Police in Brent were called by the local mental health team to an address at Elmwood Crescent, Colindale on Friday, 25 September to assist staff with a patient due to be taken to hospital.
Upon arrival officers found the man, who is aged 59, at the location; he refused to go to hospital.
They entered the address and attempted to speak with the man, but he again refused to engage with officers and barricaded himself in a room.
Officers tried to detain the man for his own safety. Three officers were subsequently attacked by the man who was in possession of a screwdriver.
A female PC, based at Wembley Police Station was taken to a north London hospital with a half inch cut to the forehead after she was injured by a screwdriver. The other officers did not require hospital treatment.
The man was subsequently arrested on suspicion of attempted murder and detained under the Mental Health Act.
Chief Superintendent Mick Gallagher, Brent Borough commander, said: “Day in day out officers show courage and professionalism. Fortunately none of the officers were seriously injured, but this does demonstrate the potential risks they face. I’ve spoken to all the officers personally, who are ready to get back out policing tonight for the rest of their late turn.”