Right prefrontal function and coping strategies in patients with remitted major depressive disorder.

BACKGROUND: Patients with remitted major depressive disorder (rMDD) generally rely on maladaptive coping strategies for stressful situations. These maladaptive copings are associated with an elevated relapse risk of rMDD; however, their neural basis remains poorly understood. METHODS: We enrolled (1) 45 patients with rMDD (17-item Hamilton Depression Rating Scale [HRSD17] total score ≤ 3) and (2) 56 healthy controls (HCs). Coping styles were measured using the Coping Inventory for Stressful Situations (CISS) according to three coping dimensions: avoidance-, emotion-, and task-oriented copings. The cognitive strategic processes of the prefrontal cortex were measured using a verbal fluency task (VFT). Furthermore, regional frontotemporal hemodynamic responses were monitored by near-infrared spectroscopy (NIRS). RESULTS: Patients with rMDD had significantly lower task-oriented coping scores and significantly higher avoidance- and emotion-oriented coping scores than HCs. Predominantly in the left frontotemporal region, patients with rMDD had lower frontotemporal hemodynamic responses during a VFT than HCs. Hemodynamic responses in the right inferior frontal gyrus of patients with rMDD were significantly and negatively associated with avoidance-oriented coping scores, but not of HCs. Conversely, those responses of HCs were significantly and positively associated with task-oriented coping scores, but not of patients with rMDD. DISCUSSION: Alteration in the right inferior frontal cortex plays an important role in dysfunction to stress response in patients with rMDD. Differential functioning patterns of the right inferior frontal cortex associated with coping strategies may link to MDD recurrence vulnerability.

Discrepancies between self- and observer-rated depression severities in patients with major depressive disorder associated with frequent emotion-oriented coping responses and hopelessness.

PURPOSE: The rating discrepancy for patients with major depressive disorder (MDD) is believed to be associated with hopelessness, risk of suicidal behavior, and personality characteristics, such as high neuroticism. However, it remains to be elucidated whether the discrepancy is also mediated by coping styles, which are conceptualized as personality characteristics. PATIENTS AND METHODS: We enrolled 154 participants and divided them into three groups: patients with MDD with a rating discrepancy (MDD-WD; n=46), patients with MDD without a rating discrepancy (MDD-WoD; n=50), and healthy controls (HCs; n=58). A rating discrepancy was defined as a high Beck Depression Inventory score and low Hamilton Depression Rating Scale score. Coping styles and hopelessness were compared among the groups. RESULTS: The MDD-WD group exhibited a higher level of hopelessness than those in the MDD-WoD and HC groups. They also demonstrated a significantly increased number of suicide attempts compared with the MDD-WoD group. Both the MDD-WD and MDD-WoD groups exhibited lesser task-oriented and greater emotion-oriented coping styles than those in the HC group, with the MDD-WD group demonstrating even greater emotion-oribented coping than that in the MDD-WoD group. Overall, high levels of hopelessness, a history of suicide attempts, and frequent use of emotion-oriented coping mechanisms were associated with rating discrepancy. CONCLUSION: Patients with MDD who showed rating discrepancy tended to use emotion-oriented coping. Planning for minimal use of emotion-oriented coping may be a psychotherapeutic intervention for such patients. Reduced emotion-oriented coping may also reduce the feeling of hopelessness and risk of developing suicidal behavior.

Delayed hemodynamic responses associated with a history of suicide attempts in bipolar disorder: a multichannel near-infrared spectroscopy study.

