Mixed Depression: A Mini-Review to Guide Clinical Practice and Future Research Developments

The debate on mixed states (MS) has been intense for decades. However, several points remain controversial from a nosographic, diagnostic, and therapeutic point of view. The different perspectives that have emerged over the years have turned into a large, but heterogeneous, literature body. The present review aims to summarize the evidence on MS, with a particular focus on mixed depression (MxD), in order to provide a guide for clinicians and encourage the development of future research on the topic. First, we review the history of MS, focusing on their different interpretations and categorizations over the centuries. In this section, we also report alternative models to traditional nosography. Second, we describe the main clinical features of MxD and list the most reliable assessment tools. Finally, we summarize the recommendations provided by the main international guidelines for the treatment of MxD. Our review highlights that the different conceptualizations of MS and MxD, the variability of clinical pictures, and the heterogeneous response to pharmacological treatment make MxD a real challenge for clinicians. Further studies are needed to better characterize the phenotypes of patients with MxD to help clinicians in the management of this delicate condition.

Electroconvulsive Therapy (ECT) in Bipolar Disorder Patients with Ultra-Rapid Cycling and Unstable Mixed States

Background and Objectives: Unstable mixed episodes or rapid switching between opposite affective poles within the scope of short cycles was first characterized in 1967 by S. Mentzos as complex polymorphous states with chaotic overlap of manic and depressive symptoms. Well-known examples include antidepressant-induced mania/hypomania and rapid/ultra-rapid/ultradian cycling, when clinicians observe an almost continuous mixed state with a constant change of preponderance of manic or depressive symptoms. Achieving stable remission in these cases is challenging with almost no data on evidence-based treatment. When mood stabilizers are ineffective, electroconvulsive therapy (ECT) has been suggested. Objectives: After reviewing the evidence from available literature, this article presents our own clinical experience of ECT efficacy and tolerability in patients with ultra-rapid cycling bipolar disorder (BD) and unstable mixed states. Materials and Methods: We conducted an open, one-year observational prospective study with a "mirror image" design, including 30 patients with rapid and ultra-rapid cycling BD on long-term mood stabilizer treatment (18 received lithium carbonate, 6 on valproate and 6 on carbamazepine) with limited effectiveness. A bilateral ECT course (5-10 sessions) was prescribed for regaining mood stability. Results: ECT was very effective in 12 patients (40%) with a history of ineffective mood stabilizer treatment who achieved and maintained remission; all of them received lithium except for 1 patient who received carbamazepine and 2 with valproate. Nine patients (30%) showed partial response (one on carbamazepine and two on valproate) and nine patients (30%) had no improvement at all (four on carbamazepine and two on valproate). For the whole sample, the duration of affective episodes was significantly reduced from 36.05 ± 4.32 weeks in the year prior to ECT to 21.74 ± 12.14 weeks in the year post-ECT (p < 0.001). Depressive episodes with mixed and/or catatonic features according to DSM-5 specifiers were associated with a better acute ECT response and/or long-term mood stabilizer treatment outcome after ECT. Conclusions: ECT could be considered as a useful option for getting mood instability under control in rapid and ultra-rapid cycling bipolar patients. Further randomized trials are needed to confirm these results.

The structure of mania: An overview of factorial analysis studies

Background.

Operational definitions of mania are based on expert consensus rather than empirical data. The aim of this study is to identify the key domains of mania, as well as the relevance of the different signs and symptoms of this clinical construct.

Methods.

A review of latent factor models studies in manic patients was performed. Before extraction, a harmonization of signs and symptoms of mania and depression was performed in order to reduce the variability between individual studies.

Results.

We identified 12 studies fulfilling the inclusion criteria and comprising 3039 subjects. Hyperactivity was the clinical item that most likely appeared in the first factor, usually covariating with other core features of mania, such as increased speech, thought disorder, and elevated mood. Depressive–anxious features and irritability–aggressive behavior constituted two other salient dimensions of mania. Altered sleep was frequently an isolated factor, while psychosis appeared related to grandiosity, lack of insight and poor judgment.

Conclusions.

