; Falzone v . Brown , 8 Vet . App . 398 , 403 ( 1995 ) ( lay person competent to testify to pain and visible flatness of his feet ) . Diagnosing a psychiatric disability is a complex medical matter ; determining whether a person ' s symptoms are merely the type of feelings that accompany the stress and worry that would normally accompany such unfortunate events , or whether these symptoms rise to the severity and frequency that would warrant a diagnosis of a psychiatric disorder requires psychiatric or psychological training . The Veteran has not been shown to have the appropriate medical training and expertise to opine on this question , and her testimony in this regard is therefore not competent . As to