Thalamocortical functional connectivity and rapid antidepressant and antisuicidal effects of low-dose ketamine infusion among patients with treatment-resistant depression.

Previous studies have shown an association between the thalamocortical dysconnectivity and treatment-resistant depression (TRD). Whether a single subanesthetic dose of ketamine may change thalamocortical connectivity among patients with TRD is unclear. Whether these changes in thalamocortical connectivity is associated with the antidepressant and antisuicidal effects of ketamine treatment is also unclear. Two resting-state functional MRIs were collected in two clinical trials of 48 patients with TRD (clinical trial 1; 32 receiving ketamine, 16 receiving a normal saline placebo) and 48 patients with TRD and strong suicidal ideation (clinical trial 2; 24 receiving ketamine, 24 receiving midazolam), respectively. All participants underwent rs-fMRI before and 3 days after infusion. Seed-based functional connectivity (FC) was analyzed in the left/right thalamus. FCs between the bilateral thalamus and right middle frontal cortex (BA46) and between the left thalamus and left anterior paracingulate gyrus (BA8) increased among patients in the ketamine group in clinical trials 1 and 2, respectively. FCs between the right thalamus and bilateral frontal pole (BA9) and between the right thalamus and left rostral paracingulate gyrus (BA10) decreased among patients in the ketamine group in clinical trials 1 and 2, respectively. However, the associations between those FC changes and clinical symptom changes did not survive statistical significance after multiple comparison corrections. Whether ketamine-related changes in thalamocortical connectivity may be associated with ketamine's antidepressant and antisuicidal effects would need further investigation. Clinical trials registration: UMIN Clinical Trials Registry (UMIN-CTR): Registration number: UMIN000016985 and UMIN000033916.

Thalamocortical Dysconnectivity in Treatment-Resistant Depression.

Thalamocortical connectivity is associated with cognitive and affective processing. The role of thalamocortical connectivity in the pathomechanism of treatment-resistant depression (TRD) remains unclear. This study included 48 patients with TRD and 48 healthy individuals. We investigated thalamocortical connectivity by performing resting-state functional MRI with the bilateral thalamus as the seed. In addition, patients with TRD were evaluated using the Montgomery-Åsberg Depression Rating Scale (MADRS). Compared with the healthy individuals, the patients with TRD exhibited increased functional connectivity (FC) of the thalamus with the insula and superior temporal cortex and reduced the FC of the thalamus with the anterior paracingulate cortex and cerebellum crus II. Our study may support the crucial role of thalamocortical dysconnectivity in the TRD pathomechanism. However, the small sample size may limit the statistical power. A future study with a large sample size of patients with TRD would be required to validate our findings.

Improving social cognition following theta burst stimulation over the right inferior frontal gyrus in autism spectrum: an 8-week double-blind sham-controlled trial.

BACKGROUND: The right inferior frontal gyrus (RIFG) is a potential beneficial brain stimulation target for autism. This randomized, double-blind, two-arm, parallel-group, sham-controlled clinical trial assessed the efficacy of intermittent theta burst stimulation (iTBS) over the RIFG in reducing autistic symptoms (NCT04987749). METHODS: Conducted at a single medical center, the trial enrolled 60 intellectually able autistic individuals (aged 8-30 years; 30 active iTBS). The intervention comprised 16 sessions (two stimulations per week for eight weeks) of neuro-navigated iTBS or sham over the RIFG. Fifty-seven participants (28 active) completed the intervention and assessments at Week 8 (the primary endpoint) and follow-up at Week 12. RESULTS: Autistic symptoms (primary outcome) based on the Social Responsiveness Scale decreased in both groups (significant time effect), but there was no significant difference between groups (null time-by-treatment interaction). Likewise, there was no significant between-group difference in changes in repetitive behaviors and exploratory outcomes of adaptive function and emotion dysregulation. Changes in social cognition (secondary outcome) differed between groups in feeling scores on the Frith-Happe Animations (Week 8, p = 0.026; Week 12, p = 0.025). Post-hoc analysis showed that the active group improved better on this social cognition than the sham group. Dropout rates did not vary between groups; the most common adverse event in both groups was local pain. Notably, our findings would not survive stringent multiple comparison corrections. CONCLUSIONS: Our findings suggest that iTBS over the RIFG is not different from sham in reducing autistic symptoms and emotion dysregulation. Nonetheless, RIFG iTBS may improve social cognition of mentalizing others' feelings in autistic individuals.