Our results confirm the multidimensional nature of mania. Hyperactivity, increased speech, and thought disorder appear as core features of the clinical construct. The mood experience could be heterogeneous, depending on the co-occurrence of euphoric (elevated mood) and dysphoric (irritability and depressive mood) emotions of varying intensity. Results are also discussed regarding their relationship with other constitutive elements of bipolar disorder, such as mixed and depressive states.

Predictors of Treatment Resistance Across Different Clinical Subtypes of Depression: Comparison of Unipolar vs. Bipolar Cases

OBJECTIVE

Treatment-resistant depression (TRD) and treatment-resistant bipolar depression (TRBD) poses a significant clinical and societal burden, relying on different operational definitions and treatment approaches. The detection of clinical predictors of resistance is elusive, soliciting clinical subtyping of the depressive episodes, which represents the goal of the present study.

METHODS

A hundred and thirty-one depressed outpatients underwent psychopathological evaluation using major rating tools, including the Hamilton Rating Scale for Depression, which served for subsequent principal component analysis, followed-up by cluster analysis, with the ultimate goal to fetch different clinical subtypes of depression.

RESULTS

The cluster analysis identified two clinically interpretable, yet distinctive, groups among 53 bipolar (resistant cases = 15, or 28.3%) and 78 unipolar (resistant cases = 20, or 25.6%) patients. Among the MDD patients, cluster "1" included the following components: "Psychic symptoms, depressed mood, suicide, guilty, insomnia" and "genitourinary, gastrointestinal, weight loss, insight". Altogether, with broadly defined "mixed features," this latter cluster correctly predicted treatment outcome in 80.8% cases of MDD. The same "broadly-defined" mixed features of depression (namely, the standard Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition-DSM-5-specifier plus increased energy, psychomotor activity, irritability) correctly classified 71.7% of BD cases, either as TRBD or not.

LIMITATIONS

Small sample size and high rate of comorbidity.

CONCLUSIONS

Although relying on different operational criteria and treatment history, TRD and TRBD seem to be consistently predicted by broadly defined mixed features among different clinical subtypes of depression, either unipolar or bipolar cases. If replicated by upcoming studies to encompass also biological and neuropsychological measures, the present study may aid in precision medicine and informed pharmacotherapy.

Mixed states in bipolar disorder: modelling, measuring and managing

OBJECTIVE:

To consider whether consensus exists in recommendations for managing bipolar mixed states published in recent reviews and treatment guidelines, and to summarise what might be their best management.

CONCLUSION:

Limitations to and changes in the definition of mixed states compromise diagnosis and management. The striking comparison between DSM-IV and DSM-5 criteria sets risks under-diagnosis and over-diagnosis. Current reviews and guidelines offer limited evidence to guide treatment; however, management should involve addressing the contribution of any antidepressant medication, and the introduction of a second-generation antipsychotic medication to stabilise the condition.

The von Neumann Entropy for Mixed States

The Araki–Lieb inequality is commonly used to calculate the entropy of subsystems when they are initially in pure states, as this forces the entropy of the two subsystems to be equal after the complete system evolves. Then, it is easy to calculate the entropy of a large subsystem by finding the entropy of the small one. To the best of our knowledge, there does not exist a way of calculating the entropy when one of the subsystems is initially in a mixed state. For the case of a two-level atom interacting with a quantized field, we show that it is possible to use the Araki–Lieb inequality and find the von Neumann entropy for the large (infinite) system. We show this in the two-level atom-field interaction.

Modelling mood disorders: An ACE solution?

OBJECTIVES

The treatment of mood disorders remains sub-optimal. A major reason for this is our lack of understanding of the underlying pathophysiology of depression and bipolar disorder. A core problem is the lack of specificity of our current diagnoses. This paper discusses the history of this problem and posits a solution in the form of a more sophisticated model.

METHOD

The authors review the notable historical works that laid the foundations of mood disorder nosology; discuss the more recent influences that shaped modern diagnoses; and examine the evidence that mood disorders are characterised by multidimensional and longitudinal symptom profiles.

RESULTS

The ACE model considers mood disorders as a combination of symptoms across three domains: Activity, Cognition, and Emotion; that vary over time. This multidimensional and longitudinal perspective is consistent with the prevalence of complex clinical presentations, such as mixed states, and highlights the importance of recurrence in mood disorders.

