Effects of chronic daily headache with subclinical depression on brain volume: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: The relationship between chronic daily headache (CDH), depression symptoms, and brain volume remains unclear. METHODS: To investigate the effects of CDH on brain volume and the impact of depressive symptoms (DSs) as well as the effects of demography and medication overuse, PubMed, Embase, and Web of Science databases were systematically searched using appropriate keyword strings to retrieve observational studies from inception to May 2023. RESULTS: Two distinct comparisons were made in CDH patients: (1) those with DSs versus their pain-free counterparts and (2) those without DSs versus pain-free controls. The first comprised nine studies enrolling 225 CDH patients with DSs and 234 controls. Beck depression inventory, Hamilton depression scale, and Hospital anxiety/depression scale were used to assess DSs, revealing significantly more DSs in CDH patients with DSs compared to their controls (all p < 0.05). Besides, the second analysed four studies involving 117 CDH patients without DSs and 155 comparators. Compared to CDH patients without DSs, those with DSs had a smaller brain volume than controls (p = 0.03). Furthermore, CDH patients with DSs who did not overuse medications showed a smaller right cerebral cortical volume than overusers (p = 0.003). A significant inverse correlation between female prevalence and brain volume (p = 0.02) was revealed using regression analysis. CONCLUSIONS: Pain-induced persistent depressive symptoms not only incur structural alterations but also encompass affective-motivational changes, involving medication use and gender-specific health concerns. SIGNIFICANCE: This study highlighted the importance of an integrated CDH treatment, emphasizing psychological interventions for the affective-motivational component alongside pain management.

A systematic review and meta-analysis of the relationship between heavy smoking and probability discounting.

BACKGROUND AND OBJECTIVES: Probability discounting (PD), which refers to the process of adjusting the value of future probabilities when making decisions, is a method of measuring impulsive decision-making; however, the relationship between PD and nicotine remains unclear. The current study aimed at investigating the significance of PD in individuals who smoke. METHODS: According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched the PubMed, Embase, PsycINFO, and Web of Science databases for articles comparing individuals who smoke and their tobacco-naïve controls using PD task as outcome measure from inception to May 2023. The main outcome was an overall difference in PD function, while subgroup analysis and meta-regression were conducted to examine the analysis methods and the moderators of PD. RESULTS: Fourteen studies in total involving 384 individuals who smoke and 493 controls (mean age = 24.32 years, range = 15.1-38.05 years) were analyzed. The effect of smoking on PD was significant (g = 0.51, p = .02). The discounting parameter from the equation, compared to the area under the curve, was more sensitive to estimating PD function (p = .01). Regression analysis showed positive correlations of PD with female percentage, age, and the number of probability options (all p < .04), but not with the number of choices at each probability and maximum reward magnitude (all p > .07). There was no significant publication bias across the eligible studies (p = .09). CONCLUSION AND SCIENTIFIC SIGNIFICANCE: Our findings, which are the first to demonstrate a smaller PD (i.e., prone to risk-taking) in individuals who smoke, shed light on the appropriate analysis method, gender effect, age, and probability options on the PD function.

Structural and Functional Neural Correlates in Individuals with Excessive Smartphone Use: A Systematic Review and Meta-Analysis.

Background: Despite known association of internet addiction with a reduced brain volume and abnormal connectivity, the impact of excessive smartphone use remains unclear. Methods: PubMed, Embase, ClinicalTrial.gov, and Web of Science databases were systematically searched from inception to July 2022 using appropriate keywords for observational studies comparing differences in brain volumes and activations between excessive smartphone users and individuals with regular use by magnetic resonance imaging. Results: Of the 11 eligible studies retrieved from 6993 articles initially screened, seven and six evaluated brain volumes and activations, respectively. The former enrolled 421 participants (165 excessive smartphone users vs. 256 controls), while the latter recruited 276 subjects with 139 excessive smartphone users. The results demonstrated a smaller brain volume in excessive smartphone users compared to the controls (g = −0.55, p < 0.001), especially in subcortical regions (p < 0.001). Besides, the impact was more pronounced in adolescents than in adults (p < 0.001). Regression analysis revealed a significant positive association between impulsivity and volume reduction. Regarding altered activations, the convergences of foci in the declive of the posterior lobe of cerebellum, the lingual gyrus, and the middle frontal gyrus were noted. Conclusions: Our findings demonstrated a potential association of excessive smartphone use with a reduced brain volume and altered activations.