Speaking from the experience of knowing people who are suffering from some form of mental illness -- I would say that it is from unconfessed sin, which has allowed for demonic strongholds.
So, in short -- yes.
In Scripture, the Demoniac is a perfect example. He was a raving lunatic (or worse), and once delivered, he sat there in his "right mind."
In real life, think about Nicky Cruz or David Berkowitz ("Son of Sam" now "Son of Hope"). They were socio/psychopaths saved by Jesus, delivered from extreme mental illness/personality disorders -- into sanity and Christian ministries.
I have nothing to hide. No, I never murdered or raped anyone, or have a criminal record. I can tell you that, just from my difficult upbringing, being bullied, slandered and teased as a kid and teenager, brought the worst out of me in my mid-late teenage years.
What initially was fear and anxiety in my earlier years, manifested itself into high anxiety, anger, bitterness, confusion and hate when I hit about sixteen. Also mild OCD. At that time, I was agnostic. I had a feeling there
was a higher power, but wasn't quite sure. No Bible in the home. My Dad's side was afflicted with alcoholism and partying. My Mother's side were mostly comprised of non-drinkers, but a very serious bunch. Not the most compassionate of people.
Looking back in hindsight, I would almost say it was almost like being possessed, when anxiety and anger took over. I'd been an easy going kid who wouldn't lash out. Some years later, all the pent up anger manifested itself, that I could no longer keep anything inside, no matter how hard I tried. I was a skinny kid with glasses and acne. Oh, I was attracted to girls but didn't like them personally. My Mother could have a cold demeanor, so I though they'd be the same way.
Now that I have some Biblical knowledge, I can say for certain that it was Satan working in my life to destroy me. He was also using the people who hurt me, so I would in turn hate them. And their sin of hurting me, against them and myself.
If I'd had died five years ago, of course by that time not being as anxious, angry or bitter, I know I'd have gone to hell. I wasn't saved then. And it wasn't until four years ago, when joining the Salvation Army, that I finally started to learn about Christianity and the Bible.