Bipolar disorder (BD) is associated with a high risk of suicide compared with other psychiatric disorders. Recent studies using near-infrared spectroscopy (NIRS) reported frontotemporal functional abnormalities in BD. However, it remains unclear whether NIRS signal changes are associated with vulnerability toward suicide in BD. We recruited 20 patients with depressed BD with a history of suicide attempts (suicide attempters; SAs) and 28 control patients with BD who did not have a history of suicide attempts (non-attempters; NAs). Regional hemodynamic responses during a verbal fluency task were monitored using NIRS. Compared with the NA group, the SA group exhibited significantly reduced activation during VFT in the bilateral precentral and superior temporal gyri and left supramarginal, inferior frontal, postcentral, and middle temporal gyri. Furthermore, compared with the NA group, the SA group exhibited delayed activation timing of the NIRS signal in the prefrontal region. In BD patients, current suicide risk was noted to be significantly and positively associated with delayed activation timing of the NIRS signal in the prefrontal region. The findings of this study suggest that the observed specific NIRS signal pattern in BD patients is associated with vulnerability toward suicide.

Shared and differential cortical functional abnormalities associated with inhibitory control in patients with schizophrenia and bipolar disorder.

Schizophrenia (SZ) and bipolar I disorder (BD-I) share genetic risk factors and cognitive impairments, but these conditions may exhibit differences in cortical functioning associated with inhibitory control. We measured hemodynamic responses during a stop-signal task using near-infrared spectroscopy (NIRS) in 20 patients with SZ, 21 patients with BD-I and 18 healthy controls (HCs). We used stop-signal reaction time (SSRT) to estimate behavioural inhibition. Compared with HCs, patients with either SZ or BD-I exhibited significantly reduced activation in the bilateral inferior, middle and superior frontal gyri. Furthermore, patients with BD-I showed inactivation of the right superior temporal gyri compared with patients with SZ or HCs. Patients with SZ or BD-I demonstrated significant negative correlations between SSRT and hemodynamic responses of the right inferior frontal gyrus. Moreover, patients with SZ exhibited correlations in the middle and superior frontal gyri. Our findings suggest that right inferior frontal abnormalities mediate behavioural inhibition impairments in individuals with SZ or BD-I. Differential patterns of orbitofrontal or superior temporal functional abnormalities may reflect important differences in psychopathological features between these disorders.

Reduced left precentral regional responses in patients with major depressive disorder and history of suicide attempts.

Previous neuroimaging studies have revealed frontal and temporal functional abnormalities in patients with major depressive disorder (MDD) and a history of suicidal behavior. However, it is unknown whether multi-channel near-infrared spectroscopy (NIRS) signal changes among individuals with MDD are associated with a history of suicide attempts and a diathesis for suicidal behavior (impulsivity, hopelessness, and aggression). Therefore, we aimed to explore frontotemporal hemodynamic responses in depressed patients with a history of suicide attempts using 52-channel NIRS. We recruited 30 patients with MDD and a history of suicidal behavior (suicide attempters; SAs), 38 patient controls without suicidal behavior (non-attempters; NAs), and 40 healthy controls (HCs) matched by age, gender ratio, and estimated IQ. Regional hemodynamic responses during a verbal fluency task (VFT) were monitored using NIRS. Our results showed that severities of depression, impulsivity, aggression, and hopelessness were similar between SAs and NAs. Both patient groups had significantly reduced activation compared with HCs in the bilateral frontotemporal regions. Post hoc analyses revealed that SAs exhibited a smaller hemodynamic response in the left precentral gyrus than NAs and HCs. Furthermore, the reduced response in the left inferior frontal gyrus was negatively correlated with impulsivity level and hemodynamic responses in the right middle frontal gyrus were negatively associated with hopelessness and aggression in SAs but not in NAs and HCs. Our findings suggest that MDD patients with a history of suicide attempts demonstrate patterns of VFT-induced NIRS signal changes different from those demonstrated by individuals without a history of suicidal behaviors, even in cases where clinical symptoms are similar. NIRS has a relatively high time resolution, which may help visually differentiate SAs from NAs.

Relationship between prefrontal hemodynamic responses and quality of life differs between melancholia and non-melancholic depression.

