Susceptibility to Treatment-Resistant Depression Within Families.

Importance: Antidepressant responses and the phenotype of treatment-resistant depression (TRD) are believed to have a genetic basis. Genetic susceptibility between the TRD phenotype and other psychiatric disorders has also been established in previous genetic studies, but population-based cohort studies have not yet provided evidence to support these outcomes. Objective: To estimate the TRD susceptibility and the susceptibility between TRD and other psychiatric disorders within families in a nationwide insurance cohort with extremely high coverage and comprehensive health care data. Design, Setting, and Participants: This cohort study assessed data from the Taiwan national health insurance database across entire population (N = 26 554 001) between January 2003 and December 2017. Data analysis was performed from August 2021 to April 2023. TRD was defined as having experienced at least 3 distinct antidepressant treatments in the current episode, each with adequate dose and duration, based on the prescribing records. Then, we identified the first-degree relatives of individuals with TRD (n = 34 467). A 1:4 comparison group (n = 137 868) of first-degree relatives of individuals without TRD was arranged for the comparison group, matched by birth year, sex, and kinship. Main Outcomes and Measures: Modified Poisson regression analyses were performed and adjusted relative risks (aRRs) and 95% CIs were calculated for the risk of TRD, the risk of other major psychiatric disorders, and different causes of mortality. Results: This study included 172 335 participants (88 330 male and 84 005 female; mean [SD] age at beginning of follow-up, 22.9 [18.1] years). First-degree relatives of individuals with TRD had lower incomes, more physical comorbidities, higher suicide mortality, and increased risk of developing TRD (aRR, 9.16; 95% CI, 7.21-11.63) and higher risk of other psychiatric disorders than matched control individuals, including schizophrenia (aRR, 2.36; 95% CI, 2.10-2.65), bipolar disorder (aRR, 3.74; 95% CI, 3.39-4.13), major depressive disorder (aRR, 3.65; 95% CI, 3.44-3.87), attention-deficit/hyperactivity disorders (aRR, 2.38; 95% CI, 2.20-2.58), autism spectrum disorder (aRR, 2.26; 95% CI, 1.86-2.74), anxiety disorder (aRR, 2.71; 95% CI, 2.59-2.84), and obsessive-compulsive disorder (aRR, 3.14; 95% CI, 2.70-3.66). Sensitivity and subgroup analyses validated the robustness of the findings. Conclusions and Relevance: To our knowledge, this study is the largest and perhaps first nationwide cohort study to demonstrate TRD phenotype transmission across families and coaggregation with other major psychiatric disorders. Patients with a family history of TRD had an increased risk of suicide mortality and tendency toward antidepressant resistance; therefore, more intensive treatments for depressive symptoms might be considered earlier, rather than antidepressant monotherapy.

Association Between Cortical Thickness or Surface Area and Divergent Thinking in Patients with Bipolar Disorder.

OBJECTIVE: Divergent thinking is a critical creative cognitive process. Its neural mechanisms have been well-studied through structural and functional imaging in healthy individuals but are less explored in patients with bipolar disorder (BD). Because of the traditional link between creativity and BD, this study investigated the structural correlates of divergent thinking in patients with BD through surface-based morphometry. METHODS: Fifty-nine patients diagnosed with BD I or BD II (35.3 ± 8.5 years) and 56 age- and sex-matched controls (33.9 ± 7.4 years) were recruited. The participants underwent structural magnetic resonance imaging and an evaluation of divergent thinking by using the Chinese version of the Abbreviated Torrance Test for Adults (ATTA). FreeSurfer 7.0 was used to generate thickness and surface area maps for each participant. Brainwise regression of the association between cortical thickness or surface area and ATTA performance was conducted using general linear models. RESULTS: Divergent thinking performance did not differ significantly between the patients with BD and the healthy controls. In these patients, total ATTA score was negatively correlated with cortical thickness in the right middle frontal gyrus, right occipital, and left precuneus but positively correlated with the surface area of the right superior frontal gyrus. By contrast, total ATTA scores and cortical thickness or surface area were not significantly correlated among the controls. CONCLUSION: The findings indicate that divergent thinking involves cerebral structures for executive control, mental imagery, and visual processing in patients with BD, and the right prefrontal cortex might be the most crucial of these structures.

