Background: Major depressive disorders (MDDs) impose substantial burdens on individuals and society; however, further detailed analysis is still needed for its long-term trends.
Aims: This study aimed to analyse the gender-specific temporal trends and cohort variations of MDD incidence among Chinese residents over the past three decades.
Methods: Employing the age-period-cohort-interaction model and leveraging data from the Global Burden of Disease Study 2019, this research identified and analysed incidence trends of MDD among Chinese males and females aged 5-94 years from 1990 to 2019 across three dimensions, encompassing age, period and birth cohort.
Results: The analysis reveals age-related effects, indicating heightened MDD risk among adolescents and older adults. Specifically, individuals entering the older adulthood at the age of 65-69 significantly increased the risk of MDD by 64.9%. People aged 90-94 years witnessed a 105.4% increase in MDD risk for the overall population, with females and males in this age group experiencing a 75.1% and 103.4% increase, respectively. In terms of period effects, the risk of MDD displayed a decline from 1990 to 1994, followed by a rebound in 2008. Cohort effects demonstrated diverse generational patterns, with generation I and generation III manifesting opposing 'age-as-level' trends. Generation II and generation IV exhibited 'cumulative disadvantage' and 'cumulative advantage' patterns, respectively. Age effects indicated an overall higher risk of MDD incidence in females, while cohort effects showed greater variations of MDD incidence among females.
Conclusions: The study underscores the substantial effects of age, period and cohort on MDD across genders in China. Priority interventions targeting vulnerable populations, including children, adolescents, older adults, females and the post-millennium birth cohort, are crucial to mitigate the impact of MDD.
Background: Structural imaging holds great potential for precise targeting and stimulation for deep brain stimulation (DBS). The anatomical information it provides may serve as potential biomarkers for predicting the efficacy of DBS in treatment-resistant depression (TRD).
Aims: The primary aim is to identify preoperative imaging biomarkers that correlate with the efficacy of DBS in patients with TRD.
Methods: Preoperative imaging parameters were estimated and correlated with the 6-month clinical outcome of patients with TRD receiving combined bed nucleus of the stria terminalis (BNST)-nucleus accumbens (NAc) DBS. White matter (WM) properties were extracted and compared between the response/non-response and remission/non-remission groups. Structural connectome was constructed and analysed using graph theory. Distances of the volume of activated tissue (VAT) to the main modulating tracts were also estimated to evaluate the correlations.
Results: Differences in fibre bundle properties of tracts, including superior thalamic radiation and reticulospinal tract, were observed between the remission and non-remission groups. Distance of the centre of the VAT to tracts connecting the ventral tegmental area and the anterior limb of internal capsule on the left side varied between the remission and non-remission groups (p=0.010, t=3.07). The normalised clustering coefficient (γ) and the small-world property (σ) in graph analysis correlated with the symptom improvement after the correction of age.
Conclusions: Presurgical structural alterations in WM tracts connecting the frontal area with subcortical regions, as well as the distance of the VAT to the modulating tracts, may influence the clinical outcome of BNST-NAc DBS. These findings provide potential imaging biomarkers for the DBS treatment for patients with TRD.
Background: Understanding synaptic alteration in obsessive-compulsive disorder (OCD) is crucial for elucidating its pathological mechanisms, but in vivo research on this topic remains limited.
Aims: This study aimed to identify the synaptic density indicators in OCD and explore the relationship between cognitive dysfunction and synaptic density changes in OCD.
Methods: This study enrolled 28 drug-naive adults with OCD aged 18-40 years and 16 healthy controls (HCs). Three-dimensional T1-weighted structural magnetic resonance imaging and 18F-SynVesT-1 positron emission tomography were conducted. Cognitive function was assessed using the Wisconsin Cart Sorting Test (WCST) in patients with OCD and HCs. Correlative analysis was performed to examine the association between synaptic density reduction and cognitive dysfunction.
