Chevreau G, Castillo M-C, Vallat-Azouvi C
Laboratoire de Psychopathologie et Neuropsychologie (LPN), Université Paris 8 Vincennes Saint-Denis, 93526 Saint-Denis, France.
Laboratoire de Psychopathologie et Neuropsychologie (LPN), Université Paris 8 Vincennes Saint-Denis, 93526 Saint-Denis, France.
Encephale. 2019 Nov;45(5):424-432. doi: 10.1016/j.encep.2019.05.009. Epub 2019 Aug 14.
Homelessness is associated with several issues (psychiatric and neurological disorders, neurodevelopmental difficulties, malnutrition…) which are also risk factors for cognitive disorders. However, little is known about the relationship between the cognition of homeless people and these eventual explicative etiologies. The aim of this work is to complete the results of Depp et al. about cognition in homelessness by proposing a systematic review of the neuropsychological disorders of homeless people associated with an analysis of the etiologies likely to explain these disorders.
We followed the PRISMA recommendations to build up this work. We analyzed the abstracts of 385 papers found on databases PSYCINFO and PubMed. Twenty-two studies have been selected for respecting our criteria (at least one valid neuropsychological test ; general group of homeless people and not a sub-group of this population ; study published in English). The prevalence quality has been evaluated through the criteria of Loney et al. Cognitive scores and etiological factors have been compared between studies.
The 22 studies represent only nine countries. More than half of them are considered as having a poor prevalence quality. In total, 4,256 participants have been evaluated. Their mean age was around 40 years, and 85 % of the participants were men. The results show a prevalence of cognitive disorders (MMSE) in 8.77 % of the sample. The mean IQ was 87.47 and the premorbid IQ 94.59. We also notice possible disorders affecting the episodic memory and the executive functions. Mean scores for short-term memory, speech and visuo-spatial functions are relatively low. None of the studies evaluated the praxia, the gnosia or the social cognition. The heterogeneity of studies and the lack of data did not allow us to give general conclusions about the etiology of these disorders. However, we see that around 40 % of the time subjects had histories of brain injuries and 89 % of childhood trauma. Intellectual disability is found in 49 % of the sample of a single study. Also, 70 % of the homeless population have been diagnosed with substance-related disorders and 65 % with psychiatric disorders. It appears that the only factors correlated with cognitive disorders would be the history of brain injuries and childhood traumas.
We confirm that homeless people often suffer from cognitive difficulties, and some of these difficulties (memory, executive functioning) are severe. Yet the etiology of these disorders remain relatively unknown: even if we observe a high prevalence of psychiatric, substance-related, neurodevelopmental and neurological issues by the homeless population, only a few of them (brain injury history and childhood trauma) seem to be correlated with cognition in homelessness. The potential explicative factors have been too rarely explored to bring a powerful explanation of cognitive disorders in homeless people. Further research needs to be done in order to give a more precise neuropsychological profile of the homeless population and to better understand what the disorders are rooted in. Last but not least, all this research and knowledge should be applied more to the care of homeless people by providing neuropsychological assessment and rehabilitation and by training the team to detect cognitive disorders and to support the person with a cognitive disability.
无家可归与若干问题（精神和神经疾病、神经发育困难、营养不良等）相关，而这些问题也是认知障碍的风险因素。然而，关于无家可归者的认知与这些可能的解释性病因之间的关系，我们所知甚少。这项工作的目的是通过对与可能解释这些障碍的病因分析相关的无家可归者神经心理障碍进行系统综述，完善德普等人关于无家可归者认知的研究结果。
我们遵循PRISMA建议开展此项工作。我们分析了在PSYCINFO和PubMed数据库中找到的385篇论文的摘要。根据我们的标准（至少一项有效的神经心理测试；无家可归者总体而非该人群的子群体；以英文发表的研究），选出了22项研究。通过洛尼等人的标准评估患病率质量。对各研究之间的认知分数和病因因素进行了比较。
这22项研究仅来自9个国家。其中一半以上被认为患病率质量较差。总共评估了4256名参与者。他们的平均年龄约为40岁，85%的参与者为男性。结果显示，样本中认知障碍（简易精神状态检查表）的患病率为8.77%。平均智商为87.47，病前智商为94.59。我们还注意到可能影响情景记忆和执行功能的障碍。短期记忆、言语和视觉空间功能的平均分数相对较低。没有研究评估失用症、认识不能或社会认知。研究的异质性和数据的缺乏使我们无法就这些障碍的病因得出一般性结论。然而，我们发现约40%的受试者有脑损伤史，89%有童年创伤史。在一项研究的样本中，49%的人有智力残疾。此外，70%的无家可归者被诊断患有物质相关障碍，65%患有精神疾病。似乎与认知障碍相关的唯一因素是脑损伤史和童年创伤。
我们证实无家可归者经常存在认知困难，其中一些困难（记忆、执行功能）较为严重。然而，这些障碍的病因仍然相对不明：即使我们观察到无家可归者中精神、物质相关、神经发育和神经问题的患病率很高，但其中只有少数（脑损伤史和童年创伤）似乎与无家可归者的认知相关。潜在的解释因素很少被探究，无法有力地解释无家可归者的认知障碍。需要进一步开展研究，以便给出更精确的无家可归者神经心理概况，并更好地了解这些障碍的根源。最后但同样重要的是，所有这些研究和知识应更多地应用于无家可归者的护理，提供神经心理评估和康复，并培训团队以检测认知障碍并支持有认知残疾的人。
