The rate of co-morbidity is very high in posttraumatic stress disorder (PTSD) especially major depressive disorder and substance abuse. It is not clear if the suicidality in PTSD patients is predominantly caused by core PTSD symptoms or by co-morbid disorders. There is a lack of randomized controlled trials for treatment of suicidality in PTSD. Selective serotonin reuptake inhibitors (SSRIs) are widely used in PTSD treatment, but there is some evidence that they can increase risk of suicidality (self-harm behavior, suicidal thoughts, and suicide attempts) in younger age groups. Benzodiazepines have not been proven effective in the treatment of PTSD core symptoms. Benzodiazepines can even worsen clinical symptoms after acute traumatic experience, and they can induce consequent PTSD and depression, which may lead to increased suicidal risk.