Ask them directly if they are thinking about suicide, don't be afraid to do this because it shows you care will actually decrease their risk. make sure you ask directly and unambiguously.

If they say yes then they are suicidal, listen to them and allow them to express how they are feeling. don't leave them alone. Stay with them or get someone who is willing to stay with them

Thoughts of suicide may return, so ask them to promise to reach out and tell someone. Asking them to promise makes it more likely they will tell someone.

Developing a serious mental health condition such as schizophrenia.

Relationships such as being isolated from other and being a victim of bullying.

Traumatic experience during childhood such has a history of sexual or physical abuse.

Eating disorder can be a cause of suicide such as anorexia.

Unemployment can lead to feelings of isolation and landing a new job can be difficult.

Someone will feel guilty for not preventing the suicide.

Failure because a person they loved felt unloved and committed suicide.

Anger and indignation to the person who committed his or her own life.

Self-loathing

Losing that person can destroy hopes and expectations for the future.