Mariah Carey has thanked fans on Instagram for their "overwhelming" support after the singer went public about her struggle with bipolar disorder. "I've been hard at work, feeling inspired by each of your stories and uplifted by your overwhelming support," Carey said Sunday alongside an image of herself taking part in a photoshoot. "Let's continue to encourage each other on our journeys," she continued. Carey announced that she was diagnosed with bipolar II disorder in 2001 after she was hospitalized for a physical and mental breakdown. Bipolar II disorder involves having periods of depression and experiencing hypomania, a less severe form of mania seen in bipolar I disorder. "It was too heavy a burden to carry and I simply couldn't do that anymore," she said of making the announcement. "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." "I'm just in a really good place now," she continued. "[Bipolar disorder] does not have to define you and I refuse to allow it to define me or control me."