TMZ has obtained the audio of 911 calls made by Mischa Barton’s neighbors last month after she had a meltdown in her backyard — and one of those neighbors claims Barton was threatening to kill herself.

Late last month, Barton was caught on video in her backyard, hanging over a fence and shouting incoherently. When police arrived, the former O.C. actress volunteered to be transported to a hospital for evaluation. She later said someone had slipped the “date rape” drug into her drink when she was out celebrating her birthday with friends.

Now, more details have emerged — and they are concerning. In one of the two 911 calls obtained by TMZ, a neighbor tells the dispatcher that Barton is threatening to kill herself and saying she wants to die. The caller also claims that Barton gets visits by police on a somewhat regular basis.

“They come see her every couple of months because she just loses it,” the caller says.

Barton reportedly threatened to take her own life in 2009, when her parents staged an intervention after the actress blacked out from overdosing on sedatives. Barton spoke publicly about that difficult period in her life, calling it a “full-on breakdown.”

Barton has not yet responded to the recent reports.

Photo: Associated Press