Preliminary controlled trial of nimodipine in ultra-rapid cycling affective dysregulation

Population Pharmacodynamic Models of Risperidone on PANSS Total Scores and Prolactin Levels in Schizophrenia

Currently, research predominantly focuses on evaluating clinical effects at specific time points while neglecting underlying patterns within the treatment process. This study aims to analyze the dynamic alterations in PANSS total scores and prolactin levels in patients with schizophrenia treated with risperidone, along with the influencing covariates. Using data from an 8-week randomized, double-blind, multicenter clinical trial, a population pharmacodynamic model was established for the PANSS total scores of and prolactin levels in patients treated with risperidone. The base model employed was the Emax model. Covariate selection was conducted using a stepwise forward inclusion and backward elimination approach. A total of 144 patients were included in this analysis, with 807 PANSS total scores and 531 prolactin concentration values. The PANSS total scores of the patients treated with risperidone decreased over time, fitting a proportionally parameterized sigmoid Emax model with covariates including baseline score, course of the disease, gender, plasma calcium ions, and lactate dehydrogenase levels. The increase in prolactin levels conformed to the ordinary Emax model, with covariates encompassing course of the disease, gender, weight, red blood cell count, and triglyceride levels. The impacts of the baseline scores and the course of the disease on the reduction of the PANSS scores, as well as the influence of gender on the elevation of prolactin levels, each exceeded 20%. This study provides valuable quantitative data regarding PANSS total scores and prolactin levels among patients undergoing risperidone treatment across various physiological conditions.

[Nimodipine in treatment of bipolar disorder]

The purpose of this review is to correlate current data on the molecular mechanisms of action of the drug Nimodipine with its clinical effects and applicability in mental disorders belonging to the spectrum of affective pathology. The article discusses the prospects for using the calcium channel blocker nimodipine as a method of both mono and combination therapy for bipolar disorders with various types of course. Nimodipine is a selective blocker of voltage-dependent calcium channels, a dihydropyridine derivative. By blocking L type calcium channels, it prevents the entry of calcium ions into the cell. Due to its pronounced ability to penetrate the blood-brain barrier, it has a selective effect on brain neurons and has a vasodilating, antihypertensive and normotimic effect. Nimodipine blocks LTCC channels in brain neurons, thereby influencing synaptic plasticity, transmitter release and excitation-transcription coupling, which makes it possible to influence various clinical conditions with pathology in the area of affect, including bipolar disorders with ultra-rapid cycling, and also, in cases with high resistance and intolerance to other mood stabilizers.

Calcium Channel Antagonists for Mood Disorders

PURPOSE

Development of new thymoleptic medications has primarily centered on anticonvulsants and antipsychotic drugs. Based on our studies of intracellular calcium ion signaling in mood disorders, we were interested in the use of novel medications that act on this mechanism of neuronal activation as potential mood stabilizers.

METHOD

We reviewed the dynamics of the calcium second messenger system and the international body of data demonstrating increased baseline and stimulated intracellular calcium levels in peripheral cells of patients with bipolar mood disorders. We then examined studies of the effect of established mood stabilizers on intracellular calcium ion levels and on mechanisms of mobilization of this second messenger. After summarizing studies of calcium channel blocking agents, whose primary action is to attenuate hyperactive intracellular calcium signaling, we considered clinical experience with this class of medications and the potential for further research.

FINDINGS

Established mood stabilizers normalize increased intracellular calcium ion levels in bipolar disorder patients. Most case series and controlled studies suggest an antimanic and possibly mood stabilizing effect of the calcium channel blocking medications verapamil and nimodipine, with fewer data on isradipine. A relatively low risk of teratogenicity and lack of cognitive adverse effects or weight gain suggest possible applications in pregnancy and in patients for whom these are considerations.

IMPLICATIONS

Medications that antagonize hyperactive intracellular signaling warrant more interest than they have received in psychiatry. Further experience will clarify the applications of these medications alone and in combination with more established mood stabilizers.

Advances toward precision medicine for bipolar disorder: mechanisms & molecules

Given its chronicity, contribution to disability and morbidity, and prevalence of more than 2%, the effective treatment, and prevention of bipolar disorder represents an area of significant unmet medical need. While more than half a century has passed since the introduction of lithium into widespread use at the birth of modern psychopharmacology, that medication remains a mainstay for the acute treatment and prevention of recurrent mania/hypomania and depression that characterize bipolar disorder. However, the continued limited understanding of how lithium modulates affective behavior and lack of validated cellular and animal models have resulted in obstacles to discovering more effective mood stabilizers with fewer adverse side effects. In particular, while there has been progress in developing new pharmacotherapy for mania, developing effective treatments for acute bipolar depression remain inadequate. Recent large-scale human genetic studies have confirmed the complex, polygenic nature of the risk architecture of bipolar disorder, and its overlap with other major neuropsychiatric disorders. Such discoveries have begun to shed light on the pathophysiology of bipolar disorder. Coupled with broader advances in human neurobiology, neuropharmacology, noninvasive neuromodulation, and clinical trial design, we can envision novel therapeutic strategies informed by defined molecular mechanisms and neural circuits and targeted to the root cause of the pathophysiology. Here, we review recent advances toward the goal of better treatments for bipolar disorder, and we outline major challenges for the field of translational neuroscience that necessitate continued focus on fundamental research and discovery.

