Neuropsychological and brain structural alterations in emerging psychosis

Despite the growing interest in personally tailored interventions in medicine and health care, it is not possible to reach sufficient accuracy in the prediction of psychosis to date. Many factors are associated with transition to psychosis, such as neuropsychological impairments and structural alterations of the brain that have been shown to predate the onset of frank psychosis.
However, the different disease trajectories male and female patients' experience may contribute to the mixed picture representing emerging psychosis. The prospective FePsy (Früherkennung von Psychosen) study was a project aiming to improve the early detection and intervention of psychosis through multilevel assessment. The in the following described articles are based on data assessed within the FePsy study.
In the first article, structural equation modelling and latent growth curve modelling were used to evaluate verbal learning and memory (VLM) performance between at-risk mental state (ARMS) and first episode psychosis (FEP) patients and healthy controls (HC). In line with our hypothesis, results indicated a worse performance of FEP compared to ARMS and HC and a performance of ARMS intermediate to those two groups. Since these differences were more pronounced in the slope than in the intercept of the learning curve, our results indicated that the verbal learning rate tends to be more impaired than attentional processes in both ARMS and FEP patients.
In the second article we investigated whether VLM performance is associated with subcortical brain volumes. A significant negative association between amygdala and pallidum volume and attention span was found in ARMS and FEP patients combined, which however did not withstand correction for multiple testing. Although VLM is among the most impaired cognitive domains in emerging psychosis, the deficits in this domain seem not to necessarily stem from alterations in subcortical structures.
In the third article, we investigated whether subcortical brain volumes are dependent on sex. Men presented with larger total brain volume and smaller caudate and hippocampus volumes than women independent of diagnostic group. These analyses confirmed previously described patterns of sexual dimorphism in total brain and caudate volume that are equally present in ARMS and FEP patients as well as HC. The only structure affected by reversed sexual dimorphism was the hippocampus (i.e. women showing higher volumes than men).
In conclusion, neuropsychological impairments in terms of VLM and subcortical brain structural alterations are present in emerging psychosis. However, subcortical volumes do not seem to be affected by altered sexual dimorphism and may thus not contribute to an effective prediction modelling of transition to psychosis.