Antidepressant response and subthreshold bipolarity in "unipolar" major depressive disorder: implications for practice and drug research

Depression Preceding Diagnosis of Bipolar Disorder

This paper focuses on depression that precedes an onset of manifest bipolar disorder as early stage bipolar disorder. First, we review how to pragmatically identify the clinical characteristics of patients presenting with an episode of depression who subsequently go on to develop episodes of mania or hypomania. The existing literature shows a strong consensus: accurate identification of depression with early onset and recurrent course with multiple episodes, subthreshold hypomanic and/or mixed symptoms, and family history of bipolar disorder or completed suicide have been shown by multiple authors as signs pointing to bipolar diagnosis. This contrasts with relatively limited information available to guide management of such "pre-bipolar" (pre-declared bipolar) patients, especially those in the adult age range. Default assumption of unipolar depression at this stage carries significant risk. Antidepressants are still the most common pharmacological treatment used, but clinicians need to be aware of their potential harm. In some patients with unrecognized bipolar depression, antidepressants can not only produce switch to (hypo)mania, but also mixed symptoms, or worsening of depression with an increased risk of suicide. We review pragmatic management strategies in the literature beyond clinical guidelines that can be considered for this at-risk group encompassing the more recent child and adolescent literature. In the future, genetic research could make the early identification of bipolar depression easier by generating informative markers and polygenic risk scores.

Agitated depression in bipolar disorder

OBJECTIVES

It has been suggested that agitated depression (AD) is a common, severe feature in bipolar disorder. We aimed to estimate the prevalence of AD and investigate whether presence of AD was associated with episodic and lifetime clinical features in a large well-characterized bipolar disorder sample.

METHOD

The prevalence of agitation, based on semi-structured interview and medical case-notes, in the most severe depressive episode was estimated in 2925 individuals with DSM-IV bipolar disorder recruited into the UK Bipolar Disorder Research Network. Predictors of agitation were ascertained using symptoms within the same episode and lifetime clinical features using multivariate models.

RESULTS

32.3% (n = 946) experienced agitation during the worst depressive episode. Within the same episode, significant predictors of presence of agitation were: insomnia (OR 2.119, P < 0.001), poor concentration (OR 1.966, P = 0.027), decreased libido (OR 1.960, P < 0.001), suicidal ideation (OR 1.861, P < 0.001), slowed activity (OR 1.504, P = 0.001), and poor appetite (OR 1.297, P = 0.029). Over the lifetime illness course, co-morbid panic disorder (OR 2.000, P < 0.001), suicide attempt (OR 1.399, P = 0.007), and dysphoric mania (OR 1.354, P = 0.017) were significantly associated with AD.

CONCLUSIONS

Agitation accompanied bipolar depression in at least one-third of cases in our sample and was associated with concurrent somatic depressive symptoms, which are also common features of mixed manic states. Furthermore, AD in our sample was associated with lifetime experience of mixed mania, in addition to severe lifetime illness course including comorbid panic disorder and suicidal behavior. Our results have implications for the diagnosis and treatment of agitated features in bipolar depression.

Patterns of response to antidepressants in major depressive disorder: Drug resistance or worsening of depression are associated with a bipolar diathesis

Resistance and worsening of depression in response to antidepressants (ADs) are major clinical challenges. In a large international sample of patients with major depressive disorder (MDD), we aim to explore the possible associations between different patterns of response to ADs and bipolarity. A total of 2811 individuals with a major depressive episode (MDE) were enrolled in the BRIDGE-II-MIX study. This post-hoc analysis included only 1329 (47%) patients suffering from MDD. Patients with (TRD-MDD, n = 404) and without (NTRD-MDD, n = 925) history of resistance to AD treatment and with (n = 184) and without (n = 1145) previous AD-induced irritability and mood lability (AIM) were compared using Chi-square, t-Student's test and logistic regression models. TRD-MDD patients resulted significantly associated with higher rates of AIM, psychotic features, history of suicide attempts, emotional lability and impulsivity, comorbid borderline personality disorder and polipharmacological treatment, compared to NTRD-MDD group. In comparison to NAIM-MDD patients, subjects in the AIM-MDD group showed significantly higher rates of first-degree family history for BD, previous TRD, atypical features, mixed features, psychiatric comorbidities, lifetime suicide attempts and lower age at first psychiatric symptoms. In addition, patients with AIM presented more often almost all the hypomanic symptoms evaluated in this study. Among these latter symptoms, logistic regressions showed that distractibility, impulsivity and hypersexuality were significantly associated with AIM-MDD. In conclusion, in MDD patients, a lifetime history of resistance and/or irritability/mood lability in response to ADs was associated with the presence of mixed features and a possible underlying bipolar diathesis.

