Glahn David C, Barrett Jennifer, Bearden Carrie E, Mintz Jim, Green Michael F, Serap Monkul E, Najt Pablo, Soares Jair C, Velligan Dawn I
Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA.
Psychol Med. 2006 Aug;36(8):1085-95. doi: 10.1017/S0033291706007902. Epub 2006 May 31.
Although memory deficits are consistently reported in schizophrenia and bipolar disorder, the mechanisms underlying these impairments are poorly understood. Clarifying the nature and degree of overlap in memory deficits between the two illnesses could help to distinguish brain systems disrupted in these illnesses, and indicate cognitive remediation strategies to improve patient outcomes.
We examined performance on a non-verbal memory task in clinically stable out-patients with bipolar disorder (n=40), schizophrenia (n=40), and healthy comparison subjects (n=40). This task includes conditions in which distinct mnemonic strategies -- namely, using context to organize familiar stimuli or using holistic representation of novel stimuli -- facilitate performance.
When compared to a reference condition, bipolar patients had deficits consistent with organizational dysfunction and poor detection of novel information. Although patients with schizophrenia performed worse than the other groups, they were only differentially impaired when organizational demands were significant. Task performance was not correlated with severity of clinical symptomatology.
This pattern of distinct memory impairments implies disturbances in partially overlapping neural systems in bipolar disorder and schizophrenia. Evidence of impairment in detection of novel stimuli that is unique to bipolar disorder suggests that, while the absolute level of cognitive dysfunction is less severe in bipolar disorder as compared to schizophrenia, subtle disruptions in memory are present. These findings can be used to plan targeted cognitive remediation programs by helping patients to capitalize on intact functions and to learn new strategies that they do not employ without training.
尽管在精神分裂症和双相情感障碍中均持续报告存在记忆缺陷，但对这些损害背后的机制却知之甚少。阐明这两种疾病记忆缺陷的重叠性质和程度，有助于区分这些疾病中受干扰的脑系统，并指明改善患者预后的认知补救策略。
我们检测了临床症状稳定的双相情感障碍门诊患者（n = 40）、精神分裂症患者（n = 40）以及健康对照者（n = 40）在一项非言语记忆任务中的表现。该任务包含不同的记忆策略条件，即利用背景来组织熟悉的刺激或利用新刺激的整体表征来促进表现。
与参照条件相比，双相情感障碍患者存在与组织功能障碍及新信息察觉不佳相一致的缺陷。尽管精神分裂症患者的表现比其他组差，但只有在组织要求较高时他们才存在差异受损。任务表现与临床症状严重程度无关。
这种独特的记忆损害模式意味着双相情感障碍和精神分裂症中部分重叠的神经系统存在紊乱。双相情感障碍特有的新刺激察觉受损的证据表明，虽然与精神分裂症相比，双相情感障碍中认知功能障碍的绝对水平没那么严重，但仍存在记忆方面的细微破坏。这些发现可用于规划有针对性的认知补救方案，帮助患者利用完好的功能，并学习未经训练就不会采用的新策略。
