Reviewing the diagnostic validity and utility of mixed depression (depressive mixed states)

Abstract

Categorically-defined mixed depression may have some diagnostic validity (family history is the current strongest validator). Its diagnostic utility seems supported by treatment response.

Lurasidone in the Treatment of Bipolar Depression With Mixed (Subsyndromal Hypomanic) Features

“…Multiple lines of evidence indicate that the presence of mixed features during a depressive episode identifies a bipolar disorder population characterized by more severe and/ or chronic depressive episodes, with shorter interepisode remissions, a higher recurrence rate, an increased risk of switch to mania during antidepressant therapy, higher rates of comorbidity (most notably anxiety disorders and/or substance use disorders), and a higher risk of suicide attempts. [1][2][3][4][5][6][7][8][9] Prevalence estimates for mixed features vary widely depending on the criteria used and on the setting and population studied. 1,2 In a community sample, 41.4% of individuals who met DSM-IV criteria for major depression also met criteria for subthreshold hypomania (≥ 4 symptoms, but not meeting DSM-IV criteria for hypomania, based on the Munich Composite International Diagnostic Interview).…”

Mixed-up about how to diagnose and treat mixed features in major depressive episodes

“…7,9 That means in practice that 13% of patients identified with mixed features actually do not have it and might inappropriately get an atypical antipsychotic rather than antidepressant monotherapy. But, less than half of patients with mixed features are at risk of getting the wrong treatment.…”

“…In the case of the DSM-5 diagnosis of mixed features, there is 100% specificity (everybody really has mixed features by this definition), but only 5.1% sensitivity. 7,9 So, all patients diagnosed will indeed have mixed features, but only 5.1% of individuals with mixed features will be identified. If the goal is impeccably accurate diagnosis, this is the way to go, particularly for research studies perhaps.…”

“…4 However, several diagnostic criteria other than the DSM-5 do include these 3 symptoms, the argument being that excluding them will lead to misdiagnosis and inappropriate, if not dangerous, treatment strategies for those patients with MDEs who narrowly miss full DSM-5 criteria. [6][7][8][9][10] For example, 4 times as many patients are identified as having MDEs with mixed features using research diagnostic criteria than with the DSM-5. 2 Imagine, for example, if we were to exclude psychosis as a diagnostic feature of schizophrenia because it overlaps with other disorders!…”

Adjuvant valproate therapy for patients with suspected mixed-depressive features

“…Mood stabilizers are expected to be effective for these 'subthreshold' affective symptoms in the same way that they work in bipolar disorders [Benazzi, 2007;Hantouche et al 2005]; however, there is no consensus about the concept of mixeddepressive features among experts in bipolar and affective disorders [Benazzi, 2008b;Koukopoulos et al 2005;Koukopoulos and Sani, 2014], and this is relatively new to psychiatrists practicing in community settings [Schneck, 2009]. Currently, only limited, yet supportive, evidence for adjuvant valproate therapy for bipolar depression has been reported [Ghaemi et al 2007], but no guidelines are available for treating depressive-mixed states [Vieta and Valenti, 2013].…”