Demi Lovato is going through more upheaval in her life after calling it quits with boyfriend Wilmer Valderrama who once famously dated Lindsay Lohan. Apparently their age gap did them in.

Lovato is 18 and 13 years younger than Valderrama, who is 31. The couple felt they age gap was too much to bridge for a lasting relationship.

“The age difference meant they were in completely different places in their lives,” a source told The New York Post.

Lovato has gone through a rough patch since she punched a backup dancer, Alex Shorty Welch, while on the “Camp Rock 2” tour in South America with the Jonas Brothers Band.

The altercation, which she provoked, landed her in rehab last November. for treatment of “emotional and physical issues.”

Some reports claim she was also fighting a cocaine addiction.

Her mother Dianna Hart de la Garza has also recently decided to get treatment for her own issues at an undisclosed location.

“It has been a tough year for Demi, and her mom has been a constant source of support,” said the source.

“But fame has also taken its toll on her family. Now that Demi is strong again, her mom could take some time to deal with her own issues.”

Demi recently revealed she suffers from bipolar disorder, something she learned while receiving treatment in the residential clinic.

“I never found out until I went into treatment that I was bipolar,” she said.

“Looking back it makes sense. There were times when I was so manic, I was writing seven songs in one night and I’d be up until 5:30 in the morning.

“I feel like I am in control now where my whole life wasn’t in control.”

Last May (2010), Lovato split from Joe Jonas and turned to Valderrama “for support.”

“There are so many crazy rumors flying around today. I’d like to clear a few things up. First, Joe and I did split but it wasn’t over the phone. Things didn’t work out but we’ll remain friends. Secondly, I am NOT dating anybody already.

Nothing is more important to me than the relationship I have with my fans. Just thought you guys should know this.”

At the time, Valderrama denied anything was going on between them. But reports earlier this year linked them.