'Mentally ill' man attacks psychiatrist in his office with sledgehammer and knife

A New York City psychiatrist has been attacked in his office by a 'mentally' ill man, who tried to bash him with a sledgehammer and then stabbed him several times with a knife, police said.

Dr Michael Weiss says he invited Jacob Nolan, 20, into his home office in an upscale highrise on West 57th Street near New York's Columbus Circle on Monday, only to be viciously attacked.

Nolan excused himself to the restroom, and then suddenly returned swinging a sledgehammer, the New York Post reports.

Luxury: Dr Michael Weiss was attacked at his home office in this building in the upscale neighborhood near Columbus Circle in New York

Luxury: Dr Michael Weiss was attacked at his home office in this building in the upscale neighborhood near Columbus Circle in New York

It is unclear where Nolan got the weapon or how he hid it from Dr Weiss.

Attack: It's unclear where Jacob Nolan got the hammer used in the attack

Attack: It's unclear where Jacob Nolan got the hammer used in the attack

When he failed to hit the psychiatrist, who specializes in treating addiction and depression, police say he pulled out a knife.

The two men wrestled for the blade, before Dr Weiss was able to take it from Nolan.

Both men were stabbed several times during the fight. 

Dr Weiss received a nasty gash to his abdomen, as well as several defensive wounds on his hands and abdomen.

They were taken to the hospital with non-life-threatening injuries

Police say Nolan is not one of Dr Weiss' patients -- the connection in personal.

Dr Weiss, 38, reportedly dated Nolan's cousin and fathered a child with her. 

Nolan was upset after a dispute about Dr Weiss paying for the child's school tuition, the Post reports.

Dr Weiss' sister told officers that Nolan has a history of mental illness.