Nimodipine improves cortical efficiency during working memory in healthy subjects

The L-type calcium channel gene, CACNA1C, is a validated risk gene for schizophrenia and the target of calcium channel blockers. Carriers of the risk-associated genotype (rs1006737 A allele) have increased frontal cortical activity during working memory and higher CACNA1C mRNA expression in the prefrontal cortex. The aim of this study was to determine how the brain-penetrant calcium channel blocker, nimodipine, changes brain activity during working memory and other cognitive and emotional processes. We conducted a double-blind randomized cross-over pharmacoMRI study of a single 60 mg dose of oral nimodipine solution and matching placebo in healthy men, prospectively genotyped for rs1006737. With performance unchanged, nimodipine significantly decreased frontal cortical activity by 39.1% and parietal cortical activity by 42.8% during the N-back task (2-back > 0-back contrast; P_FWE < 0.05; n = 28). Higher peripheral nimodipine concentrations were correlated with a greater decrease in activation in the frontal cortex. Carriers of the risk-associated allele, A (n = 14), had a greater decrease in frontal cortical activation during working memory compared to non-risk allele carriers. No differences in brain activation were found between nimodipine and placebo for other tasks. Future studies should be conducted to test if the decreased cortical brain activity after nimodipine is associated with improved working memory performance in patients with schizophrenia, particularly those who carry the risk-associated genotype. Furthermore, changes in cortical activity during working memory may be a useful biomarker in future trials of L-type calcium channel blockers.

The CINP Guidelines on the Definition and Evidence-Based Interventions for Treatment-Resistant Bipolar Disorder

BACKGROUND

Resistant bipolar disorder is a major mental health problem related to significant disability and overall cost. The aim of the current study was to perform a systematic review of the literature concerning (1) the definition of treatment resistance in bipolar disorder, (2) its clinical and (3) neurobiological correlates, and (4) the evidence-based treatment options for treatment-resistant bipolar disorder and for eventually developing guidelines for the treatment of this condition.

MATERIALS AND METHODS

The PRISMA method was used to identify all published papers relevant to the definition of treatment resistance in bipolar disorder and the associated evidence-based treatment options. The MEDLINE was searched to April 22, 2018.

RESULTS

Criteria were developed for the identification of resistance in bipolar disorder concerning all phases. The search of the literature identified all published studies concerning treatment options. The data were classified according to strength, and separate guidelines regarding resistant acute mania, acute bipolar depression, and the maintenance phase were developed.

DISCUSSION

The definition of resistance in bipolar disorder is by itself difficult due to the complexity of the clinical picture, course, and treatment options. The current guidelines are the first, to our knowledge, developed specifically for the treatment of resistant bipolar disorder patients, and they also include an operationalized definition of treatment resistance. They were based on a thorough and deep search of the literature and utilize as much as possible an evidence-based approach.

Nimodipine Reappraised: An Old Drug With a Future

Nimodipine is a dihydropyridine calcium channel antagonist that blocks the flux of extracellular calcium through L-type, voltage-gated calcium channels. While nimodipine is FDAapproved for the prevention and treatment of neurological deficits in patients with aneurysmal subarachnoid hemorrhage (aSAH), it affects myriad cell types throughout the body, and thus, likely has more complex mechanisms of action than simple inhibition of cerebral vasoconstriction. Newer understanding of the pathophysiology of delayed ischemic injury after a variety of acute neurologic injuries including aSAH, traumatic brain injury (TBI) and ischemic stroke, coupled with advances in the drug delivery method for nimodipine, have reignited interest in refining its potential therapeutic use. In this context, this review seeks to establish a firm understanding of current data on nimodipine's role in the mechanisms of delayed injury in aSAH, TBI, and ischemic stroke, and assess the extensive clinical data evaluating its use in these conditions. In addition, we will review pivotal trials using locally administered, sustained release nimodipine and discuss why such an approach has evaded demonstration of efficacy, while seemingly having the potential to significantly improve clinical care.

Beyond evidence-based treatment of bipolar disorder: Rational pragmatic approaches to management

The evidence for efficacy of many currently available treatments for bipolar disorder is based on studies of nonrefractory patients with bipolar disorder. Therefore, not surprisingly, most treatment recommendations and guidelines for the treatment of bipolar disorder and its many comorbidities depend heavily on data from placebo controlled randomized clinical trials (RCTs), but these RCTs provide little direction for the clinician as to what next steps might be optimal in non- or partial-responders and in those with ongoing medical and psychiatric comorbidities. Given this and the paucity of RCTs at later treatment junctures, we thought it appropriate to begin a discussion of the quality of the data that some experts in the field might consider using in choosing and sequencing drugs and their combination. We acknowledge that many other clinical investigators may prefer very different sequences, but thought the suggestions offered here might be useful to some clinicians in the field, might start discussions of other options in the literature, and, at the same time, provide a preliminary outline for a new round of much-needed clinical trials to better inform clinical practice. Given the very wide range of the quality of the data and clinical principles on which the current suggestions are based, only minimal references are included and a comprehensive review of the literature supporting each option would be outside the scope of this manuscript.

The Oxford study of Calcium channel Antagonism, Cognition, Mood instability and Sleep (OxCaMS): study protocol for a randomised controlled, experimental medicine study

Background

The discovery that voltage-gated calcium channel genes such as CACNA1C are part of the aetiology of psychiatric disorders has rekindled interest in the therapeutic potential of L-type calcium channel (LTCC) antagonists. These drugs, licensed to treat hypertension and angina, have previously been used in bipolar disorder, but without clear results. Neither is much known about the broader effects of these drugs on the brain and behaviour.

Methods

The Oxford study of Calcium channel Antagonism, Cognition, Mood instability and Sleep (OxCaMS) is a high-intensity randomised, double-blind, placebo-controlled experimental medicine study on the effect of the LTCC antagonist nicardipine in healthy young adults with mood instability. An array of cognitive, psychiatric, circadian, physiological, biochemical and neuroimaging (functional magnetic resonance imaging and magnetoencephalography) parameters are measured during a 4-week period, with randomisation to drug or placebo on day 14. We are interested in whether nicardipine affects the stability of these measures, as well as its overall effects. Participants are genotyped for the CACNA1C risk polymorphism rs1006737.

Discussion

The results will clarify the potential of LTCC antagonists for repurposing or modification for use in psychiatric disorders in which cognition, mood and sleep are affected.

Trial registration

ISRCTN, ISRCTN33631053. Retrospectively registered on 8 June 2018 (applied 17 May 2018).

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3175-0) contains supplementary material, which is available to authorized users.

