Intermittent theta burst stimulation over the dorsomedial prefrontal cortex modulates resting-state connectivity in depressive patients: A sham-controlled study.

The mechanisms underlying repetitive transcranial magnetic stimulation (rTMS) treatment are largely unknown. Although there is a general lack of sham controlled studies, findings show altered functional connectivity to the stimulated region following treatment. When targeting the dorsolateral prefrontal cortex (dlPFC), connectivity with the subgenual anterior cingulate cortex (sgACC) is predictive of response, but less is known about the effects on functional connectivity of targeting the dorsomedial PFC (dmPFC). Here, 30 patients with an ongoing depressive episode were recruited and randomized to 20 sessions at target intensity of either active or sham intermittent theta burst stimulation (iTBS) over dmPFC. Those receiving sham were offered active treatment in a subsequent open phase. A seven minute resting-state scan and depressive symptom assessment was performed before and after treatment. After exclusions due to attrition and excessive head movements 23 patients remained for analysis. Seed-based resting-state connectivity was calculated using two seeds for the dmPFC target as well as the sgACC. A symptom related increase in dmPFC connectivity after active treatment, compared to sham treatment, was found. The effect was observed in a region overlapping the precuneus and the posterior cingulate cortex (PCC), suggesting an increase in the connectivity between the targeted salience network and the default mode network mediating improvement in depressive symptoms. Connectivity between the precuneus and both the sgACC and the treatment target was predictive of symptom improvement following active treatment. The findings have implications for understanding the mechanisms behind iTBS and may inform future efforts to individualize the treatment.

Autonomic modulation networks in schizophrenia: The relationship between heart rate variability and functional and structural connectivity in the brain.

Heart rate variability (HRV), a measurement of autonomic nervous system (ANS) activity, has been found reduced in schizophrenia. The anterior cingulate cortex (ACC), which is important in regulating the ANS, is structurally and functionally affected in schizophrenia. We investigate the relationship between HRV and functional and structural connectivity of the ACC in patients with schizophrenia and healthy controls. Ten patients with a diagnosis of schizophrenia and ten healthy controls were recruited. Heart rate was monitored in a naturalistic out-of-clinic setting. Magnetic resonance imaging (MRI) was performed, including resting-state functional MRI and diffusion tensor imaging. Patients with schizophrenia had significantly lower HRV compared to controls. A positive correlation between ACC connectivity with the bilateral cerebellum and HRV was found in the patients. HRV was also positively correlated with amplitude of low frequency fluctuations (ALFF) in the cerebellum, and with axial diffusivity in the middle cerebellar peduncle, in the patients. There was a significant negative relationship between antipsychotic medication dosage, HRV and all neuroimaging measures related to HRV. We conclude that ACC connectivity seems to be affected in schizophrenia, both structurally and functionally, and that the ACC-cerebellum connectivity, as well as cerebellar function, is associated with ANS regulation in patients with schizophrenia.

Personality and risk for postpartum depressive symptoms.

Postpartum depression (PPD) is a common childbirth complication, affecting 10-15 % of newly delivered mothers. This study aims to assess the association between personality factors and PPD. All pregnant women during the period September 2009 to September 2010, undergoing a routine ultrasound at Uppsala University Hospital, were invited to participate in the BASIC study, a prospective study designed to investigate maternal well-being. Depressive symptoms were assessed with the Edinburgh Postnatal Depression Scale (EPDS) while the Depression Self-Rating Scale (DSRS) was used as a diagnostic tool for major depression. Personality traits were evaluated using the Swedish Universities Scale of Personality (SSP). One thousand thirty-seven non-depressed pregnant women were included in the study. Non-depressed women reporting high levels of neuroticism in late pregnancy were at high risk of developing postpartum depressive symptoms (PPDSs) at 6 weeks and 6 months after delivery, even after adjustment for confounders (adjusted odds ratio (aOR) = 3.4, 95 % confidence interval (CI) 1.8-6.5 and adjusted odds ratio (aOR) = 3.9, 95 % CI 1.9-7.9). The same was true for a DSRS-based diagnosis of major depression at 6 months postpartum. Somatic trait anxiety and psychic trait anxiety were associated with increased risk for PPDS at 6 weeks (aOR = 2.1, 95 % CI 1.2-3.5 and aOR = 1.9, 95 % CI 1.1-3.1), while high scores of mistrust were associated with a twofold increased risk for PPDS at 6 months postpartum (aOR 1.9, 95 % CI 1.1-3.4). Non-depressed pregnant women with high neuroticism scores have an almost fourfold increased risk to develop depressive symptoms postpartum, and the association remains robust even after controlling for most known confounders. Clinically, this could be of importance for health care professionals working with pregnant and newly delivered women.