Differential clinical characteristics and possible predictors of bipolarity in a sample of unipolar and bipolar inpatients

Which mixed depression model? A comparison between DSM-5-defined mixed features and Koukopoulos' criteria

BACKGROUND

The criteria of the Diagnostic and Statistical Manual of Mental Disorders 5th edition "with mixed features specifier" (DSM-5 MFS) are considered controversial since they include only typical manic symptoms. By contrast, Koukopoulos developed an alternative model of mixed depression (MxD) focusing primarily on the excitatory component.

OBJECTIVE

To compare DSM-5 MFS and Koukopoulos' MxD (KMxD) in terms of prevalence, associated clinical variables, and discriminative capacity for bipolar depression in patients with major depressive episode (MDE).

METHODS

A total of 300 patients with MDE-155 with major depressive disorder and 145 with bipolar disorder (BD)-were recruited. The discriminative capacity of DSM-5 MFS and KMxD criteria for BD was estimated using the area under the curves of receiver operating characteristic (ROC_AUC). The clinical variables associated with these two diagnostic constructs were assessed by performing a logistic regression.

RESULTS

A total of 44 and 165 patients met the DSM-5 MFS and KMxD criteria, respectively. The ROC_AUCs and their confidence intervals for BD according to DSM-5 MFS and KMxD were 77.0% (72.0%-82.1%) and 71.9% (66.2%-77.7%), respectively. The optimal thresholds (combining sensitivity and specificity measures) for BD diagnosis were ≥1 (77%/68%) for DSM-5 MFS and ≥3 symptoms (78%/66%) for KMxD. However, considering the DSM-5 MFS cut-off (≥3 symptoms), the specificity (97%) increased at the expense of sensitivity (26%).

CONCLUSIONS

KMxD and DSM-5-MFS showed an overlapping discriminative capacity for bipolar depression. The current diagnostic threshold of DSM-5 MFS did not prove to be very inclusive, if compared with the greater diagnostic sensitivity of KMxD, which also yielded better association with clinical variables related to mixedness.

Symptoms and Characteristics of Youth Hospitalized for Depression: Subthreshold Manic Symptoms Can Help Differentiate Bipolar from Unipolar Depression

Background: Most people who have major depressive disorder (MDD) or bipolar disorder (BD) will have their first episode of depression in adolescence. However, in the absence of significant [hypo]manic symptoms, there are no clear guidelines for distinguishing bipolar from unipolar depression, which can lead to misdiagnosis and ineffective/harmful treatment. We aimed to compare phenomenological differences among youth with MDD or BD hospitalized for an acute episode of depression. Methods: A retrospective electronic chart review of adolescents hospitalized in an acute care inpatient unit who had a discharge diagnosis of MDD, MDD with mixed or psychotic features (MDD+), BD-I-current episode depressed, or BD-II-current episode depressed, was performed. Results: Altogether, 598 patients (mean age = 15.1 ± 1.5 years, female = 71%, and White = 46%) met study inclusion criteria, i.e., BD-I: n = 39, BD-II: n = 84, MDD: n = 422, and MDD+: n = 53 patients. The admission Hamilton Depression Rating Scale (HAMD) total score was significantly higher in the BD-I (29.3 ± 9.1) and MDD+ (31.2 ± 9.3) groups versus the MDD group (24.3 ± 9.7) (p < 0.05). Although there were some group differences in the severity of individual depression symptoms, these did not line up neatly across BD and MDD groups. At admission, Young Mania Rating Scale (YMRS) total scores were significantly higher in the BD-I (14.4 ± 7.4), BD-II (13.8 ± 6.5), and MDD+ groups (14.3 ± 6.6) versus the MDD group (8.2 ± 4.6, p < 0.05). Additionally, 9 of 11 and 4 of 11 YMRS items scored significantly higher in the BD-II and BD-I groups versus the MDD group, respectively. The motor activity and hypersexuality items, in particular, were scored consistently higher in the BD groups than MDD groups. Limitations: All diagnoses were made based on a clinical interview and not a structured diagnostic interview, and some of the subgroup sample sizes were relatively modest, limiting the power for group comparisons. Conclusion: The presence of subsyndromal manic symptoms during an episode of MDD currently offers the clearest way by which to differentiate bipolar depression from unipolar depression.

