Reducing access to commonly used methods of suicide may be effective in preventing people taking their own lives, the conference was told.
Restricting the sale over the counter of paracetamol and aspirin, the introduction of catalytic converters in cars, safety measures on bridges and tall buildings, platform safety barriers on railway lines, and gun amnesties to reduce the number of firearms may prevent some suicides, said Dr David Gunnell, senior lecturer in epidemiology and public medicine at the University of Bristol.
Although few specific interventions were proven, he said, reducing access to methods of suicide was "the best bet" and there was some evidence that such measures did work. However, he said, they were relatively crude suggestions and did not "look at the overall picture".
Dr Gunnell said that most people who committed suicide did not make contact with the health services in the week before their death; 50 per cent of people with clinical depression were not diagnosed.
He said there was a huge increased risk of suicide, up to 200fold, for people discharged from the psychiatric services. People discharged following a suicide attempt were also at exceptionally high risk.
For these people, access to drugs in sufficient quantities to kill should be reduced, said Dr Gunnell, pointing out that 50 per cent of suicidal overdoses used drugs recently prescribed.
He drew attention to the dramatic increase in young men taking their own lives over the past decade, while there were reductions in the rate among women and the elderly. Among men there had been a doubling of the rate in most countries and much greater increases in Ireland, New Zealand and Australia. There was also an increase in the number of suicides among young women but the base rate was very low compared to young men.
Large variations in suicide rates may be found within specific areas, said Dr Gunnell. A study in one area in the UK found variations linked to levels of deprivations measured by car ownership, unemployment, overcrowding, and housing tenure.