The force has seen a surge in mental health-related call-outs and is in the “early stages” of devising plans to work more closely with health trusts.
“Radical reforms” are needed, say crime advisers, and could include health workers and nurses accompanying police on certain patrols.
Detective Chief Superintendent Stephen Clayman, head of the east area command unit, said officers are rightly called out when someone is a danger to themselves or others, but often people with complex needs end up in custody.
He said: “There is some work going on around joint mental health teams. It has provisionally been done before with joint police officers, paramedics, mental health workers [but] it wasn’t a perfect model. Ideas are being scoped.”
He added: “There are a lot of people who come into custody because of mental health and they shouldn’t be there. We know that and we are trying to divert that.”
UK police forces recorded almost half a million mental health-related call-outs last year, a 20 per cent rise on 2016.
The Met attended 39,584 calls — the highest number for any force, figures from think tank Parliament Street show.
Last year there were 16 deaths in police custody, including 10 people identified as having “mental health concerns”, according to the Independent Office for Police Conduct’s annual report.
Pressure on the mental health care system has meant police have been dealing with more incidents.
A Met spokesman said ideas about joining up with mental health services were “still in very early planning” stages.