1. How should we consider evidence about a claimant’s behavior and functioning from non-professional sources, such as parents or friends?
Answer: Evidence from non-professional sources is highly valuable in cases involving trauma. For many of the reasons documented in other comments, PTSD and other trauma-related disorders are underdiagnosed. (See submission from Kevin Liebkemann noting intermittent nature of symptoms, lack of adequate screening and access, reluctance of victims to disclose trauma or abuse, delayed onset, and symptoms that impair the ability to seek treatment.) Family and friends often have greater familiarity with the day-to-day functioning of a claimant, especially for those who, due to symptoms, have difficulty making appointments or otherwise engaging with mental health professionals. Family and friends, especially those who live with the claimant, will have more information about the claimant's functioning at its lowest. Evidence from these sources should be considered assessed and a person’s familiarity with the claimant should be a bases to give such evidence great weight.
3. What indicators can be used to rule out PTSD as an impairment, and what professional sources support this information?
Answer: According to the Diagnostic and Statistical Manual of Mental Disorders (DSM), PTSD features an extraordinarily high rate of comorbidity – 80% – with other disorders. (See DSM V at 280.) The presence of comorbidities, especially in combination with the many barriers to diagnosis, can cause an inconsistent presentation that distracts or confuses diagnosis, treatment, or claim adjudication. Moreoever, it can be difficult to differentiate PTSD from other conditions because it shares many of the same symptoms with other disorders, especially anxiety and depression, "making the process of demonstrating its distinctiveness more difficult." (See National Academy of Sciences, Postraumatic Stress Disorder Diagnosis and Assessment at 50, (2006) available at: https://www.nap.edu/catalog/11674/posttraumatic-stress-disorder-diagnosis-and-assessment). Thus, it is difficult to identify an indicator to rule out PTSD as a diagnosis. With trauma, the real priority should not be to rule out the existence of a trauma-related condition, but to develop ways to make sure that these impairments are not missed and are fully considered.