Social Function and Frontopolar Activation during a Cognitive Task in Patients with Bipolar Disorder

Subanesthetic Dose of Ketamine Administered Before Each Electroconvulsive Therapy Session Improves Antidepressant and Sleep Quality Outcomes: A Randomized, Controlled Trial

OBJECTIVES

The main purpose of this trial is to explore the effects of subanesthetic dose of ketamine on sleep quality and symptoms in patients with major depressive disorder undergoing bitemporal electroconvulsive therapy (ECT).

METHODS

Seventy-one patients with major depressive disorder and sleep disturbance were randomly divided into 2 groups, namely, the ECT without ketamine group (group ES), receiving routine ECT and saline (3 mL) at each ECT session, and the ECT-assisted ketamine group (group KS), which received ECT and ketamine (3 mL) at each ECT session. The 24 Hamilton Depression Rating Scale was used to assess depressive symptoms and the Chinese Pittsburgh Sleep Quality Index was used to evaluate sleep quality.

RESULTS

The patients in group KS required shorter ECT treatment sessions. Patients in group ES had lower sleep efficiency, longer sleep latency, and required more sleep medication than patients in group KS at the end of the ECT course.

CONCLUSIONS

Subanesthetic dose of ketamine improved sleep quality and enhanced ECT therapeutic effects in patients with sleep disturbance.

Effects of pharmacological treatments on neuroimaging findings in borderline personality disorder: A review of FDG-PET and fNIRS studies

BACKGROUND

Borderline personality disorder (BPD) is a serious mental condition characterized by instability in identity, interpersonal relationships, emotion regulation and impulsivity. These symptoms seem to be associated to specific brain alterations, which have been largely investigated. In particular, positron emission tomography (PET) and functional near-infrared spectroscopy (fNIRS) have demonstrated abnormalities in brain metabolism and hemodynamics in BPD, specifically in the fronto-limbic system. However, the role of medications on brain metabolism and hemodynamics in BPD is still largely unknown.

METHODS

We conducted a search on PubMed, Scopus and Web of Science of PET and fNIRS studies exploring the effect of medications on brain metabolism and hemodynamics in BPD. A total of 10 studies met the inclusion criteria.

RESULTS

Overall, PET studies showed an effect of psychotropic agents on brain metabolism, especially in frontal and temporal areas. Also, higher metabolic rates in frontal areas were found to correlate with clinical improvements. In contrast, fNIRS investigations reported an inconclusive or absent effects on brain hemodynamics in BPD patients.

LIMITATIONS

The small sample size, the elevated percentage of women, the heterogeneity in pharmacological agents and the presence of comorbidities limit the conclusions of the present review.

CONCLUSIONS

Serotoninergic agents and second-generation antipsychotics produce changes in frontal and temporal metabolism in BPD, which appear to correlate with clinical improvements. Differently, brain hemodynamics do not seem to be significantly affected by the most commonly prescribed drugs in BPD, suggesting that the therapeutic actions of medications are not mediated by changes in neural hemodynamics.

A scoping review of near infrared spectroscopy studies employing a verbal fluency task in bipolar disorder

BACKGROUND

Deficits in cognitive functioning, including attention, memory, and executive functions, along with impairments in language production, are present in patients with bipolar disorder (BD) patients during mood phases, but also during euthymia.Verbal fluency tasks (VFTs), being able to evaluate integrity of a wide range of cognitive domains and represent, can be used to screen for these disturbances. Neuroimaging studies, including Near-InfraRed Spectroscopy (NIRS), have repeatedly showed widespread alterations in the prefrontal and temporal cortex during the performance of VFTs in BD patients. This review aims to summarize the results of NIRS studies that evaluated hemodynamic responses associated with the VFTs in prefrontal and temporal regions in BD patients.

METHODS

We performed a scoping review of studies evaluating VFT-induced activation in prefrontal and temporal regions in BD patients, and the relationship between NIRS data and various clinical variables.

RESULTS

15 studies met the inclusion criteria. In BD patients, compared to healthy controls, NIRS studies showed hypoactivation of the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex and anterior temporal regions. Moreover, clinical variables, such as depressive and social adaptation scores, were negatively correlated with hemodynamic responses in prefrontal and temporal regions, while a positive correlation were reported for measures of manic symptoms and impulsivity.

LIMITATIONS

The heterogeneity of the studies in terms of methodology, study design and clinical characteristics of the samples limited the comparability of the findings.