Diagnostic conversion to bipolar disorder among adolescents and young adults with major depressive disorder: a nationwide longitudinal study.

Although several studies have examined a diagnostic conversion from major depressive disorder (MDD) to bipolar disorder (BD), only a few studies specifically focused on adolescents and young adults who are at the peak ages of BD onset. Data from participants (N = 130,793) aged 10-29 years who were diagnosed with MDD were extracted from the Taiwan National Health Insurance Research Database. We applied demographic analyses, survival analysis, Aalen Johansen curves, and Cox regression, investigating the diagnostic conversion rate and factors that were most or less predictive of conversion. Among the adolescents and young adults with MDD, the number of participant conversion subsample is 14,187 and the conversion rate was 13.80% (95% confidence interval: 13.54-14.06%) during the 11-year follow-up. The conversion rate was highest in the first year (4.50%; 4.39-4.61%) and decreased over time. The significant predictors were younger age of diagnosis with MDD (p < 0.001), moderate and high antidepressant resistance (p < 0.001), obesity (p < 0.001), psychiatric comorbidities (attention-deficit/hyperactivity disorder, substance use disorder, and cluster B and C personality disorder, all p < 0.001), a family history of mental disorders (schizophrenia and mood disorders, all p < 0.05), lower monthly income (p < 0.001), and more mental health visits to the clinic each year (p < 0.001). A composite of demographic characteristics, antidepressant resistance, physical and psychiatric comorbidities, and family history significantly predicted diagnostic conversion from MDD to BD (area under the curve = 0.795, p < 0.001). Compared to adult population, the adolescents and young adults had different factors that were most or less predictive of conversion, which warrants further investigation.

Suicide Attempts After a Diagnosis of Polycystic Ovary Syndrome : A Cohort Study.

BACKGROUND: Limited evidence exists about suicide risk in persons with polycystic ovary syndrome (PCOS). OBJECTIVE: To assess suicide risk in persons with PCOS, accounting for psychiatric comorbid conditions and age group. DESIGN: Cohort study. SETTING: Data from the Taiwanese nationwide database from 1997 to 2012. PATIENTS: A cohort of 18 960 patients diagnosed with PCOS, each matched with control participants in a 1:10 ratio on the basis of age, psychiatric comorbid conditions, urbanization level, and income. Suicide attempts were evaluated using Cox regression models. MEASUREMENTS: Suicide risk with hazard ratios (HRs). RESULTS: Participants with PCOS had a notable 8.47-fold increase in risk for suicide attempt compared with the control group (HR, 8.47 [95% CI, 7.54 to 9.51]), after adjustment for demographic characteristics, psychiatric comorbid conditions, Charlson Comorbidity Index scores, and frequency of all-cause clinical visits. The elevated risk was evident across the adolescent (HR, 5.38 [CI, 3.93 to 7.37]), young adult (<40 years; HR, 9.15 [CI, 8.03 to 10.42]), and older adult (HR, 3.75 [CI, 2.23 to 6.28]) groups. Sensitivity analyses involving the exclusion of data from the first year or the first 3 years of observation yielded consistent results. LIMITATION: Potential underestimation of PCOS and mental disorder prevalence due to use of administrative claims data; lack of clinical data, such as body mass index and depressive symptoms; and no assessment of a confounding effect of valproic acid exposure. CONCLUSION: This study underscores the heightened risk for suicide attempt that persons with PCOS face, even after adjustment for demographics, psychiatric comorbid conditions, physical conditions, and all-cause clinical visits. This suggests the importance of routine monitoring of mental health and suicide risk in persons diagnosed with PCOS. PRIMARY FUNDING SOURCE: Taipei Veterans General Hospital, Yen Tjing Ling Medical Foundation, and Ministry of Science and Technology of Taiwan.