CONCLUSIONS

The ACE model encourages researchers to characterise patients from a number of equally important perspectives and, by doing so, add specificity to the treatment of mood disorders.

Mixed states in bipolar and major depressive disorders: systematic review and quality appraisal of guidelines

OBJECTIVE

This systematic review provided a critical synthesis and a comprehensive overview of guidelines on the treatment of mixed states.

METHOD

The MEDLINE/PubMed and EMBASE databases were systematically searched from inception to March 21st, 2018. International guidelines covering the treatment of mixed episodes, manic/hypomanic, or depressive episodes with mixed features were considered for inclusion. A methodological quality assessment was conducted with the Appraisal of Guidelines for Research and Evaluation-AGREE II.

RESULTS

The final selection yielded six articles. Despite their heterogeneity, all guidelines agreed in interrupting an antidepressant monotherapy or adding mood-stabilizing medications. Olanzapine seemed to have the best evidence for acute mixed hypo/manic/depressive states and maintenance treatment. Aripiprazole and paliperidone were possible alternatives for acute hypo/manic mixed states. Lurasidone and ziprasidone were useful in acute mixed depression. Valproate was recommended for the prevention of new mixed episodes while lithium and quetiapine in preventing affective episodes of all polarities. Clozapine and electroconvulsive therapy were effective in refractory mixed episodes. The AGREE II overall assessment rate ranged between 42% and 92%, indicating different quality level of included guidelines.

CONCLUSION

The unmet needs for the mixed symptoms treatment were associated with diagnostic issues and limitations of previous research, particularly for maintenance treatment.

Rethinking the spectrum of mood disorders: implications for diagnosis and management - Proceedings of a symposium presented at the 30th Annual European College of Neuropsychopharmacology Congress, 4 September 2017, Paris, France

The simultaneous occurrence of manic and depressive features has been recognized since classical times, but the term 'mixed state' was first used by Kraepelin at the end of the 19th century. From the 1980s, until the advent of the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), psychiatric disorders were classified using a categorical approach. However, it was recognized that such an approach was too rigid to encompass the range of symptomatology encountered in clinical practice. Therefore, a dimensional approach was adopted in DSM-5, in which affective states are considered to be distributed across a continuum ranging from pure mania to pure depression. In addition, the copresence of symptoms of the opposite pole are captured using a 'with mixed features' specifier, applied when three or more nonoverlapping subthreshold symptoms of the opposite pole are present. Mixed features are common in patients with mood episodes, complicating the course of illness, reducing treatment response and worsening outcomes. However, research in this area is scarce and treatment options are limited. Current evidence indicates that antidepressants should be avoided for the treatment of bipolar mixed states. Evidence for bipolar mixed states supports the use of several second-generation antipsychotics, valproate and electroconvulsive therapy. One randomized controlled trial has demonstrated the efficacy of lurasidone, compared with placebo, in patients with major depressive disorder with mixed features, and there is limited evidence supporting the use of ziprasidone in such patients. Further research is required to determine whether other antipsychotic agents, or additional therapeutic approaches, might also be effective in this setting.

Anticonvulsants and suicide attempts in bipolar I disorders

OBJECTIVE

To identify risk factors for suicide attempts (SA) in individuals commencing treatment for a manic or mixed episode.

METHOD

A total of 3390 manic or mixed cases with bipolar disorder (BD) type I recruited from 14 European countries were included in a prospective, 2-year observational study. Poisson regression models were used to identify individual and treatment factors associated with new SA events. Two multivariate models were built, stratified for the presence or absence of prior SA.

RESULTS

A total of 302 SA were recorded prospectively; the peak incidence was 0-12 weeks after commencing treatment. In cases with a prior history of SA, risk of SA repetition was associated with younger age of first manic episode (P = 0.03), rapid cycling (P < 0.001), history of alcohol and/or substance use disorder (P < 0.001), number of psychotropic drugs prescribed (P < 0.001) and initiation of an anticonvulsant at study entry (P < 0.001). In cases with no previous SA, the first SA event was associated with rapid cycling (P = 0.02), lifetime history of alcohol use disorder (P = 0.02) and initiation of an anticonvulsant at study entry (P = 0.002).

