Depressed people who display "risky behaviour", agitation and impulsivity are at least 50% more likely to attempt suicide, a study has found.
Research by the European College of Neuropsychopharmacology (ECNP) concluded that the behaviour patterns "precede many suicide attempts".
The study said effective prevention measures were "urgently needed".
The World Health Organisation estimates that there were more than 800,000 suicides worldwide in 2012.
The ECNP study evaluated 2,811 patients suffering from depression, of whom 628 had previously attempted suicide.
Researchers "looked especially at the characteristics and behaviours of those who had attempted suicide", and found that "certain patterns recur" before attempts