Current suicide risk, but not lifetime history of attempted suicide, predicts treatment response to low-dose ketamine infusion: Post Hoc analysis of adjunctive ketamine study of Taiwanese patients with treatment-resistant depression.

Whether current suicide risk or a history of attempted suicide is related to the antidepressant effect of a low-dose ketamine infusion remains unclear. In total, 47 patients with treatment-resistant depression (TRD), including 32 with low current suicide risk and 15 with moderate or high current suicide risk, were randomized to groups receiving a low-dose ketamine infusion of either 0.2 or 0.5 mg/kg. Among the patients, 21 had a lifetime history of attempted suicide. Suicide risk was assessed based on the Suicidal scale of the Mini-International Neuropsychiatric Interview. The 17-item Hamilton Depression Rating Scale (HDRS) was used to measure depressive symptoms at baseline, at 40 and 240 min after infusion, and sequentially on Days 2-7 and 14 after ketamine infusion. Generalized estimating equation models indicated that the time effects of both 0.5 and 0.2 mg/kg ketamine infusions were significant during the study period. The models also indicated that current suicide risk (p = .037) but not lifetime history of attempted suicide (p = .184) was related to the trajectory of total HDRS scores. Patients with moderate-to-high current suicide risk benefited more from the low-dose ketamine infusion compared with those with the low current suicide risk. Patients with TRD having moderate or high current suicide risk may be prioritized to receive a low-dose ketamine infusion, which may aid suicide prevention. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Cause-specific mortality and comorbid neurodevelopmental disorder in 167,515 patients with bipolar disorder: An entire population longitudinal study.

OBJECTIVE: Studies addressing premature mortality in bipolar disorder (BD) patients are limited by small sample sizes. Herein, we used almost 99 % of the population of Taiwan to address this issue, and its association with comorbid neurodevelopmental disorders and severe BD. METHODS: Between 2003 and 2017, we enrolled 167,515 individuals with BD and controls matched 1:4 for sex and birth year from the National Health Insurance Database linked to the Database of National Death Registry in Taiwan. Time-dependent Cox regression models were used to examine cause-specific mortality (all-cause, natural, and unnatural causes [accidents or suicide]). RESULTS: With adjustments of sex, age, income, urbanization, and physical conditions, suicide was associated with the highest risk of mortality (reported as hazard ratio with 95 % confidence interval: 9.15; 8.53-9.81) among BD patients, followed by unnatural (4.94; 4.72-5.17), accidental (2.15; 1.99-2.32), and natural causes (1.02; 1.00-1.05). Comorbid attention-deficiency hyperactivity disorder did not contribute to the increased risk of cause-specific mortality; however, comorbid autism spectrum disorder (ASD) increased such risks, particularly for natural (3.00; 1.85-4.88) and accidental causes (7.47; 1.80-31.1). Cause-specific mortality revealed a linear trend with the frequency of psychiatric hospitalization (all, p for trend <0.001), and BD patients hospitalized twice or more each year had 34.63-fold increased risk of suicide mortality (26.03-46.07). CONCLUSIONS: BD patients with a higher frequency of psychiatric hospitalization have the highest risk of suicide mortality, and comorbid ASD was associated with an increased risk of natural and accidental causes of mortality.

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.

Delay Analysis in Closed-Loop EEG Phase-Triggered Transcranial Magnetic Stimulation.

The recent development of closed-loop EEG phase-triggered transcranial magnetic stimulation (TMS) has advanced potential applications of adaptive neuromodulation based on the current brain state. Closed-loop TMS involves instantaneous acquisition of the EEG rhythm, timing prediction of the target phase, and triggering of TMS. However, the accuracy of EEG phase prediction algorithms is largely influenced by the system's transport delay, and their relationship is rarely considered in related work. This paper proposes a delay analysis that considers the delay of the closed-loop EEG phase-triggered TMS system as a primary factor in the validation of phase prediction algorithms. An in-silico validation using real EEG data was performed to compare the performance of commonly used algorithms. The experimental results indicate a significant influence of the total delay on the algorithm performance, and the performance ranking among algorithms varies at different levels of delay. We conclude that the delay analysis framework should be widely adopted in the design and validation of phase prediction algorithms for closed-loop EEG phase-triggered TMS systems.