Efficacy and acceptability of noninvasive brain stimulation for treating posttraumatic stress disorder symptoms: A network meta-analysis of randomized controlled trials.

INTRODUCTION: Despite its high lifetime prevalence rate and the elevated disability caused by posttraumatic stress disorder (PTSD), treatments exhibit modest efficacy. In consideration of the abnormal connectivity between the dorsolateral prefrontal cortex (DLPFC) and amygdala in PTSD, several randomized controlled trials (RCTs) addressing the efficacy of different noninvasive brain stimulation (NIBS) modalities for PTSD management have been undertaken. However, previous RCTs have reported inconsistent results. The current network meta-analysis (NMA) aimed to compare the efficacy and acceptability of various NIBS protocols in PTSD management. METHODS: We systematically searched ClinicalKey, Cochrane Central Register of Controlled Trials, Embase, ProQuest, PubMed, ScienceDirect, Web of Science, and ClinicalTrials.gov to identify relevant RCTs. The targeted RCTs was those comparing the efficacy of NIBS interventions, such as transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), and transcutaneous cervical vagal nerve stimulation, in patients with PTSD. The NMA was conducted using a frequentist model. The primary outcomes were changes in the overall severity of PTSD and acceptability (to be specific, rates of dropouts for any reason). RESULTS: We identified 14 RCTs that enrolled 686 participants. The NMA demonstrated that among the investigated NIBS types, high-frequency rTMS over bilateral DLPFCs was associated with the greatest reduction in overall PTSD severity. Further, in comparison with the sham controls, excitatory stimulation over the right DLPFC with/without excitatory stimulation over left DLPFC were associated with significant reductions in PTSD-related symptoms, including depression and anxiety symptoms, and overall PTSD severity. CONCLUSIONS: This NMA demonstrated that excitatory stimulation over the right DLPFC with or without excitatory stimulation over left DLPFC were associated with significant reductions in PTSD-related symptoms. TRIAL REGISTRATION: PROSPERO CRD42023391562.

Risk of subsequent Parkinson's disease among patients with bipolar disorder or major depression: A nationwide longitudinal study in Taiwan.

AIM: Bipolar disorder (BD) and major depression have been associated with an increased risk of developing Parkinson's disease (PD); however, few studies have directly compared the risk of PD development between patients with BD and major depression while considering relevant risk factors and psychotropic medications. METHODS: Using the Taiwan National Health Insurance Research Database, 21,186 patients with BD, 21,188 patients with major depression, and 42,374 controls were enrolled between 2001 and 2009, and followed until the end of 2011. Individuals who developed PD during the follow-up period were identified. Cox regression models were used to analyze the hazard ratio (HR) of developing PD, adjusting for demographic factors, comorbidities, and psychotropic medication usage. RESULTS: Both patients with BD [HR 8.63, 95% confidence interval (CI) 6.35-11.72] and those with major depression (HR 5.68, 95% CI 4.15-7.78) had an elevated risk of subsequent PD compared to the controls. Patients with BD were associated with a 51% increased risk of subsequent PD compared with patients with major depression. Long-term treatment with antiepileptic mood stabilizers was associated with increased PD risk among patients with late-onset BD and high Charlson comorbidity index scores. Lithium was not associated with an increased PD risk. CONCLUSIONS: The study highlights an elevated PD risk in patients with BD and major depression compared to the controls, with BD patients at highest risk. Further research is needed to elucidate the complex interplay between psychotropic medications and neurodegenerative processes in BD, aiming to optimize therapeutic strategies and improve patient outcomes.

Association of Neurofilament Light Chain With the Antidepressant Effects of Low-Dose Ketamine Infusion Among Patients With Treatment-Resistant Depression.

