Olanzapine in bipolar disorder

Olanzapine is currently marketed not only for the treatment of schizophrenia, but also for the treatment of acute mania and the prevention of relapse in patients successfully treated with this drug for a manic episode. A large body of good clinical trials supports these indications. In the mania trials, olanzapine was more efficacious than placebo, equal or more efficacious than valproate and more efficacious than lithium or valproate monotherapy when used in combination with either drug. A trial that compared olanzapine with haloperidol failed to show superiority of the atypical versus the conventional. Olanzapine showed a modest but statistically significant effect in the treatment of bipolar depression; this modest effect was substantially enhanced in combination with fluoxetine. The long-term trials showed that olanzapine was better than placebo in the prevention of manic and depressive relapse and not inferior to lithium or valproate. The combination of olanzapine with lithium or valproate was also more efficacious than lithium or valproate alone in the prevention of manic relapse in patients partially non-responding to monotherapy with lithium or valproate. All these trials suggest that olanzapine may be a valuable drug in the short- and long-term treatment of bipolar I disorder. However, there are some concerns about the safety and tolerability of olanzapine in this population, as far as weight gain and metabolic syndrome are concerned, which may be addressed in future pharmacovigilance studies.     

Olanzapine: a review of its use in the management of bipolar I disorder

Olanzapine is an atypical antipsychotic that is approved in the US and Europe for the oral treatment of acute manic episodes in patients with bipolar I disorder, and for maintenance therapy to prevent recurrence in responders.Oral olanzapine is effective in the treatment of bipolar mania, both as single agent therapy and as adjunctive therapy in combination with lithium or valproate semisodium. In the treatment of acute episodes, olanzapine is superior to placebo and at least as effective as lithium, valproate semisodium, haloperidol and risperidone in reducing the symptoms of mania and inducing remission. Additional comparative studies are required to determine the efficacy of olanzapine relative to newer atypical antipsychotics, such as quetiapine, ziprasidone and aripiprazole. Olanzapine is also effective at delaying or preventing relapse during long-term maintenance therapy in treatment responders, and is currently the only atypical antipsychotic approved for this indication. Current evidence suggests that olanzapine may be more effective than lithium in preventing relapse into mania, but not relapse into depression or relapse overall. Olanzapine is generally well tolerated, and although it is associated with a higher incidence of weight gain than most atypical agents, it has a low incidence of extrapyramidal symptoms (EPS). Therefore, oral olanzapine is a useful first-line or adjunctive agent for both the acute treatment of manic episodes and the long-term prevention of relapse into manic, depressive or mixed episodes associated with bipolar I disorder.     

Spotlight on olanzapine in bipolar I disorder

Olanzapine is an atypical antipsychotic that is approved in the US and Europe for the oral treatment of acute manic episodes in patients with bipolar I disorder and for maintenance therapy to prevent recurrence in responders. Oral olanzapine is effective in the treatment of bipolar mania, both as single agent therapy and as adjunctive therapy in combination with lithium or valproate semisodium. In the treatment of acute episodes, olanzapine is superior to placebo and at least as effective as lithium, valproate semisodium, haloperidol and risperidone in reducing the symptoms of mania and inducing remission. Additional comparative studies are required to determine the efficacy of olanzapine relative to newer atypical antipsychotics such as quetiapine, ziprasidone and aripiprazole. Olanzapine is also effective at delaying or preventing relapse during long-term maintenance therapy in treatment responders and is currently the only atypical antipsychotic approved for this indication. Current evidence suggests that olanzapine may be more effective than lithium in preventing relapse into mania, but not relapse into depression or relapse overall. Olanzapine is generally well tolerated and, although it is associated with a higher incidence of weight gain than most atypical agents, it has a low incidence of extrapyramidal symptoms. Therefore, oral olanzapine is a useful first-line or adjunctive agent for both the acute treatment of manic episodes and the long-term prevention of relapse into manic, depressive or mixed episodes associated with bipolar I disorder.     

