Objective: To analyze the associations of physical activity with overweight/obesity, depressive symptoms, and their co-occurrence among junior and senior high school students, so as to provide reference for optimizing physical activity intervention strategies and promoting healthy lifestyles. Methods: From March to November 2023, a cross sectional survey was conducted among 90 457 junior and senior high school students aged 11-18 years in Zhejiang Province using a stratified cluster random sampling method. Data on physical activity and dietary behavior were collected through questionnaires, height and weight were measured. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). The Chi-square test was used to examine differences, and Logistic regression was applied to evaluate the associations of physical activity characteristics with overweight/obesity, depressive symptoms, and their co-occurrence. Additionally, the effectiveness of physical activity performed on rest days versus work days was examined. Results: The prevalence of overweight/obesity, depressive symptoms, and their co-occurrence among junior and senior high school students were 25.1%, 27.9%, and 6.7%, respectively, with significant sex differences ( χ 2=2 005.3, 587.7, 99.6, all P <0.01). Logistic regression analysis showed that students with insufficient physical activity had a higher risk of overweight/obesity compared with those with sufficient physical activity ( OR=1.12, 95%CI=1.06-1.17, P <0.01). Comparing to students who exercised 0-1 day per week, those who exercised 5-7 days per week were associated with a reduced risk of overweight/obesity and depressive symptoms ( OR=0.93, 95%CI =0.90-0.97; OR=0.95, 95%CI =0.91-0.99, both P <0.05). When total activity volume and frequency were held constant, students with sufficient rest day physical activity had lower risks of overweight/obesity, depressive symptoms, and their co-occurrence than those with insufficient rest day activity (all P < 0.01). Conclusions Sufficient amount of physical activity and higher frequency of rest day physical activity are significantly associated with lower risks of overweight/obesity, depressive symptoms, and their co-occurrence in adolescents. Physical activity performed on rest days may confer greater health benefits than activity performed on work days.

Objective To explore the differences in heartbeat-evoked response (HER) under drug-related cues and neutral cues in individuals with heroin use disorder (HUD), and analyze the correlation between HER potentials and immediate cue-induced craving scores. Methods Fifty HUD participants were recruited from the Chang’an Compulsory Isolation Drug Rehabilitation Center in Shaanxi Province from June to September 2024. Simultaneous acquisition of 64-channel electroencephalography (EEG) and electrocardiogram signals was performed. Twenty alternating segments of drug-related and neutral cue videos were presented, and participants rated their subjective craving after each segment using visual analogue scale (VAS) scores. Scalp EEG data were source analyzed to obtain cortical EEG signals and corresponding HER. Short-time Fourier transform was used to calculate the power spectral density (PSD) of EEG within a time window from 100 ms before the R-peak to 500 ms after it, using the R-peak as the time zero point. Cluster-based permutation testing was used to analyze PSD differences between drug-related and neutral cues in the HUD individuals. Pearson correlation analysis was performed to evaluate the correlation between HER potentials and VAS scores. Results In the 350–420 ms time window, HER potentials in the left posterior parietal, temporal, and posterior cingulate cortices were significantly lower under drug-related cues compared to neutral cues (P＜0.01); in the 140–210 ms time window, HER potentials in the right prefrontal cortex were significantly higher under drug-related cues compared to neutral cues (P＜0.01). Correlation analysis showed that HER potentials in the left temporal and left posterior cingulate cortices were significantly negatively correlated with VAS scores (P＜0.05). Drug-related cues enhanced PSD of γ power (30–100 Hz) in salience network (fronto-insular), parietal and occipital regions (P＜0.05). PSD integrations of low-γ power (40–60 Hz) in parietal region (350–400 ms) and high-γ power (70–100 Hz) in left salience network (fronto-parietal) and occipital regions (300–350 ms) were positively correlated with VAS scores (P＜0.05). Conclusions Drug-related cues may modulate cortical activity related to heartbeat perception in HUD individuals, and such dynamic changes in both time and frequency domains are stably associated with subjective craving.

