Association of SLC6A3 variants with treatment-resistant schizophrenia: a genetic association study of dopamine-related genes in schizophrenia

Background

Most genetic analyses that have attempted to identify a locus or loci that can distinguish patients with treatment-resistant schizophrenia (TRS) from those who respond to treatment (non-TRS) have failed. However, evidence from multiple studies suggests that patients with schizophrenia who respond well to antipsychotic medication have a higher dopamine (DA) state in brain synaptic clefts whereas patients with TRS do not show enhanced DA synthesis/release pathways.

Patients and methods

To examine the contribution (if any) of genetics to TRS, we conducted a genetic association analysis of DA-related genes in schizophrenia patients (TRS, n = 435; non-TRS, n = 539) and healthy controls (HC: n = 489).

Results

The distributions of the genotypes of rs3756450 and the 40-bp variable number tandem repeat on SLC6A3 differed between the TRS and non-TRS groups. Regarding rs3756450, the TRS group showed a significantly higher ratio of the A allele, whereas the non-TRS group predominantly had the G allele. The analysis of the combination of COMT and SLC6A3 yielded a significantly higher ratio of the putative low-DA type (i.e., high COMT activity + high SLC6A3 activity) in the TRS group compared to the two other groups. Patients with the low-DA type accounted for the minority of the non-TRS group and exhibited milder psychopathology.

Conclusion

The overall results suggest that (i) SLC6A3 could be involved in responsiveness to antipsychotic medication and (ii) genetic variants modulating brain DA levels may be related to the classification of TRS and non-TRS.

Serum levels of glial cell line-derived neurotrophic factor as a biomarker for mood disorders and lithium response

Glial cell line-derived neurotrophic factor (GDNF) plays an important role in the pathophysiology of neuropsychiatric disorders. We examined serum GDNF levels in bipolar disorder (BD) patients and major depressive disorder (MDD) patients and their association with response to lithium therapy. We used a multicenter (six sites), exploratory, cross-sectional case-control design and recruited 448 subjects: 143 BD patients, 116 MDD patients, and 158 healthy controls (HCs). We evaluated the patients' clinical severity using the Clinical Global Impression (CGI), and responses to lithium therapy using the Alda scale. The serum GDNF levels were significantly decreased in the BD and MDD groups compared to the HCs, with no significant difference between the BD and MDD groups. After adjustment, the serum GDNF levels in the BD and MDD patients in remission or depressive states were decreased compared to the HC values. Lower serum GDNF levels in BD patients were associated with higher CGI and Alda scores (i.e., severe illness and good response to lithium therapy, respectively). Our findings suggest that the serum GDNF level may be a biomarker for both BD and MDD in remission or depressive states. The serum GDNF level may be associated with the lithium response of BD patients.

Perception of and anxiety about COVID-19 infection and risk behaviors for spreading infection: an international comparison

BACKGROUND

To control the spread of the new SARS-CoV-2 infection's disease (COVID-19), appropriate precautionary behaviors by the public should be promoted. There are international differences in public cognitive and behavioral pattern, attitudes toward information sources, and anxiety about COVID-19. Information about these differences could increase understanding of the patterns of epidemic-related anxiety and behavior, and would help optimize future policies for preventing the next wave of the epidemic.

METHODS

To examine between-country differences in perception, attitude, and precautionary behaviors toward COVID-19, we conducted a cross-sectional study using an online questionnaire survey. Participants were adults who had been registered in Cross Marketing Group Inc. and living in the UK, Spain, or Japan. A total of 8,000 people stratified by age were recruited on a first-come, first-serve basis. Knowledge of and anxiety about COVID-19, the frequency of access and perceived credibility of several information sources, and the frequency of each precautionary behavior were examined on March 27-28, 2020, in Japan and April 17-21, 2020, in the UK and Spain.

