Nick Reiner was schizophrenic and became ‘erratic and dangerous’ after doctors changed his psych meds weeks before parents were slain

Nick Reiner was suffering with worsening schizophrenia and became ‘erratic and dangerous’ when doctors changed his psych medication weeks before he allegedly murdered his parents, insiders say.

Sources told TMZ that the accused killer was seeing a psychiatrist for his spiraling mental illness in the months before his Hollywood icon father Rob Reiner and mother Michele were found stabbed to death on Sunday.

According to the outlet, insiders said that Nick’s behavior had become ‘alarming’ in recent times.

He had been attending a Los Angeles rehab facility that specializes in substance abuse, and charges a staggering $70,000 a month, the report said.

In the weeks before the alleged murders, doctors reportedly changed Nick’s medication which made him more erratic, with one source saying the 32-year-old was ‘out of his head’.

On Saturday night, Nick was brought along to a star-studded holiday party hosted by Conan O’Brien because his concerned parents reportedly wanted to ‘keep an eye on him’.

Guests at the A-list packed holiday party said Nick displayed ‘antisocial behavior’ including staring at attendees, and he and Reiner reportedly had a loud argument at the bash.

Insiders told Rolling Stone that Reiner and Michele had asked if they could bring Nick to the party due to fears over his mental state. And, at one point, witnesses said Nick got into a heated moment with comedian Bill Hader.

+6
View gallery

Nick Reiner was suffering with worsening schizophrenia and became ‘erratic and dangerous’ when doctors changed his psych medication, insiders say

+6
View gallery

Hollywood legend Rob Reiner and his wife Michelle Singer were found stabbed to death in their mansion on Sunday

Rob and Michele were found dead with their throats slit in their $13.5 million California mansion on Sunday.

At the time of Nick’s arrest, his sister Romy, 27, who discovered their parents bodies, told investigators her brother ‘should be a suspect’ because he was ‘dangerous’.

The Daily Mail exclusively revealed following the alleged murders that those around Nick saw him as a ‘ticking time bomb’.

Sources said that Nick’s drug use spiraled out of control after his parents threatened to kick him out of their home.

The troubled 32-year-old had been living in his parents’ guesthouse in Los Angeles for the past five years – where his behavior had become increasingly erratic and frightening, insiders claimed.

‘Nick had been living in their guesthouse, the same one he destroyed more than once, but it had been like a revolving door all his adult life,’ a source close to Reiner told the Daily Mail on Monday.

‘He would do meth and not sleep for days and then have outbursts, breaking things, punching walls.

‘He was a ticking time bomb. His drug use was getting worse and his parents wanted him out,’ claimed the friend.

+6
View gallery

Reiner was arrested by the LAPD’s robbery homicide division with the help of US Marshals on Sunday night (pictured)

+6
View gallery

Nick, seen in September 2025, has long struggled with mental health issues and substance abuse and had been open about his numerous trips to rehab

+6
View gallery

Romy Reiner, 27, seen with her brother Nick, discovered their parents bodies, and told investigators her brother ‘should be a suspect’ because he was ‘dangerous’

According to the source, Nick, who was one of three children, frequently laughed off the destruction he caused during drug-fueled episodes.

‘He used to brag how he could get away with anything and took money from his parents for drugs and prostitutes.

‘He would talk about this stuff in meetings, but then stopped going because he said it was too cultish,’ the source claimed. ‘He laughed about destroying his parents’ guesthouse more than once. He was so nonchalant about it.’

Nick appeared in court for the first time on Wednesday, and was formally charged with the murders of his parents.

He waived his right to enter a plea, and his next hearing will be on January 7.

Investigators are still piecing together the whereabouts of Nick following the death of his parents – whose slain bodies were found in the master bedroom of their Brentwood mansion.