Applications of calcium channel blockers in psychiatry: pharmacokinetic and pharmacodynamic aspects of treatment of bipolar disorder

Introduction: Calcium channel blockers (CCBs) comprise a heterogeneous group of medications that reduce calcium influx and attenuate cellular hyperactivity. Evidence of hyperactive intracellular calcium ion signaling in multiple peripheral cells of patients with bipolar disorder, calcium antagonist actions of established mood stabilizers, and a relative dearth of treatments have prompted research into potential uses of CCBs for this common and disabling condition. Areas covered: This review provides a comprehensive overview of intracellular calcium signaling in bipolar disorder, structure and function of calcium channels, pharmacology of CCBs, evidence of efficacy of CCBs in bipolar disorder, clinical applications, and directions for future research. Expert opinion: Despite mixed evidence of efficacy, CCBs are a promising novel approach to a demonstrated cellular abnormality in both poles of bipolar disorder. Potential advantages include low potential for sedation and weight gain, and possible usefulness for pregnant and neurologically impaired patients. Further research should focus on markers of a preferential response, studies in specific bipolar subtypes, development of CCBs acting preferentially in the central nervous system and on calcium channels that are primarily involved in neuronal signaling and plasticity.

Assessment and management of rapid-cycling bipolar affective disorder

Rapid-cycling bipolar affective disorder presents a unique spectrum of therapeutic difficulties. This article outlines some practical guidelines on the assessment and management of the disorder in the light of current research and clinical practice.

From Gene to Behavior: L-Type Calcium Channel Mechanisms Underlying Neuropsychiatric Symptoms

The L-type calcium channels (LTCCs) Cav1.2 and Cav1.3, encoded by the CACNA1C and CACNA1D genes, respectively, are important regulators of calcium influx into cells and are critical for normal brain development and plasticity. In humans, CACNA1C has emerged as one of the most widely reproduced and prominent candidate risk genes for a range of neuropsychiatric disorders, including bipolar disorder (BD), schizophrenia (SCZ), major depressive disorder, autism spectrum disorder, and attention deficit hyperactivity disorder. Separately, CACNA1D has been found to be associated with BD and autism spectrum disorder, as well as cocaine dependence, a comorbid feature associated with psychiatric disorders. Despite growing evidence of a significant link between CACNA1C and CACNA1D and psychiatric disorders, our understanding of the biological mechanisms by which these LTCCs mediate neuropsychiatric-associated endophenotypes, many of which are shared across the different disorders, remains rudimentary. Clinical studies with LTCC blockers testing their efficacy to alleviate symptoms associated with BD, SCZ, and drug dependence have provided mixed results, underscoring the importance of further exploring the neurobiological consequences of dysregulated Cav1.2 and Cav1.3. Here, we provide a review of clinical studies that have evaluated LTCC blockers for BD, SCZ, and drug dependence-associated symptoms, as well as rodent studies that have identified Cav1.2- and Cav1.3-specific molecular and cellular cascades that underlie mood (anxiety, depression), social behavior, cognition, and addiction.

Mania

PURPOSE OF REVIEW

Primary mania and hypomania in full or subsyndromal forms are the defining features of bipolar disorder and are common in neurologic patients, as are manic syndromes precipitated by medications used to treat neurologic disorders. This article addresses the diagnosis, pathophysiology, treatment, and course of bipolar disorder after a manic episode as well as mania as a manifestation of neurologic disease.

RECENT FINDINGS

Mania can be a primary psychiatric disorder but can also be a symptom of a neurologic disorder, especially right-sided cerebrovascular disease. Treatments (such as corticosteroids and dopaminergic agents) for neurologic illnesses regularly induce mania. The neurobiology of primary mania and bipolar disorder involves alterations in intracellular signaling, changes in gene expression, neural network interactions, and apoptosis. Except when induced by time-limited treatment with a provoking agent, mania tends to be highly recurrent and to alternate or be exhibited alongside depression. Symptoms of mania become more complex and treatment refractory with time, although effective treatment improves the long-term outcome.

SUMMARY

Behavioral manifestations of mania may be more obvious than affective symptoms, especially in patients with aprosodia. Atypical antipsychotic drugs are often first-line acute treatments, but the evidence supporting their long-term prophylactic efficacy is questionable. In addition to being an established mood stabilizer, lithium has putative neuroprotective properties, although a side effect can be impaired memory.

Increased platelet intracellular calcium ion concentration is specific to bipolar disorder

BACKGROUND

Increased baseline ([Ca(2+)]B) and agonist-stimulated ([Ca(2+)]s) free intracellular calcium ion concentrations ([Ca(2+)]i) are well-replicated findings in bipolar disorder, but whether this finding is specific to that condition and if so, whether it is a marker of the mood disorder or a feature seen in other disorders such as psychosis has remained unclear.

METHODS

Platelet [Ca(2+)]i was assessed in 15 inpatients with psychotic and nonpsychotic mania, 17 schizophrenia inpatients, and 17 matched controls.

RESULTS

Platelet [Ca(2+)]B and [Ca(2+)]s were significantly higher than controls in bipolar disorder but not schizophrenia. Variability of [Ca(2+)]B was significantly increased in bipolar disorder regardless of the presence of psychosis, but not in schizophrenia.

LIMITATIONS

Use of antipsychotic drugs by the majority of both patient groups may have obscured elevated [Ca(2+)]i in schizophrenia, or may have masked a difference between psychotic and nonpsychotic bipolar disorder. Measurement of [Ca(2+)]i is too labor intensive to become a routine test for diagnosis or prediction of treatment response.

CONCLUSIONS

Elevated intracellular Ca(2+) signaling may be a marker of primary cellular hyperactivity that could contribute to comorbid conditions such as hypertension and neuronal apoptosis. Since lithium and carbamazepine attenuate increased [Ca(2+)]i, further research may demonstrate a correlation between normalization of [Ca(2+)]i and response to one of these medications, and further research may clarify whether a subgroup of patients may respond well to calcium channel antagonists.