BACKGROUND: The role of neurofilament light chain (NFL) in treatment-resistant depression (TRD) is unclear. Whether baseline NFL concentrations are associated with the antidepressant effects of low-dose ketamine infusion has not been determined. METHODS: The NFL concentrations of 71 patients with TRD and 17 healthy controls were assessed. Patients with TRD were randomly administered a single infusion of 0.5 mg/kg ketamine, 0.2 mg/kg ketamine, or normal saline. Depressive symptoms were assessed before infusion and sequentially at postinfusion timepoints (after 240 minutes and after 2-7 and 14 days) using the Hamilton Depression Rating Scale (HDRS). RESULTS: After adjustment for age, sex, and body mass index, patients with TRD were more likely to have higher concentrations of NFL than healthy controls (P < .001). A generalized estimating equation model with adjustments for infusion group, age, sex, body mass index, and baseline HDRS scores showed that baseline NFL concentrations were positively associated with subsequent HDRS scores following low-dose ketamine infusion (P = .038). DISCUSSION: Higher concentrations of NFL were observed among patients with TRD compared with healthy controls. Baseline NFL concentrations may predict the antidepressant effects of low-dose ketamine infusion.

A Randomized, Double-Blind, Midazolam-Controlled Trial of Low-Dose Ketamine Infusion in Patients With Treatment-Resistant Depression and Prominent Suicidal Ideation.

BACKGROUND: The benefits of low-dose ketamine for patients with treatment-resistant depression (TRD) and prominent suicidal ideation require further investigation. The effects of treatment refractoriness, the duration of the current depressive episode, and the number of prior antidepressant failures on ketamine efficacy also require clarification. METHODS: We recruited 84 outpatients with TRD and prominent suicidal ideation-defined as a score ≥4 on item 10 of the Montgomery-Åsberg Depression Rating Scale (MADRS)-and randomized them into 2 groups to receive 0.5 mg/kg ketamine or 0.045 mg/kg midazolam. We assessed depressive and suicidal symptoms prior to infusion; 240 minutes post infusion; and 2, 3, 5, 7, and 14 days post infusion. RESULTS: According to the MADRS scores, the antidepressant effect (P = .035) was significantly noted in the ketamine group up to 14 days than in the midazolam group. However, the antisuicidal effect of ketamine, as measured by the Columbia-Suicide Severity Rating Scale Ideation Severity Subscale (P = .040) and MADRS item 10 (P = .023), persisted only 5 days post infusion. Furthermore, the antidepressant and antisuicidal effects of ketamine infusion were noted particularly in patients whose current depressive episode lasted <24 months or whose number of failed antidepressants was ≤4. CONCLUSIONS: Low-dose ketamine infusion is a safe, tolerable, and effective treatment for patients with TRD and prominent suicidal ideation. Our study highlights the importance of timing; specifically, ketamine is more likely to achieve therapeutic response when the current depressive episode lasted <24 months and the number of failed antidepressants is ≤4.

A longitudinal study of the association between pro-inflammatory cytokines and mood symptoms in bipolar disorder.

BACKGROUND: Because of a relative dearth of longitudinal studies, the directionality of the relationship between mood and inflammation among patients with bipolar disorder (BD) is still unclear. We aimed to investigate the longitudinal associations of pro-inflammatory markers with mood symptom severity in BD. METHODS: Hundred and thirty-two adult patients with BD were enrolled. At the baseline and 1-year follow-up visit, all participants received mood assessment with Montgomery Åsberg depression rating scale (MADRS) and Young mania rating scale, and underwent blood draws to quantify metabolic profile and serum levels of the pro-inflammatory markers, including soluble interleukin-6 receptor, soluble tumor necrosis factor-α receptor type 1 (sTNF-αR1), monocyte chemoattractant protein-1, and C-reactive protein. A four-factor model of MADRS, consisting of sadness, negative thoughts, detachment, and neurovegetative symptoms, were applied. RESULTS: At baseline, 65 patients with BD were in depressed state, and 67 patients with BD were in euthymic state. Among patients in depressed state, baseline MADRS total score positively correlated with sTNF-αR1 level at follow-up. While baseline sTNF-αR1 level positively predicted sadness symptom in euthymic patients with BD who later developed depression (n = 22), sadness in patients with bipolar depression predicted later increase in serum sTNF-αR1 level even after remission (n = 17). Moreover, lithium had a stronger effect of lowering peripheral sTNF-αR1 level as compared with other mood stabilizers. CONCLUSION: Our results indicate the bidirectional inflammation-depression relationship in BD.

