The neurobiology of the switch process in bipolar disorder: a review

Repetitive Transcranial Magnetic Stimulation in the Treatment of Bipolar Depression: Experience From a Clinical Setting

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive Food and Drug Administration (FDA)-approved treatment for unipolar treatment-resistant depression (TRD). rTMS has been utilized clinically to treat bipolar TRD; however, there remains a lack of evidence and support for effectively utilizing this intervention for bipolar TRD. We retrospectively analyzed data from a group of patients who were treated with rTMS for unipolar or bipolar TRD and describe a case example to further delineate management techniques for employing rTMS in the treatment of bipolar TRD.

METHODS

Records of 71 patients treated with rTMS for unipolar (n=54) or bipolar (n=17) TRD between 2008 and 2017 were reviewed. The primary outcome of depression severity, the Quick Inventory of Depressive Symptomatology, was completed at baseline and after every 5 sessions throughout the course of 30 treatments. Secondary outcomes involved a comparison of outcomes and clinical characteristics within and between the bipolar and unipolar TRD groups.

RESULTS

In the total sample, patients' depression improved significantly over the course of treatment. Patients with bipolar TRD showed greater response and remission rates over the course of treatment compared with patients with unipolar TRD, but this difference was not statistically significant. Both groups showed a similar pattern of depression response over treatment time. No manic or hypomanic episodes occurred during any patient's course of rTMS treatment. A case example is provided discussing the timing of rTMS in a patient with bipolar depression to decrease the likelihood of treatment-induced hypomania.

LIMITATIONS

Limitations included the small overall sample size, the smaller size of the patient group with bipolar TRD compared with the group with unipolar TRD, and the naturalistic setting of this study.

CONCLUSIONS

Our data suggest that rTMS may be equally effective and safe for patients with both unipolar and bipolar depression. Patients with bipolar TRD showed a similar response profile over treatment time compared with patients with unipolar TRD.

A systematic review on sleep alterations anticipating the onset of bipolar disorder

Background:

Sleep alterations are frequent occurrence in Bipolar Disorder (BD), both in acute and interepisodic phases. Sleep alterations have been also described both long before BD onset, as aspecific risk syndromes, or as immediate prodromes of BD onset. The aim of the present study is to systematically review the relationship between sleep alterations anticipating for the full-blown onset of BD, both in general and according to specific polarities of onset.

Methods:

A systematic literature research according to PRISMA statement and considering: 1. prospective studies about BD patients’ offspring with sleep alterations who later developed BD. 2. prospective studies assessing patients with sleep disorders who later developed BD. 3. retrospective studies on BD patients where sleep alterations before BD onset of the disease were reported.

Results:

A total of 16 studies were included in this review. Sleep disturbances may frequently appear 1 year before the onset of BD or more, often during childhood or adolescence. A decreased need for sleep may precede the onset of the illness, specially a manic episode, while insomnia appears to anticipate either a manic or a depressive episode. Hypersomnia seems to precede bipolar depressive episodes.

Conclusions:

Sleep alterations frequently appear long before the onset of BD, and appear to be related specifically to the polarity of the index episode. The detection and treatment of sleep alterations in special high risk populations may help achieving an earlier detection of the illness.

Concluding Commentary: Schadenfreude, Gluckschmerz, Jealousy, and Hate—What (and When, and Why) Are the Emotions?

Schadenfreude, gluckschmerz, jealousy, and hate are distinctive emotional phenomena, understudied and deserving of increased attention. The authors of this special section have admirably synthesized large literatures, describing major characteristics, eliciting conditions, and functions (Chung & Harris, 2018; Fischer, Halperin, Canetti, & Jasini, 2018; R. H. Smith & van Dijk, 2018). We discuss the contributions of each article as well as the issues they raise for theories of emotions and some remaining questions, and suggest ways in which these might be profitably addressed.

Risk of manic switch with antidepressants use in patients with bipolar disorder in a Nigerian neuropsychiatric hospital

Background

Depressive disorders are common among those with bipolar affective disorder (BAD) and may necessitate the use of antidepressants. This has been suggested to precipitate manic episodes in some patients.

Objectives

This study aims to determine the prevalence of and factors associated with manic switch in patients with BAD being treated with antidepressants.

