@article {923,
	title = {Neurobiological underpinnings of cognitive subtypes in psychoses: A cross-diagnostic cluster analysis},
	journal = {Schizophrenia Research},
	volume = {229},
	year = {2021},
	pages = {102-111},
	abstract = {<p>Schizophrenia and bipolar disorder include patients with different characteristics, which may hamper the definition of biomarkers. One of the dimensions with greater heterogeneity among these patients is cognition. Recent studies support the identification of different patients{\textquoteright} subgroups along the cognitive domain using cluster analysis. Our aim was to validate clusters defined on the basis of patients{\textquoteright} cognitive status and to assess its relation with demographic, clinical and biological measurements. We hypothesized that subgroups characterized by different cognitive profiles would show differences in an array of biological data. Cognitive data from 198 patients (127 with chronic schizophrenia, 42 first episodes of schizophrenia and 29 bipolar patients) were analyzed by a K-means cluster approach and were compared on several clinical and biological variables. We also included 155 healthy controls for further comparisons. A two-cluster solution was selected, including a severely impaired group and a moderately impaired group. The severely impaired group was associated with higher illness duration and symptoms scores, lower thalamus and hippocampus volume, lower frontal connectivity and basal hypersynchrony in comparison to controls and the moderately impaired group. Moreover, both patients{\textquoteright} groups showed lower cortical thickness and smaller functional connectivity modulation than healthy controls. This study supports the existence of different cognitive subgroups within the psychoses with different neurobiological underpinnings.</p>
},
	keywords = {Cognition, Connectivity, Modulation, Volume, bipolar disorder, schizophrenia},
	issn = {0920-9964},
	doi = {https://doi.org/10.1016/j.schres.2020.11.013},
	url = {https://www.sciencedirect.com/science/article/pii/S0920996420305521},
	author = {Fern{\'a}ndez-Linsenbarth, In{\'e}s and {\'A}lvaro Planchuelo-G{\'o}mez and D{\'\i}ez, {\'A}lvaro and Arjona-Valladares, Antonio and Rodrigo de Luis-Garc{\'\i}a and Mart{\'\i}n-Santiago, {\'O}scar and Benito-S{\'a}nchez, Jos{\'e} Antonio and P{\'e}rez-Laureano, {\'A}ngela and Gonz{\'a}lez-Parra, David and Montes-Gonzalo, Carmen and Melero-Lerma, Raquel and Fern{\'a}ndez Morante, Sonia and Sanz-Fuentenebro, Javier and G{\'o}mez-Pilar, Javier and N{\'u}{\~n}ez-Novo, Pablo and Molina, Vicente}
}
@article {843,
	title = {Identificacion of MRI-based psychosis subtypes: Replication and refinement},
	journal = {Progress in Neuro-Psychopharmacology and Biological Psychiatry},
	volume = {100},
	year = {2020},
	pages = {109907},
	abstract = {<p>The identification of the cerebral substrates of psychoses such as schizophrenia and bipolar disorder is likely hampered by its biological heterogeneity, which may contribute to the low replication of results in the field. In this study we aimed to replicate in a completely new sample and supplement the results of a previous study with additional data on this topic. In the aforementioned study we identified a schizophrenia cluster characterized by high mean cortical curvature and low cortical thickness, subcortical hypometabolism and progressive negative symptoms. Here, we have used magnetic resonance images from 61 schizophrenia and 28 bipolar patients, as well as 51 healthy controls and a cluster analysis to search for possible subgroups primarily characterized by cerebral structural data. Diffusion tensor imaging (fractional anisotropy, FA), cognition, clinical data and electroencephalographic (EEG) modulation during a P300 task were used to validate the possible clusters. Two clusters of patients were identified. The first cluster (29 schizophrenia and 18 bipolar patients) showed decreased cortical thickness and area values, as well as lower subcortical volumes and higher cortical curvature in some regions, as compared to the second cluster. This first cluster also showed decreased FA in frontal lobe connections and worse cognitive performance. Although this cluster also showed longer illness duration, there were first episode patients in both clusters and treatment doses and types were not different between clusters. Both clusters of patients showed decreased EEG task-related modulation. In conclusion, our data give additional support to a distinct biologically based cluster encompassing schizophrenia and bipolar disorder patients with cortical and subcortical alterations, hampered cortical connectivity and lower cognitive performance.</p>
},
	keywords = {Biotypes, Cortical thickness, Curvature, Subtypes, bipolar disorder, schizophrenia},
	issn = {0278-5846},
	doi = {https://doi.org/10.1016/j.pnpbp.2020.109907},
	url = {http://www.sciencedirect.com/science/article/pii/S0278584619309595},
	author = {{\'A}lvaro Planchuelo-G{\'o}mez and Lubeiro, Alba and N{\'u}{\~n}ez-Novo, Pablo and Gomez-Pilar, Javier and Rodrigo de Luis-Garc{\'\i}a and del Valle, Pilar and Mart{\'\i}n-Santiago, {\'O}scar and P{\'e}rez-Escudero, Adela and Vicente Molina}
}
