Interesting Read.

Stop Minimising Mental Illness

True that.

I am possessed by a thought. Perhaps not even a thought; rather an awareness. It started as a spark as the light bulb inside my head flicked on one unidentifiable dark day. It couldn't be extinguished. The darker the days grew, the stronger it glowed so that now it has over powered anything else I have ever experienced and sits within my core, reminding me of its existence with every beat of my heart.
At first it terrified me, but with time was downgraded to a bother. I'm not sure when or where, but at some point I accepted and found peace with this new found awareness. I'm not happy about it, and never will be because it's a demon I would be better off without, but at least by accepting it it's one less thing to fight against.

Inception

Eventually, she tells me the truth that she was possessed by an idea, just one simple idea that changed everything, that our world wasn't real and in order to get back to the reality, we'll have to kill ourselves.

It starts with a thought, and if it lingers a second longer becomes an idea. It is this idea that burrows itself into the subconscious so that the light bulb remains on, even when the sparks from every other thought process disguises it. With perseverance, this idea can become an obsession, and obsessions always win.