Adler went to the desert with friends on March 25, where the group was shooting. He turned a gun and shot himself in the head while in the middle of firing, reported People magazine.
The reality star's father, Frank Adler, confirmed that he passed away from suicide a day later in the hospital on March 26, and no drugs or alcohol were found in his system.
"He had been clean for several years," Frank said.
"We are saddened by the news of Clay Adler's passing. Our thoughts and prayers are with his family and friends at this time," MTV said in a statement.