Optimally combining transcranial magnetic stimulation with antidepressants in major depressive disorder: A systematic review and Meta-analysis.

There is a critical knowledge gap in optimally combining transcranial magnetic stimulation (TMS) and antidepressants to treat patients with major depressive disorder (MDD). TMS is effective in treating MDD in patients who have failed at least one antidepressant trial, with accelerated protocols showing faster remission in treatment-resistant depression (TRD). Although clinicians routinely augment antidepressants with TMS, there is a knowledge gap in stopping versus continuing antidepressants or the dosing strategies when starting or tapering TMS. These considerations are important when considering maintenance TMS (delivered alone or in combination with suitable antidepressants) to maintain remission in MDD after the index course of TMS. As the first step towards filling this knowledge gap, we reviewed randomized controlled trials (RCTs) and open-label trials from 2 databases (PubMed/Medline and EMBASE) that compared active TMS combined with a pre-specified antidepressant dosed in the same manner for adults with MDD versus sham TMS combined with the same antidepressant as in the active arm. All studies were published between January 1, 2000, and December 31, 2023. We excluded case reports, case series, and clinical studies that augmented TMS with antidepressants and vice versa. We found 10 RCTs (n = 654 participants) and performed a meta-analysis. This showed active TMS combined with pre-specified antidepressants had greater efficacy for MDD treatment than sham TMS combined with the same antidepressants as in the active arm (Hedge's g = 1; 95 % CI [0.27, 1.73]). The review and meta-analysis indicate greater short-term efficacy in combining antidepressants with TMS from the get-go in MDD. Given the increasing role of accelerated TMS protocols in expediting remission in MDD and the results of our meta-analysis, we advocate for RCTs examining the short-term and long-term effects of various antidepressant classes on these TMS protocols in MDD. This can also optimize and individualize maintenance TMS protocols to prevent relapse in MDD.

Intermittent theta burst stimulation and functional connectivity in people living with HIV/AIDS who smoke tobacco cigarettes: a preliminary pilot study.

Background: People living with HIV (PLWHA) smoke at three times the rate of the general population and respond poorly to cessation strategies. Previous studies examined repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex (L. dlPFC) to reduce craving, but no studies have explored rTMS among PLWHA who smoke. The current pilot study compared the effects of active and sham intermittent theta-burst stimulation (iTBS) on resting state functional connectivity (rsFC), cigarette cue attentional bias, and cigarette craving in PLWHA who smoke. Methods: Eight PLWHA were recruited (single-blind, within-subject design) to receive one session of iTBS (n=8) over the L. dlPFC using neuronavigation and, four weeks later, sham iTBS (n=5). Cigarette craving and attentional bias assessments were completed before and after both iTBS and sham iTBS. rsFC was assessed before iTBS (baseline) and after iTBS and sham iTBS. Results: Compared to sham iTBS, iTBS enhanced rsFC between the L. dlPFC and bilateral medial prefrontal cortex and pons. iTBS also enhanced rsFC between the right insula and right occipital cortex compared to sham iTBS. iTBS also decreased cigarette craving and cigarette cue attentional bias. Conclusion: iTBS could potentially offer a therapeutic option for smoking cessation in PLWHA.

Comparing cigarette-cue attentional bias between people with HIV/AIDS and people with opioid use disorder who smoke.

Background: Special populations like people living with HIV/AIDS (PLWHA) and people with opioid use disorder (OUD) smoke tobacco cigarettes at rates three to four times greater than the general population. Patients with tobacco use disorder exhibit attentional bias (AB) for cigarette cues. Eye tracking can quantify this bias by measuring fixation time (FT) on cigarette and matched neutral cues, to calculate an AB score. Although previous studies have measured this bias in people who smoke without any other comorbid conditions, no study, to our knowledge, has measured or compared this bias in special populations. Methods: We performed exploratory analyses on eye tracking data collected in two separate randomized clinical trials (RCTs) (NCT05049460, NCT05295953). We compared FT and cigarette-cue AB score (measured by subtracting FT on neutral cues from FT on cigarette cues) between PLWHA and people with OUD who smoke, using a visual probe task and Tobii Pro Fusion eye tracker. We used two cigarette cue types, one encompassing people smoking cigarettes and the other consisting of cigarette paraphernalia. We used two cue presentation times, 1000 and 2000 milliseconds (ms). Results: Cues of people smoking cigarettes elicited greater AB than cues of cigarette paraphernalia across both subject groups when cues were presented for 2000 ms, but not 1000 ms. PLWHA who smoke exhibited greater AB for cues of people smoking cigarettes than cigarette paraphernalia when presented for 2000 ms compared to people with OUD who smoke. Conclusion: We use cigarette-cue AB to quantify craving and cigarette consumption in two populations smoking at elevated rates. The addition of social cues potentiates cigarette cue AB, based on cue type and stimulus presentation time. Understanding the neurobiology of this relationship can help design novel smoking cessation treatments that target AB and prevent relapse in these populations with suboptimal response to smoking cessation treatments. Trial registration: Clinical trials that provided the data for post hoc analyses are NCT05049460 and NCT05295953.

APOΕ4 lowers energy expenditure in females and impairs glucose oxidation by increasing flux through aerobic glycolysis.

BACKGROUND: Cerebral glucose hypometabolism is consistently observed in individuals with Alzheimer's disease (AD), as well as in young cognitively normal carriers of the Ε4 allele of Apolipoprotein E (APOE), the strongest genetic predictor of late-onset AD. While this clinical feature has been described for over two decades, the mechanism underlying these changes in cerebral glucose metabolism remains a critical knowledge gap in the field. METHODS: Here, we undertook a multi-omic approach by combining single-cell RNA sequencing (scRNAseq) and stable isotope resolved metabolomics (SIRM) to define a metabolic rewiring across astrocytes, brain tissue, mice, and human subjects expressing APOE4. RESULTS: Single-cell analysis of brain tissue from mice expressing human APOE revealed E4-associated decreases in genes related to oxidative phosphorylation, particularly in astrocytes. This shift was confirmed on a metabolic level with isotopic tracing of 13C-glucose in E4 mice and astrocytes, which showed decreased pyruvate entry into the TCA cycle and increased lactate synthesis. Metabolic phenotyping of E4 astrocytes showed elevated glycolytic activity, decreased oxygen consumption, blunted oxidative flexibility, and a lower rate of glucose oxidation in the presence of lactate. Together, these cellular findings suggest an E4-associated increase in aerobic glycolysis (i.e. the Warburg effect). To test whether this phenomenon translated to APOE4 humans, we analyzed the plasma metabolome of young and middle-aged human participants with and without the Ε4 allele, and used indirect calorimetry to measure whole body oxygen consumption and energy expenditure. In line with data from E4-expressing female mice, a subgroup analysis revealed that young female E4 carriers showed a striking decrease in energy expenditure compared to non-carriers. This decrease in energy expenditure was primarily driven by a lower rate of oxygen consumption, and was exaggerated following a dietary glucose challenge. Further, the stunted oxygen consumption was accompanied by markedly increased lactate in the plasma of E4 carriers, and a pathway analysis of the plasma metabolome suggested an increase in aerobic glycolysis. CONCLUSIONS: Together, these results suggest astrocyte, brain and system-level metabolic reprogramming in the presence of APOE4, a 'Warburg like' endophenotype that is observable in young females decades prior to clinically manifest AD.