Multimorbidity Pattern and Risk for Mortality Among Patients With Dementia: A Nationwide Cohort Study Using Latent Class Analysis.

OBJECTIVE: Individuals with dementia are at a substantially elevated risk for mortality; however, few studies have examined multimorbidity patterns and determined the inter-relationship between these comorbidities in predicting mortality risk. METHODS: This is a prospective cohort study. Data from 6,556 patients who were diagnosed with dementia between 1997 and 2012 using the Taiwan National Health Insurance Research Database were analyzed. Latent class analysis was performed using 16 common chronic conditions to identify mortality risk among potentially different latent classes. Logistic regression was performed to determine the adjusted association of the determined latent classes with the 5-year mortality rate. RESULTS: With adjustment for age, a three-class model was identified, with 42.7% of participants classified as "low comorbidity class (cluster 1)", 44.2% as "cardiometabolic multimorbidity class (cluster 2)", and 13.1% as "FRINGED class (cluster 3, characterized by FRacture, Infection, NasoGastric feeding, and bleEDing over upper gastrointestinal tract)." The incidence of 5-year mortality was 17.6% in cluster 1, 26.7% in cluster 2, and 59.6% in cluster 3. Compared with cluster 1, the odds ratio for mortality was 9.828 (95% confidence interval [CI]=6.708-14.401; p<0.001) in cluster 2 and 1.582 (95% CI=1.281-1.953; p<0.001) in cluster 3. CONCLUSION: Among patients with dementia, the risk for 5-year mortality was highest in the subpopulation characterized by fracture, urinary and pulmonary infection, upper gastrointestinal bleeding, and nasogastric intubation, rather than cancer or cardiometabolic comorbidities. These findings may improve decision-making and advance care planning for patients with dementia.

Congenital cleft lip and palate and elevated risks of major psychiatric disorders: A nationwide longitudinal study.

BACKGROUND: Congenital cleft lip and palate (CCLP) may be associated with major psychiatric disorders, including autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), schizophrenia, bipolar disorder, and major depressive disorder. METHODS: From the Taiwan National Health Insurance Research Database, 1,158 children and adolescents with CCLP and 11,580 age/sex-matched controls without CCLP were included in this study between 2001 and 2010; they were followed up until the end of 2011 to identify the aforementioned major psychiatric disorders. RESULTS: After adjustment for age, sex, income, residence, and family history, the Cox regression model revealed a positive relationship of CCLP with subsequent schizophrenia (hazard ratio [HR]: 7.60, 95% confidence interval [CI]: 2.03-28.54), ASD (HR: 6.03, 95% CI: 1.76-20.61), and ADHD (HR: 7.33, 95% CI: 5.01-10.73). DISCUSSION: These findings suggest that clinicians should be attentive to the presence or emergence of mental health conditions in patients with CCLP. Further studies are necessary to investigate the pathogenesis between CCLP and major psychiatric disorders.

Risk of All-Cause and Suicide Death in Patients With Schizophrenia: An Entire-Population Longitudinal Study in Taiwan.

