Many people experience suicidal thoughts at some time in their lives.
In otherwise healthy people, such thoughts are often brought about by sudden, unexpected change in life circumstances.
Suicidal ideation is part of many mental illnesses, including depression, schizophrenia, and drug or alcohol abuse.
Strong evidence exists that depression-and many other forms of mental illness-can be passed from parent to child and that a tendency toward suicidal ideation and suicide is likewise inherited.