Background: Post Traumatic Stress Disorder (PTSD) is considered as one of the most prevalent anxiety disorders during the life time and can negatively influence the individual, family and social relationships of patients.So prevention and treatment of this disorder is highly important.Depression and suicidal thoughts are co morbid with this disorder.Eye Movement Desensitization and Reprocessing (EMDR), Psychological Debriefing (PD), Imaginal Exposure (IE) are used for the treatment of PTSD, but there is controversy about long effect of these treatments especially among chronic patients.Methods: In this semi experimental research, a total of 54 PTSD Patients based on Davidson scale and psychologist diagnostic were randomly selected and then were divided into three experimental groups.Depression and Beck Scales for Suicide Ideation (BSSI) of all participants were evaluated three times: before the treatment, after the treatment and 3 months after the treatment.Data were analyzed through the repeated variance and tukey post hoc tests.Results: The results showed that PD, EMDR and IE are effective in relief of chronic PTSD depression and Suicide Ideation signs respectively and remain effective in three months follow up.Conclusion: It is concluded that all of the above mentioned methods are effective on chronic PTSD depression and Suicide Ideation patients signs, and considering the importance of psychological interventions, it is necessary that such methods be taught to psychologists so that they can use them in the traumatic situations.