Polytherapy in bipolar disorder

Bipolar disorder is a life-long condition that is associated with frequent recurrence/relapse of symptoms. Although putative mood stabilisers, such as lithium, are considered to improve the natural course of bipolar disorder, complete long-term remission is rarely achieved. In order to effectively control mood symptoms and to reduce relapse, clinicians often use polypharmacy to treat patients with bipolar disorder. In this article, we examine the recent literature on treatment strategies in bipolar disorder to determine if combination treatments provide additional benefit over monotherapy for the management of various phases of bipolar disorder. The evidence suggests that for acute mania a combination of lithium or valproate and an atypical antipsychotic is the most effective approach, with approximately 20% more patients responding to the combination than to monotherapy with any antimanic agent. Few studies have examined the use of combination therapy in comparison to monotherapy for bipolar depression. The limited evidence suggests that lithium plus an antidepressant appears to be more effective than lithium alone in those with lower serum lithium concentrations. Similarly, the combination of olanzapine plus fluoxetine is more effective than olanzapine alone. There is consensus that antidepressant monotherapy is not appropriate because of concerns of a manic switch, but monotherapy with lithium or lamotrigine may be adequate for mild to moderate bipolar depression. For maintenance treatment, commonly used agents, such as lithium, valproate or olanzapine appear to be most effective in preventing manic relapses, whereas lamotrigine is more effective in preventing depressive relapses. As a result of these findings, it makes intuitive sense to combine lamotrigine with lithium, valproate or an atypical antipsychotic to achieve better mood stability. However, the efficacy and safety of such combinations have not been systematically compared with monotherapy. Preliminary studies suggest that lithium plus valproate may be more effective than lithium alone in preventing affective relapses. Similarly, the combination of lithium or valproate plus olanzapine seems to be more effective than monotherapy with a mood stabiliser in preventing manic episodes.     

Olanzapine: new indication. Prevention of bipolar disorder: unconvincing trials

(1) Lithium, the standard preventive treatment for patients with bipolar disorder, reduces the number of relapses and suicide attempts. (2) Olanzapine is the first neuroleptic to be approved in France for prevention of relapse in patients with bipolar disorder. Many neuroleptics are already used for this indication but their efficacy has not been established in comparative clinical trials. (3) One placebo-controlled double-blind trial involved 361 patients who were treated just after recovering from a manic episode. The trial was supposed to last 48 weeks, but only 146 patients were treated for more than 8 weeks. Therefore, the trial results, including an observed effect on mania, cannot be interpreted to imply long-term prevention. (4) One double-blind trial compared olanzapine plus a mood stabiliser with placebo plus a mood stabiliser in 344 patients who had recovered from an acute episode. Only 21 patients completed the 12-month trial, and the percentage of patients who had relapses (manic or depressive) did not differ significantly between the groups. (5) In a third double-blind trial, 431 patients in remission from a manic episode after treatment with olanzapine + lithium were treated for 12 months with lithium or olanzapine. This trial suggested that olanzapine was more effective in preventing depressive and manic relapses (30% of patients, compared to 38.8% with lithium), but only 171 patients completed the trial. Most dropouts were due to adverse events (19% with olanzapine, 26% with lithium). The impact of treatment on suicide risk was not studied. (6) In a fourth study, 101 patients in remission from a mixed or manic episode continued their initial treatment with olanzapine or sodium divalproate in double-blind manner for 11 months. The risk of relapse was not significantly different between the groups, but the study sample size was too small to tell whether or not the treatments were equally effective. (7) Trials focusing on prevention of relapse in patients with bipolar disorder confirmed the known adverse effects of olanzapine, including weight gain and QTc prolongation. Olanzapine was associated with more weight gain and sedation than lithium. Hyperglycaemia occurring on olanzapine can cause life-threatening ketoacidosis. (8) Lithium remains the standard treatment for preventing recurrent bipolar disorder. There is no firm evidence that olanzapine is more effective than a mood stabiliser after lithium failure, or that it boosts the efficacy of lithium.     

