People with mental health problems who are cared for by community crisis teams are far more likely to kill themselves than those treated in hospital, research shows.
Some 200 suicides occur every year among those receiving crisis resolution and home treatment (CRHT) - three times the figure for inpatients.
Experts behind the new study - from the University of Manchester's National Confidential Inquiry into Suicide and Homicide by People with Mental Illness (NCISH) - questioned whether there was too much reliance on home treatment.
Their report said "crisis teams are unlikely to be a safe setting for patients at high risk or who live alone".
A CHRT team is a group of mental health professionals who support a person at home during a mental health crisis. They usually include a psychiatrist, mental health nurses, social workers and support workers.
The CRHT team offers help such as administering medication, carrying out frequent home visits, and offering psychological and practical support. It can also decide whether somebody should be admitted to hospital for treatment.
The new study found that a third of patients under CRHT who died from suicide had been using the service for less than a week, while a third had been discharged from hospital in the previous two weeks. Some 43% lived alone.
The report said "these features suggest that CRHT may not have been a suitable setting for their care" and there are "concerns that CRHT has become the default option for acute mental health care because of pressure on other services".
Overall, 5% of patients who died from suicide had been living in the UK for less than five years - accounting for 87 deaths per year. Twenty people over four years were asylum seekers and there were rising suicides among the unemployed and homeless.
The study said: "There is evidence that economic factors are becoming more common as antecedents in patient suicides. Unemployment and homelessness have increased and 13% of patients who died by suicide had experienced serious financial difficulties in the previous three months."
Professor Louis Appleby, director of NCISH and the Government's former national director for mental health, said: "This year's report reflects the increasing reliance on crisis teams in response to the strains felt by acute mental health services.
"Our findings suggest that we are accepting too much risk in the home treatment these teams offer, and that the crisis team is now the priority for suicide prevention in mental health."
The research also found that more than half of the 1,700 mental health patients per year who die from suicide have a history of alcohol or drug misuse, but only a small number receive specialist substance misuse treatment.
Overall, suicides by mental health patients treated in hospital are falling, with around a 60% drop between 2004 and 2014. Suicides among people cared for by CRHT teams was rising but is now static.
Samantha Nicklin, head of campaigns at Rethink Mental Illness, said: "Every suicide is preventable. We are still losing too many brothers, sisters, parents, children and friends this way.
"While progress is being made in our understanding of how to support people with mental illness and prevent suicide, we are still seeing people struggling to get the help they need before they reach crisis point, with over-stretched services and patchy care across the country."