Rapid cycling mood disorder: A review

Objectives: Rapid cycling mood disorder is an important clinical phenomenon. The concept of rapid cycling has evolved since it was first described in 1974. The purpose of this review is to summarise current diagnostic criteria, postulated risk factors and suggested management strategies.

Method: A Medline and Psych-Lit computerised literature search was supplemented by tracing back through the references from existing review work.

Results: Over 80 papers were identified which discussed diagnosis and management of rapid cycling.

Conclusions: DSM-IV provides a useful but narrow definition of rapid cycling. Standard treatment of affective disorder may exacerbate rapid cycling. If a rapid cycling course develops, discontinuation of antidepressants and use of mood stabilisers is recommended.

Impaired mitochondrial function in psychiatric disorders

Major psychiatric illnesses such as mood disorders and schizophrenia are chronic, recurrent mental illnesses that affect the lives of millions of individuals. Although these disorders have traditionally been viewed as 'neurochemical diseases', it is now clear that they are associated with impairments of synaptic plasticity and cellular resilience. Although most patients with these disorders do not have classic mitochondrial disorders, there is a growing body of evidence to suggest that impaired mitochondrial function may affect key cellular processes, thereby altering synaptic functioning and contributing to the atrophic changes that underlie the deteriorating long-term course of these illnesses. Enhancing mitochondrial function could represent an important avenue for the development of novel therapeutics and also presents an opportunity for a potentially more efficient drug-development process.

L-type calcium channels and psychiatric disorders: A brief review

Emerging evidence from genome-wide association studies (GWAS) support the association of polymorphisms in the alpha 1C subunit of the L-type voltage-gated calcium channel gene (CACNA1C) with bipolar disorder. These studies extend a rich prior literature implicating dysfunction of L-type calcium channels (LTCCs) in the pathophysiology of neuropsychiatric disorders. Moreover, calcium channel blockers reduce Ca(2+) flux by binding to the α1 subunit of the LTCC and are used extensively for treating hypertension, preventing angina, cardiac arrhythmias and stroke. Calcium channel blockers have also been studied clinically in psychiatric conditions such as mood disorders and substance abuse/dependence, yielding conflicting results. In this review, we begin with a summary of LTCC pharmacology. For each category of disorder, this article then provides a review of animal and human data. In particular, we extensively focus on animal models of depression and clinical trials in mood disorders and substance abuse/dependence. Through examining rationale and study design of published clinical trials, we provide some of the possible reasons why we still do not have definitive evidence of efficacy of calcium-channel antagonists for mood disorders. Refinement of genetic results and target phenotypes, enrollment of adequate sample sizes in clinical trials and progress in physiologic and pharmacologic studies to synthesize tissue and isoform specific calcium channel antagonists, are all future challenges of research in this promising field. © 2010 Wiley-Liss, Inc.

Time of mood switches in ultra-rapid cycling disorder: a brief review

The aim of this review is to assess the typical time of day that mood switches occur in ultra-rapid cycling disorder. It shall be determined, whether switches into depression or (hypo)mania are likelier to occur at particular times of the day or night, and whether a pattern of mood switch times can be discerned for different cycle lengths. Case reports giving information about cycle lengths and the times of day when switches have occurred were systematically compiled (sources: Medline and Web of Science). Cases with ultra-rapid (cycle lengths of days to weeks, including 48-h cycling) or ultra-ultra-rapid cycling (cycle lengths up to 24 h) were included (35 publications with 42 case reports). In cases with cycle lengths of days to weeks (n=11), switches appeared to occur at any time of the day. Patients with regular 48-h cycling (n=28) switched to depression or mania most often during nighttime hours. In all three patients with cycle lengths up to 24 h (ultra-ultra-rapid cycling), switches into depression occurred at night and switches into mania occurred at daytime. These findings indicate that in patients with mood cycles of 48h or less the switch process is closely linked to circadian aspects.

Extracting a needle from a haystack: reanalysis of whole genome data reveals a readily translatable finding

There is significant unmet need for more effective treatments for bipolar disorder. The drug discovery process is becoming prohibitively expensive. Hence, biomarker clues to assist or shortcut this process are now widely sought. Using the publicly available data from the whole genome association study conducted by the Wellcome Trust Case Control Consortium, we sought to identify groups of genetic markers (single nucleotide polymorphisms) in which each marker was independently associated with bipolar disorder, with a less stringent threshold than that set by the original investigators (p< or =1 x 10(-4)). We identified a group of markers occurring within the CACNA1C gene (encoding the alpha subunit of the calcium channel Cav1.2). We then ascertained that this locus had been previously associated with the disorder in both a smaller and a whole genome study, and that a number of drugs blocking this channel (including verapamil and diltiazem) had been trialled in the treatment of bipolar disorder. The dihydropyridine-based blockers such as nimodipine that bind specifically to Cav1.2 and are more penetrant to the central nervous system have shown some promising early results; however, further trials are indicated. In addition, migraine is commonly seen in affective disorder, and calcium channel antagonists are successfully used in the treatment of migraine. One such agent, flunarizine, is structurally related to other first-generation derivatives of antihistamines such as antipsychotics. This implies that flunarizine could be useful in the treatment of bipolar disorder, and, furthermore, that other currently licensed drugs should be investigated for antagonism of Cav1.2.

Developmental psychobiology of cyclic affective illness: Implications for early therapeutic intervention

The recurrent affective disorders are discussed from the perspective of accumulating inherited and experiential effects on gene expression. Stress and episodes of affective illness are viewed as leaving biochemical and microstructural residues in the central nervous system (CNS) in relation to their patterning, severity, and recurrence. Comorbid factors such as substance abuse and developmental disturbances may also interact with these illness-related variables. In addition to the primary pathological processes, secondary adaptive changes can also be induced, which, in concert with pharmacological interventions, may be sufficient to counter episode occurrences and illness progression. We postulate that the balance of primary pathological and secondary adaptive changes at multiple levels of CNS regulation accounts for recurrence and cyclicity in the affective disorders. The importance of early, effective, long-term interventions in the recurrent affective disorders and the therapeutic potential of several new treatment modalities including repeated transcranial magnetic stimulation (rTMS) are discussed.

