As many as six in 10 people who consider or attempt suicide do not receive any treatment, a new review indicates.

Scottish and US researchers set out to review the main psychological factors that can contribute to a person considering or attempting suicide, such as negative life events and personality issues.

They found that around 60% of people who are struggling with thoughts or behaviours relating to suicide do not receive any help.

Furthermore, among those who do receive help, there is little evidence that treatments works.

"Although a range of risk factors that contribute to suicidal behaviour have been identified, it is not clear how or why these factors work together to increase the risk of suicidal behaviour and there is little known about what protects against suicide among those who are vulnerable," commented Prof Rory O'Connor of the University of Glasgow.

He said that more studies on this issue are ‘urgently needed' in order to develop ‘psychological treatments for those at risk of suicide alongside efforts to eliminate barriers that lead to underuse of mental health resources'.

The researchers emphasised that ‘significant advances' have been made in our understanding of suicidal behaviour in the last few years.

"We now have a strong foundation of knowledge about suicidal behaviour on which to build, as well as some exciting new findings about psychological factors that seem to put people at risk for thinking about suicide, and other factors that increase their likelihood of acting on suicidal thoughts," noted Prof Matthew Nock of Harvard University.

However, he added that it is ‘vitally important' that society now heavily invests in making further advances, ‘so that we can start to decrease the suffering and loss of life due to suicidal behaviour'.

Details of these findings are published in the journal, The Lancet Psychiatry.