Researchers have developed a number of theories to help understand why people die by suicide.
Some theories focus on experiences such as feeling disconnected from other people, believing we are a burden, becoming trapped in unbearable sorrow, losing hope, or feeling defeated.
Other theories try to explain an especially important question in suicide research: why many people experience suicidal thoughts, but only some go on to attempt suicide.
These theories can help us identify patterns, generate research questions and think about where prevention might make a difference.
But no single theory can explain every suicide or capture the complexity of an individual life.
Different theories highlight different parts of the picture, and our understanding continues to develop as new evidence emerges.
Our guide introduces some of the major psychological theories of suicide in plain language – what each proposes, what the research tells us, and what they might mean for prevention.