Neuropsychiatric consequences of cardiovascular medications

The use of cardiovascular medications can have a variety of neuropsychiatric consequences. Many cardiovascular agents cause higher rates of fatigue and sedation than placebo, and case reports of medication-induced mood syndromes, psychosis, and cognitive disturbances exist for many cardiovascular drugs. Depression has been associated with β-blockers, methyldopa, and reserpine, but more recent syntheses of the data have suggested that these associations are much weaker than originally believed. Though low cholesterol levels have been associated with depression and suicide, lipid-lowering agents have not been associated with these adverse effects. Finally, cardiovascular medications may have beneficial neuropsychiatric consequences; for example, the use of clonidine in patients with attention deficit-hyperactivity disorder, the use of prazosin for patients with post-traumatic stress disorder, and the use of propranolol for performance anxiety and akathisia.

Insular cortex and neuropsychiatric disorders: A review of recent literature

The insular cortex is located in the centre of the cerebral hemisphere, having connections with the primary and secondary somatosensory areas, anterior cingulate cortex, amygdaloid body, prefrontal cortex, superior temporal gyrus, temporal pole, orbitofrontal cortex, frontal and parietal opercula, primary and association auditory cortices, visual association cortex, olfactory bulb, hippocampus, entorhinal cortex, and motor cortex. Accordingly, dense connections exist among insular cortex neurons. The insular cortex is involved in the processing of visceral sensory, visceral motor, vestibular, attention, pain, emotion, verbal, motor information, inputs related to music and eating, in addition to gustatory, olfactory, visual, auditory, and tactile data. In this article, the literature on the relationship between the insular cortex and neuropsychiatric disorders was summarized following a computer search of the Pub-Med database. Recent neuroimaging data, including voxel based morphometry, PET and fMRI, revealed that the insular cortex was involved in various neuropsychiatric diseases such as mood disorders, panic disorders, PTSD, obsessive-compulsive disorders, eating disorders, and schizophrenia. Investigations of functions and connections of the insular cortex suggest that sensory information including gustatory, olfactory, visual, auditory, and tactile inputs converge on the insular cortex, and that these multimodal sensory information may be integrated there.

Maintenance treatment of bipolar disorder: Applying research to clinical practice

The authors review available controlled trials of bipolar maintenance treatment and discuss the strengths and weaknesses of various study designs. Bipolar maintenance trials are organized according to the features of their designs, such as use of responder-enriched samples; inclusion following an index manic versus an index depressive episode; outcome defined as relapse into mania, depression, or either; and use of survival analysis. Pivotal studies of lithium, divalproex, lamotrigine, olanzapine, aripiprazole, and other medications are reviewed. The directional efficacy of the different medications as maintenance treatment is discussed, with treatments differentiated in terms of whether they primarily prolong time to mania or to depression or have bidirectional effects. Also discussed are findings concerning the continuation of acute treatments, including antidepressants, into the maintenance phase; dosage adjustments for maintenance treatment; the rationale for combination treatments; and implications of comorbid substance abuse and strategies for its management. Directions for future research are suggested.

Clinical use of carbamazepine for bipolar disorders

Two recently completed large, randomised, double-blind, placebo-controlled trials supporting the efficacy of carbamazepine (CBZ) extended-release capsules (ERC) for the treatment of acute manic and mixed episodes have resulted in US FDA approval of CBZ-ERC, and have reinvigorated the importance of understanding the role of CBZ in bipolar disorder (BD) pharmacotherapy. Additional data suggest that CBZ may have a use in BD maintenance treatment and possibly in acute BD depression. Optimal use of CBZ requires sound knowledge of adverse effects and pharmacokinetic interactions with this agent. Adverse effects commonly involve benign side effects but can rarely include serious haematological, dermatological and hepatic manifestations. On the other hand, metabolic adverse effects (thyroid, glucose, lipid disturbances and significant weight gain) can be less problematic with CBZ, compared with lithium, valproate and atypical antipsychotics. Pharmacokinetic considerations (cytochrome P450 3A3/4 metabolism, active epoxide metabolite and catabolic enzyme induction) can influence the clinical use of CBZ. Managing adverse effects and pharmacokinetic complexities is important for optimising pharmacotherapy with CBZ in patients with BD. This paper reviews the chemistry, pharmacodynamics and pharmacokinetics of CBZ, as well as reviews of the controlled trials of CBZ in acute bipolar mania, acute bipolar depression and bipolar maintenance treatment.

Preliminary findings of uncoupling of flow and metabolism in unipolar compared with bipolar affective illness and normal controls

Cerebral metabolism (CMR for glucose or oxygen) and blood flow (CBF) have been reported to be closely correlated in healthy controls. Altered relationships between CMR and CBF have been reported in some brain disease states, but not others. This study examined relationships between global and regional CMRglu vs. CBF in controls and medication-free primary affective disorder patients. Nine bipolars, eight unipolars, and nine healthy controls had [15O]-water positron emission tomography (PET) scans at rest, and [18F]-fluorodeoxyglucose PET scans during an auditory continuous performance task. Patients had [15O]-water and FDG PET scans in tandem the same day; controls had an average of 45+/-27 days between scans. Maps of regional coupling were constructed for each subject group. In controls and bipolars, global and virtually all regional correlation coefficients for CMRglu and CBF were positive, albeit more robustly so in controls. However, correlative relationships in unipolars were qualitatively different, such that global and most regional measures of flow and metabolism were not positively related. Unipolars had significantly fewer positive regional correlation coefficients than healthy controls and bipolars. These were significantly different from controls in orbital cortex, anterior cingulate, posterior cingulate, and posterior temporal cortex, and different from bipolars in pregenual anterior cingulate. In unipolars, the degree of flow-metabolism uncoupling was inversely correlated with Hamilton depression scores, indicating the severity of uncoupling was directly related to the severity of depression. These preliminary data suggest abnormal relationships between cerebral metabolism and blood flow globally and regionally in patients with unipolar depression that warrant replication and extension to potential pathophysiological implications.