Effects of melancholic features on positive and negative suicidal ideation in patients with treatment-resistant depression and strong suicidal ideation receiving low-dose ketamine infusion.

The role of melancholic features on the antisuicidal effect of 0.5 mg/kg ketamine infusion has remained unclear in patients with treatment-resistant depression (TRD) and strong suicidal ideation (SI). Whether ketamine diminishes suicidal ideation in patients with TRD-SI was also unknown. We enrolled 84 patients with TRD-SI, including 27 with melancholic features and 57 without, and then randomly administered a single infusion of 0.5 mg/kg ketamine or 0.045 mg/kg midazolam. The clinician-rated Montgomery-Åsberg Depression Rating Scale (MADRS) item 10, Columbia Suicide Severity Rating Scale-Ideation Severity Subscale (CSSRS-ISS), and self-reported Positive and Negative Suicide Ideation Inventory (PANSI) were used to assess suicidal symptoms from baseline to day 7. Generalized estimating equation models showed that only patients without melancholic features (MADRS item 10: infusion group effect, p = 0.017; CSSRS-ISS: infusion group × time effect, p = 0.008; PANSI-negative suicidal ideation: infusion group effect, p = 0.028) benefited from the antisuicidal effect of low-dose ketamine. The PANSI-positive ideation scores were higher in the ketamine group than in the midazolam group (p = 0.038) for patients with melancholic features. Additional studies are necessary to clarify the neuromechanisms underlying the ketamine-related positive effect against SI and antisuicidal effects among patients with TRD-SI. Additional studies are necessary to clarify the neuromechanisms underlying the ketamine-related positive effect against SI and antisuicidal effects among patients with TRD-SI.

Antidepressant effects of prolonged intermittent theta-burst stimulation monotherapy at the bilateral dorsomedial prefrontal cortex for medication and standard transcranial magnetic stimulation-resistant major depression: a three arm, randomized, double blind, sham-controlled pilot study.

The dorsomedial prefrontal cortex (DMPFC) plays a pivotal role in depression and anxiosomatic symptom modulation. However, DMPFC stimulation using a double-cone coil has demonstrated inconsistent results for antidepressant efficacy. No study thus far has investigated the antidepressant and anti-anxiosomatic effects of prolonged intermittent theta-burst stimulation (piTBS) bilaterally over DMPFC. Furthermore, head-to-head comparisons of antidepressant effects between standard iTBS and piTBS warrant investigation. This double-blind, randomized, sham-controlled trial recruited 34 patients with highly treatment-resistant depression (TRD) unresponsive to antidepressants and standard repetitive transcranial magnetic stimulation (rTMS)/piTBS. These patients were randomly assigned to one of three monotherapy groups (standard iTBS, piTBS, or sham), with treatment administered bilaterally over the DMPFC twice per day for 3 weeks. The primary outcome was the overall changes of 17-item Hamilton Depression Rating Scale (HDRS-17) over 3-weeks intervention. The changes in Depression and Somatic Symptoms Scale (DSSS) as the secondary outcome and the anxiosomatic cluster symptoms as rated by HDRS-17 as the post-hoc outcome were measured. Multivariable generalized estimating equation analysis was performed. Although no differences in overall HDRS-17 changes between three groups were found, the antidepressant efficacy based on DSSS was higher in piTBS than in iTBS and sham at week 3 (group effect,p = 0.003, post-hoc: piTBS > iTBS, p = 0.002; piTBS > sham, p = 0.038). In post-hoc analyses, piTBS had more alleviation in anxiosomatic symptoms than iTBS (group effect, p = 0.002; post-hoc, p = 0.001). This first randomized sham-controlled study directly compared piTBS and iTBS targeting the DMPFC using a figure-of-8 coil and found piTBS may fail to demonstrate a significant antidepressant effect on overall depressive symptoms, but piTBS seems superior in alleviating anxiosomatic symptoms, even in depressed patients with high treatment resistance. This Trial registration (Registration number: NCT04037592). URL: https://clinicaltrials.gov/ct2/show/NCT04037592 .