CONCLUSION

The introduction of anticonvulsants for a recent-onset manic or mixed episode may be associated with an increased risk of SA. Further BD studies must determine whether this link is causal.

Treatment of mixed features in bipolar disorder

Mood episodes with Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)-defined mixed features are highly prevalent in bipolar disorder (BD), affecting ~40% of patients during the course of illness. Mixed states are associated with poorer clinical outcomes, greater treatment resistance, higher rates of comorbidity, more frequent mood episodes, and increased rates of suicide. The objectives of the current review are to identify, summarize, and synthesize studies assessing the efficacy of treatments specifically for BD I and II mood episodes (ie, including manic, hypomanic, and major depressive episodes) with DSM-5-defined mixed features. Two randomized controlled trials (RCTs) and 6 post-hoc analyses were identified, all of which assessed the efficacy of second-generation antipsychotics (SGAs) for the acute treatment of BD mood episodes with mixed features. Results from these studies provide preliminary support for SGAs as efficacious treatments for both mania with mixed features and bipolar depression with mixed features. However, there are inadequate data to definitively support or refute the clinical use of specific agents. Conventional mood stabilizing agents (eg, lithium and divalproex) have yet to have been adequately studied in DSM-5-defined mixed features. Further study is required to assess the efficacy, safety, and tolerability of treatments specifically for BD mood episodes with mixed features.

Athanasios Koukopoulos' Psychiatry: The Primacy of Mania and the Limits of Antidepressants

BACKGROUND

Athanasios Koukopoulos provided a radical model for understanding depressive and manic conditions.

OBJECTIVE

To review, explain, and analyze Koukopoulos' concept of the primacy of mania, with special attention to the role of antidepressants.

METHOD

A conceptual review of Koukopoulos' writings and lectures on this topic is given.

RESULTS

Koukopoulos held that depressive states are caused by manic states; the former do not occur without the latter. The most common scenario of the inseparability of depressive and manic symptoms occurs in mixed states, which we estimate to represent about one-half of all depressive episodes in all patients (not just bipolar illness). In a review of the empirical evidence for this topic, we conclude that empirical evidence exists to support the primary of mania thesis in almost 80% of depressed patients. Since antidepressants worsen mania, they would be expected to worsen depression as well in this model. We provide evidence that supports this view in most persons with depressive states.

CONCLUSION

Koukopoulos' model of affective illness is one where manic states are the primary pathology, and depressive conditions are a secondary consequence. Hence treatment of depression with antidepressants would be less effective than treatment with mood stabilizers, since treating an effect is less successful than treating its cause. This approach would reverse current assumptions in psychiatry.

Exclusion of overlapping symptoms in DSM-5 mixed features specifier: heuristic diagnostic and treatment implications

This article focuses on the controversial decision to exclude the overlapping symptoms of distractibility, irritability, and psychomotor agitation (DIP) with the introduction of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) mixed features specifier. In order to understand the placement of mixed states within the current classification system, we first review the evolution of mixed states. Then, using Kraepelin's original classification of mixed states, we compare and contrast his conceptualization with modern day definitions. The DSM-5 workgroup excluded DIP symptoms, arguing that they lack the ability to differentiate between manic and depressive states; however, accumulating evidence suggests that DIP symptoms may be core features of mixed states. We suggest a return to a Kraepelinian approach to classification-with mood, ideation, and activity as key axes-and reintegration of DIP symptoms as features that are expressed across presentations. An inclusive definition of mixed states is urgently needed to resolve confusion in clinical practice and to redirect future research efforts.

What is the role of conventional antidepressants in the treatment of major depressive episodes with Mixed Features Specifier?