Background: Schizophrenia increases mortality from all causes and specific causes. Comprehensive research on modifiable risk factors for early mortality from multiple sources is needed.Methods: Taiwan's National Health Insurance Research Database, which contains claims data from a lifetime insurance program for the whole population, provided extensive medical inpatient and outpatient data categorized by ICD-9-CM and ICD-10 for this nationwide retrospective longitudinal cohort study. The National Mortality Registry provided data on all-cause, natural, suicide, and accidental deaths. 191,553 patients with schizophrenia and 26,362,448 individuals without schizophrenia were monitored from January 1, 2003, to December 31, 2017. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for mortality risk were calculated using Cox regression models. We compared different mortality risks associated with schizophrenia across age, sex, and Charlson Comorbidity Index (CCI) subgroups.Results: We found that schizophrenia results in a relatively higher increase in suicidal mortality in those aged ≤ 20 years (aHR = 15.55; 95% CI, 13.95-17.34), and that effect decreased with age. The effect of schizophrenia in female individuals (suicide death: female, aHR = 11.82, 95% CI, 11.21-12.46; male, aHR = 8.11, 95% CI, 7.77-8.47; difference, P < .001) and individuals without comorbidity (natural cause of death, CCI = 0 aHR = 5.94, 95% CI, 5.68-6.22; CCI = 1-2 aHR = 3.62, 95% CI, 3.52-3.73; CCI > 2 aHR = 1.61, 95% CI, 1.58-1.64) led to comparatively higher mortality risks. The effect of schizophrenia in individuals with AIDS (suicide death, aHR = 2.73, 95% CI, 1.70-4.39) resulted in a relatively smaller increase in suicide mortality compared to individuals with other comorbidities; however, in patients with connective tissue diseases, a diagnosis of schizophrenia still leads to an alarming increase in natural and unnatural mortality.Conclusions: Schizophrenia in combination with younger age, female sex, comorbid connective tissue disease, or major organ problems necessitates more tailored countermeasures to lessen the higher mortality risk in these patients compared with patients who have these characteristics and conditions but do not have schizophrenia.

Role of klotho on antidepressant and antisuicidal effects of low-dose ketamine infusion among patients with treatment-resistant depression and suicidal ideation.

OBJECTIVE: Previous studies have found an association between klotho, an anti-aging hormone, and major depressive disorder. However, whether low-dose ketamine infusion alters klotho levels among patients with treatment-resistant depression (TRD) remains unknown. METHODS: In total, 48 patients with TRD and strong suicidal ideation were randomly assigned to a single 0.5 mg/kg ketamine or 0.045 mg/kg midazolam regimen and were subjected to a 2-week follow-up. Depressive and suicidal symptoms were assessed before the infusion and during the follow-up. The serum levels of klotho were assessed at baseline and 3 days postinfusion. RESULTS: A generalized linear model with adjustment of baseline klotho levels showed that, despite the fact that ketamine did not significantly increase levels of klotho, patients in the ketamine group had higher levels of klotho at Day 3 postinfusion than patients in the midazolam group (p = 0.043). However, we found no association between changes in klotho levels and changes in depressive and suicidal symptoms (all p > 0.05). Higher klotho levels at baseline were associated with poorer antidepressant effect of low-dose ketamine during postinfusion follow-up. DISCUSSION: Klotho may play a role in the antidepressant effect of low-dose ketamine. Additional molecular studies are necessary to elucidate the neuromechanisms of TRD, ketamine, and klotho.

The longer, the better ? Longer left-sided prolonged intermittent theta burst stimulation in patients with major depressive disorder: A randomized sham-controlled study.

BACKGROUND: Prolonged intermittent theta-burst stimulation (iTBS) is effective for major depressive disorder (MDD). However, whether longer piTBS treatment in a single session could have antidepressant efficacy remains elusive. Therefore, this double-blind, randomized, sham-controlled study aimed to investigate the antidepressant efficacy of 2 daily piTBS sessions for treating MDD patients with a history of poor responses to at least 1 adequate antidepressant trial in the current episode. METHODS: All patients received 2 uninterrupted sessions per day for 10 weekdays (i.e., 2 weeks; a total of 20 sessions). Seventy-two patients were recruited and 1:1:1 randomly assigned to one of three groups: piTBS (piTBSx2), 10-Hz rTMS (rTMSx2), or sham treatment (shamx2, randomly assigned to piTBS or rTMS). 10-Hz rTMS group was included as an active comparison group to enhance assay sensitivity. RESULTS: piTBSx2 group had significantly more responders at week 2 than shamx2 group, but it did not yield better antidepressant effects regarding the %depression changes. The changes of antidepressant scores were not different among the three groups at week 1 (-26.2% vs. -23.3% vs. -22.%) or at week 2 (-34.1% vs. -37.1% vs. -30.1%). Longer treatment duration did not result in stronger placebo effects [sham(piTBS)x2: - 31.7% vs. sham(rTMS)x2: - 26.7%]. CONCLUSION: The present sham-controlled study confirmed that piTBS is an effective antidepressant option, but found no evidence to support that longer piTBS treatment duration resulted in more rapid or better antidepressant effects. A high placebo effect was observed, but longer treatment duration of brain stimulation was not linearly associated with stronger placebo effects.