Cancer risk in patients with bipolar disorder and unaffected siblings of such patients: A nationwide population-based study.

Increasing evidence suggests that patients with bipolar disorder are more likely to develop malignant cancer than in the general population. However, the overall cancer risk in the unaffected siblings of such patients remains unknown. From the National Health Insurance Research Database of Taiwan, 25 356 patients with bipolar disorder, 25 356 age-matched unaffected siblings of patients with bipolar disorder and 101 422 age-matched controls without severe mental disorders between 1996 and 2010 were enrolled in our study. Patients who developed cancer between the time of enrollment and the end of 2011 were identified. Cancers were divided into three subgroups based on the related layer of embryonic development: ectodermal, mesodermal and endodermal cancers. Patients with bipolar disorder (odds ratio [OR] = 1.22, 95% confidence interval [CI]: [1.06, 1.40]) and unaffected siblings of such patients (OR = 1.17, 95% CI [1.02, 1.34]) had greater risk of developing malignant cancer than did controls. Furthermore, only those aged <50 years, for both patients with bipolar disorder (OR = 1.90, 95% CI [1.38, 2.61]) and unaffected siblings (OR = 1.65, 95% CI [1.19, 2.28]), were more likely to develop the ectodermal cancer, especially breast cancer, than the control group. The associations of bipolar disorder and susceptibility to bipolar disorder with increased cancer risk in the younger population may imply a genetic overlap in neurodevelopment and malignancy pathogenesis. Our findings may encourage clinicians to monitor cancer risk factors and warning signs closely in patients with bipolar disorder and unaffected siblings of such patients.

Critical role of rhythms in prefrontal transcranial magnetic stimulation for depression: A randomized sham-controlled study.

Repetitive transcranial magnetic stimulation (rTMS) is an alternative treatment for depression, but the neural correlates of the treatment are currently inconclusive, which might be a limit of conventional analytical methods. The present study aimed to investigate the neurophysiological evidence and potential biomarkers for rTMS and intermittent theta burst stimulation (iTBS) treatment. A total of 61 treatment-resistant depression patients were randomly assigned to receive prolonged iTBS (piTBS; N = 19), 10 Hz rTMS (N = 20), or sham stimulation (N = 22). Each participant went through a treatment phase with resting state electroencephalography (EEG) recordings before and after the treatment phase. The aftereffects of stimulation showed that theta-alpha amplitude modulation frequency (fam ) was associated with piTBS_Responder, which involves repetitive bursts delivered in the theta frequency range, whereas alpha carrier frequency (fc ) was related to 10 Hz rTMS, which uses alpha rhythmic stimulation. In addition, theta-alpha amplitude modulation frequency was positively correlated with piTBS antidepressant efficacy, whereas the alpha frequency was not associated with the 10 Hz rTMS clinical outcome. The present study showed that TMS stimulation effects might be lasting, with changes of brain oscillations associated with the delivered frequency. Additionally, theta-alpha amplitude modulation frequency may be as a function of the degree of recovery in TRD with piTBS treatment and also a potential EEG-based predictor of antidepressant efficacy of piTBS in the early treatment stage, that is, first 2 weeks.

Familial coaggregation of major psychiatric disorders in first-degree relatives of individuals with autism spectrum disorder: a nationwide population-based study.