ObjectiveThe present study aimed to investigate alterations in white matter microstructure and spontaneous neural activity in male college smokers, and to further explore their associations with nicotine dependence. Given that adolescence and early adulthood represent critical periods for brain maturation, particularly for white matter development, understanding the neural correlates of smoking behavior during this stage is of substantial importance for both neuroscience and public health. MethodsA total of 115 male undergraduate students were initially recruited for this study. After quality control and exclusion procedures, 52 male college smokers and 42 demographically matched healthy non-smokers were included in the final analysis. All participants underwent multimodal magnetic resonance imaging (MRI), including diffusion tensor imaging (DTI) and resting-state functional MRI (rs-fMRI). White matter fiber tracts were reconstructed using the automated fiber quantification (AFQ) method, which enables precise identification and quantification of major fiber bundles. Eighteen major white matter tracts were segmented for each participant. Along the core trajectory of each tract, 100 equidistant nodes were sampled. Fractional anisotropy (FA) was calculated at each node to assess white matter microstructural integrity, while amplitude of low-frequency fluctuation (ALFF) was computed to evaluate spontaneous neural activity within white matter tracts. Between-group differences in FA and ALFF were assessed using two-sample t-tests, with appropriate corrections applied for multiple comparisons. Furthermore, Pearson correlation analyses were conducted to examine the relationships between imaging-derived metrics (FA and ALFF values in regions showing significant group differences) and nicotine dependence severity, as measured by the Fagerström test for nicotine dependence (FTND). ResultsCompared with healthy non-smokers, male college smokers exhibited significantly increased FA values in several white matter tracts, including the left thalamic radiation, right corticospinal tract, forceps major of the corpus callosum, left uncinate fasciculus, and right arcuate fasciculus. These findings suggest altered microstructural organization or increased directional coherence within these pathways. In addition, smokers demonstrated significantly elevated ALFF values in the forceps major, right uncinate fasciculus, and left arcuate fasciculus, indicating enhanced spontaneous neural activity in these white matter regions. Correlation analyses revealed that FA values in the left thalamic radiation and right corticospinal tract were negatively correlated with FTND scores, suggesting that higher levels of nicotine dependence were associated with reduced microstructural integrity or altered fiber organization in these regions. In contrast, ALFF values in the forceps major and right uncinate fasciculus were positively correlated with FTND scores, indicating that greater nicotine dependence was associated with increased spontaneous neural activity in specific white matter pathways. ConclusionThe present study provides evidence that male college smokers exhibit distinct alterations in both white matter microstructure and functional activity. These abnormalities are not uniformly distributed but rather localized to specific fiber tracts implicated in sensorimotor processing, interhemispheric communication, and higher-order cognitive and emotional regulation. Importantly, the observed associations between imaging metrics and nicotine dependence severity suggest that these structural and functional alterations may reflect neurobiological mechanisms underlying addiction. The combination of AFQ-based tract profiling and multimodal MRI offers a sensitive approach for detecting subtle changes along white matter pathways, highlighting its potential utility in identifying neuroimaging biomarkers of nicotine dependence. Overall, these findings indicate that smoking during early adulthood may disrupt ongoing white matter maturation, potentially leading to long-term consequences for brain function. This study provides novel insights into the neural basis of nicotine dependence and underscores the importance of early intervention and prevention strategies targeting young smokers.

