Stockholm syndrome is a proposed condition or theory that tries to explain why hostages sometimes develop a psychological bond with their captors.

Stockholm syndrome is a "contested illness" due to doubts about the legitimacy of the condition.

Emotional bonds can possibly form between captors and captives, during intimate time together, but these are considered irrational by some in light of the danger or risk endured by the victims. Stockholm syndrome has never been included in the Diagnostic and Statistical Manual of Mental Disorders (DSM), the standard tool for diagnosis of psychiatric illnesses and disorders in the United States, mainly due to the lack of a consistent body of academic research.