BACKGROUND: Family coaggregation of attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), bipolar disorder (BD), major depressive disorder (MDD) and schizophrenia have been presented in previous studies. The shared genetic and environmental factors among psychiatric disorders remain elusive. METHODS: This nationwide population-based study examined familial coaggregation of major psychiatric disorders in first-degree relatives (FDRs) of individuals with ASD. Taiwan's National Health Insurance Research Database was used to identify 26 667 individuals with ASD and 67 998 FDRs of individuals with ASD. The cohort was matched in 1:4 ratio to 271 992 controls. The relative risks (RRs) and 95% confidence intervals (CI) of ADHD, ASD, BD, MDD and schizophrenia were assessed among FDRs of individuals with ASD and ASD with intellectual disability (ASD-ID). RESULTS: FDRs of individuals with ASD have higher RRs of major psychiatric disorders compared with controls: ASD 17.46 (CI 15.50-19.67), ADHD 3.94 (CI 3.72-4.17), schizophrenia 3.05 (CI 2.74-3.40), BD 2.22 (CI 1.98-2.48) and MDD 1.88 (CI 1.76-2.00). Higher RRs of schizophrenia (4.47, CI 3.95-5.06) and ASD (18.54, CI 16.18-21.23) were observed in FDRs of individuals with both ASD-ID, compared with ASD only. CONCLUSIONS: The risk for major psychiatric disorders was consistently elevated across all types of FDRs of individuals with ASD. FDRs of individuals with ASD-ID are at further higher risk for ASD and schizophrenia. Our results provide leads for future investigation of shared etiologic pathways of ASD, ID and major psychiatric disorders and highlight the importance of mental health care delivered to at-risk families for early diagnoses and interventions.

Identifying common and distinct subcortical volumetric abnormalities in 3 major psychiatric disorders: a single-site analysis of 640 participants.

BACKGROUND: Subcortical volumetric abnormalities in schizophrenia, bipolar disorder and major depressive disorder (MDD) have been consistently found on a single-diagnosis basis in previous studies. However, whether such volumetric abnormalities are specific to a particular disorder or shared by other disorders remains unclear. METHODS: We analyzed the structural MRIs of 160 patients with schizophrenia, 160 patients with bipolar disorder, 160 patients with MDD and 160 healthy controls. We calculated the volumes of the thalamus, hippocampus, amygdala, accumbens, putamen, caudate, pallidum and lateral ventricles using FreeSurfer 7.0 and compared them among the groups using general linear models. RESULTS: We found a significant group effect on the volumes of the thalamus, hippocampus, accumbens and pallidum. Further post hoc analysis revealed that thalamic volumes in patients with schizophrenia, bipolar disorder and MDD were significantly reduced compared to those in healthy controls, but did not differ from one another. Patients with schizophrenia and bipolar disorder also shared a significant reduction in hippocampal volumes. Among the 3 clinical groups, patients with schizophrenia showed significantly lower hippocampal volumes and higher pallidal volumes than patients with bipolar disorder and MDD. LIMITATIONS: Differences in psychotropic use and duration of illness among the patient groups may limit the interpretation of our findings. CONCLUSION: Our findings indicate that decreased thalamic volume is a common feature of schizophrenia, bipolar disorder and MDD. Smaller hippocampal and larger pallidal volumes differentiate schizophrenia from bipolar disorder and MDD and may provide clues to the biological basis for the Kraepelinian distinction between these illnesses.

Frontal asymmetry as a core feature of major depression: a functional near-infrared spectroscopy study.

BACKGROUND: Frontal asymmetry plays a major role in depression. However, patients with treatment-resistant depression (TRD) have widespread hypofrontality. We investigated whether patients with TRD have a characteristic frontal activation pattern in functional near-infrared spectroscopy (fNIRS) findings and how the frontal cortex responds to different levels of cognitive tasks. METHODS: We enrolled 27 right-handed patients with TRD, 27 patients without TRD and 27 healthy controls. We used multichannel fNIRS to evaluate activation of the bilateral dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC) and left motor area in response to 3 tasks: finger tapping, a low cognitive-load motor task; verbal fluency, a moderate cognitive-load task; and a dual task involving simultaneous finger tapping and verbal fluency, a high cognitive-load task. RESULTS: We found significant between-group differences in left DLPFC activation for all 3 tasks. The healthy controls had cortical activation in the left motor area during finger tapping and the bilateral frontal cortex during the dual task. However, patients without TRD had right VLPFC activation during finger tapping and left DLPFC activation during the dual task. Patients with TRD had bilateral DLPFC activation during finger tapping but exhibited increased bilateral VLPFC and left motor area activation during verbal fluency and increased left motor area activation during the dual task. In healthy controls and patients without TRD, we found that the right VLPFC was positively correlated with depression severity. LIMITATIONS: Our cohort included only patients with late-onset depression. CONCLUSION: We found different patterns of abnormal frontal activation between patients with and without TRD. In patients without TRD, the right prefrontal cortex (PFC) was recruited during simple motor tasks. However, in patients with TRD, the bilateral PFC was recruited during simple tasks and motor cortical resources were used compensatorily during PFC-demanding complex cognitive tasks.