ObjectiveTo reveal the molecular mechanism by which the traditional Chinese medicine compound prescription Qiangjing tablets regulate the aging of the testicular tissue and Leydig cells in rats through the cyclin-dependent kinase 4 （CDK4）-early 2 factor （E2F） signaling pathway. MethodsFor the cell experiment， 2-month-old SPF-grade SD male rats were selected and randomly assigned into a blank control group （administrated with an equal volume of 0.9% sodium chloride injection） and a Qiangjing tablets group （20 rats in each group） according to body weight. The Leydig cell model of aging was established by treatment of TM3 cells with 100 μmol·L^-1 H₂O₂， and the modeling performance was evaluated based on the levels of p16 and p21 determined by Western blot. The antioxidant NAC （1 mmol·L^-1） was used as the positive control for eliminating reactive oxygen species （ROS）. Cells were intervened with Qiangjing tablets-containing serum at low （2.5%）， medium （5%）， and high （10%） concentrations. The testosterone level in the cell supernatant was determined by enzyme-linked immunosorbent assay （ELISA）， and the protein levels of CDK4， E2F1， and E2F2 were analyzed by Western blot. In the animal experiment， 19-month-old naturally aging rats were used as the model group， and 2-month-old rats as the young control group. The positive control group was subcutaneously injected with 5.21 mg·kg^-1·d^-1 testosterone propionate. Qiangjing tablets were administered by gavage at low， medium， and high doses of 0.72， 1.44， 2.88 g·kg^-1·d^-1， respectively. The general conditions of rats were observed， and the protein levels of CDK4， E2F1， and E2F2 in the testicular tissue were determined by Western blot. ResultsIn the cell experiment， compared with the blank control group， the model group showed upregulated expression of CDK4 and E2F1 （P<0.05） and slightly downregulated expression of E2F2. Compared with that in the model group， the expression of CDK4 was upregulated in the NAC group and the low-dose Qiangjing tablets group （P<0.05）， slightly upregulated in the medium-dose Qiangjing tablets group， and downregulated in the high-dose Qiangjing tablets group （P<0.05）. The NAC group showed downregulated expression of E2F1 （P<0.05） and E2F2， and the low-， medium-， and high-dose Qiangjing tablets groups showed downregulated expression of both E2F1 and E2F2 （P<0.05）. Compared with that in the NAC group， the expression of CDK4 was upregulated in the low-dose Qiangjing tablets group and downregulated in the medium-dose and high dose （P<0.05） groups. The expression of E2F1 was down-regulated in all the three dose groups， with statistically significance in the high dose group （P<0.05）， and that of E2F2 were downregulated in all the three dose groups （P<0.05）. In the animal experiment， compared with the young control group， the model group exhibited downregulated expression of CDK4 （P<0.05） and slightly upregulated expression of E2F1 and E2F2. Compared with that in the model group， the expression of CDK4 decreased in the testosterone propionate group and the low-dose Qiangjing tablets group （P<0.05） but increased in the medium-dose （P<0.05） and high-dose groups. In addition， the expression of E2F1 decreased （P<0.05）， and that of E2F2 was slightly elevated. Compared with that in the NAC group， CDK4 expression was elevated in the Qiangjing tablets groups， with statistical significance in the medium- and high-dose groups （P<0.05）. Similarly， the E2F1 expression was also upregulated in the Qiangjing tablets groups， with statistical significance in the medium-dose group （P<0.05）. The expression of E2F2 was downregulated in all the Qiangjing tablets groups. ConclusionQiangjing tablets delay the aging process of Leydig cells and testicular tissue by up-regulating the expression of CDK4 and lowering the levels of E2F1 and E2F2.