This study aimed to determine whether quality of life (QOL) reflects specific functional abnormalities of frontotemporal hemodynamic responses in melancholia. We recruited 30 patients with major depressive disorder (MDD) with melancholic features (MDD-MF), 52 with non-melancholic features (MDD-NMF), and 68 healthy control subjects who were matched for age, sex ratio, and years of education. QOL was assessed using the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36), and regional hemodynamic responses during a verbal fluency task were monitored with near-infrared spectroscopy (NIRS). Patients with MDD-MF scored significantly lower than those with MDD-NMF on the role emotional domain of SF-36. Both MDD patient groups exhibited lower hemodynamic responses in the frontotemporal regions than the control group. Hemodynamic responses in the frontotemporal regions were significantly smaller in patients with MDD-MF than in those with MDD-NMF. The role emotional domain of patients with MDD-MF was significantly and positively correlated with hemodynamic responses in the prefrontal region, whereas that of patients with MDD-NMF revealed no significant correlation. In conclusion, our results indicate that patients with MDD-MF exhibit qualitatively distinct prefrontal dysfunction patterns associated with emotional role functioning compared with patients with MDD-NMF.

Left temporal activation associated with depression severity during a verbal fluency task in patients with bipolar disorder: a multichannel near-infrared spectroscopy study.

BACKGROUND: Neuroimaging studies using multichannel near-infrared spectroscopy (NIRS) have provided compelling evidence about the dysfunction of the frontotemporal cortices in patients with bipolar disorder (BD). However, it remains unclear whether the dysfunction is associated with mood state or symptom severity. Using NIRS, we aimed to clarify differences in oxygenated hemoglobin (oxy-Hb) activation between depressive and euthymic states as well as regional brain dysfunction in relation to symptom severity in BD. METHODS: Fifty-five patients with BD, including 30 with bipolar depression (BPD) and 25 with euthymic bipolar disorder (BPE), and 28 healthy controls (HCs) participated in the study. Regional hemodynamic changes during a verbal fluency task (VFT) were monitored using a 52-channel NIRS apparatus. RESULTS: The mean oxy-Hb changes induced by VFT were significantly smaller in the BD patients than in the HCs in 18 channels in the frontotemporal regions (false-discovery rate p<0.05, p=0.000-0.011). The BPD group exhibited significantly smaller changes in mean oxy-Hb compared with the BPE group in three channels of the left temporal region (p=0.005-0.014). In the BD patients, significant negative correlations were observed between mean oxy-Hb changes in the left temporal regions and the severity of depression. LIMITATIONS: Our sample size was small, making the results susceptible to type II errors. CONCLUSIONS: BD patients have persistent hypofunction of the frontotemporal cortical regions. Moreover, the hemodynamic response in the left temporal regions is associated with symptom severity.

Prefrontal cortex activation is associated with a discrepancy between self- and observer-rated depression severities of major depressive disorder: a multichannel near-infrared spectroscopy study.

BACKGROUND: Studies on major depressive disorder (MDD) show that the degree of correlation between the Beck Depression Inventory (BDI) and Hamilton Depression Rating Scale (HAMD) varies widely. We aimed to determine whether this discrepancy reflects specific functional abnormalities in the frontotemporal cortex. METHODS: Mildly depressed or euthymic patients with MDD (n=52), including 21 patients with MDD with the discrepancy, i.e., those with low HAMD17 scores (≤13) but high BDI-II scores (>28), and 31 patients without the discrepancy, i.e., those with low HAMD17 scores and low BDI-II scores (≤28), participated in the study along with 48 control subjects. Regional changes of oxygenated hemoglobin (oxy-Hb) levels during a verbal fluency task (VFT) were monitored using a 52-channel near-infrared spectroscopy (NIRS) device. RESULTS: In the frontotemporal regions, mean oxy-Hb changes induced by the VFT were significantly smaller in patients with MDD than in control subjects. In 5 channels within frontal regions, the increase in mean oxy-Hb levels was significantly greater in MDD patients with the BDI-HAMD discrepancy than in those without the discrepancy. In 6 channels within the frontal region of the patients with MDD, significant positive correlations were observed between mean oxy-Hb changes and BDI total scores (ρ=0.38-0.59; P<0.05, false discovery rate corrected). LIMITATIONS: Our findings required replication in severely depressed patients, particularly those with melancholia. CONCLUSIONS: The distinct pattern of activation of the prefrontal cortex suggests that MDD with the BDI-HAMD discrepancy is pathophysiologically different from MDD without the discrepancy.

