Freda Scheffler

Freda Scheffler

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Freda Scheffler

Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 March 2023 in Proceedings of the National Academy of Sciences
Verified
Journal Article
Open access
DSDick Schijven
Dick Schijven
MPMerel C. Postema
Merel C. Postema
MFMasaki Fukunaga
Masaki Fukunaga
JMJunya Matsumoto
Junya Matsumoto
KMKenichiro Miura
Kenichiro Miura
CFClyde Francks
Clyde Francks
Left–right asymmetry is an important organizing feature of the healthy brain that may be altered in schizophrenia, but most studies have used relatively small samples and heterogeneous approaches, resulting in equivocal findings. We carried out the largest case–control study of structural brain asymmetries in schizophrenia, with MRI data from 5,080 affected individuals and 6,015 controls across 46 datasets, using a single image analysis protocol. Asymmetry indexes were calculated for global and regional cortical thickness, surface area, and subcortical volume measures. Differences of asymmetry were calculated between affected individuals and controls per dataset, and effect sizes were meta-analyzed across datasets. Small average case–control differences were observed for thickness asymmetries of the rostral anterior cingulate and the middle temporal gyrus, both driven by thinner left-hemispheric cortices in schizophrenia. Analyses of these asymmetries with respect to the use of antipsychotic medication and other clinical variables did not show any significant associations. Assessment of age- and sex-specific effects revealed a stronger average leftward asymmetry of pallidum volume between older cases and controls. Case–control differences in a multivariate context were assessed in a subset of the data (N = 2,029), which revealed that 7% of the variance across all structural asymmetries was explained by case–control status. Subtle case–control differences of brain macrostructural asymmetry may reflect differences at the molecular, cytoarchitectonic, or circuit levels that have functional relevance for the disorder. Reduced left middle temporal cortical thickness is consistent with altered left-hemisphere language network organization in schizophrenia.

22 December 2017 in Psychological Medicine
Verified
Journal Article
Closed access
PDF file
SKS Kilian
S Kilian
LAL Asmal
L Asmal
BCBonginkosi Chiliza
Bonginkosi Chiliza
MOM R Olivier
M R Olivier
LPL Phahladira
L Phahladira
RER Emsley
R Emsley
Background: Childhood adversity is associated with cognitive impairments in schizophrenia. However, findings to date are inconsistent and little is known about the relationship between social cognition and childhood trauma. We investigated the relationship between childhood abuse and neglect and cognitive function in patients with a first-episode of schizophrenia or schizophreniform disorder (n = 56) and matched healthy controls (n = 52). To the best of our knowledge, this is the first study assessing this relationship in patients and controls exposed to similarly high levels of trauma.Methods: Pearson correlational coefficients were used to assess correlations between Childhood Trauma Questionnaire abuse and neglect scores and cognition. For the MCCB domains displaying significant (p < 0.05) correlations, within group hierarchical linear regression, was done to assess whether abuse and neglect were significant predictors of cognition after controlling for the effect of education.Results: Patients and controls reported similarly high levels of abuse and neglect. Cognitive performance was poorer for patients compared with controls for all cognitive domains except working memory and social cognition. After controlling for education, exposure to childhood neglect remained a significant predictor of impairment in social cognition in both patients and controls. Neglect was also a significant predictor of poorer verbal learning in patients and of attention/vigilance in controls. However, childhood abuse did not significantly predict cognitive impairments in either patients or controls.Conclusion: These findings are cross sectional and do not infer causality. Nonetheless, they indicate that associations between one type of childhood adversity (i.e. neglect) and social cognition are present and are not illness-specific.

1 June 2018 in Schizophrenia Bulletin
Verified
Journal Article
Open access
PDF file
LALaila Asmal
Laila Asmal
SKSanja Kilian
Sanja Kilian
SPStefan du Plessis
Stefan du Plessis
FSFrederika Scheffler
Frederika Scheffler
BCBonginkosi Chiliza
Bonginkosi Chiliza
RERobin Emsley
Robin Emsley
Schizophrenia is associated with brain connection irregularities within and between brain regions. Childhood trauma increases the risk of schizophrenia suggesting that the relationships between childhood trauma and brain connectivity requires further investigation. Here, we examine the relationship between childhood trauma (as measured by the Childhood Trauma Questionnaire) and fractional anisotropy (FA) in 54 minimally treated first-episode schizophrenia (FES) patients and 51 community matched controls. Patients who experienced high levels of trauma had significantly lower FA in the inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF), and inferior fronto-occipital fasciculus (IFOF) compared with controls who experienced high levels of childhood trauma. A history of childhood sexual abuse in patients was associated with lower FA in the IFOF, ILF, SLF, and forceps major compared with patients without a history of sexual abuse. However, patients who had experienced childhood emotional neglect had higher FA in the right SLF compared to patients with low levels of emotional neglect. Our findings highlight altered cortico-limbic circuitry in FES patients compared with controls and differential effects of childhood emotional neglect and sexual abuse on white matter in patients. Although stress-related white matter (WM) pathways appear to be involved in both schizophrenia and otherwise healthy controls previously exposed to childhood trauma, the pattern of disruption of WM integrity in FES patients appears to be distinct.

1 April 2019 in Schizophrenia Research
Verified
Journal Article
Closed access
HLH. Luckhoff
H. Luckhoff
LPL. Phahladira
L. Phahladira
FSF. Scheffler
F. Scheffler
LAL. Asmal
L. Asmal
SPS. du Plessis
S. du Plessis
RER. Emsley
R. Emsley

1 September 2018 in Schizophrenia Research
Verified
Journal Article
Closed access
FSF. Scheffler
F. Scheffler
SKS. Kilian
S. Kilian
BCBonginkosi Chiliza
Bonginkosi Chiliza
LAL. Asmal
L. Asmal
LPL. Phahladira
L. Phahladira
RER. Emsley
R. Emsley

17 April 2022 in Journal of Neuroscience Research
Verified
Journal Article
Open access
CHChanellé Juanita Hendrikse
Chanellé Juanita Hendrikse
SPStéfan du Plessis
Stéfan du Plessis
HLHilmar Klaus Luckhoff
Hilmar Klaus Luckhoff
MVMatthijs Vink
Matthijs Vink
LHLeigh Luella van Den Heuvel
Leigh Luella van Den Heuvel
RERobin Emsley
Robin Emsley
The association between childhood trauma exposure and risk of developing psychopathology may in part be mediated by the effects of chronic stress on dopaminergic neurotransmission. However, little is known about the differential effects of distinct trauma types on reward processing, particularly in adults without concurrent medical or psychiatric disorders. We examined the association of childhood trauma exposure, including the differential effects of abuse and neglect, with reward processing in healthy adults (n = 114). Functional magnetic resonance imaging during a monetary incentive delay task was used to assess neural activity in the ventral striatum and orbitofrontal cortex in relation to reward anticipation and reward outcome, respectively. Exposure to childhood trauma, including abuse and neglect, was assessed using the Childhood Trauma Questionnaire‐Short Form. We found a significant effect for abuse on ventral striatal activation during reward anticipation, adjusting for age, sex, scanner site, educational level, and household monthly income. There were no effects for abuse or neglect, independently or combined, on orbitofrontal cortex activation during reward outcome. Our findings suggest differential effects of childhood abuse on ventral striatum activation during reward anticipation in healthy adults.