Mechanism of Intermittent Theta-Burst Stimulation in Synaptic Pathology in the Prefrontal Cortex in an Antidepressant-Resistant Depression Rat Model.

Intermittent theta-burst stimulation (iTBS), a form of repetitive transcranial magnetic stimulation, is considered a potential therapy for treatment-resistant depression. The synaptic mechanism of iTBS has long been known to be an effective method to induce long-term potentiation (LTP)-like plasticity in humans. However, there is limited evidence as to whether the antidepressant effect of iTBS is associated with change in synaptic function in the prefrontal cortex (PFC) in preclinical study. Hence, we applied an antidepressant (i.e., fluoxetine)-resistant depression rat model induced by severe foot-shocks to investigate the antidepressant efficacy of iTBS in the synaptic pathology. The results showed that iTBS treatment improved not only the impaired LTP, but also the aberrant long-term depression in the PFC of antidepressant-resistant depression model rats. Moreover, the mechanism of LTP improvement by iTBS involved downstream molecules of brain-derived neurotrophic factor, while the mechanism of long-term depression improvement by iTBS involved downstream molecules of proBDNF. The aberrant spine morphology was also improved by iTBS treatment. This study demonstrated that the mechanism of the iTBS paradigm is complex and may regulate not only excitatory but also inhibitory synaptic effects in the PFC.

Low-dose ketamine infusion in treatment-resistant double depression: Revisiting the adjunctive ketamine study of Taiwanese patients with treatment-resistant depression.

BACKGROUND: Whether a single low-dose ketamine infusion may have rapid antidepressant and antisuicidal effects in patients with treatment-resistant double depression remains unclear. METHODS: This study enrolled 35 patients with treatment-resistant double depression, 12 of whom received 0.5 mg/kg ketamine, 11 received 0.2 mg/kg ketamine, and 12 received normal saline as a placebo. The patients were assessed using the 17-item Hamilton Rating Scale for Depression (HDRS) prior to the initiation of infusions, at 40 and 240 min post-infusion, and sequentially on Days 2-7 and on Day 14 after ketamine or placebo infusions. RESULTS: A single 0.5 mg/kg ketamine infusion had rapid antidepressant (p = 0.031, measured by the HDRS) and antisuicidal (p = 0.033, measured by the HDRS item 3 scores) effects in patients with treatment-resistant double depression. However, 0.2 mg/kg ketamine was insufficient to exert rapid antidepressant and antisuicidal effects in this patient population with severe and chronic illness. DISCUSSION: In this patient population, the commonly used dose of 0.5 mg/kg was sufficient. Additional studies are required to investigate whether repeated infusions of low-dose ketamine may also maintain antidepressant and antisuicidal effects in patients with treatment-resistant double depression.

Baseline Working Memory Predicted Response to Low-Dose Ketamine Infusion in Patients with Treatment-Resistant Depression.

INTRODUCTION: Pretreatment neurocognitive function may predict the treatment response to low-dose ketamine infusion in patients with treatment-resistant depression (TRD). However, the association between working memory function at baseline and the antidepressant efficacy of ketamine infusion remains unclear. METHODS: A total of 71 patients with TRD were randomized to one of three treatment groups: 0.5 mg/kg ketamine, 0.2 mg/kg ketamine, or normal saline. Depressive symptoms were measured using the 17-item Hamilton Depression Rating Scale (HDRS) at baseline and after treatment. Cognitive function was evaluated using working memory and go-no-go tasks at baseline. RESULTS: A generalized linear model with adjustments for demographic characteristics, treatment groups, and total HDRS scores at baseline revealed only a significant effect of working memory function (correct responses and omissions) on the changes in depressive symptoms measured by HDRS at baseline (F=12.862, p<0.05). Correlation analysis further showed a negative relationship (r=0.519, p=0.027) between pretreatment working memory function and changes in HDRS scores in the 0.5 mg/kg ketamine group. DISCUSSION: An inverse relationship between pretreatment working memory function and treatment response to ketamine infusion may confirm that low-dose ketamine infusion is beneficial and should be reserved for patients with TRD.