Novel treatments for bipolar disorder

Treatments other than lithium have recently emerged as equally important in the management of bipolar disorder. The spectrum of efficacy of newer treatments differs from lithium and among the novel drug treatments valproate, generally used as the better tolerated divalproex form, principally benefits manic symptomatology both acutely and in prophylaxis. Atypical antipsychotic drugs have demonstrated efficacy in reducing acute manic symptoms. No controlled evidence of efficacy in prophylaxis has been published. Lamotrigine has demonstrated efficacy in both acute bipolar depression and maintenance efficacy in rapid cycling bipolar patients, especially those patients with bipolar II disorder, which is principally manifested as depression. Randomised, double-blind, placebo- controlled studies provide good evidence that regimens of risperidone or olanzapine in combination with lithium or valproate provide greater improvement in acute mania than the mood stabilisers alone. Similarly, valproate combined with antipsychotics provided greater improvement in mania than antipsychotic medication alone and resulted in lower dosage of the antipsychotic medication. A positive but unclear placebo-controlled study of omega-3 fatty acids added to lithium in bipolar disorder needs confirmation in standard clinical trial paradigms. Several other drugs that were reported as beneficial in various facets of bipolar disorder in open trials have not differed from placebo when studied in randomised, placebo-controlled trials.     

Novel treatments for bipolar disorder

Treatments other than lithium have recently emerged as equally important in the management of bipolar disorder. The spectrum of efficacy of newer treatments differs from lithium and among the novel drug treatments valproate, generally used as the better tolerated divalproex form, principally benefits manic symptomatology both acutely and in prophylaxis. Atypical antipsychotic drugs have demonstrated efficacy in reducing acute manic symptoms. No controlled evidence of efficacy in prophylaxis has been published. Lamotrigine has demonstrated efficacy in both acute bipolar depression and maintenance efficacy in rapid cycling bipolar patients, especially those patients with bipolar II disorder, which is principally manifested as depression. Randomised, double-blind, placebo- controlled studies provide good evidence that regimens of risperidone or olanzapine in combination with lithium or valproate provide greater improvement in acute mania than the mood stabilisers alone. Similarly, valproate combined with antipsychotics provided greater improvement in mania than antipsychotic medication alone and resulted in lower dosage of the antipsychotic medication. A positive but unclear placebo-controlled study of omega-3 fatty acids added to lithium in bipolar disorder needs confirmation in standard clinical trial paradigms. Several other drugs that were reported as beneficial in various facets of bipolar disorder in open trials have not differed from placebo when studied in randomised, placebo-controlled trials.     

Pharmacological interventions for the prevention of relapse in bipolar disorder: a systematic review of controlled trials

We conducted a systematic review and meta-analysis of randomised and quasi-randomised controlled trials evaluating all clinically relevant pharmacological interventions for the prevention of relapse in people with bipolar disorder. Thirty-four trials were included in the review. Direct comparisons with placebo and with lithium were available for most drugs. In addition, there were direct comparisons of valproate vs. olanzapine, imipramine vs. lithium plus imipramine, olanzapine plus mood stabilisers vs. mood stabilisers and perphenazine plus mood stabilisers vs. mood stabilisers. Methodological quality varied across studies and the strength of evidence was not equal for all treatments or for all comparisons. There is evidence from placebo-controlled trials for the efficacy of lithium, valproate and lamotrigine as maintenance therapy for the prevention of relapse in bipolar disorder. Three drugs have a significant effect in the prevention of manic relapses (lithium, olanzapine and aripiprazole) and three in the prevention of depressive symptoms (valproate, lamotrigine and imipramine). Imipramine is little used in practice, because of concern about adverse effects. The significant effects of olanzapine and aripiprazole were demonstrated in selected responsive bipolar I patients only. Despite widespread use in clinical practice, there is little evidence to support the efficacy of combination therapy.     

