Time for an ecosystem approach to public health? Lessons from two infectious disease outbreaks in Canada.

Ecosystem approaches recognize the complexity of many contemporary public health challenges and offer an alternative for dealing with problems that have proven intractable and unresponsive to conventional public health strategies. Infectious disease outbreaks are among the most dramatic aspects of systems failure, and the Canadian cases of SARS (Severe Acute Respiratory Syndrome) in Toronto, and the E. coli outbreak in Walkerton, serve as useful illustrative examples. This paper examines some of the limitations of current public health approaches, the fundamental tenets of an alternative, transdisciplinary ecosystem approach, and changes necessary for implementation, including those in philosophical approach, communications and education, and, finally, institutions and governance.

New data on the use of lithium, divalproate, and lamotrigine in rapid cycling bipolar disorder.

The rapid cycling variant of bipolar disorder is defined as the occurrence of four periods of either manic or depressive illness within 12 months. Patients suffering from this variant of bipolar disorder have an unmet need for effective treatment. This review examines two major studies in an attempt to update understanding of the current therapies available to treat rapid cycling patients. The first trial compares lamotrigine versus placebo in 182 patients studied for 6 months. The second is a recently completed, 20-month trial comparing divalproate and lithium in 60 patients. Both trials had a double-blind, randomized parallel-group design. The data from the latter study indicate that there are no large differences in efficacy between lithium and divalproate in the long-term treatment of rapid cycling bipolar disorder. In addition, lamotrigine has the potential to complement the spectrum of lithium and divalproate through its greater efficacy for depressive symptoms.

Evolving methodologies in bipolar disorder maintenance research.

BACKGROUND: During the development of a new treatment for bipolar disorder, maintenance studies are used to evaluate the ability of the putative mood stabilizer to prevent relapse and recurrence of further episodes. Comparisons with the early bipolar disorder maintenance studies indicate that the methodologies of recent trials have evolved substantially. AIMS: To review the methods used in the first- and second-generation maintenance studies, highlighting the differences of the various designs. METHOD: Literature review. RESULTS: Methods that have evolved the most include patient enrollment, randomisation schemes and the use of outcome measures and statistical analyses. In addition, regulatory and commercial issues have also influenced study design. CONCLUSION: There is little consensus on the methodology of bipolar disorder maintenance studies. As the integration of newer therapies into routine clinical practice is dependent on the evidence from controlled studies, it is essential that future maintenance trials in bipolar disorder achieve adequate methodological rigour without sacrificing overall feasibility.

Bipolar rapid cycling: focus on depression as its hallmark.

The phenomenon of frequent cycling in bipolar disorder was first recognized by Emil Kraepelin in 1913. More recently, rapid cycling has been reported to be a predictor of nonresponse to treatment. At the time of presentation, most patients with DSM-IV-defined rapid cycling appear to be in the depressed phase of their illness. Frequent and more severe episodes of depression appear to be the hallmark of rapid cycling. Reported in this article are recent preliminary data suggesting that the combination of lithium and divalproex sodium administered continuously over 6 months appears to result in marked acute and continuation antimanic efficacy in 85% of patients and marked antidepressant efficacy in 60%. However, only one half of patients experienced bimodal stabilization. Comorbid alcohol, cannabis, and/or cocaine abuse and/or dependence did not appear to directly affect the spectrum of efficacy of lithium and divalproex or response rates in compliant patients. Comorbidity appeared to alter prognosis by increasing the prevalence of poor compliance. The majority of patients receiving lithium and divalproex who required additional treatment were depressed, suggesting that the frequent recurrence of depression is the primary unmet need in patients with rapid cycling. The use of antidepressants in this population has been discouraged because of concerns about the possibility of cycle acceleration. There exists a need for a pharmacotherapy that not only possesses marked acute antidepressant properties, but that does so without inducing switching or cycle acceleration. A double-blind, placebo-controlled trial of lamotrigine monotherapy in bipolar I depression has demonstrated efficacy without causing switching at a rate exceeding placebo; however, this initial study excluded patients with rapid cycling. To explore the efficacy of lamotrigine in rapid cycling, a recent multicenter study has examined lamotrigine as a maintenance therapy for this population. The results indicate that lamotrigine may be a useful treatment for patients with rapid-cycling bipolar II disorder and that this drug has begun to address this unmet need.

Evolving methodologies in bipolar disorder maintenance research.

Background During the development of a new treatment for bipolar disorder, maintenance studies are used to evaluate the ability of the putative mood stabiliser to prevent relapse and recurrence of further episodes. Comparisons with the early bipolar disorder maintenance studies indicate that the methodologies of recent trials have evolved substantially. Aims To review the methods used in the first- and second-generation maintenance studies, highlighting the differences of the various designs. Method Literature review. Results Methods that have evolved the most include patient enrolment, randomisation schemes and the use of outcome measures and statistical analyses. In addition, regulatory and commercial issues have also influenced study design. Conclusion There is little consensus on the methodology of bipolar disorder maintenance studies. As the integration of newer therapies into routine clinical practice is dependent on the evidence from controlled studies, it is essential that future maintenance trials in bipolar disorder achieve adequate methodological rigour without sacrificing overall feasibility.

