Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
British Columbia Mental Health and Substance Use Services, Vancouver, BC, Canada.
Acta Psychiatr Scand. 2021 Feb;143(2):151-161. doi: 10.1111/acps.13245. Epub 2020 Nov 28.
Distinct cognitive subgroups are seen in patients with long duration bipolar I disorder (BDI), possibly reflective of underlying pathophysiological differences. It is unknown whether such cognitive heterogeneity is present at illness onset. We applied latent class analysis (LCA) to cognitive test scores in first episode BDI patients. Exploratory analysis elucidated whether impaired subgroups were characterized by 'early neurodevelopmental' (low premorbid IQ and intracranial volume) versus 'later neurodevelopmental' (decline from premorbid to current IQ, changes in relative grey (GM)/white (WM) matter volumes) pathology.
Recently recovered first manic episode BDI patients (n = 91) and healthy controls (HC, n = 63) comprised the study sample. LCA identified subgroups based on processing speed, verbal memory, non-verbal memory, executive functioning, attention and working memory scores. Subgroups were compared amongst each other and HC on premorbid/current IQ, intracranial (ICV), total brain and regional volumes.
Three cognitive subgroups emerged: (i) globally impaired (GI, n = 31), scoring 0.5-1 SD below demographically corrected norms across domains, (ii) selectively impaired (SI, n = 47), with predominant processing speed deficits and (iii) high performing (HP, n = 13), with above-average cognitive performance. GI patients showed a 'later neurodevelopmental' pattern, with normal ICV, significant decline from premorbid to current IQ, higher total GM and lower total WM (with respect to total brain volume) versus SI and HC (p = 0.003). GI patients had higher left frontal pole GM versus HC (p < 0.05, FWE corrected).
A globally impaired patient subgroup is identifiable in first episode BDI, possibly characterized by unique neurodevelopmental pathologic processes proximal to illness onset.
在患有长病程双相情感障碍（BDI）的患者中可以看到不同的认知亚组，这可能反映了潜在的病理生理差异。目前尚不清楚这种认知异质性是否在发病时存在。我们应用潜在类别分析（LCA）对首发BDI 患者的认知测试评分进行分析。探索性分析阐明了受损亚组是否具有“早期神经发育”（低发病前智商和颅内体积）与“后期神经发育”（从发病前到当前智商下降，相对灰质（GM）/白质（WM）体积变化）病理学特征。
最近恢复的首发躁狂发作 BDI 患者（n=91）和健康对照（HC，n=63）组成了研究样本。LCA 根据处理速度、言语记忆、非言语记忆、执行功能、注意力和工作记忆评分确定亚组。在彼此之间以及 HC 之间比较亚组的发病前/当前智商、颅内体积（ICV）、总脑和区域体积。
出现了三个认知亚组：（i）整体受损（GI，n=31），在所有领域的评分均低于与人口统计学校正标准相差 0.5-1 个标准差，（ii）选择性受损（SI，n=47），以明显的处理速度缺陷为主，（iii）表现良好（HP，n=13），认知表现高于平均水平。GI 患者表现出“后期神经发育”模式，具有正常的 ICV，从发病前到当前智商显著下降，与 SI 和 HC 相比，总 GM 更高，总 WM 更低（相对于总脑体积）（p=0.003）。与 HC 相比，GI 患者的左侧额极 GM 更高（p<0.05，经 FWE 校正）。
在首发 BDI 中可以识别出一个整体受损的患者亚组，其特征可能是与发病前近端的独特神经发育病理过程有关。
