There are few controlled studies evaluating the treatment of bipolar mixed states. Evidence suggests that mixed states may be more responsive to some anticonvulsants than to lithium. Olanzapine alone or in combination with divalproate or lithium has been adequately evaluated in randomized clinical trials involving mixed-state patients, whereas risperidone and quetiapine have not. There is also some evidence demonstrating the efficacy of ziprasidone and aripiprazole. The risk of switching to depression is high in mixed states. Conventional antipsychotics, such as haloperidol, may be less efficacious at protecting against a switch to depression than atypical antipsychotics, divalproate or lithium. When choosing drugs for the treatment of mania, and especially for the treatment of mixed states, their efficacy against manic and depressive symptoms, and their safety in terms of the risk of switching to depression should be taken into account.

Mixed states address the relationships between episodes and the course of an illness, presenting significant clinical challenges. Recurrent affective disorders were described thousands of years ago as dimensional disturbances of the basic elements of behavior, combining the characteristics of what we would now consider manic and depressive episodes. It was recognized from the beginning that combinations of depressive and manic features are associated with a severe illness course, including increased suicide risk. Early descriptions of affective disorders formulated them as systemic illnesses, a concept supported by more recent data. Descriptions of affective disorders and their course, including mixed states, became more systematic during the 19th century. Structured criteria achieved importance with evidence that, in addition to early onset, frequent recurrence, and comorbid problems, mixed states had worse treatment outcomes than other episodes. In contrast to 2000 years of literature on recurrent affective episodes and mixed states, the unipolar–bipolar disorder distinction was formalized in the mid-20th century. Mixed-state criteria, initially developed for bipolar disorder, ranged from fully combined depression and mania to the DSM–5 criteria, no longer limited to bipolar disorder, of a primary depressive or manic episode with at least three symptoms of the other episode type. The challenges involved in understanding and identifying mixed states center largely on what drives them, including (1) their formulation as either categorical or dimensional constructs, (2) the specificity of their relationships to depressive or manic episodes, and (3) specificity for bipolar versus major depressive disorder. Their existence challenges the distinction between bipolar and major depressive disorders. The challenges involved in identifying the underlying physiological mechanisms go to the heart of these questions.

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.

Mixed affective states, defined as the coexistence of depressive and manic symptoms, are complex presentations of manic-depressive illness that represent a challenge for clinicians at the levels of diagnosis, classification, and pharmacological treatment. The evidence shows that patients with bipolar disorder who have manic/hypomanic or depressive episodes with mixed features tend to have a more severe form of bipolar disorder along with a worse course of illness and higher rates of comorbid conditions than those with non-mixed presentations. In the updated Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–5), the definition of “mixed episode” has been removed, and subthreshold nonoverlapping symptoms of the opposite pole are captured using a “with mixed features” specifier applied to manic, hypomanic, and major depressive episodes. However, the list of symptoms proposed in the DSM–5 specifier has been widely criticized, because it includes typical manic symptoms (such as elevated mood and grandiosity) that are rare among patients with mixed depression, while excluding symptoms (such as irritability, psychomotor agitation, and distractibility) that are frequently reported in these patients. With the new classification, mixed depressive episodes are three times more common in bipolar II compared with unipolar depression, which partly contributes to the increased risk of suicide observed in bipolar depression compared to unipolar depression. Therefore, a specific diagnostic category would imply an increased diagnostic sensitivity, would help to foster early identification of symptoms and ensure specific treatment, as well as play a role in suicide prevention in this population.

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.

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.

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.

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.

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.

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.