Prevention of recurrent postpartum depression: a randomized clinical trial.

BACKGROUND: Women who have suffered one episode of postpartum-onset major depression (PPMD) comprise a high-risk group for subsequent episodes. We conducted a double-blind, randomized clinical trial to test the efficacy of nortriptyline in the prevention of recurrent PPMD. METHOD: Nondepressed women who had at least one past episode of PPMD (Research Diagnostic Criteria) were recruited during pregnancy. Subjects were randomly assigned to nortriptyline or placebo. Treatment began immediately postpartum. Each subject was assessed for 20 sequential weeks with the Hamilton Rating Scale for Depression and Research Diagnostic Criteria for recurrence of major depression. RESULTS: No difference was found in the rate of recurrence in women treated with nortriptyline compared with those treated with placebo. Of 26 subjects who took nortriptyline preventively, 6 (0.23, 95% exact confidence interval [CI] = 0.09 to 0.44) suffered recurrences. Of 25 subjects who took placebo, 6 (0.24, 95% exact CI = 0.09 to 0.45) suffered recurrence (Fisher exact p = 1.00). CONCLUSION: Nortriptyline did not confer additional preventive efficacy beyond that of placebo. The rate of recurrence of PPMD (one fourth of women) was unacceptably high.

Current research on rapid cycling bipolar disorder and its treatment.

Rapid cycling is a pattern of presentation of bipolar disorder that specifies the course of the illness and is associated with a greater morbidity. The validity of rapid cycling as a distinct course modifier for bipolar disorder has been demonstrated and the term has been incorporated into the DSM-IV. The phenomenon of rapid cycling tends to appear late in the course of the disorder, occurs more frequently among females, and is more frequently seen in patients with bipolar type II disorder. Stimulants such as cocaine may also play some role in rapid-cycling. It is generally accepted that a recent history of rapid cycling predicts non-response to monotherapy with lithium and probably carbamazepine as well; however it is also possible that concurrent use of antidepressants may play a role in destabilizing the illness course under these agents. Thus, clinical considerations suggest that discontinuing antidepressants may facilitate the recovery process. Among clinically available monotherapies, valproate and lamotrigine appear to be the most useful clinically. However, other treatments such as lithium, carbamazepine, the atypical antipsychotic agents, thyroid hormone, and bupropion are frequently needed augmentation strategies. Electroconvulsive therapy may also prove efficacious in selected cases. The present paper provides a critical review of the evidence for the foregoing clinical issues in rapid cycling.

Development and validation of a screening instrument for bipolar spectrum disorder: the Mood Disorder Questionnaire.

OBJECTIVE: Bipolar spectrum disorders, which include bipolar I, bipolar II, and bipolar disorder not otherwise specified, frequently go unrecognized, undiagnosed, and untreated. This report describes the validation of a new brief self-report screening instrument for bipolar spectrum disorders called the Mood Disorder Questionnaire. METHOD: A total of 198 patients attending five outpatient clinics that primarily treat patients with mood disorders completed the Mood Disorder Questionnaire. A research professional, blind to the Mood Disorder Questionnaire results, conducted a telephone research diagnostic interview by means of the bipolar module of the Structured Clinical Interview for DSM-IV. RESULTS: A Mood Disorder Questionnaire screening score of 7 or more items yielded good sensitivity (0.73) and very good specificity (0.90). CONCLUSIONS: The Mood Disorder Questionnaire is a useful screening instrument for bipolar spectrum disorder in a psychiatric outpatient population.

Controlled trials in bipolar I depression: focus on switch rates and efficacy.

Until recently, the rate at which patients switch from bipolar depression to the manic or hypomanic phase of the disorder during treatment with antidepressant medications was poorly defined. The completion of three large-scale, double-blind controlled trials in bipolar I depression has improved understanding of this phenomenon. The low switching rates observed in these studies of lamotrigine, paroxetine and moclobemide may indicate a special application of these drugs in the management of patients prone to antidepressant-induced switching. These studies also confirm prior suggestions that tricyclic antidepressants present the highest risk of switching. At present there is no consensus over the optimal definition of switching. Standardising the definition may lead to improvements in the clinical management of bipolar disorder.

Mood stabilizers and the evolution of maintenance study designs in bipolar I disorder.

The designs employed in bipolar maintenance studies have evolved greatly over the last 28 years. Consequently, there has been minimal consensus set for methods used to demonstrate the ability of any new putative mood stabilizers to prevent relapse and recurrence in bipolar disorder. The methods that have evolved the most include enrollment procedures, randomization schemes, use of outcome measures, statistical analyses, and country-specific commercial and regulatory issues. This article contrasts the various methods employed in first- and second-generation placebo-controlled bipolar I maintenance studies. This article also explores the advantages and disadvantages associated with various designs.