The newly introduced Mixed Features Specifier of Major Depressive Episode and Disorder (MDE/MDD) is especially challenging in terms of pharmacological management. Prior to the publication of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, the symptoms of the mixed features specifier were intradepressive hypomanic symptoms, always and only associated with bipolar disorder (BD). Intradepressive hypomanic symptoms, mostly referred to as depressive mixed states (DMX), have been poorly characterized, and their treatment offers significant challenges. To understand the diagnostic context of DMX, we trace the nosological changes and collocation of intradepressive hypomanic symptoms, and examine diagnostic and prognostic implications of such mixed features. One of the reasons so little is known about the treatment of DMX is that depressed patients with rapid cycling, substance abuse disorder, and suicidal ideation/attempts are routinely excluded from clinical trials of antidepressants. The exclusion of DMX patients from clinical trials has prevented an assessment of the safety and tolerability of short- and long-term use of antidepressants. Therefore, the generalization of data obtained in clinical trials for unipolar depression to patients with intradepressive hypomanic features is inappropriate and methodologically flawed. A selective review of the literature shows that antidepressants alone have limited efficacy in DMX, but they have the potential to induce, maintain, or worsen mixed features during depressive episodes in BD. On the other hand, preliminary evidence supports the effective use of some atypical antipsychotics in the treatment of DMX.

Treating mixed mania/hypomania: a review and synthesis of the evidence

The DSM-5 incorporates a broad concept of mixed states and captured ≥3 nonoverlapping symptoms of the opposite polarity using a "with mixed features" specifier to be applied to manic/hypomanic and major depressive episodes. Pharmacotherapy of mixed states is challenging because of the necessity to treat both manic/hypomanic and depressive symptoms concurrently. High-potency antipsychotics used to treat manic symptoms and antidepressants can potentially deteriorate symptoms of the opposite polarity. This review aimed to provide a synthesis of the current evidence for pharmacotherapy of mixed states with an emphasis on mixed mania/hypomania. A PubMed search was conducted for randomized controlled trials (RCTs) that were at least moderately sized, included a placebo arm, and contained information on acute-phase and maintenance treatments of adult patients with mixed episodes or mania/hypomania with significant depressive symptoms. Most studies were post-hoc subgroup and pooled analyses of the data from RCTs for acute manic and mixed episodes of bipolar I disorder; only two prospectively examined efficacy for mixed mania/hypomania specifically. Aripiprazole, asenapine, carbamazepine, olanzapine, and ziprasidone showed the strongest evidence of efficacy in acute-phase treatment. Quetiapine and divalproex/valproate were also efficacious. Combination therapies with these atypical antipsychotics and mood stabilizers can be considered in severe cases. Olanzapine and quetiapine (alone or in combination with lithium/divalproex) showed the strongest evidence of efficacy in maintenance treatment. Lithium and lamotrigine may be beneficial given their preventive effects on suicide and depressive relapse. Further prospective studies primarily focusing on mixed states are needed.

Treatment recommendations for DSM-5-defined mixed features

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) mixed features specifier provides a less restrictive definition of mixed mood states, compared to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR), including mood episodes that manifest with subthreshold symptoms of the opposite mood state. A limited number of studies have assessed the efficacy of treatments specifically for DSM-5-defined mixed features in mood disorders. As such, there is currently an inadequate amount of data to appropriately inform evidence-based treatment guidelines of DSM-5 defined mixed features. However, given the high prevalence and morbidity of mixed features, treatment recommendations based on the currently available evidence along with expert opinion may be of benefit. This article serves to provide these interim treatment recommendations while humbly acknowledging the limited amount of evidence currently available. Second-generation antipsychotics (SGAs) appear to have the greatest promise in the treatment of bipolar disorder (BD) with mixed features. Conventional mood stabilizing agents (ie, lithium and divalproex) may also be of benefit; however, they have been inadequately studied. In the treatment of major depressive disorder (MDD) with mixed features, the comparable efficacy of antidepressants versus other treatments, such as SGAs, remains unknown. As such, antidepressants remain first-line treatment of MDD with or without mixed features; however, there are significant safety concerns associated with antidepressant monotherapy when mixed features are present, which merits increased monitoring. Lurasidone is the only SGA monotherapy that has been shown to be efficacious specifically in the treatment of MDD with mixed features. Further research is needed to accurately determine the efficacy, safety, and tolerability of treatments specifically for mood episodes with mixed features to adequately inform future treatment guidelines.

Dysphoric mania, mixed states, and mania with mixed features specifier: are we mixing things up?

Various terms have been used to describe mania when it is accompanied by depressive symptoms. In this article, we attempt to define and discuss 3 of these terms: dysphoric mania, mixed state, and mania with mixed features specifier. We conclude that whatever term is used, it is important to be aware that mania is more often unpleasant than pleasant, and that the unpleasantness is not limited to depression.

