The 38-year-old, the club's longest-serving player, is set to end his association with the Magpies on Sunday and recounts his "dark days" several years previously
The 38-year-old will be making his 199th appearance for the Magpies against Arsenal before ending his 20-year spell and he has fond memories of St James' Park.
|HARPER'S NEWCASTLE CAREER
|YEARS AT CLUB
Harper told the Daily Mirror: "I was probably about 30 at the time and it was really tough. You need help. You can't fight it yourself. You have to speak to people and get help. That is what I did.
"There have been times when it has been anything but comfortable. The way I got through it was through the support of my family, particularly Lynsey, my wife, by going to see a little old lady, a counsellor, and with medication from the doctors.
"It helps you through it, because it was very tough and, the more you try to fight it yourself, it gets a hold of you.
"Fortunately, more people are speaking of it now and it is almost more acceptable but, seven or eight years ago, having had that tough time, I like to keep an eye on players now who I think are maybe struggling."
|6/1||Newcastle are 6/1 with William Hill to keep a clean sheet against Arsenal
"I probably blame Sir Bobby, to be honest," he explained. "I remember rapping on his door many a time and asking for a move and he said: 'I need you, Shay might get injured.'
"He had that persuasive, loveable thing where you might enter the room like a bear with a sore head and leave it giving him a hug!"
"At this club, the people - the fans and everyone - know if you've put the shift in, day in day out, and given your all out on the pitch," Harper continued. "They'll back you to the hilt.
"It's a great club to play for but it can be a difficult club to play for. It can be a heavy shirt, the Newcastle shirt, and you need to stand up and be counted."