Recurrent brief depression revisited

Recurrent Brief Depressive Disorder (RBD) is a well-defined and prevalent mood disorder with an increased risk of suicidal behavior and significant clinical impairment in the community and general practice. Occurring at least monthly with depressive episodes lasting only a few days defines recurrent Brief Depressive Disorder. The lifetime co-occurrence of both RBD and Major Depressive Disorder (MDD), called Combined Depression (CD), substantially increases the risk for attempted suicide, even more than that known for 'pure' MDD. The diagnostic criteria for RBD found in the ICD-10 and DSM-IV are helpful in research and clinical routine as well as several methodological issues, which make clinical diagnostic and drug response evaluation of RBD very different from MDD. Formal differences in the course of RBD and MDD require different designs for drug treatment studies. Denials of disorder, specific methodological requirements, and highly selected patient samples have probably been responsible for false negative results in double blind, placebo-controlled treatment studies. Although several authors reported successful treatment of RBD with different compounds in about 60 patients, it is still not possible to deduce a treatment algorithm for RBD to date. Obviously future treatment studies without the limitations of previous studies are clearly required for RBD. Results of ongoing studies will soon provide the first data on the biological underpinnings of RBD.

The World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for the biological treatment of bipolar disorders, part III: maintenance treatment

As with the two preceding guidelines of this series, these practice guidelines for the pharmacological maintenance treatment of bipolar disorder were developed by an international task force of the World Federation of Societies of Biological Psychiatry (WFSBP). Their purpose is to supply a systematic overview of all scientific evidence relating to maintenance treatment. The data used for these guidelines were extracted from a MEDLINE and EMBASE search, from recent proceedings from key conferences and various national and international treatment guidelines. The scientific justification of support for particular treatments was categorised into four levels of evidence (A-D). As these guidelines are intended for clinical use, the scientific evidence was not only graded, but also reviewed by the experts of the task force to ensure practicality.

Convergences in course of illness and treatments of the epilepsies and recurrent affective disorders

The failure to achieve and maintain remission is a critical problem for a high percentage of patients with epilepsy and the primary affective disorders. Early illness onset and delayed initiation of treatment may contribute to primary treatment resistance or that associated with loss of efficacy (tolerance phenomenon). Neurobiological data and principles drawn from the amygdala kinding model of seizure progression are reviewed for their heuristic value in conceptualizing molecular mechanisms of illness progression and its prevention with pharmacological agents in the epilepsies and, indirectly, the recurrent affective disorders. Caveats in the use of this model and convergences and divergences in its predictive validity for seizures and affective disorders are noted.

Potential mechanisms of action of lamotrigine in the treatment of bipolar disorders

Based on the mood-stabilizing properties of carbamazepine and valproate, new anticonvulsants have been explored for use in bipolar disorders. One such agent, lamotrigine, has a novel clinical profile in that it may "stabilize mood from below," as it appears to maximally impact depressive symptoms in bipolar disorders. In this paper, we review the mechanisms of action of lamotrigine in an effort to understand the basis of its distinctive clinical use in the management of bipolar disorders as well as its diverse antiseizure effects. We consider lamotrigine mechanisms, emphasizing commonalities and dissociations among actions of lamotrigine, older mood stabilizers, and other anticonvulsants. Although ion channel effects, especially sodium channel blockade, may importantly contribute to antiseizure effects, such actions may be less central to lamotrigine thymoleptic effects. Antiglutamatergic and neuroprotective actions are important candidate mechanisms for lamotrigine psychotropic effects. Lamotrigine has a variable profile in kindling and contingent tolerance experiments and does not appear to have robust gamma-aminobutyric acid or monoaminergic actions. Lamotrigine intracellular signaling effects warrant investigation. Although lamotrigine mechanisms overlap those of other mood-stabilizing anticonvulsants, important dissociations suggest candidate mechanisms, which could contribute to lamotrigine's distinctive psychotropic profile.

Reconsidering the classification of schizophrenia and manic depressive illness--a critical analysis and new conceptual model

The idea of 'disease entity' in psychiatry and the nosologic map of insanity with the distinction between dementia praecox (schizophrenia since Bleuler 1911) and manic depressive insanity, originally developed by Emil Kraepelin (1986), is an important landmark in the history of psychiatry (Jablensky 1995). This classification, however, has been vigorously debated throughout the years, and new evidence emerging from epidemiological, clinical, genetic and biological research demonstrates that the two nosological categories have distinct features as well as share many similarities in their risk factors, genetic predisposition, brain pathology, neurophysiology, clinical phenomenology and response to treatment, thus raising questions about the validity of the categorical classification of psychoses. In this paper we examine some of the similarities and differences between schizophrenia and bipolar illness emerging from recent biological and clinical research and attempt to clarify major inherent logical contradictions in the application of the 'disease' model of psychiatric diagnosis to the categorical classification of schizophrenia and bipolar illness. Then we examine how similar predicaments have been resolved in other natural classification systems, namely the biological classification of species and the periodic table of the elements. Finally we propose a hypothetical conceptual approach to the classification of psychoses that has been greatly informed by the organizing principle underlying the periodic table of the elements, and is distinct from the 'disease' model of psychiatric classification.