Asenapine: a review of its use in the management of mania in adults with bipolar I disorder

Asenapine is an atypical antipsychotic agent available in sublingual formulations (5 or 10 mg) and indicated in the US (Saphris) for the acute treatment, as monotherapy or adjunctive therapy, of manic and mixed episodes and in the EU (Sycrest) for the treatment of moderate to severe manic episodes, in adult patients with bipolar I disorder. In two large (both n = 480), well designed, 3-week trials in adult patients with bipolar I disorder, asenapine monotherapy was significantly more effective than placebo at improving mania symptoms, as assessed using the Young Mania Rating Scale total score (YMRS; primary endpoint), with significant differences between the asenapine and placebo groups occurring after 2 days of treatment. In both trials, Clinical Global Impression for Bipolar Disorder (CGI-BP) scale mania severity scores exceeded those of placebo. In one trial, response and remission rates exceeded those of placebo. In a 9-week extension study that recruited completers from the monotherapy trials, there were no significant differences between asenapine and olanzapine groups in terms in Montgomery-?sberg Depression Rating Scale (MADRS) scores, CGI-BP mania severity scores, YMRS response rates or YMRS remission rates during the extension phase. In the extension study, the efficacy of asenapine monotherapy appeared to be maintained over 40 weeks (total treatment duration of 52 weeks). In a 12-week trial of asenapine as adjunctive therapy to lithium or valproate, asenapine was more effective than placebo in improving manic symptoms, based on the difference between groups in the YMRS total score at week 3 (primary endpoint). Most adverse events associated with asenapine were of mild to moderate severity, with <7% of asenapine recipients experiencing serious adverse events (vs 7% with placebo). In a pooled analysis of the monotherapy trials, the most common adverse events (occurring in ≥ 5% of patients and at twice the incidence of placebo) reported during acute phase asenapine monotherapy for bipolar mania were somnolence, dizziness, extrapyramidal symptoms (EPS, other than akathisia) and increased bodyweight, which were similar in nature to those occurring during longer-term monotherapy with asenapine. EPS did not worsen in severity during longer-term asenapine monotherapy. Asenapine had minimal effects on plasma glucose, lipid and prolactin levels over both short- and longer-term treatment periods, and had little pro-arrhythmogenic potential. Further active comparator trials and longer-term tolerability and safety data are required. In the meantime, asenapine is a further option for the management of manic and/or mixed symptoms in patients with bipolar I disorder and may be of particular value for patients who are at high risk for metabolic abnormalities.     

Acute and maintenance treatment with mood stabilizers

Treatment of bipolar disorder is complicated by the multiple phases of the illness, dimensional symptomatology that varies considerably across individuals, and a limited spectrum of activity for all mood stabilizers. Randomized, blinded, placebo-controlled studies provide clear guidelines to the overall efficacy of treatments for mania. However, for secondary questions, such as the treatment to employ when lithium or valproate is inadequate as monotherapy, evidence is incomplete, and usually derived from both smaller and less well-designed studies. For mania, the spectrum of efficacy of valproate is broader than for other mood stabilizers. However, many patients obtain inadequate benefit from monotherapy regimens of all mood stabilizers. Recent studies indicate that for patients who develop mania while taking a mood stabilizer, combinations of an antipsychotic and a mood stabilizer yield greater improvement than does continuation of the mood stabilizer alone. Maintenance-treatment studies support the efficacy of lithium, valproate and lamotrigine, although with a different spectrum of benefits and limitations for each. Valproate and lithium provide greater benefits for prevention of manic relapses and control of manic symptomatology than for depression. Several studies indicate actual worsening in depressive aspects of bipolar disorder with lithium treatment. Lamotrigine appears effective in delaying relapse into a new episode, with most benefits limited to delaying time to depression. Lamotrigine has not shown anti-manic activity in placebo-controlled studies. In contrast to traditional antidepressant medications, lamotrigine has not been associated with induction of mania, or of rapid-cycling illness symptomatology. Recent studies reported that carbamazepine was inferior to valproate in acute mania, and inferior to lithium in maintenance treatment. Other putative mood stabilizers have to date yielded negative or inconclusive results in studies in mania. Systematic studies are needed to clarify treatment guidelines for youth with bipolar disorder, and for other special populations, e.g. pregnant women and the elderly.     

Treatment of bipolar disorder: a systematic review of available data and clinical perspectives

This paper is a systematic review of the available data concerning the treatment of bipolar disorder: a systematic Medline search concerning treatment guidelines and clinical trials. The search for treatment guidelines returned 583 articles and 913 papers for RCTs. The search was last performed on 1 March 2008. An additional search included repositories of clinical trials and previous systematic reviews in order to trace especially older trials. The literature suggests that lithium is useful during the acute manic and the maintenance phase. Both first- and second-generation antipsychotics are efficacious in the treatment of acute mania. Quetiapine and the olanzapine-fluoxetine combination are also effective for treating bipolar depression, while olanzapine, quetiapine and aripiprazole are effective during the maintenance phase. Anticonvulsants, particularly valproate and carbamazepine have antimanic properties, whereas lamotrigine may be preferably effective in the treatment of depression but not mania. Antidepressants should always be used in combination with an antimanic agent because they were reported to induce switching to mania or hypomania, mixed episodes, and rapid cycling when given as monotherapy. The best evidence-based psychosocial interventions for bipolar disorder are group- and family-focused psychoeducation. Electroconvulsive therapy is an option for refractory patients. Although a variety of treatment options for bipolar disorder is currently available, their effectiveness is far from satisfactory, especially against bipolar depression and maintenance. Combination therapy may improve treatment outcome but it also carries the burden of more side-effects. Further research as well as the development of better guidelines and algorithms for step-by-step rational treatment are necessary.     

Divalproex in the treatment of bipolar disorder

Valproate is commonly used as a first-line agent for the treatment of acute bipolar I mania. Its efficacy in the treatment of acute mania has been established in randomized, controlled trials versus placebo, lithium, haloperidol, and olanzapine. Only preliminary data regarding the efficacy of valproate in acute bipolar depression are currently available. The efficacy of valproate in the maintenance treatment of bipolar disorder has not been definitively established but most evidence from randomized, controlled trials suggests that it may have comparable efficacy to lithium and olanzapine. The results of randomized, controlled trials of valproate in the treatment of bipolar disorder are reviewed along with their implications for clinical practice.     

Aripiprazole: a review of its use in the management of mania in adults with bipolar I disorder

Aripiprazole (Abilify?) is an atypical antipsychotic indicated for the treatment of mania associated with bipolar I disorder. It is unique in its class, as it is a partial agonist of dopamine D(2) and D(3), and serotonin 5-HT(1A) receptors and a modest antagonist of 5-HT(2A) receptors. This article reviews the pharmacological properties, clinical efficacy and tolerability of oral aripiprazole in the management of mania associated with bipolar I disorder in adults. In well designed clinical trials in patients with recent manic or mixed episodes associated with bipolar I disorder, oral aripiprazole monotherapy or adjunctive therapy to lithium or valproate improved symptoms of mania following short-term (≤12 weeks) or maintenance (≤100 weeks) treatment. In addition, maintenance treatment with aripiprazole (as monotherapy or adjunctive therapy) prevented the recurrence of any mood episodes or manic episodes (but not depressive episodes) in patients who had previously been stabilized and maintained on aripiprazole. Aripiprazole was generally well tolerated in these studies and was associated with a low risk of prolactin elevation, corrected QT interval prolongation and metabolic disturbances. Extrapyramidal symptoms occurred in up to 28% of aripiprazole recipients, but after longer-term treatment (≤100 weeks), symptom severity did not differ significantly from that in placebo recipients. Aripiprazole treatment generally did not increase bodyweight to a clinically relevant extent; however, more patients receiving aripiprazole monotherapy than placebo had clinically significant bodyweight gain during 100 weeks' treatment. Additionally, in a comparative trial, aripiprazole monotherapy was at least as effective as haloperidol monotherapy in terms of improving symptoms of mania, but had the advantage of a lower incidence of some adverse events, such as extrapyramidal symptom-related adverse events. Further trials comparing aripiprazole with other agents, including atypical antipsychotics, would help to definitively position aripiprazole relative to these agents. Current guidelines recommend aripiprazole as a first-line option (as monotherapy or adjunctive therapy) for the short-term treatment of mania associated with bipolar I disorder, and as a first-line (as monotherapy) or second-line (as adjunctive therapy) option for preventing the recurrence of mood episodes during longer-term therapy.     

Polarity index of pharmacological agents used for maintenance treatment of bipolar disorder

Over one half of bipolar patients have been reported to be more prone to either depressive or manic relapses. This study aimed to define profiles of drugs used for maintenance treatment of bipolar disorder (BD) by the means of Polarity Index. Polarity Index is a new metric indicating the relative antimanic versus antidepressive preventive efficacy of drugs. Polarity Index was retrieved by calculating Number Needed to Treat (NNT) for prevention of depression and NNT for prevention of mania ratio, as emerging from the results of randomized placebo-controlled trials. Included trials were randomized and double blind, with a minimal duration of 24 weeks, assessing effectiveness of a mood stabilizer or antipsychotic drug alone or in combination with a mood stabilizing agent versus a placebo comparator in BD maintenance treatment. Polarity Index value above 1.0 indicates a relative greater antimanic prophylactic efficacy, number below 1.0 a relative greater antidepressive efficacy. The polarity index for the drugs used in maintenance therapy for bipolar disorder was 12.09 for risperidone, 4.38 for aripiprazole, 3.91 for ziprasidone, 2.98 for olanzapine, 1.39 for lithium, 1.14 for quetiapine, and 0.40 for lamotrigine. Polarity index of valproate and oxcarbazepine may not be reliable due to the failure of their maintenance trials. The polarity index provides a measure of how much antidepressant versus antimanic a drug is in bipolar disorder prophylaxis, and may guide the choice of maintenance therapy in bipolar patients.     

Quetiapine: a review of its use in acute mania and depression associated with bipolar disorder

Quetiapine (Seroquel), an atypical antipsychotic with established efficacy in the treatment of schizophrenia, shows efficacy in the treatment of acute mania and depression associated with bipolar disorder.Quetiapine, either as monotherapy or in combination with lithium or divalproex sodium (valproate semisodium), is generally well tolerated and effective in reducing manic symptoms in adult and adolescent patients with acute bipolar mania, and is approved for use in adults for this indication. As monotherapy, the drug is also effective in reducing depressive symptoms in patients with bipolar depression. It is associated with a low incidence of extrapyramidal symptom (EPS)-related adverse events and low EPS ratings in bipolar disorder. Quetiapine thus shows potential in the treatment of bipolar depression, and represents a useful agent for the treatment of acute bipolar mania.     

Spotlight on quetiapine in acute mania and depression associated with bipolar disorder

Quetiapine (Seroquel), an atypical antipsychotic with established efficacy in the treatment of schizophrenia, shows efficacy in the treatment of acute mania and depression associated with bipolar disorder.Quetiapine, either as monotherapy or in combination with lithium or divalproex sodium (valproate semisodium), is generally well tolerated and effective in reducing manic symptoms in adult and adolescent patients with acute bipolar mania, and is approved for use in adults for this indication. As monotherapy, the drug is also effective in reducing depressive symptoms in patients with bipolar depression. It is associated with a low incidence of extrapyramidal symptom (EPS)-related adverse events and low EPS ratings in bipolar disorder. Quetiapine thus shows potential in the treatment of bipolar depression, and represents a useful agent for the treatment of acute bipolar mania.     

Efficacy of Antimanic Treatments: Meta-analysis of Randomized, Controlled Trials

We conducted meta-analyses of findings from randomized, placebo-controlled, short-term trials for acute mania in manic or mixed states of DSM (III–IV) bipolar I disorder in 56 drug–placebo comparisons of 17 agents from 38 studies involving 10 800 patients. Of drugs tested, 13 (76%) were more effective than placebo: aripiprazole, asenapine, carbamazepine, cariprazine, haloperidol, lithium, olanzapine, paliperdone, quetiapine, risperidone, tamoxifen, valproate, and ziprasidone. Their pooled effect size for mania improvement (Hedges'' g in 48 trials) was 0.42 (confidence interval (CI): 0.36–0.48); pooled responder risk ratio (46 trials) was 1.52 (CI: 1.42–1.62); responder rate difference (RD) was 17% (drug: 48%, placebo: 31%), yielding an estimated number-needed-to-treat of 6 (all p<0.0001). In several direct comparisons, responses to various antipsychotics were somewhat greater or more rapid than lithium, valproate, or carbamazepine; lithium did not differ from valproate, nor did second generation antipsychotics differ from haloperidol. Meta-regression associated higher study site counts, as well as subject number with greater placebo (not drug) response; and higher baseline mania score with greater drug (not placebo) response. Most effective agents had moderate effect-sizes (Hedges'' g=0.26–0.46); limited data indicated large effect sizes (Hedges'' g=0.51–2.32) for: carbamazepine, cariprazine, haloperidol, risperidone, and tamoxifen. The findings support the efficacy of most clinically used antimanic treatments, but encourage more head-to-head studies and development of agents with even greater efficacy.     

Effectiveness of psychotropic medications in the maintenance phase of bipolar disorder: a meta-analysis of randomized controlled trials

The purpose of this meta-analysis was to examine the efficacy of maintenance treatments for bipolar disorder. Placebo-controlled or active comparator bipolar maintenance clinical trials of ≥6 months' duration with at least 15 patients/treatment group were identified using Medline, EMBASE, clinicaltrials.gov, and Cochrane databases (1993 to July 2010). The main outcome measure was relative risk for relapse for patients in remission. Twenty trials (5,364 patients) were identified. Overall, lithium and quetiapine were the most studied agents (eight and five trials, respectively). The majority of studies included patients who had previously responded to treatment for an acute episode. All interventions, with the exception of perphenazine+mood stabilizer, showed a relative risk for manic/mixed or depressive relapse below 1.0, although there was variation in the statistical significance of the findings vs. placebo. No monotherapy was associated with a significantly reduced risk for both manic/mixed and depressed relapse. Of the combination treatments, only quetiapine+lithium/divalproex, was associated with a significantly reduced risk vs. comparator (placebo+lithium/valproate) for relapse at both the manic/mixed and depressed poles of bipolar illness. Limitations for the analysis include differences in study durations and definitions of relapse. In conclusion, available maintenance therapies show considerable variation in efficacy. The efficacy of lithium and divalproex has been confirmed, but newer therapies, such as a number of atypical antipsychotics were also shown to be effective in bipolar disorder. Efficacy of all maintenance interventions needs to be balanced against the safety and tolerability profiles of individual agents.     

Treatment of mixed bipolar states

Mixed bipolar states are associated with more severe symptoms and outcome. Our aim is to review the literature examining their treatment. We conducted a literature search of randomized clinical studies and post-hoc analyses on mixed bipolar states' treatment. Remarkably, there is only one double-blind, placebo-controlled trial, recruiting a mixed episode cohort, and one post-hoc analysis of this trial, while most data come from post-hoc analyses of trials including both manic and mixed patients. Improvement of manic symptoms in mixed episodes is similar to that seen in pure manic episodes and independent of baseline depressive features. The magnitude of response to manic symptoms' treatment probably exceeds that of depressive symptoms, which appear to resolve later. Valproate and carbamazepine are effective in acute mixed episodes, but the efficacy of lithium appears questionable. Atypical antipsychotic monotherapy improves both manic and depressive symptoms. Mood-stabilizer-atypical antipsychotic combination increases this effect. Atypical antipsychotic-antidepressant combination against acute mixed depression does not increase the risk for mania, although its superior efficacy vs. atypical antipsychotic monotherapy cannot be supported by current data. As regards prophylaxis, atypical antipsychotic monotherapy is associated with a lower incidence of and a longer time to relapse of any kind. The augmentation of lithium or divalproex with atypical antipsychotics increases prophylactic efficacy. Lithium or divalproex monotherapy have not been associated with significant prophylactic benefits following mixed mania. New, randomized prospective trials involving homogeneous cohorts of mixed bipolar patients are needed in order to delineate the appropriate pharmacological treatment of mixed states.