RESULTS

Knowledge, anxiety, and the frequency of precautionary behaviors were higher in the UK and Spain than in Japan. Participants with infected acquaintances were more concerned about COVID-19. However, participants in the UK rarely wore a medical mask. Participants in the UK and Spain were more eager to obtain information about COVID-19 than those in Japan. Participants in Spain tended not to trust official information and to believe specialists' comments instead.

CONCLUSION

The rapidity of the spread of COVID-19, cultural background, and recent political situations seemed to contribute to the international differences here.

Association between serum levels of glial cell line-derived neurotrophic factor and inattention in adult patients with attention deficits/hyperactivity disorder

Glial cell line-derived neurotrophic factor (GDNF) may play an important role in attention. We investigated the association between serum GDNF levels and clinical status in unmedicated adults with attention deficit/hyperactivity disorder (ADHD) (n = 16) and healthy controls (n = 33); the levels were comparable between the ADHD and control groups (107.2 ± 31.7 vs. 110.5 ± 40.0 pg/mL, respectively; p = 0.77). In the ADHD group, higher GDNF serum levels were associated with severe subjective inattention (r = 0.528, p = 0.035). These preliminary results suggest that the serum GDNF level may not be a suitable biomarker for adult ADHD, although it may be associated with the pathophysiology of persistent inattention in adult ADHD.

Relationship between perception and anxiety about COVID-19 infection and risk behaviors for spreading infection: A national survey in Japan

Background

The novel corona virus infection (COVID-19) quickly became a pandemic state. Identifying characteristics of “possible super spreaders”, suggested as a dominant cause of rapid spreading transmission, will help us to design proper prevention strategies.

Methods

We conducted a nation-wide online survey to investigate the relationship of perception and anxiety levels about COVID-19 to the possible risk behaviors for spread of the virus in Japan. We recruited a total of 4,000 citizens, who responded to the questionnaire including several questions regarding the level of fear and anxiety about COVID-19, infection preventive behaviors and access to media with trust level about the virus as well as some demographic and socioeconomic data during March 27th and 28th, 2020.

Findings

Thirteen-point-three percent of the participants rated “1” on a nine-point Likert with respect to the knowledge about COVID-19. Ten-point-one percent and 11.7% presented no anxiety of being infected and transmission to others. Ten-point-eight percent showed no worry about symptomatic aggravation. Eight-point-one percent had no serious concern about expanding infection. The distribution of these items was highly correlated with each other. Participants with the low level of knowledge about COVID-19 were likely to less frequently access any information sources and neither trust them. They were less anxious about their health status, and less likely to put precautionary behaviors such as washing hands and avoiding crowded spaces, suggested by statistical analyses.

Interpretation

The present study suggests that it is greatly important to enlighten those have no concerns about this crisis of COVID-19 and modify their risk behavior via various ways, in order to prevent and control this viral pandemic.

Funding

This study was funded by the management grand provided to Chiba University Graduate School of Medicine and the Japan Society for the Promotion of Science KAKENHI grants.

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Lack of knowledge about COVID-19 is core trait of potential super spreaders, who occupy more than 10% of citizens.

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Super spreaders may be in a vicious circle of cognitive indifference, lack of information, and recurrent risky behaviors.

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Providing proper knowledge to indifferent individuals with any means is essential to resolve the pandemic of COVID-19.

Clozapine-induced myocarditis: Follow-up for 3.5 years after successful retrial

Schizophrenia patients have significantly lower life expectancy than the general population. Clozapine is the most effective antipsychotic to reduce the mortality rate in these patients. Here, we report a schizophrenic patient with clozapine-induced myocarditis and successful retrial. In the first trial, clozapine was discontinued due to myocarditis. In the second trial, the titration rate was slower, and sodium valproate was not coadministered with clozapine. The patient has not developed myocarditis over 3.5 years of observation. It may be possible to take clozapine for a long time even after clozapine-induced myocarditis, and thus improve the life expectancy of schizophrenia patients.