Recurrent brief depression--past and future

Recurrent brief depressive disorder (RBD) is a well-defined and significantly prevalent affective disorder with an increased risk of suicidal behavior and significant clinical impairment in the community and general practice. RBD is characterized by depressive episodes occurring at least once a month and lasting for only a few days. The lifetime co-occurrence of both RBD and major depressive disorder (MDD), called combined depression (CD), increases substantially the risk for suicide attempts, even more than is known for "pure" MDD. Diagnostic criteria for RBD can be found in the ICD-10 and DSM-IV and are helpful in both, research and clinical routine. Furthermore, several methodological issues are covered in this paper, which make clinical diagnostic and drug response evaluation of RBD very different from MDD. However, clinical procedures rather bear a resemblance to those used in the treatment of migraine or epilepsy. Formal differences in the course of RBD and MDD create different needs concerning the design of drug treatment studies. Absence of special methodological requirements and highly selected patient samples has probably been responsible for false negative results in double-blind, placebo-controlled treatment studies. Although several authors reported successful treatment of RBD with different compounds in about 60 patients, it is still not possible to deduce a treatment algorithm for RBD to date. Obviously, future treatment studies without the limitations of previous studies are clearly required for RBD.

Low CSF somatostatin associated with response to nimodipine in patents with affective illness

BACKGROUND

In patients with depression, treatment with nimodipine has been shown to increase cerebrospinal fluid (CSF) somatostatin (SRIF) and ameliorate baseline global cerebral hypometabolism. This study was conducted to assess whether a low baseline level of CSF SRIF was associated with response to nimodipine treatment.

METHODS

Twenty-one depressed patients underwent lumbar puncture for analysis of CSF somatostatin-like immunoreactivity (SRIF-LI) during a medication-free period and after at least 6 weeks of nimodipine monotherapy. Twenty-five healthy control subjects were utilized as a comparison group. Clinical improvement was assessed using the Clinical Global Impression Scale for Bipolar Illness.

RESULTS

As predicted, baseline CSF SRIF-LI was significantly lower in eventual nimodipine responders (33.1 +/- 2.8 pg/mol) compared to eventual nonresponders [41.9 +/- 2.6 pg/mL; t(19) = 1.98, p =.03, one-tailed].

CONCLUSIONS

Low baseline CSF somatostatin in depression may be associated with response to nimodipine, which in turn may be related to the ability of nimodipine to increase CSF somatostatin.

Unique design issues in clinical trials of patients with bipolar affective disorder

Two National Institute of Mental Health-sponsored meetings of experts on bipolar illness (in 1989 and 1994) noted a paucity of clinical psychopharmacological trials in this illness which has now extended over the past two decades. One of the reasons elucidated for this neglect was a lack of agreement in the field as to what constituted an optimal clinical trial design, consequently resulting in low-priority scores for funding of studies in bipolar illness. In this paper, we note some of the characteristics of bipolar illness that make it particularly difficult to study and find such agreed upon trial designs. Some of the assets and liabilities of the well-accepted traditional parallel group, placebo-controlled, randomized clinical trial (RCT) are reviewed, and a series of other potential design options, such as crossover, enrichment, off-on-off-on (B-A-B-A), and N-of-1 trials, are discussed that may help to better address some of the unique clinical characteristics of bipolar illness. Finally, a variety of statistical approaches to analyzing data in off-on-off-on trial designs, and in helping to predetermine necessary durations of clinical trials in individual patients with bipolar disorders, are suggested. Acceptance of a wider variety of clinical trial designs may help facilitate the funding and accelerate the acquisition of new data on treatment of bipolar illness.

Pharmacotherapy of bipolar disorder: the role of atypical antipsychotics and experimental strategies

Bipolar disorder, despite being a common and debilitating illness, has remarkably few pharmacological therapeutic options, the majority of which, with the exception of lithium, have been borrowed from other medical indications. Furthermore the quantity and quality of controlled clinical data are considerably smaller than in conditions of comparable severity and frequency. Not surprisingly, the clinical outcome of bipolar disorder is frequently suboptimal. Fortunately there are a growing number of novel therapeutic options for its treatment such as atypical antipsychotics, calcium channel blockers and omega-3 fatty acids. This paper summarizes some of the data regarding these "experimental" therapeutic options, focusing principally on atypical antipsychotics as these are now widely prescribed in the management of bipolar disorder.

The expanding pharmacopoeia for bipolar disorder

Over the past decade, the number of treatments available for bipolar disorder has undergone an extraordinary expansion. In that period, valproate and olanzapine have received regulatory approval in the United States for the acute treatment of mania, and carbamazepine has been indicated for this condition in many other countries. In addition to those agents, a number of other anticonvulsants (in particular lamotrigine, gabapentin, and topiramate) are in trials, as are the atypical antipsychotics clozapine and risperidone, and other novel compounds. This article critically reviews the evidence from controlled trials of these proposed "mood stabilizers," highlighting the strengths and limitations of the data for each compound. A major challenge to the field is the capacity to prove the prophylactic properties of agents for which effectiveness in acute mania and/or bipolar depression has been demonstrated. Finally, as the mechanisms of agents such as lithium are now becoming apparent, and the possibility of understanding the molecular defects underpinning the condition is no longer highly fanciful, the prospect of targeted therapies is considered feasible by both academia and the pharmaceutical industry.

Clinical relevance and treatment possibilities of bipolar rapid cycling

Bipolar rapid cycling (RC) is defined as 4 or more affective episodes within 1 year. It has been postulated that RC is related to a poor response to lithium, to the same extent as mixed episodes or other atypical symptoms of the illness. This article reviews the current status of alternative pharmacological or otherwise supportive therapies of RC. Biological parameters and characteristics of the illness associated with RC like gender prevalence in women, hyperthyroidism, catecholamine-O-methyltransferase allele, the influence of sleep, different subtypes of bipolar disorder and the risk of antidepressant-induced cycling will be discussed in detail.

Rapid cycling bipolar disease: new concepts and treatments

Having been recognized by Kraeplin at the beginning of the 20th century, rapid cycling was first described as a specific entity by Dunner et al. in 1974. The prevalence of rapid cycling ranges from 12% to 20% in patients with bipolar disorder who are not selected for a high rate of cycling.

Rapid cycling bipolar disorder

Rapid cycling bipolar disorder (RCBD) is defined in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) as a type of manic-depressive illness in which the patient experiences four or more episodes of mania and/or major depression per year. It was first reported as a consequence of the reduced effectiveness of lithium carbonate in the treatment and prophylaxis of this form of bipolar disorder (BD) in contrast to those with less frequent cycling. Among the anticonvulsants, there have been reports with different degrees of controlled data concerning carbamazepine, valproate, lamotrigine, topiramate, gabapentin and primidone. There is a paucity of double-blind studies, but what is available supports the use of lamotrigine. There is open data supporting the use of carbamazepine, valproate and topiramate. Regarding other classes, nimodipine may have specific utility in ultradian- (ultra-ultra-) or ultra-RCBD and there is double-blind data regarding the specific utility of olanzapine in RCBD. Low thyroid function may be a factor in development of RCBD; therapies aimed at elevating thyroid levels, even beyond the usual range, have frequently produced benefits in open trials. More research is needed into the possible therapeutic benefits of verapamil, bupropion, choline, light therapy and electroconvulsive therapy (ECT).

Treatment-resistant bipolar disorder

Over the last few years, the number of potential pharmacotherapies for bipolar disorder has greatly expanded. Yet the database for virtually all these newer treatments consists of case reports and case series. Among these newer treatments, recently released anticonvulsants are most promising. Lamotrigine has already shown efficacy for treating bipolar depression, while gabapentin's efficacy has yet to be documented in a controlled study. Alone among its medication class, topiramate, another anticonvulsant, is associated with weight loss. Novel antipsychotics are effective in treating acute mania. With the exception of clozapine, their efficacy as true mood stabilizers is still unknown. Utilizing combinations of mood stabilizers is common and appropriate but demands knowledge of potential pharmacokinetic interactions. Other approaches for treatment resistant bipolar disorder include high-dose thyroid hormones, calcium channel blockers, electroconvulsive therapy, and omega-3 fatty acids. Finally, the efficacy of adjunctive psychosocial strategies is a topic of active investigation.

Nicardipine improves the antidepressant action of ECT but does not improve cognition

INTRODUCTION

Cognitive impairment, the most important adverse effect of electroconvulsive therapy (ECT), may involve elevated intracellular calcium ion signaling. Animal research suggests that calcium channel-blocking agents, which attenuate excessive intracellular calcium activity, may reduce cognitive dysfunction caused by ECT.

METHOD

The lipid-soluble calcium channel-blocking drug nicardipine or matching placebo were randomly assigned to 26 patients with major depressive disorder receiving ECT. A rater blind to the experimental condition administered the Hamilton Depression Rating Scale, the Montgomery-Asberg Depression Rating Scale, the Beck Depression Inventory, the Mini-Mental State Examination and a comprehensive battery of neuropsychological tests prior to ECT, at the completion of ECT, and 6 months after ECT completion.

RESULTS

Compared with patients receiving placebo, patients taking nicardipine had significantly lower scores on the Hamilton and Montgomery-Asberg but not the Beck Depression rating scale scores at the completion of ECT. There were no differences between placebo and nicardipine groups in depression scores 6 months after ECT. Cognitive function declined over the course of ECT and improved over the next 6 months in both groups, but changes were statistically significant for only two subtests on the neuropsychological battery. Changes in Mini-Mental State Examination scores were small and were not significant at any point. There were no significant differences between nicardipine and placebo treated groups in any assessment of cognition.

DISCUSSION

Standard approaches to ECT in younger patients without preexisting neurological impairment do not produce cognitive side effects of sufficient severity for calcium channel-blocking agents to reduce these side effects demonstrably. Studies of treatments for cognitive impairment should be conducted in patients with risk factors for more severe cognitive impairment such as geriatric patients or patients with a history of interictal delirium during previous treatment with ECT. A possible effect of nicardipine in enhancing the antidepressant action of ECT requires further investigation in a study designed to test this action.

Emerging trends in the treatment of rapid cycling bipolar disorder: a selected review

Recent evidence suggests that lithium therapy (even as supplemented by antidepressants and neuroleptics) is inadequate for the majority of patients with bipolar illness, and particularly those with rapid cycling. Valproate and carbamazepine have emerged as adjuncts and alternatives, but they, too, often require additional approaches with lithium, thyroid hormones, and other putative mood stabilizers, including nimodipine (and related dihydropyridine calcium channel blockers), lamotrigine, gabapentin, topiramate, and the atypical neuroleptics. Evaluating how these agents and the unimodal antidepressants are optimally applied and sequenced in the treatment of bipolar illness with its multiple subtypes, patterns and comorbidities will require much future investigation and the development of new methodological clinical trial approaches.

Methodological issues in developing new acute treatments for patients with bipolar illness

One important aim of the recent reorganization of the National Institute of Mental Health (NIMH) is to streamline the development of new treatments for patients with severe mental illnesses, such as bipolar disorder. Researching new treatments for patients with bipolar disorder presents specific problems not readily addressed by traditional efficacy trial methodologies that aim to maximize internal validity. This article reexamines several assumptions that have guided the design of these efficacy trials but that also create obstacles for studies of bipolar disorder and suggests potential solutions. This article draws on literature from neurology and psychiatry and discussions at a MacArthur Foundation-sponsored Conference on Longitudinal Methodology in 1992 (David J. Kupfer, M.D., Chair), which brought together investigators to consider alternative designs for patients with severe and persistent mental illness. In addition, we benefited from discussions at two NIMH-sponsored conferences, one held in 1989 (Prien and Potter 1990) and the other in 1994 (Prien and Rush 1996), at which investigators and methodologists discussed issues surrounding the development and conduct of informative efficacy trials for patients with bipolar disorder. Based on these discussions and recent literature reviews, we 1) outline common problems in the development and evaluation of effective acute treatments for bipolar disorder and 2) suggest possible solutions to these impediments. We also discuss alternative designs by which to build a sequence of acute treatment studies from which efficacy, safety, and the comparative value of different treatments can be established.