An intrusive thought is an unwelcome, involuntary thought, image, or unpleasant idea that may become an obsession, is upsetting or distressing, and can feel difficult to manage or eliminate. (source: Wikipedia ) Common examples of intrusive thoughts include unwanted, intrusive thoughts about the safety of oneself or others, causing distress, and thoughts of performing dangerous actions. These thoughts may lead to negative behaviors, which may increase vulnerability to future experiences of trauma. Intrusive thoughts have been linked to recent life stress, sleep deprivation, prior anxiety, and childhood abuse. The state of depression , suicidal ideation, or anxiety may also be caused by the release of stress hormones. Analysis of studies in subjects who had experienced prolonged periods of post-traumatic stress disorder (PTSD) found that intrusive thoughts and flashbacks are associated with greater than 50% of symptoms, especially memory fragmentation. Intrusive thoughts often occur