The ER doc sounded genuinely concerned, which is never a good sign. “Sixty-year-old guy, no real medical history, dude is seriously hallucinating. Head imaging is negative. Can you come take a look at him?” I flitted through the chart. A car accident a few years ago that left him with chronic, poorly controlled migraines. Depression, on Prozac and well controlled. That was pretty much it. I grabbed my stethoscope and headed down to the ER.

I opened the patient’s door, and stepped into a scene of biblical intensity. The man before me was frantic, gesticulating wildly with his right arm and clutching a small white bible with his left. He had a noble, square, clean-shaven face with a shock of white hair and a pair of thick-framed glasses riding somewhat unevenly across his nose. His eyes were everywhere: first to me as I walked in, then to his wife, back to me, then away, his gaze darting and dancing across the room.

I walked over to his side. I introduced myself, extending my hand to his. He grabbed it and held it, clutching the tendons of my hand as if they were a life preserver. “Doc,” he said in a stately, somber baritone, “they’re everywhere.” “Who?” I said. “The devil and his army,” he said plainly. “They’re everywhere. I see them, I see.” He voice was honest, earnest. He put special emphasis on certain words. “The great red eye. The great de-ceeei-ver. You’ll have no power over me, you hear? You have no power, Satan. You see? No power here.”

I asked him how long he’d been seeing this. “For about…about a year. Yes, a year. A year of marching, a year of the red flame…” From the corner of my eye, his wife slowly shook her head ‘no.’ After I examined him, I stepped out of the room with his wife. “It’s the craziest thing, he was totally normal yesterday. Then, all of a sudden, at around midnight, he woke up from sleep and started waving his arms, talking about the devil.” “Is he very religious? A pastor, Sunday school teacher?” “Nope. Truck driver. He was raised protestant but we’re not particularly religious.”

After obtaining the rest of the history from his wife, I went back into the patient’s room. Once more, I held his hand. “I’m not sure what’s going on. But we’re going to get to the bottom of this. I’m going to admit you to the hospital for the next few days. Hang in there.” He looked back up at me. “Please, doc. Help me.” I headed back to my team room.

The man’s hallucinations were extraordinary for their timing. People in their sixties don’t usually wake up one day seeing things that aren’t there. Sudden changes in perception usually indicate extrinsic circumstances like drug use or extremely traumatic events. Our patient had neither. He also had no signs of prior mental illness besides his depression. If our patient had a longer term thought disorder, we’d expect more clues in his history. Years of hallucinations, extensive psychiatric history, and antipsychotic meds would all be documented in the chart. But there was nothing. I sat in a frustrated silence in my team room. What the hell was going on?

I ordered the basic set of labs that most patients get upon admission to a hospital. These include sodium, calcium, and glucose levels. Fluctuations of these chemicals in the body can cause mental status changes – perhaps they were the culprit. I ordered a vitamin B12 level, a rapid plasma reagin test, and a thyroid stimulating hormone level. A B12 deficiency can cause neurological changes. The rapid plasma reagin was to test for syphilis (which can affect the brain in untreated chronic cases). Thyroid stimulating hormone levels would tell me if he had an underlying thyroid condition potentiating his psychosis. I also ordered urine studies – sometimes urinary tract infections can cause altered mental status.

By the next day, all my labs had resulted. Everything was stone cold normal. No vitamin deficiencies, no latent infections, no electrolyte abnormalities. Hmmm. I went to see him that morning. It was like I had never left. He was still waving his arms, gesturing angrily to an empty corner of the room to “leave me be, devil. Leave me be. You have no power here.”

But then he did something else. After waving his arms for a few more seconds, he brought them up to his temples, and started to massage them. “Migraines again, honey?” His wife asked. “They’re back,” he said. “They’re back, the pain, the great pain. Pain in my skull. My head. My forehead. ”

My mentor, Dr. Niraj Mehta, has a great saying about what to do when things aren’t making sense: ‘You either have the wrong patient, the wrong diagnosis, or the wrong treatment.’ Never mind the wrong diagnosis, I didn’t even have a diagnosis. I needed more of the history.

I spoke to the patient’s wife again. I wanted to know more about the chronic migraines. I asked her about how they had been treated. “Oh, it’s been awful. Ever since that car accident he gets them all the time. He’s seen the neurologists constantly, almost every month. They’re always changing the meds but nothing seems to work.” “What did they try most recently?” “Well, we just started scheduled ibuprofen and phenergan. They also just took him off valproic acid, which he’d been on for a few years now.”

Boom. The neurology notes! I’d read over them, but hadn’t paid close enough attention to the med changes. Valproic acid is an anti-epileptic drug, but works remarkably well as a mood stabilizer. It can even be used to treat depression associated with bipolar disorder. Now we’re getting somewhere!

I had a theory now. What if the valproic acid had been secretly keeping his hallucinations at bay since the car crash! Furthermore, what if he didn’t just have depression, but a thought disorder that also featured depression! I immediately started the patient on an antipsychotic medication called olanzapine. Antipsychotic drugs slow the surge of dopamine in the brain responsible for the symptoms of psychosis: thoughts, voices, visions, hallucinations. I also restarted his valproic acid. And then I waited.

The next day, I lingered by the door before walking in. Please work. I slowly opened the door, and for the first time since he’d been in the hospital, I heard beautiful silence. My patient was sitting bolt upright in bed, legs folded underneath him. His eyes were closed. He appeared to be meditating. His eyes fluttered open as I approached the bed.

“Good morning, doc.” His words were even and steady. They radiated calm. The Dalai Lama himself couldn’t have projected a more serene aura.

“How do you feel?”

“Doc, I feel better. The army… they aren’t coming after me as much. And there are less of them. The devil’s presence is fading. I can feel it.” His wife was beaming from the corner. “He slept perfectly through the night, nine straight hours!”

“Doc, when will it go away? When will I be myself again, back to normal?”

“I’m not sure,” I said. “Probably months. But the fact you responded so well to the medication is a great sign. This isn’t the sort of illness that corrects in a day. You’ll have to see a psychiatrist to manage your medications and to start therapy. They’re the real experts with this sort of thing. But you’re doing much better. I have a good feeling about this.”

“Sounds good, doc. Thank you.” He reached out again and held my hand. But this time, he wasn’t holding on for dear life. His grasp was firm and strong. He released my hand, and closed his eyes again, his expression determined but at ease.

Perhaps he was readying himself for the next encounter with the demonic army. Perhaps he was enjoying his newly gained mental solitude. Maybe he was just tired. Whatever the reason, he had more than earned this moment of tranquility. He’d been to hell and back over the past few days, pushed to the brink of sanity by demons of his own creation. He confronted chaos and fear head on, uncertain if he was losing his mind. He faced the ultimate test.

It didn’t take a doctor to realize that he had won.