Bipolar features in major depressive disorder: Results from the Iranian mental health survey (IranMHS)

BACKGROUND

Past research suggests that individuals suffering from depressive disorders with bipolar features might have different clinical outcomes resembling bipolar disorders. The objectives of this study are to determine the prevalence of bipolar features among individuals meeting the criteria for 12-month major depressive disorder (MDD) in the Iranian population and to examine the demographic and clinical characteristics associated with these features.

METHODS

Data were drawn from the Iranian Mental Health Survey (IranMHS), a representative household survey of the Iranian population aged 15-64 years. The study sample consisted of all individuals with a 12-month MDD (n = 1014) ascertained by the Composite International Diagnostic Interview (CIDI 2.1) without a lifetime history of bipolar I or II disorders. Mood Disorder Questionnaire (MDQ) was used to screen for the lifetime history of bipolar features among participants with MDD.

RESULTS

Among participants meeting the 12-month MDD criteria, 22.1% (95% CI: 19.6-24.7) had a lifetime history of bipolar features. Compared with those without these features, participants with bipolar features had higher odds of endorsing suicidal ideations and suicide attempts, comorbid anxiety and substance use disorders, severe impairment, history of psychotic symptoms, some features of atypical depression and fewer depressive symptoms. Associations with comorbid anxiety disorders [Odds Ratio (OR) = 1.43; 95% confidence interval (CI): 1.00-2.03] and history of psychotic symptoms (OR = 2.63 95% CI: 1.81-3.81) persisted in multivariable models.

LIMITATION

Relying on self-reports of lifetime bipolar symptoms which is open to recall bias, and cross-sectional study design which limits interpretation of outcome and course of MDD are two major limitations of this study.

CONCLUSION

The presence of bipolar features is associated with a distinct demographic and clinical profile in MDD. Identifying these cases would enhance the homogeneity of the depressive disorder phenotype in general population surveys. Identifying MDD patients with these features has potential clinical implications.

The World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for the Biological Treatment of Bipolar Disorders: Acute and long-term treatment of mixed states in bipolar disorder

OBJECTIVES

Although clinically highly relevant, the recognition and treatment of bipolar mixed states has played only an underpart in recent guidelines. This WFSBP guideline has been developed to supply a systematic overview of all scientific evidence pertaining to the acute and long-term treatment of bipolar mixed states in adults.

METHODS

Material used for these guidelines is based on a systematic literature search using various data bases. Their scientific rigour was categorised into six levels of evidence (A-F), and different grades of recommendation to ensure practicability were assigned. We examined data pertaining to the acute treatment of manic and depressive symptoms in bipolar mixed patients, as well as data pertaining to the prevention of mixed recurrences after an index episode of any type, or recurrence of any type after a mixed index episode.

RESULTS

Manic symptoms in bipolar mixed states appeared responsive to treatment with several atypical antipsychotics, the best evidence resting with olanzapine. For depressive symptoms, addition of ziprasidone to treatment as usual may be beneficial; however, the evidence base is much more limited than for the treatment of manic symptoms. Besides olanzapine and quetiapine, valproate and lithium should also be considered for recurrence prevention.

LIMITATIONS

The concept of mixed states changed over time, and recently became much more comprehensive with the release of DSM-5. As a consequence, studies in bipolar mixed patients targeted slightly different bipolar subpopulations. In addition, trial designs in acute and maintenance treatment also advanced in recent years in response to regulatory demands.

CONCLUSIONS

Current treatment recommendations are still based on limited evidence, and there is a clear demand for confirmative studies adopting the DSM-5 specifier with mixed features concept.

Antidepressant-induced hypomania/mania in patients with major depression: Evidence from the BRIDGE-II-MIX study

BACKGROUND

The issue of antidepressant-induced mood switches to hypomania, mania, or mixed states within the course of mayor depressive disorder (MDD) has been a controversial topic. The present post-hoc analysis of the BRIDGE-II-MIX study focuses on the clinical features of patients with history of antidepressant-induced hypomania/mania (AIHM) in a large international sample of patients with major depressive episode (MDE).

METHODS

2811 subjects with major depression were enrolled in this multicentre cross-sectional study. Current mixed symptoms, socio-demographic and other clinical variables were collected and compared among MDD-AIHM, MDD and BD patients.

