Sure the fog of paranoia would lift eventually, I tried to save her from herself. She wouldn’t talk to me on the phone, but I attempted to reason with her via Facebook instant message.

“I want you to know your posts are causing a lot of concern and worry,” I wrote. “I know you feel the urge to write but Facebook is not the best place. At least not anymore.”

But she felt compelled to continue the prolific posts for her own safety.

“Facebook’s not the best place when it is the ONLY reason I am alive?” she responded. “You are going to get me killed.”

Only a few years ago, things were very different. My beautiful sister made friends quickly, laughing easily and often, her bright brown eyes and long brown hair shining. Despite struggling through grade school and graduating from high school with a solid C average, she managed to rack up some impressive life achievements—a prestigious scholarship abroad, a graduate degree at an Ivy League School, a marriage to a handsome, well-respected professor and author.

It was during her grad student years that we first started to worry. Graduate school can be stressful for anyone, and though she made some close friends, her experience was marked by strife and controversies that seemed too personal, too turbulent.

Her personality seemed to change. She fought like a teenager with our mother. Long the closest person in my life, she didn't seem to care that I was getting married. She was distant and mistrustful toward my fiancé. She made odd remarks about people we’d known all our lives, telling stories about them I had a hard time believing, and labeling them jealous or cruel for reasons I couldn’t understand.

Things began to deteriorate the winter after her graduation. Her husband called me with panic in his voice. “She really needs her family right now,” he said, desperate for someone to do something. “Call her.”

He stuck it out for a while, but in the end it was too much for him, and he finally asked for a divorce.

She lived with us for a few months when she moved back to the United States, alone. She was depressed, understandably, but we hoped that with the help of therapy and medication she’d pull out of it eventually, meet someone new, and get a job. Ideally one with benefits. Her husband was in no rush to finalize the divorce, so she could continue to access his health care benefits, but that couldn’t last forever.

Eventually she moved to San Francisco, renting a big room in a shared apartment. She worked part-time at a yoga studio, took dance classes, wandered the streets smoking cigarettes, attended daily support groups.

When she came to visit her nieces and nephew, she was an adoring aunt but not always a kind sister. I had to explain to my kids. “Your aunt is sick,” I told them one day when she suddenly exploded at me after hours of nursing a perceived slight. “Her brain tells her things that aren’t true, so she doesn’t always act right. She can’t help it, and she loves us." I needed them to understand that this wasn’t normal adult behavior. They nodded and asked questions, sad but understanding.