We aimed to utilize diffusion tensor imaging (DTI) to identify unique white matter cerebral changes in deficit schizophrenia (DS) compared with non-deficit schizophrenia (NDS) and healthy controls (HC) in an Asian sample. A total of 289 subjects (111 HC, 133 NDS and 45 DS) underwent DTI and completed rating scales which assessed the severity of psychopathology, psychosocial functioning and premorbid intelligence.
The identified brain white matter changes especially in the PTR relate to deficits of cognitive control and emotional awareness, which may underlie psychopathology associated with deficit status like inattention and affective blunting. These potential biomarkers of DS warrant further examination to determine their utility for monitoring illness progression and intervention response in schizophrenia.
Since its first proposal by Carpenter et al. (Carpenter et al. 1988), there is evidence that patients with deficit schizophrenia (DS) present with distinct symptom profiles exhibiting more severe anhedonia and anergia than those with non-deficit schizophrenia (NDS) (Grover and Kulhara 2008), suffer from poorer neuropsychological functioning with impaired social cognition and verbal fluency (Bora et al. 2017), have increased likelihood of family history of schizophrenia (Dollfus et al. 1998), display structural and functional neurobiology differences such as altered cerebral blood flow (Grover and Kulhara 2008), and face poorer long-term outcomes with low likelihood of disease remission (Strauss et al. 2010).
In conclusion, we found that FA reductions especially involving the right posterior thalamic radiation are associated with the deficit syndrome of schizophrenia. These findings represent potential brain white matter biomarkers of DS which deserve further investigation to determine their utility for monitoring illness progression and response to intervention in deficit schizophrenia.
One commonly reported DTI index, fractional anisotropy (FA), is a quantitative measure of WM tract microstructure (Beaulieu 2002), with areas of sparse, poorly myelinated, or divergent fibers displaying lower FA values (Amodio et al. 2018).
The disconnection hypothesis (Friston 1998) posits abnormal connectivity between brain regions and white matter (WM) organization disturbances as the key pathophysiology underlying schizophrenia (Friston et al. 2016).