Methods

Case notes of patients who were treated at a Nigerian neuropsychiatric hospital for a BAD from 2004 to 2015 were reviewed. BAD diagnosis was made using ICD-10 criteria. Treatment for bipolar depression included monotherapy (i.e. antidepressants, antipsychotics or mood stabilisers) or combination therapy (mood stabiliser with an antidepressant or a combination of mood stabilisers, antipsychotics and antidepressants). The primary outcome measure was a switch to mania or hypomania within 12 weeks of commencing an antidepressant.

Results

Manic or hypomanic switch (MS) was observed in 109 (44.3%) of the participants. Female gender, younger age, number of previous episodes and a past history of psychiatric hospitalisation were all significantly associated with a risk of MS. There was no significant difference in the rate of MS in either those treated with adjunct antidepressants therapy with a mood stabiliser or an antipsychotic or those placed on a combination of antidepressants, antipsychotics and mood-stabilising agents.

Conclusion

A large proportion of patients with BAD on antidepressants experience medication-induced manic or hypomanic switch.

ErbB4 deletion in noradrenergic neurons in the locus coeruleus induces mania-like behavior via elevated catecholamines

Dysfunction of the noradrenergic (NE) neurons is implicated in the pathogenesis of bipolar disorder (BPD). ErbB4 is highly expressed in NE neurons, and its genetic variation has been linked to BPD; however, how ErbB4 regulates NE neuronal function and contributes to BPD pathogenesis is unclear. Here we find that conditional deletion of ErbB4 in locus coeruleus (LC) NE neurons increases neuronal spontaneous firing through NMDA receptor hyperfunction, and elevates catecholamines in the cerebrospinal fluid (CSF). Furthermore, Erbb4-deficient mice present mania-like behaviors, including hyperactivity, reduced anxiety and depression, and increased sucrose preference. These behaviors are completely rescued by the anti-manic drug lithium or antagonists of catecholaminergic receptors. Our study demonstrates the critical role of ErbB4 signaling in regulating LC-NE neuronal function, reinforcing the view that dysfunction of the NE system may contribute to the pathogenesis of mania-associated disorder.

Bipolar disorder is a mental illness that affects roughly 1 in 100 people worldwide. It features periods of depression interspersed with episodes of mania – a state of delusion, heightened excitation and increased activity. Evidence suggests that changes in a brain region called the locus coeruleus contribute to bipolar disorder. Cells within this area produce a chemical called norepinephrine, whose levels increase during mania and decrease during depression. But it is unclear exactly how norepinephrine-producing cells, also known as noradrenergic cells, contribute to bipolar disorder.

The answer may lie in a protein called ErbB4, which is found within the outer membrane of many noradrenergic neurons. ErbB4 is active in both the developing and adult brain, and certain people with bipolar disorder have mutations in the gene that codes for the protein. Might changes in ErbB4 disrupt the activity of noradrenergic neurons? And could these changes increase the risk of bipolar disorder?

To find out, Cao, Zhang et al. deleted the gene for ErbB4 from noradrenergic neurons in the locus coeruleus of mice. The mutant mice showed mania-like behaviors: compared to normal animals, they were hyperactive, less anxious, and consumed more of a sugary solution. Treating the mice with lithium, a medication used in bipolar disorder, reversed these changes and made the rodents behave more like non-mutant animals. Further experiments revealed that noradrenergic neurons in the mutant mice showed increased spontaneous activity. These animals also had more of the chemicals noradrenaline and dopamine in the fluid circulating around their brains and spinal cords.

The results thus suggest that losing ErbB4 enhances the spontaneous firing of noradrenergic neurons in the locus coeruleus. This increases release of noradrenaline and dopamine, which in turn leads to mania-like behaviors. Future research should examine whether drugs that target ErbB4 could treat mania and improve the lives of people with bipolar disorder and related conditions.

Looking for bipolarity in antidepressant discontinuation manic states: Update and diagnostic considerations of the phenomenon

BACKGROUND

Antidepressant withdrawal manic states are intriguing and under-recognized phenomena. The associated patho-physiological pathways are ill defined and the inclusion of the phenomena in the bipolar spectrum disorders is questionable. This study aims to update a review on antidepressant discontinuation manic states published in 2008 and to look for hints alluding to bipolar disorder in the affected published cases and in the literature. It also reviews the different hypotheses proposed to explain discontinuation mania.

METHODS

We searched Pubmed using the key words: 'antidepressant withdrawal' or 'antidepressant discontinuation' plus 'mania' or 'hypomania' from January 2008 until January 2018.