Differential Dynamical Pattern of Regional Homogeneity in Bipolar and Unipolar Depression: A Preliminary Resting-State fMRI Study

Background: Bipolar depression (BD) and unipolar depression (UD) are both characterized by depressive moods, which are difficult to distinguish in clinical practice. Human brain activity is time-varying and dynamic. Investigating dynamical pattern alterations of depressed brains can provide deep insights into the pathophysiological features of depression. This study aimed to explore similar and different abnormal dynamic patterns between BD and UD. Methods: Brain resting-state functional magnetic resonance imaging data were acquired from 36 patients with BD type I (BD-I), 38 patients with UD, and 42 healthy controls (HCs). Analysis of covariance was adopted to examine the differential pattern of the dynamical regional homogeneity (dReHo) temporal variability across 3 groups, with gender, age, and education level as covariates. Post-hoc analyses were employed to obtain the different dynamic characteristics between any 2 groups. We further applied the machine-learning methods to classify BD-I from UD by using the detected distinct dReHo pattern. Results: Compared with patients with UD, patients with BD-I demonstrated decreased dReHo variability in the right postcentral gyrus and right parahippocampal gyrus. By using the dReHo variability pattern of these two regions as features, we achieved the 91.89% accuracy and 0.92 area under curve in classifying BD-I from UD. Relative to HCs, patients with UD showed increased dReHo variability in the right postcentral gyrus, while there were no dReHo variability differences in patients with BD-I. Conclusions: The results of this study mainly report the differential dynamic pattern of the regional activity between BD-I and UD, particular in the mesolimbic system, and show its promising potential in assisting the diagnosis of these two depression groups.

Differentiating unipolar and bipolar depression: Contribution of the Rorschach test (Comprehensive System)

OBJECTIVE

The aim of this study was to contribute to differential diagnoses of unipolar and bipolar depression using cognitive variables of the Rorschach test (Comprehensive System).

METHOD

One hundred forty one depressed inpatients (71 bipolar, 70 unipolar; mean age = 46, SD = 15.8; 64% women) previously evaluated and comparable regarding clinical characteristics of their illness (including current mood symptoms) were blindly tested using the Rorschach test (C.S.).

RESULTS

The cognitive profile of bipolar depressed patients was more impaired than the cognitive profile of unipolar depressed patients. Combining four cognitive specificities (tolerance to ambiguity, discrimination failure, difficulties in controlling ideational impulses, and impulsive or negligent processing) in a logistic regression model allows the identification of bipolarity with acceptable accuracy.

CONCLUSIONS

Some aspects of cognitive functioning, as assessed with the Rorschach test (CS), appear to be useful to capture some important cognitive specificities of bipolar depression and could contribute to differential diagnoses of mood disorders.

Comparison of blood lipid profile/thyroid function markers between unipolar and bipolar depressed patients and in depressed patients with anhedonia or suicidal thoughts

Background

This study aimed to investigate the differences in the serum levels of glucose, lipid, and thyroid function markers between unipolar and bipolar depressed patients, as well as the effect of anhedonia and suicidal thoughts on the levels of these biochemical parameters.

Methods

A total of 287 unmedicated depressed patients from January 2016 to December 2017 were included in this study, including 92 bipolar depressions and 195 unipolar depressions. Anhedonia was determined using the item 32 of Symptom Checklist (SCL-90). Suicide ideation was assessed by item 15 of SCL-90.

Results

The bipolar group had significantly lower lipid levels (including triglycerides, cholesterol, low-density lipoprotein cholesterol [LDL], very low-density lipoprotein cholesterol [VLDL]) and insulin resistance index but higher levels of prolactin, low triiodothyronine (T3) and free T3 (FT3) as well as higher incidence of anhedonia as compared with the unipolar group. Depressed patients with anhedonia had significantly higher LDL level than those without anhedonia. Depressed patients with suicidal thoughts had cholesterol and high-density lipoprotein cholesterol (HDL) level. The above-mentioned differences were confirmed by logistic regression analysis. Receiver operating characteristic curve (ROC) analysis showed that the area under the ROC curve (AUC) ranged from 0.546 to 0.685.

Conclusion

Triglycerides, cholesterol, LDL, VLDL T3, FT3 levels were significantly different between unipolar and bipolar depressed patients, which might have the potential to be the markers for differential diagnosis. Patients with anhedonia had lower LDL level, while patients with suicidal thoughts had higher levels of cholesterol and HDL as compared with the corresponding control groups.