ObjectiveTo explore the mechanism by which Qiangjing tablets （QJT） alleviate the spermatogenic function damage caused by varicocele （VC） based on the Kelch-like ECH-associated protein 1 （Keap1）/nuclear factor erythroid 2-related factor 2 （Nrf2） signaling pathway-mediated oxidative stress. MethodsTen Sprague-Dawley （SD） rats were randomly assigned into a control group and a model group. Pathological examination confirmed the stability of the model. Thirty-six SD rats were randomized into control， model， low-dose （0.23 g·kg^-1） QJT， medium-dose （0.46 g·kg^-1） QJT， high-dose （0.92 g·kg^-1） QJT， and mazhilin （61.7 mg·kg^-1） groups， with 6 rats in each group. A rat model of experimental left varicocele （ELV） was established by partially ligating the left renal vein to simulate the human nutcracker syndrome. The rats were administrated with corresponding agents once a day for 28 consecutive days. The in vitro testicular culture model of rats was established through the Transwell chamber method and intervened with QJT-containing sera （2.3， 4.6， and 9.2 g·kg^-1）. Microscopic observation was carried out for the morphology of the left kidney. A micrometer was used to measure the diameter of the left spermatic vein （LSV）. The body weights of rats were recorded weekly， and the epididymis and testis weights were measured. The pathological changes of the testicular tissue was observed via hematoxylin-eosin （HE） staining. The levels of testosterone （T） in the cell culture supernatant and reactive oxygen species （ROS） in the rat testicular tissue were measured by enzyme-linked immunosorbent assay （ELISA）. Flow cytometry was employed to determine the ROS content. Immunohistochemical staining was conducted to analyze Keap1， Nrf2， 3β-hydroxysteroid dehydrogenase （3β-Hsd）， GATA-binding protein-4 （Gata-4）， and proto-oncogene receptor tyrosine kinase （C-kit）. The ultrastructure of the tissue was observed by transmission electron microscopy （TEM）. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL） staining. The expression of Keap1， Nrf2， glutathione S-transferase α2 （Gsta2）， glutathione S-transferase μ1 （Gstm1）， heme oxygenase-1 （HO-1）， quinone oxidoreductase 1 （Nqo1）， and thioredoxin reductase 1 （Txnrd1） was quantified by Real-time quantitative polymerase chain reaction（Real-time PCR） and Western blot. ResultsCompared with the control group， the ROS content and the percentage of apoptotic cells in the model group were significantly increased （P<0.01）， the T concentration was significantly decreased （P<0.01）， the mRNA and protein expressions of Keap1 were significantly increased （P<0.01）， and the mRNA and protein expressions of Nrf2， Gsta2， Gstm1， HO-1， Nqo1 and Txnrd1 were significantly decreased （P<0.05）. Compared with the model group， the ROS content and the percentage of apoptotic cells in each dose group of the Qiangjing Tablets were significantly reduced （P<0.05）， and the mRNA and protein expressions of Keap1 were significantly decreased （P<0.05）， while the mRNA and protein expressions of Nrf2， Gsta2， Gstm1， HO-1， Nqo1 and Txnrd1 were significantly increased （P<0.05）. ConclusionQJT improves sperm motility in the rat model of VC by modulating the Keap1/Nrf2 signaling pathway and reducing oxidative stress injury.

Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.

BackgroundPatients with colorectal cancer are frequently comorbid with depression， which severely affects the quality of life and treatment compliance， while compromising the efficacy of anticancer treament and prognosis. Current therapeutic strategies still have notable limitations， particularly the lack of systematic and targeted synergistic regimens that integrate oncological management and anti-depressive intervention. It is of great clinical significance to explore a safe and effective new comprehensive intervention protocol and clarify its underlying mechanism of action. ObjectiveTo explore the effectiveness and safety of Shugan Yunpi Decoction in alleviating depressive and anxiety symptoms in colorectal cancer patients with depressive disorder through the PI3K-AKT signaling pathway， in order to provide references for the comprehensive treatment of colorectal cancer and depressive disorder. MethodsThis study was a randomized controlled trial. A total of 106 patients admitted to the Baoding No.1 Hospital of traditional Chinese medicine from November 2023 to July 2025 were enrolled， who met the diagnostic criteria for the Chinese protocol of diagnosis and treatment of colorectal cancer （2023 edition） and the diagnostic criteria for depressive disorder as specified in the Chinese Classification and Diagnostic Criteria of Mental Disease， third edition （CCMD-3）. Patients were divided into the study group and the control group using a random number table， with 53 cases in each group. The control group received conventional chemotherapy combined