Exposure to childhood maltreatment can contribute to multiple behavioral and clinical manifestations, including the development of psychotic illnesses and pain-related abnormalities. Aberrant pain perception in individuals with psychosis may be associated with the worsening psychiatric symptoms, including an increase in mood episodes and a higher risk for suicidality. Despite the multiple connections between psychosis, pain, and childhood maltreatment, the combined investigation of these three domains remains limited.
In this study, patients with schizophrenia (SZ, n = 20) or bipolar I disorder (BD, n = 24) and healthy controls (HC, n = 24) underwent a comprehensive clinical evaluation followed by quantitative sensory testing (QST), where behavioral sensitivity to thermal stimuli was quantified. Central pain circuitry was probed using a combination of functional and structural magnetic resonance imaging. Neuroimaging analyses focused on thermal stimulation fMRI responses, resting-state connectivity, and gray matter morphological properties.
fMRI demonstrated diminished sensorimotor activation during an evoked pain state for both SZ and BD patients, where reduced activity in thalamic subdivisions (i.e., pulvinar nucleus) in BD patients negatively correlates with the severity of childhood maltreatment. Resting-state connectivity analyses revealed altered connectivity of various cortical regions with the postcentral gyri and thalamic nuclei, suggesting potential altered neural mechanisms underlying pain perception in patients with SZ and BD. Morphological analysis identified reduced gray matter thickness in the postcentral sulcus of BD patients, which correlated with the severity of childhood maltreatment.
These findings provide insight into the multidimensional nature of clinical presentations in SZ and BD and contribute to our understanding of the complex relationship between childhood maltreatment and central pain processing in patients with psychotic illnesses.