Altered thalamic volumes and functional connectivity in the recovered patients with psychosis.

BACKGROUND: Investigating neural correlates in recovered patients with psychosis is important in terms of identifying biological markers associated with recovery status or predicting a possible future relapse. We sought to examine thalamic nuclei volumes and thalamus-centered functional connectivity (FC) in recovered patients with psychosis who discontinued their medication. METHODS: Thirty patients with psychosis who satisfied the criteria for full recovery and 50 healthy controls (HC) matched for age, sex, and education underwent magnetic resonance imaging and clinical evaluation. The recovered patients were divided into the maintained and relapsed subjects according to their clinical status on the follow-ups. Thalamic nuclei volumes and thalamus-centered FC were measured between the recovered patients and HC. Correlations between the thalamic nuclei or altered FC, and clinical symptoms and cognitive functioning were explored. RESULTS: Modest cognitive impairments and reduced thalamic nuclei volumes were evident in the recovered patients. Moreover, we found altered thalamo-cortical connectivity and its associations with negative symptoms and cognitive functioning in the recovered patients compared with HC. CONCLUSION: These findings suggest that there are still cognitive impairments, and aberrant neuronal changes in the recovered patients. The implication of differential FC patterns between the maintained and the relapsed patients remain to be further explored.

Altered functional connectivity in psychotic disorder not otherwise specified.

BACKGROUND: Few studies have investigated functional connectivity (FC) in patients with psychotic disorder not otherwise specified (PNOS). We sought to identify distinct FC differentiating PNOS from schizophrenia (SZ). METHODS: In total, 49 patients with PNOS, 42 with SZ, and 55 healthy controls (HC) matched for age, sex, and education underwent functional magnetic resonance imaging (fMRI) brain scans and clinical evaluation. Using six functional networks consisting of 40 regions of interest (ROIs), we conducted ROI to ROI and intra- and inter-network FC analyses using resting-state fMRI (rs-fMRI) data. Correlations of altered FC with symptomatology were explored. RESULTS: We found common brain connectomics in PNOS and SZ including thalamo-cortical (especially superior temporal gyrus) hyperconnectivity, thalamo-cerebellar hypoconnectivity, and reduced within-thalamic connectivity compared to HC. Additionally, features differentiating the two patient groups included hyperconnectivity between the thalamic subregion and anterior cingulate cortex in PNOS compared to SZ and hyperconnectivity of the thalamic subregions with the posterior cingulate cortex and precentral gyrus in SZ compared to PNOS. CONCLUSIONS: These findings suggest that PNOS and SZ exhibit both common and differentiating changes in neuronal connectivity. Furthermore, they may support the hypothesis that PNOS should be treated as a separate clinical syndrome with distinct neural connectomics.