'Out of His Head': Nick Reiner's Nightmare Med Change Before Slaughtering Parents

It's the unspoken epidemic gripping America: In an age where street drugs can render anyone functionally impaired, society often dismisses erratic behavior as mere intoxication.

But when that spiral lands someone in a psychiatric facility, the prescribed medications—far more potent and debilitating than anything available illicitly—can cement a lifetime of severe mental illness, trapping individuals in a cycle of forced treatment and diminished capacity. Never fully clear-headed again.

This grim reality now underscores the tragic case of Nick Reiner, the 32-year-old son of legendary Hollywood director Rob Reiner, charged with murdering his parents amid a reported schizophrenia diagnosis and a troubling medication adjustment.

Recently diagnosed with schizophrenia, Nick Reiner exhibited increasingly erratic behavior after a change in his psychiatric medication, sources close to the matter told TMZ on Friday.

Reiner, charged with two counts of first-degree murder in the stabbing deaths of his father, Rob Reiner, 78, and mother, Michele Singer Reiner, 70, had been under psychiatric care.

Three to four weeks before the killings, doctors altered his prescription in an attempt to stabilize him, but the adjustment reportedly backfired, rendering him more unstable—especially when compounded by ongoing substance abuse.

"Nick was out of his head," one source told TMZ.

Sources said the medication switch made Reiner "erratic and dangerous," with his behavior becoming "alarming" in the month leading up to the deaths.

Reiner had received treatment at an exclusive Los Angeles facility specializing in mental health and substance abuse, which charges up to $70,000 per month.

The suspect has battled drug addiction since age 15, cycling through more than a dozen rehabilitation programs over 17 years.

The murders occurred sometime early Sunday, Dec. 14, hours after Reiner and his father engaged in a heated public argument at comedian Conan O’Brien’s Christmas party.

Rob Reiner’s body was discovered around 3:40 p.m. that day by his daughter, Romy Reiner, 28.

She initially was unaware her mother had also been slain until paramedics located Michele Reiner’s body.

Romy Reiner alerted authorities that her brother should be considered dangerous, sources said.

Nick Reiner, meanwhile, was spotted wandering streets, purchasing a drink at a store and briefly checking into a Santa Monica hotel, where investigators later found a blood-covered sink.

Los Angeles Police Department’s Gang and Narcotics Division arrested him around 9:15 p.m. Sunday at a gas station about 15 miles from the Brentwood home.

Video captured the dramatic takedown.

Reiner made his initial court appearance Wednesday, clad in a suicide-prevention vest and displaying a vacant expression.

He spoke only to say "yes, your honor" when waiving his right to a speedy arraignment.

He is scheduled to return to court Jan. 7 for formal arraignment.

The high-profile family tragedy has raised renewed questions about the intersection of mental illness, addiction and treatment failures.

Authorities continue to investigate, with prosecutors weighing special circumstances that could lead to life without parole or the death penalty.