McCready was found dead outside her Arkansas home from an apparent gunshot wound on Sunday, according to police.
"At 3:31 p.m., Sunday, Feb. 17, deputies from the Cleburne County Sheriff's Office were dispatched to a report of gun shots fired," local police said in a statement released late Sunday night. "Officers arrived on the scene at 3:58 p.m. and discovered the body of 37-year-old Melinda Gayle McCready on the front porch of the residence."
"Ms. McCready was pronounced dead at the scene from what appears to be a single self-inflicted gunshot wound. At this time family members have been notified of the incident. Ms. McCready will be transported to the Arkansas State Crime Lab for an autopsy and the matter will be fully investigated."
McCready's boyfriend, singer-songwriter David Wilson, died of a gunshot wound last month and his death remains under investigation.
McCready had denied any involvement in Wilson's death and become severely depressed afterwards -- resulting in a judge placing McCready's 6-year-old son and 10-month-old baby boy in foster care and ordering she undergo "involuntary admission" for treatment for mental illness and addiction issues, according to E! News.
"Since boyfriend (David Wilson) shot himself she has been in bed for 3 wks," her father Tim McCready stated in court documents earlier this month. "Sleeps all day. Drinks all night and is taking Rx drugs. Not bathing or even helping take care of her 2 children."
McCready reportedly spent one day at an in-patient treatment center for mental-health and alcohol-abuse evaluation but was then released to undergo outpatient treatment instead. Her father had been staying with her until Sunday morning when he left to return to Florida.
"She was in good spirits and seemed to be fine [when he left]," a source told E! News.
However later on Sunday, neighbors heard multiple gunshots at the house and called the police.
"She shot herself and the dog," the source explained.
McCready appeared on the third season of Celebrity Rehab with Dr. Drew in 2010, where she was publicly treated for prescription drug and alcohol abuse.
Last summer, former The Real World: Hollywood star Joey Kovar -- who participated in the same Celebrity Rehab edition as McCready -- died at age 29 from an apparent fatal combination of cocaine, Viagra and alcohol and former second-season Celebrity Rehab participant Rodney King was found dead in his pool at age 47 in June.