For individuals suffering from posttraumatic stress disorder (PTSD), the emotional numbing and isolation that are a core aspect of their suffering and consistently impedes remediation often remains after first-line treatments are administered. Few interventions have proven successful for enhancing the empathy and social connectedness that will ultimately allow patients to flourish, and the search for target therapies is made more difficult by the fact that very little is known about the underlying physiology of emotional numbing and social isolation. The proposed study is designed to (1) investigate the hormonal, neural and immunological biomarkers related to emotional numbing, and (2) test whether cognitively-based compassion training (CBCT), an intervention designed and proven to enhance empathy, will reduce emotional numbing and increase empathy and social connectedness in veterans. To this end, thirty medically healthy males diagnosed with PTSD who continue to report emotional numbing symptoms after prolonged exposure therapy will receive 8 weeks of training in CBCT. Prior to, and again after the training, the investigators will assess patients' levels of oxytocin, inflammation, and self-reported emotional numbing and social connectedness. The investigators will also assess their neural response during a video task that assesses their ability to accurately read others' emotions. The investigators hypothesize that oxytocin, neural activity, and inflammation will predict social numbing, isolation, and empathy, and also that CBCT will positively impact the social outcomes that will pave the way toward health and well-being.

Thirty otherwise medically healthy males between the ages of 25 and 55 who have previously met criteria for PTSD and have undergone prolonged exposure therapy (PET) yet continue to report emotional numbing symptoms as a chief complaint will be assessed for baseline levels of plasma oxytocin (OT), markers of pro-inflammatory cytokines, total mRNA expression in peripheral blood mononuclear cells (PBMCs), self-reported emotional numbing and social connectedness, and empathy. Real-world social connectedness will be assessed using an Electronically Activated Recorder (EAR) for two days, which will randomly record 50 second snippets of audio every 9 minutes and which will allow for quantification of time spent with others. Measures of empathy will include empathic accuracy during a dynamic empathic accuracy (EA) video task, which asks participants to rate what story-tellers are feeling while they tell positively and negatively valenced autobiographical stories. Because previous studies have shown that PTSD may interfere with subtle social processing skills and because one of the primary aims of this proposal is to uncover specific biomarkers related to self-reported emotional numbing, the investigators will also assess eye gaze and arousal covariance (correlation between skin conductance of video subject and that of study participant) during the EA task. Following baseline assessments, participants will participate in 8 weeks of CBCT, which entails twice-weekly meetings consisting of didactic information sessions and approximately 20 minutes of CBCT practice. Participants will be asked to practice at home for 20 minutes per day, and will be given a audio compact discs to guide at-home meditation. Upon completion of CBCT (Time 2), and again after 8-12 weeks (Time 3), all Time 1 assessments will be repeated.

Inclusion Criteria:

• previously met criteria for PTSD
• completed front-line treatment such as prolonged exposure therapy
• continue to report emotional numbing symptoms as a chief complaint

Exclusion Criteria (at the discretion of the researchers):

• Self-reported psychotic symptoms, current major depression, or suicidal ideation
• Self-reported active alcohol or drug abuse within the past six months
• Self-reported depression serious enough to require hospitalization, or that resulted in a suicide attempt, within the last year.
• Self-reported auto-immune disease such as lupus, crohn's disease, irritable bowel syndrome, or rheumatoid arthritis.
• Self-reported use of psychotropic medication, including antidepressants, mood stabilizers, antipsychotics or chronic benzodiazepine therapy that has changed in the past 6 weeks.
• Self-reported use of any medication that might strongly affect your stress or immune systems, including non-steroidal anti-inflammatory agents, COX-2 inhibitors, corticosteroids, beta-blockers or statins.
• Claustrophobia
• Ferromagnetic implants contraindicated by functional MRI (fMRI) safety regulations