RESULTS

475 patients out of 2811 had history of AIHM (16.90%). In the MDD-AIHM group, familiarity for BD and rates of atypical features and comorbid anxiety, eating and borderline personality disorders were similar to BD and significantly more frequent compared to MDD group. MDD-AIHM patients had more frequently more than 3 episodes and reported higher rates of treatment resistance, mood lability and irritability following treatment with antidepressants. Frequencies of depression with mixed features and (hypo)manic symptoms were similar in patients of MDD-AIHM and BD groups and significantly higher in both groups than in MDD.

LIMITATIONS

there were widely varying rates of hospitalized patients across countries and the participating centres were not randomly selected.

CONCLUSIONS

Our results strongly support the DSM-5 inclusion of MDD patients with AIHM within the rubric of bipolar disorder. Differences with other MDD and BD were also observed suggesting the possibility that MDD-AIHM may represent a specific sub-population, particularly sensitive to exogenous input from antidepressants.

Treatment response in relation to subthreshold bipolarity in patients with major depressive disorder receiving antidepressant monotherapy: a post hoc data analysis (KOMDD study)

BACKGROUND

The aim of this observational study was to determine whether subthreshold bipolarity affects treatment response and remission in patients with major depressive disorder receiving antidepressant (AD) monotherapy over a 6-month follow-up period.

METHODS

Seventy-eight patients with major depressive disorder were stratified into two subgroups according to the presence of subthreshold bipolarity, identified using the Korean version of the Mood Disorder Questionnaire (K-MDQ), which classifies patients as positive for a screening of bipolarity based on the cutoff for the total K-MDQ score (ie, 7 points). They received AD monotherapy such as escitalopram, sertraline, paroxetine, or tianeptine for 6 months. The Beck Depression Inventory (BDI), Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Scale, and Beck Scale for Suicide Ideation were applied at baseline, 1 week, 3 weeks, 2 months, 3 months, and 6 months.

RESULTS

The mean HAMD, BDI, and Beck Scale for Suicide Ideation scores were higher in the bipolarity group than in the nonbipolarity group at 3 weeks. The mean BDI score was also higher in the bipolarity group than in the nonbipolarity group at 6 months. Evaluation of the ratio of improvement for each scale revealed different patterns of percentage changes between the two groups over the 6-month follow-up period. Furthermore, the response and remission rates (as assessed using BDI and HAMD scores) were higher in the nonbipolarity group than in the bipolarity group, with the exception of HAMD scores at the 3-week follow-up time point.

CONCLUSION

The findings of this study showed that depressed patients with bipolarity had a worse response to AD monotherapy than did those without bipolarity.

Onset polarity and illness course in bipolar I and II disorders: The predictive role of broadly defined mixed states

Several studies investigating bipolar disorders have shown that polarity of onset can predict differences in symptomatology, course, and prognosis. Frequently, however, research on the topic has examined only bipolar I inpatients and has not included patients with mixed onset. The aim of the present naturalistic study was to evaluate the clinical characteristics and illness course of a consecutive sample (407 outpatients, 58.7% with bipolar I (BD-I) and 41.3% with bipolar II (BD-II) disorder) according to polarity of onset: depressive (DP-o); manic/hypomanic (HM-o); or mixed--broadly defined to include agitated depression for BD-II--onset (MX-o). As compared with patients in the other two groups: a) DP-o patients (67.3%) were more frequently affected by BD-II and had lower ratings for psychotic symptoms; b) HM-o patients (17%) had a higher rate of family history for psychosis and a lower rate of suicide attempts; and c) patients in the MX-o group (15.7%) more frequently showed substance abuse and had a higher number of mixed recurrences per year. In the BD-II group, MX-o patients more frequently attempted suicide. The present study's main limitations are those of retrospective assessment of onset polarity and lack of treatment-impact evaluations over illness course. In conclusion, we confirm clinical expression differences in bipolar disorder in function of polarity of onset and underscore the importance of carefully considering broadly defined mixed state when examining polarity of onset. Further investigations are required to confirm the present study's results.

Short-term antidepressant treatment of bipolar depression: are ISBD recommendations useful in clinical practice?

OBJECTIVES

The study aimed to test the effectiveness of the ISBD Guidelines for short-term AD treatment of BP depression.

METHODS

The study sample included 255 patients with mood disorders (154 UP, 49 BP-I, 52 BP-II). Response was defined as a HDRS21 total score<7 at 12 weeks of treatment and remission as a ≥50% reduction of baseline HDRS21 total score sustained for 8 weeks.