CONCLUSIONS

Given its non-invasiveness, good time-resolution and no need of posturalconstraint, NIRS technique could represent a useful tool for the evaluation of prefrontal and temporal haemodynamic correlates of cognitive performances in BD patients.

Functional near-infrared spectroscopy during the verbal fluency task of English-Speaking adults with mood disorders: A preliminary study

Functional near-infrared spectroscopy (fNIRS) provides a direct and objective assessment of cerebral cortex function. It may be used to determine neurophysiological differences between psychiatric disorders with overlapping symptoms, such as major depressive disorder (MDD) and bipolar disorder (BD). Therefore, this preliminary study aimed to compare fNIRS signals during the verbal fluency task (VFT) of English-speaking healthy controls (HC), patients with MDD and patients with BD. Fifteen HCs, 15 patients with MDD and 15 patients with BD were recruited. Groups were matched for age, gender, ethnicity and education. Relative oxy-haemoglobin and deoxy-haemoglobin changes in the frontotemporal cortex was monitored with a 52-channel fNIRS system. Integral values of the frontal and temporal regions were derived as a measure cortical haemodynamic response magnitude. Both patient groups had lower frontal and temporal region integral values than HCs, and patients with MDD had lower frontal region integral value than patients with BD. Moreover, patients could be differentiated from HCs using the frontal and temporal integral values, and patient groups could be differentiated using the frontal region integral values. VFT performance, clinical history and symptom severity were not associated with integral values. These results suggest that prefrontal cortex haemodynamic dysfunction occurs in mood disorders, and it is more extensive in MDD than BD. The fNIRS-VFT paradigm may be a potential tool for differentiating MDD from BD in clinical settings, and these findings need to be verified in a larger sample of English-speaking patients with mood disorders.

Common variants in CREB1 gene confer risk for bipolar disorder in Han Chinese

Recently, we have identified involvement of the gene encoding cAMP responsive element-binding 1 (CREB1) in risk of BD in European ancestry. CREB1 has significant genetic diversity between Europeans and Chinese, thereby resulting in diverged CREB1 genetic backgrounds. In this study, we aimed to determine whether CREB1 confers susceptibility to BD and cognitive dysfunction in Han Chinese. We recruited 572 patients with BD and 611 healthy controls for genetic study. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used for cognitive evaluation. SNP rs10932201 and rs3770704 within CREB1 were genotyped. The frequency of the G allele of rs10932201 was significantly greater in BD patients (41.8 %) than that in control subjects (37.2 %), with P = 0.02, corrected P = 0.04. There were significant differences in the scores of RBANS attention and total scores between the patients with different genotypes of rs10932201 polymorphism (P = 0.002 and 0.003, corrected P = 0.012 and 0.018, respectively). Post-hoc comparisons showed that rs10932201 G/G or G/A carriers had lower RBANS attention and total scores than those with A/A carriers (P = 0.002 and 0.004, P = 0.002 and 0.006, respectively). We observed a significant association between the rs10932201 and CREB1 expression in intralobular white matter (P = 0.037). Carriers with G allele have significantly lower levels of CREB1 expression in intralobular white matter than those without G allele. In conclusion, this study identified a novel BD risk SNP rs10932201 in Han Chinese and this SNP may be a risk factor for cognitive dysfunction in patients with BD.

Cortical haemodynamic response during the verbal fluency task in patients with bipolar disorder and borderline personality disorder: a preliminary functional near-infrared spectroscopy study

BACKGROUND

Functional near-infrared spectroscopy (fNIRS) is an emerging neuroimaging modality that provides a direct and quantitative assessment of cortical haemodynamic response during a cognitive task. It may be used to identify neurophysiological differences between psychiatric disorders with overlapping symptoms, such as bipolar disorder (BD) and borderline personality disorder (BPD). Hence, this preliminary study aimed to compare the cerebral haemodynamic function of healthy controls (HC), patients with BD and patients with BPD.

METHODS

Twenty-seven participants (9 HCs, 9 patients with BD and 9 patients with BPD) matched for age, gender, ethnicity and education were recruited. Relative oxy-haemoglobin and deoxy-haemoglobin changes in the frontotemporal cortex was monitored with a 52-channel fNIRS system during a verbal fluency task (VFT). VFT performance, clinical history and symptom severity were also noted.

