Combined treatment with lithium and nimodipine in a bipolar I manic syndrome

The Challenges of Children with Bipolar Disorder

Childhood onset bipolar disorder (CO-BD) presents a panoply of difficulties associated with early recognition and treatment. CO-BD is associated with a variety of precursors and comorbidities that have been inadequately studied, so treatment remains obscure. The earlier the onset, the longer is the delay to first treatment, and both early onset and treatment delay are associated with more depressive episodes and a poor prognosis in adulthood. Ultra-rapid and ultradian cycling, consistent with a diagnosis of BP-NOS, are highly prevalent in the youngest children and take long periods of time and complex treatment regimens to achieve euthymia. Lithium and atypical antipsychotics are effective in mania, but treatment of depression remains obscure, with the exception of lurasidone, for children ages 10-17. Treatment of the common comorbid anxiety disorders, oppositional defiant disorders, pathological habits, and substance abuse are all poorly studied and are off-label. Cognitive dysfunction after a first manic hospitalization improves over the next year only on the condition that no further episodes occur. Yet comprehensive expert treatment after an initial manic hospitalization results in many fewer relapses than traditional treatment as usual, emphasizing the need for combined pharmacological, psychosocial, and psycho-educational approaches to this difficult and highly recurrent illness.

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.

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.

Antidepressant-like activity of liposomal formulation containing nimodipine treatment in the tail suspension test, forced swim test and MAOB activity in mice

Previous studies have shown that intracellular calcium ion dysfunction may be an etiological factor in affective illness. Nimodipine (NMD) is a Ca(2+) channel blocker that has been extensively investigated for therapy of central nervous system (CNS) disorders. In this work, we have evaluated the antidepressant-like activity of nimodipine encapsulated into liposomes (NMD-Lipo) in mice through tail suspension and forced swim assays, as well as MAOB activity. During the tail suspension test, the administration of NMD-Lipo at 0.1, 1 and 10mg/kg was able to promote a reduction in the immobility time of animals greater than the positive control (imipramine). In the forced swim test, the immobility time of mice treated with NMD-Lipo was reduced. This reduction was significantly greater than that found in the animals treated with imipramine and paroxetine. This may suggest that NMD-Lipo provides more antidepressant-like activity than in positive controls. The groups that received a combination of liposomal NMD and antidepressant drugs showed lower immobility time than the groups, which were treated only with imipramine or paroxetine. The mice treated with the combination of NMD-Lipo and reserpine presented an increase in the time of immobility compared with animals treated only with NMD-Lipo. There was a significant decrease in MAOB activity in animals treated with NMD-Lipo compared with untreated animals. The results of the tail suspension test, forced swim test and MAOB activity suggested that the antidepressant activity of NMD-Lipo may be related to an increase in the cerebral monoamine concentrations.

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.

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.

Dysregulation of ion fluxes in bipolar affective disorder

Bipolar disorder has attracted numerous research from different neurobiological angles. This review will summarize selected findings focusing on the role of disturbed transmem-braneous ion fluxes. Several mood stabilizers exhibit a distinct profile including effects on sodium, calcium and potassium conductance. In summary, some decisive mechanisms of action as calcium antagonism and modulation of potassium currents may play a crucial role in the success of any given mood stabilizer in bipolar disorder.

The use of nimodipine in the treatment of mood disorders

Nimodipine, a dihydropyridine calcium entry blocker, has been shown to protect from neuronal damage due to ischemia by providing for increased postischemic perfusion. Further, it has also been demonstrated to have antiepileptic properties. These two properties--calcium channel blockade and anticonvulsant benefits have been applied with success to mood disorder treatment. Although found helpful nearly a decade ago for uncomplicated mania, nimodipine may have particular benefits for those diagnostic subclasses of bipolar disorder most resistant to therapy, e.g., ultra-rapid-cycling bipolars and brief recurrent depressions.

Calcium channel blockers in psychiatric disorders: a review of the literature

OBJECTIVES

To review the published literature of the past 15 years regarding use of calcium channel blockers (CCBs) in psychiatric practice. These drugs, especially verapamil, have been recommended as possible treatments for mania and other disorders.

METHODS

The Cumulative Medical Index and other databases were searched and back-tracked to locate relevant articles. Sixty-one such articles were uncovered: 37 anecdotal reports, 7 partially controlled reports, and 17 controlled trials.

RESULTS

Most studies involved treatment of mania using verapamil. Although anecdotal reports were generally favourable, results from partially controlled reports or controlled clinical trials were mixed. Generally, verapamil was less effective than was lithium or placebo. Treatment of depression with CCBs was not very successful, regardless of the type of trial; the best trial was negative. The same was true for the treatment of schizophrenia, although the cases studied were extremely chronic and treatment-resistant. Evidence for efficacy in other illnesses, such as Alzheimer's disease or tardive dyskinesia was scanty but suggested that further trials might be in order.

CONCLUSIONS

CCBs do not at present have an established place in psychiatric treatment. Nonetheless, clinicians faced with a manic patient not responsive to other antimanic drugs, either alone or in combination, might consider adding verapamil as an adjunct. A study bearing on this specific issue is needed to determine whether or not such off-label use would really be justified.

Mood stabilizers in children and adolescents

OBJECTIVE

The efficacy of mood stabilizers in children and adolescents has not been studied adequately. This article will review existing studies and highlight some important issues in designing future studies on these agents.

METHOD

Electronic databases including Medline, Psycholnfo, and CRISP were searched for data in children receiving compounds that have mood-stabilizing properties in adults.

RESULTS

Some open clinical data and an extremely modest amount of controlled research data suggest lithium, carbamazepine, and valproate may be effective mood stabilizers in children and adolescents. There are no controlled data on other potential mood stabilizers in children.

CONCLUSIONS

The disorders that may be responsive to mood stabilizers are among the most morbid in child psychiatry. More studies are needed to clarify the efficacy of these compounds in children and adolescents and to provide a rational basis for choosing among them.