A pragmatic approach to the diagnosis and treatment of mixed features in adults with mood disorders

Mixed features specifier (MFS) is a new nosological entity defined and operationalized in the Diagnostic and Statistical Manual of Mental Disorders (DSM), 5th Edition. The impetus to introduce the MFS and supplant mixed states was protean, including the lack of ecological validity, high rates of misdiagnosis, and guideline discordant treatment for mixed states. Mixed features specifier identifies a phenotype in psychiatry with greater illness burden, as evidenced by earlier age at onset, higher episode frequency and chronicity, psychiatric and medical comorbidity, suicidality, and suboptimal response to conventional antidepressants. Mixed features in psychiatry have historical, conceptual, and nosological relevance; MFS according to DSM-5, is inherently neo-Kraepelinian insofar as individuals with either Major Depressive Disorder (MDD) or Bipolar Disorder (BD) may be affected by MFS. Clinicians are encouraged to screen all patients presenting with a major depressive episode (or hypomanic episode) for MFS. Although "overlapping symptoms" were excluded from the diagnostic criteria (eg, agitation, anxiety, irritability, insomnia), clinicians are encouraged to probe for these nonspecific symptoms as a possible proxy of co-existing MFS. In addition to conventional antidepressants, second generation antipsychotics and/or conventional mood stabilizers (eg, lithium) may be considered as first-line therapies for individuals with a depressive episode as part of MDD or BD with mixed features.

Relationships between mixed features and borderline personality disorder in 2811 patients with major depressive episode

OBJECTIVE

The study focused on the relationship between mixed depression and borderline personality disorder (BPD).

METHOD

The sample comprised 2811 patients with a major depressive episode (MDE). Clinical characteristics were compared in patients with (BPD+) and without (BPD-) comorbid BPD and in BPD+ with (MXS+) and without (MXS-) mixed features according to DSM-5 criteria.

RESULTS

A total of 187 patients (6.7%) met the criteria for BPD. A DSM-IV-TR diagnosis of bipolar disorder (BD) was significantly more frequent in patients with BPD+ than in patients with BPD. Patients with BPD+ were significantly younger and reported lower age at onset than BPD-. Patients with BPD+ also showed more hypomania/mania in first-degree relatives in comparison with patients with BPD-, as well as more psychiatric comorbidity, mixed features, atypical features, suicide attempts, prior mood episodes and antidepressant-induced hypo/manic switches. Mixed features according to DSM-5 criteria were observed in 52 (27.8%) BPD+. In comparison with MXS-, MXS+ were significantly younger at age of onset and at prior mood episode and had experienced more mood episodes and hypo/manic switches with antidepressant treatments.

CONCLUSION

Major depressive episode patients with comorbid BPD reported a high prevalence of mixed features and BD. The presence of DSM-5 mixed features in MDE patients with BPD may be associated with complex course and reduced treatment response.

Controlling Charge Carrier Overlap in Type-II ZnSe/ZnS/CdS Core-Barrier-Shell Quantum Dots

We describe the synthesis and spectroscopic characterization of colloidal ZnSe/ZnS/CdS nanocrystals, which exhibit a type-II electronic structure and wave function overlap that is strongly dependent on the thickness of the ZnS barrier. Barrier thickness is controlled by both the amount of deposited material and the reaction and annealing temperature of CdS shell growth. The results show that a single monolayer of ZnS mitigates the overlap significantly, while four and more monolayers effectively suppress band edge absorption and emission. Transient absorption spectra reveal a broad distribution of excitons with mixed S and P symmetry, which become allowed due to alloy formation and contribute to charge carrier relaxation across the barrier. We present a model of the core/shell interface based on cation diffusion, which allows one to estimate the extent of the diffusion layer from optical spectra.

DSM-5-defined 'mixed features' and Benazzi's mixed depression: which is practically useful to discriminate bipolar disorder from unipolar depression in patients with depression?

AIMS

Irritability, psychomotor agitation, and distractibility in a major depressive episode (MDE) should not be counted as manic/hypomanic symptoms of DSM-5-defined mixed features; however, this remains controversial. The practical usefulness of this definition in discriminating bipolar disorder (BP) from major depressive disorder (MDD) in patients with depression was compared with that of Benazzi's mixed depression, which includes these symptoms.

