"It has become clear to me and those close to me that after many years putting my work first, I need to spend some time on myself in order to be the best person I can be," the 21-year-old singer said in a statement.
Gomez has yet to open up about her voluntary stint in rehab, but told the crowd at the We Day conference in Oakland, Calif., that she felt pressured to live up to expectations.
"I'm surrounded by people who are supposed to guide me, and some of them have and others haven't," Gomez told the crowd. "They pressure me: There's so much pressure. You gotta be sexy, you gotta be cute, you gotta be nice, you gotta be all these things."
"They tell me what to wear, how to look, what I should say, how I should be. Until recently I had given into that pressure, I lost sight of who I was," she continued. "I listened to opinions of people and I tried to change who I am because I thought others would accept me for it. And I realized I don't know how to be anything but myself."
"Please stay true to yourself," she said.
Watch the full speech below: