Olanzapine and fluoxetine combination therapy for treatment-resistant depression: review of efficacy, safety, and study design issues

Efficacy and safety of low-dose amisulpride versus olanzapine-fluoxetine combination in post-schizophrenic depression: A randomized controlled trial

Post-schizophrenic depression (PSD) increases the morbidity, mortality, and health burden in patients with schizophrenia. However, treatment of PSD is challenging due to the lack of substantial evidence of standard clinical practice. This study was aimed at comparing the efficacy and safety of low-dose amisulpride versus olanzapine-fluoxetine combination (OFC) in PSD. This was a randomized controlled trial conducted in sixty patients with PSD fulfilling the eligibility criteria. Recruited patients were randomized to receive either amisulpride at low dose (i.e., 100-300 mg/day) or OFC (5/10 mg + 20 mg) for eight weeks. The Calgary Depression Scale for Schizophrenia (CDSS), the Clinical Global Impression-Severity (CGI-S) and serum BDNF levels were assessed at baseline and after eight weeks of treatment. The change in the CDSS scores from baseline over eight weeks was significant in both the amisulpride and OFC groups. However, the changes were not significant when compared between the groups. Similarly, the changes in CGI-S scores and serum BDNF levels were significant in each group; but non-significant between the groups. A significant negative correlation was found between the changes in the CDSS scores and the serum BDNF levels in each group. No significant adverse events were noted in either group. Thus, to conclude, low-dose amisulpride can be a potential monotherapy in PSD with a favourable clinical outcome and safety profile (ClinicalTrials.gov ID: NCT04876521).

Pharmacological treatments for psychotic depression: a systematic review and network meta-analysis

BACKGROUND

There are no recommendations based on the efficacy of specific drugs for the treatment of psychotic depression. To address this evidence gap, we did a network meta-analysis to assess and compare the efficacy and safety of pharmacological treatments for psychotic depression.

METHODS

In this systematic review and network meta-analysis, we searched ClinicalTrials.gov, CENTRAL, Embase, PsycINFO, PubMed, Scopus, and Web of Science from inception to Nov 23, 2023 for randomised controlled trials published in any language that assessed pharmacological treatments for individuals of any age with a diagnosis of a major depressive episode with psychotic features, in the context of major depressive disorder or bipolar disorder in any setting. We excluded continuation or maintenance trials. We screened the study titles and abstracts identified, and we extracted data from relevant studies after full-text review. If full data were not available, we requested data from study authors twice. We analysed treatments for individual drugs (or drug combinations) and by grouping them on the basis of mechanisms of action. The primary outcomes were response rate (ie, the proportion of participants who responded to treatment) and acceptability (ie, the proportion who discontinued treatment for any reason). We calculated risk ratios and did separate frequentist network meta-analyses by using random-effects models. The risk of bias of individual studies was assessed with the Cochrane risk-of-bias tool and the confidence in the evidence with the Confidence-In-Network-Meta-Analysis (CINeMA). This study was registered with PROSPERO, CRD42023392926.

FINDINGS

Of 6313 reports identified, 16 randomised controlled trials were included in the systematic review, and 14 were included in the network meta-analyses. The 16 trials included 1161 people with psychotic depression (mean age 50·5 years [SD 11·4]). 516 (44·4%) participants were female and 422 (36·3%) were male; sex data were not available for the other 223 (19·2%). 489 (42·1%) participants were White, 47 (4·0%) were African American, and 12 (1·0%) were Asian; race or ethnicity data were not available for the other 613 (52·8%). Only the combination of fluoxetine plus olanzapine was associated with a higher proportion of participants with a treatment response compared with placebo (risk ratio 1·91 [95% CI 1·27-2·85]), with no differences in terms of safety outcomes compared with placebo. When treatments were grouped by mechanism of action, the combination of a selective serotonin reuptake inhibitor with a second-generation antipsychotic was associated with a higher proportion of treatment responses than was placebo (1·89 [1·17-3·04]), with no differences in terms of safety outcomes. In head-to-head comparisons of active treatments, a significantly higher proportion of participants had a response to amitriptyline plus perphenazine (3·61 [1·23-10·56]) and amoxapine (3·14 [1·01-9·80]) than to perphenazine, and to fluoxetine plus olanzapine compared with olanzapine alone (1·60 [1·09-2·34]). Venlafaxine, venlafaxine plus quetiapine (2·25 [1·09-4·63]), and imipramine (1·95 [1·01-3·79]) were also associated with a higher proportion of treatment responses overall. In head-to-head comparisons grouped by mechanism of action, antipsychotic plus antidepressant combinations consistently outperformed monotherapies from either drug class in terms of the proportion of participants with treatment responses. Heterogeneity was low. No high-risk instances were identified in the bias assessment for our primary outcomes.

INTERPRETATION

According to the available evidence, the combination of a selective serotonin reuptake inhibitor and a second-generation antipsychotic-and particularly of fluoxetine and olanzapine-could be the optimal treatment choice for psychotic depression. These findings should be taken into account in the development of clinical practice guidelines. However, these conclusions should be interpreted cautiously in view of the low number of included studies and the limitations of these studies.

FUNDING

None.

Integrative Research of Neuropharmacology and Informatics Pharmacology for Mental Disorder

Mental illness poses a huge social burden, accounting for approximately 14% of all deaths. Depression, a major component of mental illness, affects approximately 300 million people worldwide, mainly in developed countries, and is not only a major social burden but also a cause of suicide. The social burden of depression is estimated to increase further in developing countries, and overcoming it is a pressing issue for all countries, including Japan. Although clinical evidence has demonstrated the efficacy of serotonergic neurotransmission enhancers in the treatment of depression, the full picture of their therapeutic effects has not yet been fully elucidated. In this review, we show that the hyperactivity of serotonin neurons, especially those in the dorsal raphe nucleus, is commonly induced by various antidepressants within a period corresponding to the onset of their clinical efficacy. We established quantitative prediction methods for pharmacological activity using only chemical structures to translate the biological understanding of mental disorders, including major depressive disorders, into clinically effective therapeutics. Our method exhibited better performance than the previously reported methods of quantitative prediction, while targeting a larger number of proteins. Our article suggests the importance of integrative neuropharmacology and informatics-based pharmacology studies to understand the biological basis of mental disorders and facilitate drug development for these disorders.

Post-weaning Social Isolated Flinders Sensitive Line Rats Display Bio-Behavioural Manifestations Resistant to Fluoxetine: A Model of Treatment-Resistant Depression

Treatment-resistant depression (TRD) complicates the management of major depression (MD). The underlying biology of TRD involves interplay between genetic propensity and chronic and/or early life adversity. By combining a genetic animal model of MD and post-weaning social isolation rearing (SIR), we sought to produce an animal that displays more severe depressive- and social anxiety-like manifestations resistant to standard antidepressant treatment. Flinders Sensitive Line (FSL) pups were social or isolation reared from weaning [postnatal day (PND) 21], receiving fluoxetine (FLX) from PND 63 (10 mg/kg × 14 days), and compared to Sprague Dawley (SD) controls. Depressive-, anxiety-like, and social behaviour were assessed from PND 72 in the forced swim test (FST) and social interaction test (SIT). Post-mortem cortico-hippocampal norepinephrine (NE), serotonin (5-HT), and dopamine (DA), as well as plasma interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-α), corticosterone (CORT), and dopamine-beta-hydroxylase (DBH) levels were assayed. FSL rats displayed significant cortico-hippocampal monoamine disturbances, and depressive- and social anxiety-like behaviour, the latter two reversed by FLX. SIR-exposed FSL rats exhibited significant immobility in the FST and social impairment which were, respectively, worsened by or resistant to FLX. In SIR-exposed FSL rats, FLX significantly raised depleted NE and 5-HT, significantly decreased DBH and caused a large effect size increase in DA and decrease in CORT and TNF-α. Concluding, SIR-exposed FSL rats display depressive- and social anxiety-like symptoms that are resistant to, or worsened by, FLX, with reduced plasma DBH and suppressed cortico-hippocampal 5-HT, NE and DA, all variably altered by FLX. Exposure of a genetic animal model of MD to post-weaning SIR results in a more intractable depressive-like phenotype as well as changes in TRD-related biomarkers, that are resistant to traditional antidepressant treatment. Given the relative absence of validated animal models of TRD, these findings are especially promising and warrant study, especially further predictive validation.