METHODS

The prevalence of both definitions of mixed depression in 217 patients with MDE (57 bipolar II disorder, 35 BP not otherwise specified, and 125 MDD cases), and their operating characteristics regarding BP diagnosis were compared.

RESULTS

The prevalence of both Benazzi's mixed depression and DSM-5-defined mixed features was significantly higher in patients with BP than it was in patients with MDD, with the latter being quite low (62.0% vs 12.8% [P < 0.0001], and 7.6% vs 0% [P < 0.0021], respectively). The area under the receiver operating curve for BP diagnosis according to the number of all manic/hypomanic symptoms was numerically larger than that according to the number of manic/hypomanic symptoms excluding the above-mentioned three symptoms (0.798; 95% confidence interval, 0.736-0.859 vs 0.722; 95% confidence interval, 0.654-0.790). The sensitivity/specificity of DSM-5-defined mixed features and Benazzi's mixed depression for BP diagnosis were 5.1%/100% and 55.1%/87.2%, respectively.

CONCLUSIONS

DSM-5-defined mixed features were too restrictive to discriminate BP from MDD in patients with depression compared with Benazzi's definition. To confirm this finding, studies that include patients with BP-I and using tools to assess manic/hypomanic symptoms during MDE are necessary.

Clinical decision making in the treatment of mixed states

OBJECTIVES

We reviewed the treatment of bipolar mixed states using efficacy data of licensed and non-licensed physical or pharmacological treatments.

METHODS

We conducted a literature search to identify published studies reporting data on mixed states. Grading was done using an in-house level of evidence and we compared the efficacy with treatment recommendations of mixed states in current bipolar disorder guidelines.

RESULTS

A total of 133 studies reported data on mixed states, and seven guidelines differentiate the acute treatment of mixed states from pure states. The strongest evidence in treating co-occurring manic and depressive symptoms was for monotherapy with aripiprazole, asenapine, extended release carbamazepine, valproate, olanzapine, and ziprasidone. Aripiprazole was recommended in three guidelines, asenapine in one, and carbamazepine and ziprasidone in two. As adjunctive treatment, the strongest evidence of efficacy was for olanzapine plus lithium or valproate. For maintenance, there is evidence for the efficacy of monotherapy with valproate, olanzapine, and quetiapine. In the six guidelines valproate or olanzapine are first line monotherapy options; one recommends quetiapine. Recommended add-on treatments are lithium or valproate plus quetiapine.

CONCLUSIONS

There is a lack of studies designed to address the efficacy of medications in mixed affective symptoms. Guidelines do not fully reflect the current evidences.

Continuum of depressive and manic mixed states in patients with bipolar disorder: quantitative measurement and clinical features

Bipolar mixed states combine depressive and manic features, presenting diagnostic and treatment challenges and reflecting a severe form of the illness. DSM-IV criteria for a mixed state require combined depressive and manic syndromes, but a range of mixed states has been described clinically. A unified definition of mixed states would be valuable in understanding their diagnosis, mechanism and treatment implications. We investigated the manner in which depressive and manic features combine to produce a continuum of mixed states. In 88 subjects with bipolar disorder (DSM-IV), we evaluated symptoms and clinical characteristics, and compared depression-based, mania-based, and other published definitions of mixed states. We developed an index of the extent to which symptoms were mixed (Mixed State Index, MSI) and characterized its relationship to clinical state. Predominately manic and depressive mixed states using criteria from recent literature, as well as Kraepelinian mixed states, had similar symptoms and MSI scores. Anxiety correlated significantly with depression scores in manic subjects and with mania scores in depressed subjects. Discriminant function analysis associated mixed states with symptoms of hyperactivity and negative cognitions, but not subjective depressive or elevated mood. High MSI scores were associated with severe course of illness. For depressive or manic episodes, characteristics of mixed states emerged with two symptoms of the opposite polarity. This was a cross-sectional study. Mixed states appear to be a continuum. An index of the degree to which depressive and manic symptoms combine appears useful in identifying and characterizing mixed states. We propose a depressive or manic episode with three or more symptoms of the opposite polarity as a parsimonious definition of a mixed state.