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.

Effects of low-dose ketamine infusion on vascular endothelial growth factor and matrix metalloproteinase-9 among patients with treatment-resistant depression and suicidal ideation.

BACKGROUND: Evidence indicates that vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) influence the pathophysiology of depression. However, whether low-dose ketamine regulates VEGF and MMP-9 levels and whether changes in VEGF and MMP-9 levels are associated with the antidepressant and antisuicidal effects of ketamine remained unclear. METHODS: Forty-eight patients with treatment-resistant depression and strong suicidal ideation (TRD-SI) were randomly assigned to a single infusion of 0.5-mg/kg ketamine or 0.045-mg/kg midazolam. The Montgomery-Åsberg Depression Rating Scale (MADRS) and Columbia-Suicide Severity Rating Scale-Ideation Severity Subscale (CSSRS-ISS) were used at baseline and subsequently at several postinfusion timepoints. VEGF and MMP-9 serum levels were analyzed at baseline and on day 3 postinfusion. RESULTS: After adjustment for baseline levels, no significant differences in VEGF (p = .912) and MMP-9 (p = .758) levels were identified on day 3 postinfusion between the study groups. Baseline VEGF levels but not MMP-9 levels were negatively associated with MADRS and CSSRS-ISS scores following infusion. DISCUSSION: A single infusion of low-dose ketamine did not alter the VEGF and MMP-9 levels of the patients with TRD-SI. Higher baseline VEGF levels were associated with greater antidepressant and antisuicidal effects of single low-dose ketamine infusion.

Next generation antidepressants with novel mechanisms for treatment resistant depression.

Evidence has suggested that the modulation of N-methyl-d-aspartate receptors (NMDARs) and 5-hydroxytryptamine receptors (5-HTRs) via the psychedelic drugs, such as ketamine and psilocybin, rapidly alters the state of consciousness and the neuroplasticity. The United State Food and Drug Administration approved the indications of esketamine for treatment-resistant depression (TRD) in 2019 and major depressive disorder with suicidal ideation in 2020. The phase 2 clinical trials also discovered the rapid and sustained antidepressant effects of psilocybin among patients with TRD. In this chapter, we discussed the complex among the consciousness, neuroplasticity, and novel rapid-acting antidepressants and their possible neuromechanisms.

Baseline cognitive function predicts full remission of suicidal symptoms among patients with treatment-resistant depression and strong suicidal ideation after low-dose ketamine infusion.

BACKGROUND: Whether pretreatment working memory and response inhibition function are associated with the rapid and sustained antisuicidal effect of low-dose ketamine among patients with treatment-resistant depression (TRD) and strong suicidal ideation is unclear. METHODS: We enrolled 65 patients with TRD, comprising 33 who received a single infusion of 0.5 mg/kg ketamine and 32 who received a placebo infusion. The participants performed working memory and go/no-go tasks prior to infusion. We assessed suicidal symptoms at baseline and on postinfusion Days 2, 3, 5, and 7. RESULTS: The full remission of suicidal symptoms persisted for 3 days after a single ketamine infusion and the ketamine-related antisuicidal effect persisted for 1 week. Lower cognitive impairment at baseline (indicated by a higher rate of correct responses on a working memory task) was associated with the rapid and sustained antisuicidal effect of low-dose ketamine in patients with TRD and strong suicidal ideation. DISCUSSION: Patients with TRD and strong suicidal ideation but low cognitive impairment may benefit the most from the antisuicidal effect of low-dose ketamine.