Efficacy of vortioxetine monotherapy compared with combined therapy vortioxetine and olanzapine in the treatment of major depression – first results

Vortioxetine is a novel antidepressant with two mechanisms of action – direct effect on several serotonin receptors and serotonin reuptake inhibition. Atypical antipsychotics, such as olanzapine, used in the augmentation of antidepressants causes not only a better response to treatment, but also increased number of remissions. The aim of our work was to evaluate the efficacy of vortioxetine monotherapy compared to the combined treatment vortioxetine and olanzapine in adult patients with depression during the acute phase of treatment lasting 6 weeks. Depressive symptomatology was assessed by the MADRS scale, anxiety symptoms were assessed by the HAM-A scale and global clinical impression were evaluated by the CGI-S scale. The number of patients in full-analysis set was 28. The results showed statistically significant improvement in CGI-S for both groups. Patients with vortioxetine monotherapy showed significant improvement in MADRS total score from the third week of treatment (p = 0.009) compared to patients with combined therapy that showed significant improvement since the end of first week of treatment (p = 0.036). Both groups showed significant improvement in HAM-A total score from the second week of treatment. Our results show the possibility of olanzapine in the augmentation strategy in treatment of major depressive disorder in adult patients.

Efficacy and safety of olanzapine/fluoxetine combination in the treatment of treatment-resistant depression: a meta-analysis of randomized controlled trials

BACKGROUND

Whether olanzapine/fluoxetine combination (OFC) is superior to olanzapine or fluoxetine monotherapy in patients with treatment-resistant depression (TRD) remains controversial. Thus, we conducted this meta-analysis of randomized controlled trials (RCTs) to compare the efficacy and safety of OFC with olanzapine or fluoxetine monotherapy for patients with TRD.

MATERIALS AND METHODS

RCTs published in PubMed, Embase, Web of Science, and the ClinicalTrials.gov registry were systematically reviewed to assess the efficacy and safety of OFC. Outcomes included mean changes from baseline in Montgomery-Asberg Depression Rating Scale (MADRS), Clinical Global Impression-Severity (CGI-S), Hamilton Rating Scale for Anxiety (HAM-A), Brief Psychiatric Rating Scale (BPRS) scores, response rate, remission rate, and adverse events. Results were expressed with weighted mean difference (WMD) with 95% confidence intervals (CIs) and risk ratio (RR) with 95% CIs.

RESULTS

A total of five RCTs with 3,020 patients met the inclusion criteria and were included in this meta-analysis. Compared with olanzapine or fluoxetine monotherapy, OFC was associated with greater changes from baseline in MADRS (WMD =-3.37, 95% CI: -4.76, -1.99; P<0.001), HAM-A (WMD =-1.82, 95% CI: -2.25, -1.40; P<0.001), CGI-S (WMD =-0.37, 95% CI: -0.45, -0.28; P<0.001), and BPRS scores (WMD =-1.46, 95% CI: -2.16, -0.76; P<0.001). Moreover, OFC had significantly higher response rate (RR =1.35, 95% CI: 1.12, 1.63; P=0.001) and remission rate (RR =1.71, 95% CI: 1.31, 2.23; P<0.001). The incidence of treatment-related adverse events was similar between the OFC and monotherapy groups (RR =1.01, 95% CI: 0.94, 1.08; P=0.834).

CONCLUSION

OFC is more effective than olanzapine or fluoxetine monotherapy in the treatment of patients with TRD. Our results provided supporting evidence for the use of OFC in TRD. However, considering the limitations in this study, more large-scale, well-designed RCTs are needed to confirm these findings.

RISK OF NEW ONSET TYPE II DM IN MDD PATIENTS RECEIVING SECOND-GENERATION ANTIPSYCHOTICS TREATMENT: A NATIONWIDE COHORT STUDY

BACKGROUND

Second-generation antipsychotics (SGA) augmentation treatment has showed better efficacy in patients with major depressive disorder (MDD). However, the association between SGA and diabetes mellitus (DM) in MDD patients deserves further investigation. The study aimed to examine the risk of new onset type II DM in MDD patients receiving SGA treatment.

METHODS

From the Psychiatric Inpatient Medical Claim Dataset, MDD patients treated with SGA continuously for more than 8 weeks were analyzed in a 1:1 propensity score matched pair sample to 1,049 patients that had never been treated with SGA. Patients were followed up to 5 years based on ICD-9 CM codes indicating incident type II DM. Cumulative incidences of type II DM were calculated and the Cox proportional hazards model with competing risk was applied to determine the risk factors for type II DM onset.

