看不出因果关系

The idea that there is a psychological basis for pain was also reflected in the earlier editions of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM). Each of the previous editions of the DSM addressed the problem of pain and in doing so sought to define the extent to which it might be considered a mental disorder. In DSM-II (38), painful conditions caused by emotional factors were included as “psychophysiological disorders.” DSM-III introduced a new category specifically addressing pain, “Psychogenic Pain Disorder” (39), and one of the essential diagnostic features was that along with pain, there should be evidence of psychological factors playing an etiologic role, and either absence of organic pathology to account for the pain, or if identifiable organ pathology was present, the degree of pain was not consistent with the physical findings. The evidence for an etiologic psychological factor could be either the presence of a psychosocial stressor that was temporally related to the onset of pain, or if the patient was getting some form of gain (secondary gain) from the pain symptoms. The diagnosis of psychogenic pain lacked reliability and predictive validity; often it was a diagnosis of exclusion when the existing investigational techniques failed to find a cause for the patient’s symptoms, and because of the distress caused by their disabilities, so called “etiological psychological” factors were easy to find.

疼痛有心理基础的观点也反映在美国精神病学协会的《精神疾病诊断和统计手册》（DSM）的早期版本中。DSM早先的每一个版本都提到了疼痛问题，并在这过程中试图确定疼痛在多大程度上可能被认为是一种精神障碍。在DSM-II（38）中，情绪因素引起的疼痛性疾病被列为“心理生理障碍”。DSM-III引入了一个专门针对疼痛的新类别—“心因性疼痛障碍”（39），诊断的基本特点之一是：除了疼痛之外，还应该有心理因素在疼痛中发挥致病作用的证据、或者没有器质性病变来解释疼痛、或者虽存在可识别的器质性病变，但疼痛的程度与体检结果不一致。病因性心理因素的证据可以是疼痛发作有时间上相关的心理社会应激源，也可以是患者是否从疼痛症状中获得了某种形式的获益（再度获益）。心因性疼痛的诊断缺乏可靠性和预测效度，当现有的研究技术找不到患者症状的原因时，往往是排除性诊断，而且由于疼痛性残疾造成的痛苦，所谓的“病理性心理”因素很容易找到。

虽然有because但我看不出因果关系？而且最后一句话的前半句和后半句感觉连不起来