Mariah Carey celebrates boyfriend Brian Tanaka's birthday after addressing her bipolar disorder

Mariah Carey was all smiles on Wednesday after bravely addressing her bipolar II disorder diagnosis in a revealing new interview.

Clad in a fitted black bodycon dress that showcased her curves, the 48-year-old singer stepped out to celebrate boyfriend Bryan Tanaka's 35th birthday at Mastro's Steakhouse in Beverly Hills, California. Carey paired the look with a black leather jacket and matching peep-toe booties. Tanaka, who was carrying a birthday gift bag, donned a navy blue jacket and jeans.

Mariah Carey steps out for boyfriend Bryan Tanaka's birthday

This was Carey's first public appearance since revealing in an interview with People magazine that she was diagnosed with bipolar disorder in 2001, after being hospitalized and having a mental and physical breakdown.

"Until recently I lived in denial and isolation and in constant fear someone would expose me,” she says of keeping the diagnosis under wraps. “It was too heavy a burden to carry and I simply couldn’t do that anymore. I sought and received treatment, I put positive people around me and I got back to doing what I love -- writing songs and making music."

See Mariah Carey and boyfriend Brian Tanaka:

The GRAMMY winner, who co-parents 6-year-old twins Monroe and Moroccan with ex-husband Nick Cannon, adds that she is on medication as part of her treatment plan.

"I’m actually taking medication that seems to be pretty good. It’s not making me feel too tired or sluggish or anything like that," she continues. "Finding the proper balance is what is most important."

Several other stars have also come forward in the hopes of reducing the stigma associated with mental illness including Demi Lovato, Catherine Zeta-Jones and the late actress Carrie Fisher.