Results: Compared with HCs, patients with OCD showed reduced synaptic density in regions of the cortico-striato-thalamo-cortical circuit such as the bilateral putamen, left caudate, left parahippocampal gyrus, left insula, left parahippocampal gyrus and left middle occipital lobe (voxel p<0.001, uncorrected, with cluster level above 50 contiguous voxels). The per cent conceptual-level responses of WCST were positively associated with the synaptic density reduction in the left middle occipital gyrus (R2=0.1690, p=0.030), left parahippocampal gyrus (R2=0.1464, p=0.045) and left putamen (R2=0.1967, p=0.018) in patients with OCD.
Conclusions: Adults with OCD demonstrated lower 18F-labelled difluoro analogue of 18F-SynVesT-1 compared with HCs, indicating potentially lower synaptic density. This is the first study to explore the synaptic density in patients with OCD and provides insights into potential biological targets for cognitive dysfunctions in OCD.
Background: Globally, populations afflicted by armed conflict are known to have high rates of mental health disorders.
Aims: This meta-analysis aims to estimate the prevalence of post-traumatic stress disorder (PTSD) and depressive symptoms among civilians residing in armed conflict-affected regions.
Methods: This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A literature search employing MEDLINE(R), Embase Classic+Embase, APA PsycINFO, Ovid Healthstar, Journal@Ovid Full Text, Cochrane, PTSDpubs and CINAHL was conducted from inception until 19 March 2024 to identify relevant studies. Quality assessment was performed using the Joanna Briggs Institute Critical Appraisal Checklist for Prevalence Studies, and a Comprehensive Meta-Analysis was used to conduct the statistical analysis.
Results: The search yielded 38 595 articles, of which 57 were considered eligible for inclusion. The included studies comprised data from 64 596 participants. We estimated a prevalence of 23.70% (95% CI 19.50% to 28.40%) for PTSD symptoms and 25.60% (95% CI 20.70% to 31.10%) for depressive features among war-afflicted civilians. The subgroup analysis based on time since the war and the country's economic status revealed the highest prevalence for both PTSD and depressive symptoms was present during the years of war and in low/middle-income countries.
Conclusions: The results of this study provide conclusive evidence of the detrimental impacts of armed conflict on mental health outcomes. Hence, it is crucial to emphasise the significance of both physical and mental health in the aftermath of war and take appropriate humanistic measures to overcome challenges in the management of psychiatric illnesses.
Prospero registration number: CRD42023416096.
Background: Attention-deficit/hyperactivity disorder (ADHD) is one of the most frequently diagnosed psychiatric conditions in children and adolescents. Although the symptoms appear to be well described, no coherent conceptual mechanistic framework integrates their occurrence and variance and the associated problems that people with ADHD face.
Aims: The current study proposes that altered event segmentation processes provide a novel mechanistic framework for understanding deficits in ADHD.
Methods: Adolescents with ADHD and neurotypically developing (NT) peers watched a short movie and were then asked to indicate the boundaries between meaningful segments of the movie. Concomitantly recorded electroencephalography (EEG) data were analysed for differences in frequency band activity and effective connectivity between brain areas.
Results: Compared with their NT peers, the ADHD group showed less dependence of their segmentation behaviour on social information, indicating that they did not consider social information to the same extent as their unaffected peers. This divergence was accompanied by differences in EEG theta band activity and a different effective connectivity network architecture at the source level. Specifically, NT adolescents primarily showed error signalling in and between the left and right fusiform gyri related to social information processing, which was not the case in the ADHD group. For the ADHD group, the inferior frontal cortex associated with attentional sampling served as a hub instead, indicating problems in the deployment of attentional control.
Conclusions: This study shows that adolescents with ADHD perceive events differently from their NT peers, in association with a different brain network architecture that reflects less adaptation to the situation and problems in attentional sampling of environmental information. The results call for a novel conceptual view of ADHD, based on event segmentation theory.