RESULTS

Compared to HCs, both patient groups had lower mean oxy-haemoglobin in the frontotemporal cortex during the VFT. Moreover, mean oxy-haemoglobin in the left inferior frontal region is markedly lower in patients with BPD compared to patients with BD. Task performance, clinical history and symptom severity were not associated with mean oxy-haemoglobin levels.

CONCLUSIONS

Prefrontal cortex activity is disrupted in patients with BD and BPD, but it is more extensive in BPD. These results provide further neurophysiological evidence for the separation of BPD from the bipolar spectrum. fNIRS could be a potential tool for assessing the frontal lobe function of patients who present with symptoms that are common to BD and BPD.

Brain activation during verbal fluency task in type II bipolar disorder patients: a near-infrared spectroscopy study

BACKGROUND

Previous studies have shown that BD patients exhibited impairment when performing a verbal fluency task (VFT) and abnormal prefrontal cortex activation during this task. However, no study has specifically examined whether patients with type II BD demonstrate difficulty in performing VFT and impairments in relevant neural correlates or whether these are related to psychotic symptoms, the present study aimed to examine these issues.

METHODS

Forty-nine patients with type II BD (21 patients with psychotic symptoms [BDIIp] and 28 patients without psychotic symptoms [BDIIn]) and 45 matched healthy controls (HCs) participated the study and completed the VFTs, while their brain activity was recorded with near-infrared spectroscopy (NIRS).

RESULTS

Both BDIIp and BDIIn patients showed poorer performance on VFTs than HCs. In addition, BDII patients showed lower brain activation than HCs in bilateral dorsolateral prefrontal cortex and right frontal pole, these results were mainly driven by BDIIn patients. Moreover, subjective psychotic symptoms were positively significantly correlated with left dorsolateral prefrontal cortex activation in BDII patients.

CONCLUSIONS

Type II BD patients showed significant impairment when performing VFTs and reduced activation in the prefrontal cortex, and subjective psychotic symptoms were associated with brain activation in left dorsolateral prefrontal cortex in BDII patients.

Differentiating between bipolar and unipolar depression using prefrontal activation patterns: Promising results from functional near infrared spectroscopy (fNIRS) findings

BACKGROUND

Bipolar depression (BD) is a unique, severe and prevalent mental illness that shares many similarities in symptoms with unipolar depression (UD). Improving precision of their diagnoses would enhance treatment outcome and prognosis for both conditions. This study aims to provide evidence from functional Near-Infrared Spectroscopy (fNIRS) as a potential tool to differentiate UD and BD based on their differences in hemodynamic change in the prefrontal cortex during verbal fluency tasks (VFT).

METHODS

We enrolled 179 participants with clinically confirmed diagnoses, including 69 UD patients, 68 BD patients and 42 healthy controls(HC). Every participant was assessed using a 45-channel fNIRS and various clinical scales.

FINDINGS

Compared with HC, region-specific fNIR leads show UD patients had significant lower hemodynamic activation in 4 particular pre-frontal regions: 1) the left dorsolateral prefrontal cortex (DLPFC), 2) orbitofrontal cortex (OFC), 3) bilateral ventrolateral prefrontal cortex (VLPFC) and 4) left inferior frontal gyrus (IFG). In contrast, BD vs. HC comparisons showed only significant lower hemodynamic activation in the LIFG area. Furthermore, compared to BD patients, UD patients showed decreased hemodynamic activation changes in the VLPFC region.

CONCLUSION

Our results show significant frontal lobe activation pattern differences between UD and BD groups. fNIRS can be a potential tool to increase diagnostic precision for these conditions. In particular, the VLPFC area holds promise to be a useful site for such differentiation for further investigations.

FKBP5 Gene Variants May Modulate Depressive Features in Bipolar Disorder

BACKGROUND

Previous evidence suggested the possible association of FK506 binding protein 5 (FKBP5) gene variants in bipolar disorder (BPD).

OBJECTIVE

Given the need of refinement of the findings obtained in large but poorly phenotyped samples, this study investigated the possible role of variants within FKBP5 in a small but deeply phenotyped BPD sample.

METHODS

A sample (N = 131) of bipolar patients were investigated with 10 polymorphisms within the FKBP5 gene. A control sample (N = 65) was also used for the analyses. Treatment response and remission of symptoms were evaluated using of the Hamilton Depression Rating Scale (HDRS), Hamilton Anxiety Rating Scale (HARS), and Young Mania Rating Scale (YMRS). The same analyses were also performed on the depressive subsample of BPD (D.BPD).