Clinical studies on the use of lamotrigine in bipolar disorder.

New mood stabilizers that possess efficacy in the depressed phase of bipolar disorder are needed. The use of marketed antidepressants puts bipolar patients at some increased risk for drug-induced hypomania/mania and rapid cycling. During the development of the antiepileptic, lamotrigine, the drug was observed to improve mood, alertness, and social interactions in some patients with epilepsy. These early observations provided the rationale for investigations into lamotrigine's potential efficacy in bipolar disorder. There are now 14 open clinical reports involving a total of 207 lamotrigine-treated patients with bipolar disorder that suggest this drug possesses a broad spectrum of efficacy in the management of the depressed, hypomanic, manic, and mixed phases of bipolar disorder. In an attempt to replicate and extend these preliminary open-label prospective findings, a series of multicenter, double-blind, placebo-controlled studies evaluating the efficacy and dose-response relationships of lamotrigine in the various phases of the illness, including both acute and maintenance designs in both bipolar I and II disorder, is ongoing.

Stress response.

Global Ecology in Human Perspective by C.H. Southwick Oxford University Press, 1996. £16.50 hbk (xxi +392 pages) ISBN 0 19 509867 6 Ecology: A Bridge Between Science and Society by E.P. Odum Sinauer Associates, 1997. £17.95 pbk (xiv +330 pages) ISBN 0 87893 630 0.

Assessing ecosystem health.

Evaluating ecosystem health in relation to the ecological, economic and human health spheres requires integrating human values with biophysical processes, an integration that has been explicitly avoided by conventional science. The field is advancing with the articulation of the linkages between human activity, regional and global environmental change, reduction in ecological services and the consequences for human health, economic opportunity and human communities. Increasing our understanding of these interactions will involve more active collaboration between the ecological, social and health sciences. In this, ecologists will have substantive and catalytic roles.

Ecosystem health: challenges for ecotoxicology and environmental health.

Restoring and safeguarding ecosystem health is a major challenge for the 21st century. Man-made substances, particularly persistent bioaccumulative substances have been among the forces that have contributed to weakening the health of ecosystems. However there are other stresses that interact synergistically with chemical stress. These forces, such physical restructuring (habitat change) tend to enhance the impacts of chemical stresses. A dose-response framework that encompasses an array of stresses with synergistic and occasional antagonistic effects is proposed for the assessment of ecosystem health. The flow of ecosystem services is curtailed in damaged systems. These services, such as provision of biodiversity, potable water, foodstuffs, sequestering of contaminants, will determine the suitability of ecosystems for humans. Linking ecotoxicology to ecosystem health provides an avenue for relating a variety of pressures on ecosystems to the conditions essential to sustain life that includes human communities.

Lamotrigine in rapid-cycling bipolar disorder.

BACKGROUND: We evaluated the antidepressant and mood-stabilizing effects of lamotrigine, a novel anticonvulsant, in a group of rapid-cycling bipolar patients. Most were already nonresponders or poor partial responders to other conventional mood-stabilizing agents. METHODS: This open, naturalistic, and prospective study was conducted with five rapid-cycling bipolar patients (DSM-IV). Each received lamotrigine titrated to a minimum dose of 150 mg/day as monotherapy or in combination with other psychotropic agents. Patients were assessed with the Global Assessment Scale (GAS), Beck Depression Inventory (BDI), and Young Mania Rating Scale (YMRS) for evidence of cycling mood. RESULTS: Lamotrigine was used at a mean +/- SD dose of 185.0 +/- 33.5 mg/day for 225.8 +/- 28.0 days. Random regression modeling of data showed significant dose- and time-dependent improvements in depressive symptoms and social function of patients taking lamotrigine (Dose: z = 2.17, p < .03 for BDI, z = 4.44, p < .001 for GAS; Time: z = -3.79, p < .001 for BDI, z = 2.16, p < .03 for GAS). Further random regression modeling analysis of change over time in symptoms prior to lamotrigine compared with symptoms during lamotrigine treatment showed a significant treatment by time effect for GAS (z = 2.40, p < .016) and a trend for BDI scores (z = -1.79, p < .073). No significant time or dosage effect or time by treatment effect was observed for YMRS. Finally, t statistics showed a significant reduction in mean BDI scores following treatment with lamotrigine (t = -5.26, p < .006). Lamotrigine was well tolerated by all patients; only one patient experienced several side effects, which were probably due to interaction between several psychotropic medications. CONCLUSION: Lamotrigine augmentation therapy and monotherapy appeared to have mood-stabilizing and antidepressant efficacy in the treatment of five rapid-cycling bipolar patients. The effect persisted for an average of 7.5 months.