Risks and familial coaggregation of death by suicide, accidental death and major psychiatric disorders in first-degree relatives of individuals who died by suicide.

BACKGROUND: Evidence suggests a familial coaggregation of major psychiatric disorders, including schizophrenia, bipolar disorder, major depression (MDD), autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD). Those disorders are further related to suicide and accidental death. However, whether death by suicide may coaggregate with accidental death and major psychiatric disorders within families remains unclear. AIMS: To clarify the familial coaggregation of deaths by suicide with accidental death and five major psychiatric disorders. METHOD: Using a database linked to the entire Taiwanese population, 68 214 first-degree relatives of individuals who died by suicide between 2003 and 2017 and 272 856 age- and gender-matched controls were assessed for the risks of death by suicide, accidental death and major psychiatric disorders. RESULTS: A Poisson regression model showed that the first-degree relatives of individuals who died by suicide were more likely to die by suicide (relative risk RR = 4.61, 95% CI 4.02-5.29) or accident (RR = 1.62, 95% CI 1.43-1.84) or to be diagnosed with schizophrenia (RR = 1.53, 95% CI 1.40-1.66), bipolar disorder (RR = 1.99, 95% CI 1.83-2.16), MDD (RR = 1.98, 95% CI 1.89-2.08) or ADHD (RR = 1.34, 95% CI 1.24-1.44). CONCLUSIONS: Our findings identified a familial coaggregation of death by suicide with accidental death, schizophrenia, major affective disorders and ADHD. Further studies would be required to elucidate the pathological mechanisms underlying this coaggregation.

All-cause mortality and suicide mortality in autistic individuals: An entire population longitudinal study in Taiwan.

LAY ABSTRACT: Our study was the first population-based study in an Asian country to investigate the mortality rates among autistic individuals. Among the entire Taiwanese population (N = 29,253,529), between 2003 and 2017, 45,398 autistic individuals were identified and 1:4 age-/sex-matched to 181,592 non-autistic individuals. We found that autistic individuals had increased risks of all-cause mortality, natural-cause mortality, and suicide mortality compared with non-autistic individuals. Furthermore, autistic males were more likely to die by suicide, and autistic females were more likely to die of accident compared with the non-autistic individuals.

Right dorsolateral prefrontal cortex volumetric reduction is associated with antidepressant effect of low-dose ketamine infusion: A randomized, double-blind, midazolam-controlled PET-MRI clinical trial.

BACKGROUND: Evidence has shown a rapid antidepressant and antisuicidal effects of low-dose ketamine infusion among patients with treatment-resistant depression (TRD) and prominent suicidal ideation (SI). The dorsolateral prefrontal cortex (DLPFC) plays a crucial role in the TRD pathomechanisms. OBJECTIVE: Whether the structural and functional changes of the DLPFC, particularly Brodmann area 46, are associated with the antidepressant and antisuicidal effects of ketamine infusion among such patients is unknown. METHODS: We randomized 48 patients with TRD and SI into groups receiving a single infusion of 0.5 mg/kg ketamine or 0.045 mg/kg midazolam. The Hamilton Depression Rating Scale and the Montgomery-Asberg Depression Rating Scale were used to assess symptoms. Positron emission tomography (PET)-magnetic resonance imaging was conducted prior to infusion and on Day 3 postinfusion. We performed longitudinal voxel-based morphometry (VBM) analysis to evaluate the gray matter (GM) volume changes of the DLPFC. The standardized uptake value ratio (SUVr) of 18F-fluorodeoxyglucose PET images was calculated using the SUV of the cerebellum as a reference region. RESULTS: The VBM analysis revealed a small but significant volumetric reduction in the right DLPFC in the ketamine group compared with that in the midazolam group. A greater reduction in depressive symptoms was associated with a smaller decrease in right DLPFC volumes (p = 0.025). However, we found no SUVr changes of the DLPFC between baseline and post-Day 3 ketamine infusion. DISCUSSION: The optimal modulation of the right DLPFC GM volumes may play an essential role in the antidepressant neuromechanisms of low-dose ketamine.