Pro-inflammatory cytokines and cognitive dysfunction among patients with bipolar disorder and major depression.

AIM: Bipolar disorder and major depressive disorder (MDD) have been demonstrated to be associated with proinflammatory states and cognitive function deficits. We aimed to investigate the differences of cognitive function and proinflammatory cytokines between patients with bipolar I disorder (BDI), bipolar II disorder (BDII), and MDD. METHODS: Thirty-seven patients with BDI, 33 with BDII, 25 with MDD, and 54 age-, sex-matched controls were enrolled. All patients had a clinical global impression-severity scale ≤2. Serum levels of proinflammatory markers, including soluble interleukin-6 receptor, C-reactive protein, and soluble tumor necrosis factor receptor 1 (sTNF-αR1) were measured. Performance in the Word List Memory Task (WLMT), Wisconsin Card Sorting Task (WCST), 2-back task, Go/No-Go task, and divided attention task was assessed. RESULTS: Patients with BDI had higher levels of sTNF-αR1 than patients with MDD and controls (P < 0.001). Patients with BDI performed worse on WLMT, WCST, 2-back task, divided attention_visual and divided attention_auditory tasks than the other three groups (all P < 0.05). Furthermore, sTNF-αR1 levels were negatively correlated with cognitive function measured using the WLMT and divided attention_auditory (all P < 0.05). CONCLUSIONS: Patients with BDI had higher levels of sTNF-αR1 and cognitive function impairments than the remaining groups. Future studies are needed to explore the pathophysiology of sTNF-αR1 in the contribution of cognitive alterations.

Multiple comparison of different noninvasive brain stimulation and pharmacologic interventions in patients with methamphetamine use disorders: A network meta-analysis of randomized controlled trials.

AIM: In recent decades, the prevalence of amphetamine and methamphetamine use disorders has at least doubled in some regions/countries, with accompanying high risks of drug overdose-associated mortality. Noninvasive brain stimulation (NIBS) methods may be effective treatments. However, the comparative efficacy of the NIBS protocol for amphetamine/methamphetamine use disorder (AUD/MUD) remains unknown to date. The aim of this network meta-analysis (NMA) was to compare the efficacy and acceptability of various NIBS methods/protocols for AUD/MUD management. METHODS: A frequentist model-based NMA was conducted. We included randomized controlled trials (RCTs) that investigated the efficacy of NIBS and guideline-recommended pharmacologic treatments to reduce craving severity in patients with either AUD or MUD. RESULTS: Twenty-two RCTs including 1888 participants met the eligibility criteria. Compared with the sham/placebo group (study = 19, subjects = 891), a combination of intermittent theta burst stimulation over the left dorsolateral prefrontal cortex (DLPFC) and continuous TBS over the left ventromedial prefrontal cortex (study = 1, subjects = 19) was associated with the largest decreases in craving severity [standardized mean difference (SMD) = -1.50; 95% confidence intervals (95%CIs) = -2.70 to -0.31]. High-frequency repetitive transcranial magnetic stimulation over the left DLPFC was associated with the largest improvements in depression and quality of sleep (study = 3, subjects = 86) (SMD = -2.48; 95%CIs = -3.25 to -1.71 and SMD = -2.43; 95%CIs = -3.38 to -1.48, respectively). The drop-out rate of most investigated treatments did not significantly differ between groups. CONCLUSION: The combined TBS protocol over the prefrontal cortex was associated with the greatest improvement in craving severity. Since few studies were available for inclusion, additional large-scale randomized controlled trials are warranted.