Chief Constable Gary Roberts says one in five incidents police are called to involve people with mental health issues.
He was giving evidence to Tynwald's Social Affairs Policy Review committee on Friday when he made the claim.
Mr Roberts was asked whether the number of such incidents had fallen after police began working with other agencies.
He said so far there'd been no change, although he did expect the figure to fall in future:
Road closed after crash
Police say a road in the west of the Island will be closed until this evening.
Worries about fire pollution in Glen Maye
Commissioners in the west of the Island says they'll look into the pollution from coal fires and log burners.
UK businessman wants to hear about mobile signal at sea
Can you pick up a mobile signal in the middle of the Irish Sea?
Minister quizzed over new Meat Plant director
Agriculture Minister Clare Barber says a former MHK was appointed to the board of the Island's meat plant because the company urgently needed two directors.
Yellow weather warning this weekend
A yellow weather warning for coastal overtopping has been issued for this weekend.
Education boss retires
The Department of Education, Sport and Culture says it'll be looking for a new chief officer next year.
Steam Packet warns of sailing delays today
The Steam Packet says some of its sailings will be running late today.
Know someone who's made a difference to their community?
Nominations have opened for a special community award in Onchan.
