Suicide warning signs (adapted from helpguide.org) include:
Appearing agitated, anxious, irritable, or showing anger or hostility that is out of character
Becoming extremely sensitive and strongly reactive to criticism
Talking, writing, journaling or joking about suicide
Making statements like “I’d be better off dead”
Withdrawal from activities once enjoyed or friends/social connections
Gathering special items to give friends or family
Saying what sounds like a final goodbye
Seeking out the means to kill themselves – a weapon, substance, or dangerous location