with traditional Chinese medicine five-element music therapy， while the study group received conventional chemotherapy combined with Shugan Yunpi Decoction therapy. Both groups were treated for 8 weeks. Depressive and anxiety symptoms were assessed using the Hamilton Depression Scale-17 item（HAMD-17） and Hamilton Anxiety Scale （HAMA）， respectively. Western blot protein immunoblotting was used to detect the expression levels of PI3K， AKT， and pAKT. Real-time fluorescence quantitative reverse transcription polymerase chain reaction （qRT-PCR） was used to detect the expression levels of PI3K mRNA and AKT mRNA. Adverse reactions were recorded using a self-designed adverse reaction record form. ResultsRepeated measures analysis of variance showed that the time effects （F=139.336， 234.747）， group effects （F=43.900， 101.266）， and time-group interaction effects （F=13.409， 43.216） for HAMD-17 and HAMA scores in both groups were statistically significant （P<0.01）. After 4 and 8 weeks of treatment， the HAMD-17 and HAMA scores in both groups were lower than those before treatment， with statistically significant differences （P<0.05）. HAMD-17 and HAMA scores in the study group were lower than those in the control group （P<0.05）. The time effects （F=571.356， 309.266， 414.492）， group effects （F=6.901， 26.361， 39.362）， and time-group interaction effects （F=18.592， 19.266， 33.484） for the protein expression levels of PI3K， AKT， and pAKT in both groups were all statistically significant （P<0.01）. After 8 weeks of treatment， the protein expression levels of PI3K and pAKT in the study group were lower than those in the control group， while the AKT protein expression level was higher than that in the control group（P<0.01）. The time effects （F=338.555， 225.059）， group effects （F=5.429， 9.726）， and time-group interaction effects （F=12.953， 21.214） for PI3K mRNA and AKT mRNA expression levels in two groups were all statistically significant （P<0.01）. After 8 weeks of treatment， the expression levels of PI3K mRNA and AKT mRNA in the study group were lower than those in the control group （P<0.05）. The incidence of adverse reactions in the study group was lower than that in the control group （χ²=4.810， P<0.05）. ConclusionShugan Yunpi Decoction may help to ameliorate depressive and anxiety symptoms in colorectal cancer patients with depressive disorder by regulating the PI3K-AKT signaling pathway， decreasing the levels of PI3K， pAKT， PI3K mRNA， and AKT mRNA， with a favorable safety profile. ［Funded by Baoding City Science and Technology Planning Project （number， 2341ZF291）］

ObjectiveMethylthioadenosine phosphorylase (MTAP) is found to be frequently deleted in malignant cancers, but the role of MTAP underlying metastasis and stemness of liver cancer remains far from clear. 5-fluorouracil (5-Fu) is clinically used in treating advanced liver cancer, however, chemoresistance is one of the major barriers impeding its efficacy. Liver cancer stem cells are considered to be the reservoir for tumor progression and chemoresistance. This study aims to explore the role of MTAP in regulating stemness and chemoresistance of 5-Fu in liver cancer. It is designed to elucidate the molecular mechanisms underlying MTAP-manipulated stemness. How MTAP influences metastasis and chemoresistance against 5-Fu in liver cancer is also elaborated. MethodsThe correlation of MTAP expression with stemness marker CD133 was evaluated by flow cytometry. Colony formation assays were conducted to analyze the tumorigenic ability. Western blot assays were applied to delineate the molecular mechanisms underlying MTAP-regulated stemness. Trans-well assays were conducted to analyze the metastatic potential of liver cancer cells.In vivo experiments were performed using subcutaneous xenograft and lung metastasis model on nude mice. Tumor size and weight were analyzed upon 5-Fu treatment. Metastatic nodules on lungs were evaluated. Immunohistochemical and TUNNEL assays were performed on slides obtained from tumor tissues. ResultsMTAP overexpression inhibited expression of CD133 and colony formation, which is further ablated by MTAP inhibitor. MTAP deprivation augmented stemness and colony formation, which is reversed by protein arginine methyltransferase 5 (PRMT5) overexpression but not its catalytically inactive counterparts. Critically, SRY-box transcription factor 2 (SOX2) was found to be a downstream regulator of MTAP/PRMT5, leading to stemness of liver cancer cells. MTAP overexpression suppressed SOX2 expression, while MTAP inhibition augmented expression of SOX2. Critically, MTAP overexpression inhibited migration and invasion of liver cancer cells. In vivo experiments in animal model found that MTAP deprivation promotes tumor growth and metastatic nodules of liver cancer. Additionally, MTAP overexpression inhibits tumor growth. Moreover, MTAP deprivation