signs of suicidal behaviour
https://www.suicideprograms.com.au/warning-signs/warning-signs/

Suicide Programs offer training programs for suicide prevention Australia. The programs are created by people who are experts in suicide intervention, mental health awareness and counselling skills training. There are more than 3,000 deaths that occur by suicide in Australia every year. The first step of these student prevention training programs is to identify the warning signs of suicide. These signs may be mood swings, isolation, changes in sleep, personality, and appearance patterns, exhibiting harmful behaviours, or recent significant losses.