RESULTS

rs3800373 was associated with disorder risk in the depressive BPD subsample with the G allele being more frequent in subjects with a D.BPD phenotype. This was the only association that survived statistical correction.

CONCLUSIONS

rs3800373 FKBP5 may increase the risk of developing predominantly depressed BPD, probably through the creation of an enhancer consensus sequence in the 3'UTR of the gene, thus potentially increasing its expression. This finding seems to be partially supported by literature data, which evidenced increased levels of FKBP5 in psychiatric subjects.

Intraday Activity Levels May Better Reflect the Differences Between Major Depressive Disorder and Bipolar Disorder Than Average Daily Activity Levels

It is important to establish an objective index to differentiate mood disorders (i.e., bipolar disorder; BD and major depressive disorder; MDD). The present study focused on the pattern of changes of physical activity in the amount of activity intraday, and examined the relationship between activity patterns and mood disorders. One hundred and eighteen inpatients with MDD or BD in a depressive state provided the activity data by using wearable activity trackers for 3 weeks. In order to illuminate the characteristic patterns of intraday activities, Principal Component Analysis (PCA) was adopted to extract the main components of intraday activity changes. We found that some of the PCs reflected the differences between the types of mood disorder. BD participants showed high activity pattern in the morning and low activity pattern in evenings. However, MDD showed the opposite. Our results suggest that activity tracking focused on daytime activity patterns may provide objective auxiliary diagnostic information.

Prefrontal activation during a working memory task differs between patients with unipolar and bipolar depression: A preliminary exploratory study

BACKGROUND

To identify bipolar disorder during the initial stages of a depressive episode has always been a great clinical challenge. Patterns of functional brain activity may underlie the differences in the neural mechanisms of bipolar depression (BD) and unipolar depression (UD). This study aimed to investigate the differences in neural activity between BD and UD patients during executive task.

METHODS

We performed a 52-channel near-infrared spectroscopy (NIRS) scan in 39 patients with BD, 35 patients with UD, and 36 healthy controls (HCs). The relative concentration changes in oxygenated hemoglobin ([oxy-Hb]) and deoxygenated hemoglobin ([deoxy-Hb]) during a 1-back working memory task were measured for each channel. Clinical characteristics including current mood were evaluated within one week prior to NIRS examination.

RESULTS

Compared to HCs, BD (CH34: Z = -2.354, P = 0.019) and UD patients (CH18: Z = -2.358, P = 0.018; CH30: Z = -2.174, P = 0.030; CH34: Z = -1.990, P = 0.047) showed reduced activation of [oxy-Hb] in the inferior prefrontal region. Compared to patients with UD, patients with BD showed less decreased [oxy-Hb] changes in the left frontopolar cortex (FPC) (CH18: Z = -2.366, P = 0.018), left pars opercularis and pars triangularis (POPE/PTRI) regions (Broca's area) (CH30: Z = -2.333, P = 0.020). No correlation existed between clinical characteristics and NIRS measurements.

LIMITATIONS

The effect of medication could not be excluded, and behavioral data was not systematically collected.

CONCLUSION

The results from this preliminary exploratory study suggest distinct prefrontal activation patterns underlie BD and UD, especially in the left frontopolar region and Broca's area. The NIRS-based prefrontal activation measurement may serve as a potential marker to aid in differentiating bipolar from unipolar depression.

Functional near infra-red spectroscopy (fNIRS) in schizophrenia: A review

The research on the alterations in functional connectivity in schizophrenia has been facilitated by development of an array of functional neuroimaging techniques. Functional Near Infra Red Spectroscopy (fNIRS) is a novel diffuse optical neuromonitring method with its own advantages and limitations. The advantages of fNIRS have made it to be frequently used as a research tool by medical community in different settings. In fNIRS the property of haemoglobin to absorb near infrared light is used to measure brain activity. It provides the indirect measurement of the neuronal activity in the areas of interest. The advantage of fNIRS being less restrictive has made it to be used more commonly in the research of psychiatric disorders in general, schizophrenia in particular. The fNIRS studies on patients with schizophrenia have shown haemodynamic hypo activation primarily in the prefrontal cortex during various cognitive tasks. In this review, initially we have briefly explained the basic principles of fNIRS followed by detailed review of fNIRS findings in patients with schizophrenia.