Mackenzie Phillips told Fox News Digital at the Chiller Theatre Expo that she and co‑star Valerie Bertinelli used cocaine and wine during lunch breaks while filming the CBS sitcom "One Day at a Time" from 1975 to 1984. Phillips said the pair would drive to her house, dip in a pool and indulge, while noting Bertinelli never struggled with addiction the way she did.

Lunch‑break cocaine trips on the set of a 1970s sitcom

According to the interview, Phillips and Bertinelli would leave the studio, head to Phillips' home, and combine wine with cocaine in the pool area. She described these moments as occasional, occurring "in the dressing room on occasion" rather than a daily routine. The revelation shines a light on the permissive backstage culture of 1970s television production.

Valerie Bertinelli’s role in the saga: occasional participant, not an addict

Phillips clarified that while she and Bertinelli used cocaine together, Bertinelli did not share Phillips' long‑term addiction issues. the actress emphasized that Bertinelli’s involvement was limited to the shared sessions, distinguishinng her own decades‑long battle with substance abuse from her co‑star’s more casual experimentation.

Friendship forged in teenage years survived decades of turmoil

The two actresses first met as teenagers—Phillips was 15 and Bertinelli 14—when they began work on the series. Phillips said their bond felt like family, even as her addiction strained the relationship at times. She now reaches out during perioods of sobriety, leaving voicemails to update Bertinelli without expecting a reply.

Phillips’ reflection: pain, faith and gratitude shape her present

Phillips, daughter of musician John Phillips of The Mamas & the Papas, said her struggles have made her who she is today. She credited faith for keeping her grounded and expressed that she would not erase her past, even if she could, because it taught her resilience.

Who else knows? The missing voices in the story

The interview provides Phillips’ perspective, but no comment from Bertinelli or other crew members was included. It remains unclear how widespread substance use was among the cast and crew, and whether the production company had any policies addressing it at the time.