Ikebuchi Emi
Seishin Shinkeigaku Zasshi. 2015;117(3):179-94.
The negative symptoms of schizophrenia are usually treatment-refractory, and considered to be a major cause of a poor outcome. Recently, it has become an important issue to elucidate the etiology of and develop treatment for negative symptoms in order to improve the outcome of schizophrenia patients. Firstly, the history of negative symptoms was reviewed. Several lines of factor-analysis studies have suggested that negative symptoms are independent from other symptoms of schizophrenia, and consist of two factors, the poverty of expression and avolition, while the results depend upon the assessment scale employed in each analysis. Anhedonia, a part of avolition, may be considered as the impairment of pleasure-seeking behavior, the impairment of remembering non-current feelings, and a person's belief that he/she cannot experience pleasure, rather than the loss of pleasure itself. As neurological bases for avolition, decreases in reward expectancy, value representation, and the behavior to seek uncertain reward were observed, which resulted in poor social functioning due to the difficulties of initiating adaptive behaviors for the future. These impairments are the bases of decreased intrinsic motivation. The negative symptoms were considered to result in poor social functioning mediated by neuro-and social cognitive dysfunction and dysfunctional cognition, such as low self-efficacy and self-stigma. Pharmacotherapy for negative symptoms remains to be established due to a lack of evidence. Several psycho-social interventions in self-efficacy, self-stigma, intrinsic motivation, and environmental contexts are now being developed, while their effects are rather limited. The principles of psychiatric rehabilitation, i.e., respecting one's own value system and preference, self-determination, and motivation, are worth revisiting from the viewpoint of neuro-cognitive science. Furthermore, a hope-oriented approach, the presence of peers, and reconstructing social values as barrier-free may be considered to be of marked help not only for treating negative symptoms through re-establishing self-esteem, but also to aid the general population.
精神分裂症的阴性症状通常难以治疗，被认为是导致不良预后的主要原因。近来，阐明阴性症状的病因并开发相应治疗方法以改善精神分裂症患者的预后已成为一个重要问题。首先，回顾了阴性症状的历史。多项因素分析研究表明，阴性症状独立于精神分裂症的其他症状，由两个因素组成，即表达贫乏和意志缺乏，不过结果取决于每次分析所采用的评估量表。快感缺失作为意志缺乏的一部分，可被视为寻求愉悦行为的受损、对非当前感受的记忆受损以及个体认为自己无法体验愉悦，而非愉悦本身的丧失。作为意志缺乏的神经学基础，观察到奖赏预期、价值表征以及寻求不确定奖赏行为的减少，这由于难以启动未来的适应性行为而导致社交功能不良。这些损害是内在动机降低的基础。阴性症状被认为通过神经和社会认知功能障碍以及功能失调的认知（如低自我效能感和自我污名化）介导导致社交功能不良。由于缺乏证据，阴性症状的药物治疗仍有待确立。目前正在开发针对自我效能感、自我污名化、内在动机和环境背景的几种心理社会干预措施，但其效果相当有限。从神经认知科学的角度来看，精神康复所遵循的原则，即尊重个人自身的价值体系和偏好、自我决定以及动机，值得重新审视。此外，以希望为导向的方法、同伴的存在以及将社会价值观重建为无障碍的价值观，可能不仅有助于通过重建自尊来治疗阴性症状，而且对普通人群也有显著帮助。
