

I would argue that in special cases, yes, a mental illness can be contagious but it depends highly on the psychology of the one 'catching' the illness. If that one happened to be a repeated witness to, say, depressive-type behavior while in a highly impressionable state, their brain might subconsciously adapt and start to cause the one to develop depression-like symptoms or to imitate depressive behavior.

Consider the following scenario. A family of three, a father, mother and 14 year-old son, has depression; none of them know they have depression yet they all exhibit common symptoms of the depressive. They decide to adopt a 10 year-old son. He is ingratiated, and develops a strong, healthy, normal relationship with each of his new family members quickly. Given what we know about the brain and how personal relationships affect a person psychologically, I don't think it's too far out to think that he might then develop depression secondhand, which I think is a better way to think about it than to say he caught a mental illness. Consider the 'raised by wolves'/Tarzan idea.

[Sher!ock]

[responding to OP without reading any other responses first]

First of all, I'm wondering if this was an actual diagnosis or self-diagnosis or what...
Either your fiance's therapist is ridiculously diagnosis-happy or your fiance is a really unlucky person. confused
Unless I'm just unaware of common comorbidities.

Anyway, while it is theoretically possible
for there to be some kind of contagious viral/bacterial/fungal/whatever infection
that causes personality change
(probably via damage to brain tissue or disruption of brain signals),
it seems highly unlikely to be the issue in your case.
Occam's Razor suggests we consider known factors before assuming some yet unknown factor is the culprit.

Your fiance may have tried to hide his illnesses from your mother,
but people can be quite perceptive and she could have picked up on it anyway.
Another (not mutually exclusive) explanation is that she may just have her own problems
completely independent of your fiance.
You, on the other hand, are probably building up stress from dealing with your fiance's illnesses,
on top of your mom's new personality changes.
Those all sound like more reasonable, parsimonious explanations than a new contagious disease.
It can be difficult to handle another person's challenges,
whether it be a mental illness or not.
People who care for those with physical handicaps like paraplegia or dementia can burn out over time,
and the same is very true for those who deal with mental illness.
It's taxing, and if you don't take care of yourself, it can break you.

If your mental health is suffering, you should consider seeking therapy or counseling.
Even just calling a suicide hotline (even if you're not suicidal) could potentially help when you're feeling particularly stressed.