The Croatia international's comments come a week after Hannover goalkeeper Robert Enke committed suicide.

His widow revealed he had battled the illness for years.

Simunic, 31, claimed he was tempted to abandon his career because of depression.

"I wanted to stop with football," he said in an interview with Sport Bild. "I was very depressed, physically at the end.

"I once went for seven days in a row without sleeping."

Simunic experienced his problems during his spells at Hamburg and Hertha Berlin, whom he left in the summer.