RESULTS

Five new eligible reports were identified since the last review in 2008, involving the antidepressants Amitriptyline, Fluoxetine, Escitalopram and Mirtazapine. Hypotheses involve the implication of Catecholamines, Acetylcholine and Serotonin in the pathophysiology of this paradoxical phenomenon. Careful analysis of the total 29 cases revealed psychiatric histories in favor of a bipolar spectrum disorder in 12 individuals while five were already known to have bipolar disorder.

LIMITATIONS

This review is based on case reports with associated recall bias, and lack of in-depth description at times.

CONCLUSIONS

Antidepressant discontinuation manic or hypomanic states do not occur randomly. An individual susceptibility to bipolar disorder must be considered.

Clinical and psychopathological features associated with treatment-emergent mania in bipolar-II depressed outpatients exposed to antidepressants

BACKGROUND

Treatment-emergent affective switch (TEAS), including treatment-emergent mania (TEM), carry significant burden in the clinical management of bipolar depression, whereas the use of antidepressants raises both efficacy, safety and tolerability concerns. The present study assesses the prevalence and clinical correlates of TEM in selected sample of Bipolar Disorder (BD) Type-II (BD-II) acute depression outpatients.

METHODS

Post-hoc analysis of the clinical and psychopathological features associated with TEM among 91 BD-II depressed outpatients exposed to antidepressants.

RESULTS

Second-generation antipsychotics (SGA) (p = .005), lithium (≤ .001), cyclothymic/irritable/hyperthymic temperaments (p = ≤ .001; p = .001; p = .003, respectively), rapid-cycling (p = .005) and depressive mixed features (p = .003) differed between TEM⁺ cases vs. TEM^- controls. Upon multinomial logistic regression, the accounted psychopathological features correctly classified as much as 88.6% of TEM⁺ cases (35/91 overall sample, or 38.46% of the sample), yet not statistically significantly [Exp(B) = .032; p = ns]. Specifically, lithium [B = - 2.385; p = .001], SGAs [B = - 2.354; p = .002] predicted lower rates of TEM⁺ in contrast to the number of lifetime previous psychiatric hospitalizations [B = 2.380; p = .002], whereas mixed features did not [B = 1.267; p = ns].

LIMITATIONS

Post-hoc analysis. Lack of systematic pharmacological history record; chance of recall bias and Berkson's biases. Permissive operational criterion for TEM. Relatively small sample size.

CONCLUSIONS

Cyclothymic temperament and mixed depression discriminated TEM⁺ between TEM^- cases, although only lithium and the SGAs reliably predicted TEM^+/- grouping. Larger-sampled/powered longitudinal replication studies are warranted to allow firm conclusions on the matter, ideally contributing to the identification of clear-cut sub-phenotypes of BD towards patient-tailored-pharmacotherapy.

Rethinking the spectrum of mood disorders: implications for diagnosis and management - Proceedings of a symposium presented at the 30th Annual European College of Neuropsychopharmacology Congress, 4 September 2017, Paris, France

The simultaneous occurrence of manic and depressive features has been recognized since classical times, but the term 'mixed state' was first used by Kraepelin at the end of the 19th century. From the 1980s, until the advent of the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), psychiatric disorders were classified using a categorical approach. However, it was recognized that such an approach was too rigid to encompass the range of symptomatology encountered in clinical practice. Therefore, a dimensional approach was adopted in DSM-5, in which affective states are considered to be distributed across a continuum ranging from pure mania to pure depression. In addition, the copresence of symptoms of the opposite pole are captured using a 'with mixed features' specifier, applied when three or more nonoverlapping subthreshold symptoms of the opposite pole are present. Mixed features are common in patients with mood episodes, complicating the course of illness, reducing treatment response and worsening outcomes. However, research in this area is scarce and treatment options are limited. Current evidence indicates that antidepressants should be avoided for the treatment of bipolar mixed states. Evidence for bipolar mixed states supports the use of several second-generation antipsychotics, valproate and electroconvulsive therapy. One randomized controlled trial has demonstrated the efficacy of lurasidone, compared with placebo, in patients with major depressive disorder with mixed features, and there is limited evidence supporting the use of ziprasidone in such patients. Further research is required to determine whether other antipsychotic agents, or additional therapeutic approaches, might also be effective in this setting.