Right temporal activation differs between melancholia and nonmelancholic depression: a multichannel near-infrared spectroscopy study.

The aim of this study was to determine whether melancholia differs from nonmelancholic depression in frontotemporal functioning by means of multichannel near-infrared spectroscopy. We recruited 32 major depressive disorder (MDD) patients with melancholic features (MDD-MF), 28 MDD patients with nonmelancholic features (MDD-NMF), and 24 healthy controls. Regional hemodynamic changes induced by a verbal fluency task (VFT) were monitored, and their correlations with depressive symptoms were examined. In comparison with the controls, significant differences were observed in mean oxygenated hemoglobin (oxy-Hb) changes induced by VFT in patients with MDD-MF in 25 channels (p = 0.000-0.047) and in those with MDD-NMF in 12 channels (p = 0.000-0.023). Moreover, patients with MDD-MF had significantly smaller mean oxy-Hb changes than those with MDD-NMF in 8 channels of the right temporal region (p = 0.001-0.048). No significant correlations were observed between mean oxy-Hb changes and the Hamilton rating scale for depression (HAMD) 17 total score in both groups of patients with MDD. On examining each item of HAMD17, psychomotor retardation in patients with MDD-MF showed a significant positive correlation with mean oxy-Hb changes in the right temporal region (ch43; ρ = 0.55; p = 0.001), whereas that in patients with MDD-NMF showed a significant negative correlation with mean oxy-Hb changes in the frontal and left temporal regions in 3 channels (ρ = -0.60 to -0.53; p = 0.000-0.004). In conclusion, our results indicate that melancholia is qualitatively distinct from nonmelancholic depression both clinically and biologically.

Discrepancy between self- and observer-rated depression severities as a predictor of vulnerability to suicide in patients with mild depression.

BACKGROUND: Discrepancies in depression severity between the Hamilton Depression Rating Scale (HAMD) and the Beck Depression Inventory (BDI) have been reported. However, whether these discrepancies impact vulnerability to suicide in patients with major depressive disorder (MDD) remains unclear. METHODS: Patients with mild MDD (n=161) were enrolled in the study and divided into the following 3 groups: (1) patients with MDD with the discrepancy (n=45), i.e., those with low HAMD17 scores (8-13) and high BDI-II scores (≥29), (2) patients with MDD without the discrepancy (n=46), i.e., those with low HAMD17 scores and low BDI-II scores (≤28), and (3) patients not currently depressed (n=70), i.e., those with HAMD17 scores ≤7 (affective controls). We examined the relationship of demographic, clinical, and neuropsychological variables with any discrepancy between self-rating and observer rating. RESULTS: Patients with MDD with the discrepancy had significantly higher hopelessness than those without the discrepancy and affective controls. Verbal fluency task performance of patients with MDD with the discrepancy was significantly impaired compared with that of those without the discrepancy and affective controls. Stepwise logistic regression analysis revealed that a history of suicide attempt [odds ratio (OR), 3.57; 95% confidence interval (CI), 1.12-11.37] and hopelessness (OR, 1.23; 95% CI, 1.09-1.38) increased odds of the discrepancy. LIMITATIONS: Results require replication. CONCLUSIONS: Clinicians should examine discrepancies between self- and observer-rated depression severities, which are associated with vulnerability to suicide in patients with MDD, even if objectively evaluated as mild.