contributes to chemoresistance shown by increased tumor size and weight treated by 5-Fu. In contrast, MTAP overexpression led to further decline in tumor size and weight elicited by 5-Fu treatment. Accordingly, SOX2 was inhibited in tumor tissues after MTAP overexpression. Marker of proliferation Ki67 (Ki67) expression was dampened while apoptosis was found in MTAP-overexpressed tumor tissues. ConclusionIn this study, plethora of experimental studies collectively demonstrated that MTAP deprivation enhances stemness of liver cancer by regulating SOX2, exerting anti-cancer and chemoresistant role against 5-Fu in liver cancer. It is also worth noting that MTAP inhibition promoted metastasis of liver cancer. MTAP overexpression augmented tumor shrinking elicited by 5-Fu and SOX2 was involved in this process. These results concluded that MTAP/PRMT5/SOX2 signaling axis was involved in regulating stemness and chemoresistance of liver cancer. These findings help to exploit novel therapies by targeting stemness in MTAP-depleted liver cancer. It shed novel light on unveiling MTAP-regulated stemness in antagonizing 5-Fu treatment in liver cancer. It also adds mounting evidence to the theoretical basis for accomplishing personalized chemotherapy of liver cancer patients by targeting MTAP or its downstream PRMT5/SOX2.

ObjectiveTobacco-related diseases remain one of the leading preventable public health challenges worldwide and are among the primary causes of premature death. In recent years, accumulating evidence has supported the classification of nicotine addiction as a chronic brain disease, profoundly affecting both brain structure and function. Despite the urgency, effective diagnostic methods for smoking addiction remain lacking, posing significant challenges for early intervention and treatment. To address this issue and gain deeper insights into the neural mechanisms underlying nicotine dependence, this study proposes a novel graph neural network framework, termed TI-GNN. This model leverages functional magnetic resonance imaging (fMRI) data to identify complex and subtle abnormalities in brain connectivity patterns associated with smoking addiction. MethodsThe study utilizes fMRI data to construct functional connectivity matrices that represent interaction patterns among brain regions. These matrices are interpreted as graphs, where brain regions are nodes and the strength of functional connectivity between them serves as edges. The proposed TI-GNN model integrates a Transformer module to effectively capture global interactions across the entire brain network, enabling a comprehensive understanding of high-level connectivity patterns. Additionally, a spatial attention mechanism is employed to selectively focus on informative inter-regional connections while filtering out irrelevant or noisy features. This design enhances the model’s ability to learn meaningful neural representations crucial for classification tasks. A key innovation of TI-GNN lies in its built-in causal interpretation module, which aims to infer directional and potentially causal relationships among brain regions. This not only improves predictive performance but also enhances model interpretability—an essential attribute for clinical applications. The identification of causal links provides valuable insights into the neuropathological basis of addiction and contributes to the development of biologically plausible and trustworthy diagnostic tools. ResultsExperimental results demonstrate that the TI-GNN model achieves superior classification performance on the smoking addiction dataset, outperforming several state-of-the-art baseline models. Specifically, TI-GNN attains an accuracy of 0.91, an F1-score of 0.91, and a Matthews correlation coefficient (MCC) of 0.83, indicating strong robustness and reliability. Beyond performance metrics, TI-GNN identifies critical abnormal connectivity patterns in several brain regions implicated in addiction. Notably, it highlights dysregulations in the amygdala and the anterior cingulate cortex, consistent with prior clinical and neuroimaging findings. These regions are well known for their roles in emotional regulation, reward processing, and impulse control—functions that are frequently disrupted in nicotine dependence. ConclusionThe TI-GNN framework offers a powerful and interpretable tool for the objective diagnosis of smoking addiction. By integrating advanced graph learning techniques with causal inference capabilities, the model not only achieves high diagnostic accuracy but also elucidates the neurobiological underpinnings of addiction. The identification of specific abnormal brain networks and their causal interactions deepens our understanding of addiction pathophysiology and lays the groundwork for developing targeted intervention strategies and personalized treatment approaches in the future.