Demi Lovato's Ex-Boyfriend Wilmer Valderrama 'Shattered' by Singer's Apparent Drug Overdose, Source Says

A source tells ET the actor 'did not anticipate' for this to happen, as the singer recently celebrated six years of sobriety.

Demi Lovato's celebrity friends are continuing to share their love and support, but those closest to her are not taking the news of her hospitalization lightly.

One of those people is Wilmer Valderrama, whom the singer dated for six years. Though they called it quits in June 2016, the two have remained close friends, and now, a source close to the actor tells ET that he is "shattered" by his ex's drug overdose.

"Even after they broke up, they continued to be very good friends," the source says. "They have mutual admiration for each other and he has and will always believe in her. He's watched her fall and has seen her rise."

"[Wilmer] was aware she was going through a bumpy patch because she was forthright with him when she relapsed," the source adds. "But he did not anticipate this."

Lovato has been very vocal about her her struggles with sobriety, substance abuse and self-harm over the years. She celebrated six years of sobriety in March, but seemingly revealed in June that she had relapsed with the release of her latest song, "Sober." At the time, an additional source told ET Lovato had, in fact, relapsed, and it happened at some point in between the North American leg of her Tell Me You Love Me world tour, which ended on April 2 in Newark, New Jersey, and her European leg, which started in Belfast, Ireland, on May 24.

As ET previously reported, a source told ET on Tuesday that Lovato was stable, and "awake and responsive" following her hospitalization. Her rep also released the following statement:

"Demi is awake and with her family, who want to express thanks to everyone for the love, prayers and support. Some of the information being reported is incorrect and they respectfully ask for privacy and not speculation as her health and recovery is the most important thing right now."

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If you or someone you know is struggling with substance abuse, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-HELP (4357).