RESULTS

Cumulative incidences of new-onset type II DM between the two groups were similar. Use of SGA showed no significant increase in risk for new-onset type II DM (hazard ratio [HR] = 0.898; 95% confidence interval [CI], 0.605-1.334; P-value = 0.596). Increased risk for type II DM was shown to be associated with aging (per year) (HR = 1.039; 95% CI, 1.026-1.053; P-value < 0.001) and history of hyperlipidemia (HR = 2.323; 95% CI, 1.469-3.675; P-value < 0.001).

CONCLUSIONS

This study indicated that there is no significant difference in the risk of developing type II DM between MDD patients with and without SGA exposure. More studies focused on the benefit-risk assessment of SGA treatment in patients with MDD are warranted.

Efficacy and safety of fluoxetine monotherapy in bipolar depression: a systematic review

INTRODUCTION

The treatment of depressive episodes in bipolar disorder (BD) remains a challenge for clinicians and is a hot topic in current psychiatric practice. In the present review, we focused on efficacy and safety of fluoxetine monotherapy in order to identify published randomized double-blind trials and open-label trials, written in English, reporting the outcome of fluoxetine treatment in depressed bipolar patients.

AREAS COVERED

We searched Pubmed to identify published randomized double-blind trials and open-label trials, written in English, reporting the results of fluoxetine treatment in depressed bipolar patients. The following key words were used: fluoxetine AND bipolar AND depression AND treatment. A total number of seven prospective studies (four randomized clinical trials and three open-label trials) and one two-phase retrospective study were reviewed.

EXPERT OPINION

Fluoxetine showed to be efficacious in bipolar depression, confirming its well-known activity in major depressive episodes, with a low percentage of mood switch, despite the general view that antidepressants may increase the rate of manic/hypomanic episodes in BDs. More studies with larger sample sizes, comparing fluoxetine with other antidepressants, mood stabilizers and antipsychotics are needed.

Bipolarity and inadequate response to antidepressant drugs: clinical and psychopharmacological perspective

OBJECTIVES

The reason why depression may respond poorly to treatment with antidepressant drugs may be connected with the features of bipolarity. Evidence to this effect has accumulated in recent studies of various kinds of depression in mood disorders. Additional evidence for such a connection may be the efficacy of mood-stabilizing drugs in the augmentation of antidepressants in treatment-resistant depression.

METHODS

This review is based on clinical and psychopharmacological research performed over the past five years. The clinical investigation was based on the response to antidepressants of bipolar depression or to symptoms of hypomania, assessed mainly by the Mood Disorder Questionnaire (MDQ) and the Hypomania Checklist-32 (HCL-32). The psychopharmacological research tested the efficacy of augmentation of antidepressants in treatment-resistant depression by mood-stabilizing drugs of the 1st and 2nd generations.

RESULTS

A number of studies have pointed to an association between bipolar depression, or symptoms of hypomania and an inadequate response to antidepressants. Such a connection was also found in the Polish TRES-DEP study which included 1051 depressed patients. Pharmacological studies have demonstrated the efficacy of first generation mood-stabilizing drugs (lithium, carbamazepine) and second generation drugs (quetiapine, olanzapine, risperidone, ziprasidone, lamotrigine) for augmentation of antidepressants in treatment-resistant depression. Some evidence has been presented that mixed depressive episodes may also belong to this category.

CONCLUSIONS

The results of these clinical and psychopharmacological studies appear to confirm an association between bipolarity and a poor response of depression to treatment with antidepressant drugs.

Therapeutic options in treatment-resistant depression

The phenomenon of treatment-resistant depression (TRD), described as the occurrence of an inadequate response after an adequate treatment with antidepressant agents (in terms of dose, duration, and adherence), is very common in clinical practice. It has been broadly defined in the context of unipolar major depression, but alternative definitions for bipolar depression have also been suggested. In both cases, there is a remarkable lack of consensus amongst professionals concerning its operative definition. A relatively wide variety of treatment options for unipolar TRD are available, whilst the evidence is very scanty for bipolar TRD. TRD is associated to poor clinical, functional, and social outcomes. Several novel therapeutic options are currently being investigated as promising alternatives, targeting the neurotransmitter system outside of the standard monoamine hypothesis. Augmentation or combination with lithium or atypical antipsychotics appears as a valid option for both conditions, and the same occurs with electroconvulsive therapy. Other non-pharmacological strategies such as deep brain stimulation may be promising alternatives for the future. The use of cognitive behaviour therapy is recommended for unipolar TRD, but there is no evidence supporting its use in bipolar TRD.

