Purpose: The purpose of the study was to identify the discriminating power of dissociation as defined by depression, obsession, and Minnesota Multiphasic Personality Inventory(MMPI; psychopathology) in patients with psychological trauma. Methods: Participants were patients (N=114) from "S" clinic for psychological trauma. Data were collected from April to June 2014 through semi-structured interviews and self-reports using a modified Lifetime Incidence of Traumatic Events, Dissociative Experience Scale (DES), Beck Depression Inventory-2, Maudsley Obsessional Compulsive Inventory, and MMPI-2. Results: Participants were grouped in to two groups depending on DES scores; dissociative (n=15) and non-dissociative (n=99). Depression, F-scale (infrequency), Ma (Hypomania), and Hs (Hypochondriasis) scale of MMPI correctly discriminated 86.8% of the sample. There were also significant differences in Obsession, K-scale (korrection), D (Depression), Hy (Hysteria), Pd (Psychopathic Deviate), Pa (Paranoia), Pt (Psychasthenia), Sc (Schizophrenia), Si (Social Introversion) scales of MMPI between two groups, but they were not significant discriminant factors. Conclusion: Future interventions for patients with high levels of dissociation and psychological trauma should focus on the prevention of suicide and chronic dissociation by assessing depression-related factors; suicidal behavior, impulsivity, aggression, and alexithymia. Therapists should also interpret patients’ MMPI profiles carefully, especially in the presence of an extremely elevated F-scale.