RESULTS

Response was achieved by 64.9% of patients with UP disorder, 75.5% of patients with BP-I disorder and 75.0% with BP-II disorder without significant differences (χ²=3.0, p=0.219). The remission rate did not differ significantly among groups (χ²=3.8, p=0.151). The dropout rate was significantly higher for patients with UP (18.2%) than for patients with BP-I (2%) and BP-II (7.7%) disorder (χ²=10.1, p=0.006). Concerning AD safety, one patient with BP-I depression committed a suicide attempt and AD-emerging switch was observed in 2.9% of patients, 2 with BP-I and 1 with BP-II disorder.

LIMITATIONS

The observational nature of the study and unblinded outcomes assessment.

CONCLUSIONS

Our findings confirm the usefulness of ISBD Guidelines for short-term AD treatment of BP depression. These patients appear to have similar response and remission rate to those observed in UP depression and do not exhibit significant switch rates or risk of suicide. Our results are limited to patients with pure bipolar depression (excluding those with broadly defined mixed states), treated with ADs-mood stabilizers combination. We suggest to partially modify ISBD Recommendations 1 and 4, to include potential responders and to improve safety.

Characterization of patients with mood disorders for their prevalent temperament and level of hopelessness

BACKGROUND

Mood disorders (MD) are disabling conditions throughout the world associated with significant psychosocial impairment. Affective temperaments, as well as hopelessness, may play a significant role in the pathophysiology of MD. The present study was designed to characterize patients with MD for their prevalent affective temperament and level of hopelessness.

METHODS

Five hundred fifty-nine (253 men and 306 women) consecutive adult inpatients were assessed using the Temperament Evaluation of Memphis, Pisa, Paris and San Diego-Autoquestionnaire version (TEMPS-A), the Gotland Scale for Male Depression (GSMD), the Beck Hopelessness Scale (BHS) and the Mini International Neuropsychiatric Interview (MINI).

RESULTS

Higher cyclothymia and irritable temperaments were found in bipolar disorder-I (BD-I) patients compared to those with other Axis I diagnoses. Major depressive disorder (MDD) patients had lower hyperthymia than BD-I and BD-II patients and higher anxiety than patients with other Axis I diagnoses. Severe "male" depression was more common in BD-II patients compared to BD-I and MDD patients. BD-I patients and those with other axis I diagnoses reported lower BHS ≥9 scores than those with BD-II and MDD.

LIMITATIONS

The study had the limitations of all naturalistic designs, that is, potentially relevant variables were not addressed. Furthermore, the cross-sectional nature of the study did not allow conclusions about causation, and the use of self-report measures could be potentially biased by social desirability.

CONCLUSION

MDD patients were more likely to have higher anxious temperament, higher hopelessness and lower hyperthymic temperament scores, while BD-I patients more often had cyclothymic and irritable temperaments than patients with other Axis I diagnoses. The implications of the present results were discussed.

Predictive value of baseline resistance in early response to antidepressants

BACKGROUND

Major Depressive Disorder (MDD) is the 3rd source for burden worldwide according to the World Health Organization (WHO). This comes partly from unsatisfactory response rates after usual treatment, highlighting the need for early indicators such as early improvement of depressive symptoms to adapt treatment strategies, especially for severe inpatients. Thus our objective was to assess the predictive value of baseline partial resistance in early antidepressant response (EAR), hypothesizing that previous treatment failures would decrease the probability of early response.

METHODS

We included 122 consecutive inpatients with current unipolar MDE. The Mini-Neuropsychiatric Interview was used to ascertain DSM-IV diagnoses of MDD as well as psychiatric comorbidities, and to exclude patients with a history of bipolar disorder. A specifically designed questionnaire was used to collect data on previous treatment trials for the current episode so as to generate scores on the five existing methods for quantifying treatment resistance. We prospectively assessed EAR, defined as a 50% decrease in MADRS after 14 days of steady regimen of antidepressant.

RESULTS

In the per protocol sample (N=76), multivariate analyses showed that psychotic features at baseline remained an independent predictor of absence of EAR (p<.01), unlike baseline partial resistance, which may rather be associated with a lack of any improvement.

LIMITATIONS

Lack of data about further response and non-randomized treatment allocation.

CONCLUSION

Available methods for quantifying treatment resistance are heterogeneous and do not predict short-term response among severely depressed inpatients, despite potential usefulness in predicting a lack of early improvement.