Acute Bipolar Depression: A Review of the Use of Olanzapine/Fluoxetine

Depression is the predominant mood state in patients with bipolar I or II disorder over the course of illness. In spite of this, relatively few pharmacological treatments have been shown to be effective for treating depressive episodes associated with bipolar disorder in adults. Combination therapy with olanzapine and fluoxetine (OFC) is approved in the US for the treatment of acute depressive episodes in adults with bipolar I disorder. The short-term efficacy and safety of OFC for the treatment of bipolar depression are supported by results of four randomized, acute-phase studies. OFC has been associated with significantly greater depressive symptom improvement than placebo, and with higher rates of treatment response and remission than placebo and olanzapine monotherapy. OFC has also been shown to improve depressive symptoms to a greater degree than modestly dosed lamotrigine, with similar rates of positive treatment response and remission. Although OFC was generally well tolerated in each of the reviewed studies, clinically significant weight gain, adverse changes in glycemic and lipid profile, and prolactin elevation may complicate both short- and long-term treatment. OFC was not associated with significantly increased risk of treatment-emergent mania in any of the reviewed studies. The broader effectiveness of OFC for the treatment of bipolar depression across clinically relevant subtypes (eg, patients with bipolar II disorder and comorbid substance abuse) and over long-term follow-up are needed. Comparative effectiveness studies of OFC and other available agents are also needed in order to determine its place among other available options for treating acute bipolar depressive episodes.

Efficacy, safety and tolerability of Symbyax for acute-phase management of treatment-resistant depression

Treatment resistance is frequently encountered during the long-term care of patients with major depression. A number of 'next step' therapeutic options exist in such cases, including switching to an alternative antidepressant, combining antidepressants from different pharmacological classes, adding evidence-supported psychotherapies to ongoing antidepressant treatment and augmentation with a nonantidepressant drug. Augmenting antidepressants with atypical antipsychotic drugs has generated considerable clinical interest. Three atypical antipsychotics (aripiprazole, quetiapine and olanzapine) have received regulatory approval for adjunctive use with antidepressants for treatment-resistant major depression (TRD) in adults. Symbyax (olanzapine-fluoxetine combination or OFC), the combination of olanzapine and the selective serotonin-reuptake inhibitor fluoxetine, is also approved for this indication. The short-term effectiveness of OFC for TRD is supported by results of five published randomized, controlled, acute-phase studies of generally similar design. In each study, OFC was associated with rapid reduction in depressive symptoms. In two studies, significantly greater improvement in depressive symptoms occurred in OFC-treated patients at study end point compared with those who received antidepressant monotherapy. These effects appeared to be strongest in cases where antidepressant failure was established during the current depressive episode. Although OFC was well-tolerated, increases in body weight and prolactin concentration were greater with OFC than antidepressant monotherapy, and were similar to olanzapine monotherapy. Increases in random total cholesterol levels were greatest for OFC, and were significantly greater than those of olanzapine and antidepressant monotherapy. The long-term efficacy and tolerability of OFC for TRD has not been investigated, and the comparative effectiveness of OFC versus other next-step options is unknown. As such, the exact place of OFC among the available therapeutic options for TRD is not fully understood at this time.

Analysis of Classes Used in the Treatment of Depression by Physician-reported Severity

We analyzed use of therapeutic drug classes for the treatment of depression by the three levels of physician-reported disease severity (mild, moderate, and severe) to understand if the mix of therapeutic classes used to treat depression changes as disease severity increases. Prior to analyzing drug uses in each severity category, we established that in the 12 months ending November 2009, the majority of patients (65%) were assigned a severity rating of 'moderate' by their physician; 27 percent and eight percent of patients were designated as 'mild' and 'severe,' respectively. In general, we found that as disease severity changes, so too do the proportions of the various therapeutic classes used in depression. The differences in class mix by severity have persisted at least since the 12 months ending December 2008, and it appears that the mix of drug classes used in severe depression are becoming less similar to the class mix for moderate depression over time.