The use of triiodothyronine (T3) in the treatment of bipolar depression: A review of the literature

BACKGROUND

There is a paucity of treatment options for bipolar depression. The use of triiodothyronine (T3) has been suggested as adjunctive treatment.

METHODS

A search on Medline, Limo and ScienceDirect was performed using the search terms bipolar disorder, bipolar depression, treatment resistant, treatment refractory, thyroid hormones, triiodothyronine, T3, acceleration and augmentation.

RESULTS

We retrieved three open studies, one comparative study, two double blind and one retrospective chart review. The three open studies observed improvement in respectively 56%, 75% and 79% of patients, the retrospective chart review noted improvement in 89% of cases and the mirror design showed improvement in 66%. In the comparative study T3 performed significantly better than placebo. The only randomized double blind study could not prove any substantial difference between T3 and placebo.

LIMITATIONS

Available studies are scarce and flawed. All have (very) low number of subjects: overall, only 353 subjects and only 194 of which in prospective trials. In only two of the prospective trials bipolar patients were analyzed separately. Comparing the studies is hampered by a high variability in assessment tools, baseline medication and degree of treatment-resistance.

CONCLUSIONS

The few available studies are small and flawed. They do show promising results. We found many clues suggesting that T3 could augment and accelerate treatment response not only with antidepressants, but also with lithium and perhaps with other treatment options, that it might protect against rapid cycling bipolar disorder, as well as against relapse during the first few years of treatment.

Coping with the New Era: Noise and Light Pollution, Hperactivity and Steroid Hormones. Towards an Evolutionary View of Bipolar Disorders

Human population is increasing in immense cities with millions of inhabitants, in which life is expected to run 24 hours a day for seven days a week (24/7). Noise and light pollution are the most reported consequences, with a profound impact on sleep patterns and circadian biorhythms. Disruption of sleep and biorhythms has severe consequences on many metabolic pathways. Suppression of melatonin incretion at night and the subsequent effect on DNA methylation may increase the risk of prostate and breast cancer. A negative impact of light pollution on neurosteroids may also affect mood. People who carry the genetic risk of bipolar disorder may be at greater risk of full-blown bipolar disorder because of the impact of noise and light pollution on sleep patterns and circadian biorhythms. However, living in cities may also offers opportunities and might be selective for people with hyperthymic temperament, who may find themselves advantaged by increased energy prompted by increased stimulation produced by life in big cities. This might result in the spreading of the genetic risk of bipolar disorder in the coming decades. In this perspective the burden of poor quality of life, increased disability adjusted life years and premature mortality due to the increases of mood disorders is the negative side of a phenomenon that in its globality also shows adaptive aspects. The new lifestyle also influences those who adapt and show behaviors, reactions and responses that might resemble the disorder, but are on the adaptive side.

Dosage-related nature of escitalopram treatment-emergent mania/hypomania: a case series

OBJECTIVE

Several studies have documented that treatment with various antidepressant agents can result in mood switching during major depressive episodes. Escitalopram, one of the newer selective serotonin reuptake inhibitors (SSRIs), is considered preferable due to its relatively high efficacy and acceptability. Although a few cases of escitalopram treatment-emergent mania have been reported, it remains unknown whether this effect is dose-related.

METHOD

In the present report, we discuss three cases of treatment-emergent mania/hypomania in patients receiving escitalopram for major depressive episodes. No patients had a family or personal history of bipolar disorder.

RESULTS

In all three cases, manic or hypomanic symptoms emerged within 1 month right after the dosage of escitalopram was increased to 20 mg/day. Moreover, manic episodes subsided as the dosage of escitalopram was reduced. Mood switching was not observed after the cessation of escitalopram treatment.

CONCLUSION

Our case series indicates that escitalopram may induce treatment-emergent mania/hypomania in a dose-related manner. Treatment at lower doses and with careful upward titration might be favorable in certain patients with bipolar depression and major depressive disorder in order to minimize the risk of mood switching.

Toward Precision Psychiatry in Bipolar Disorder: Staging 2.0

Personalized treatment is defined as choosing the "right treatment for the right person at the right time." Although psychiatry has not yet reached this level of precision, we are on the way thanks to recent technological developments that may aid to detect plausible molecular and genetic markers. At the moment there are some models that are contributing to precision psychiatry through the concept of staging. While staging was initially presented as a way to categorize patients according to clinical presentation, course, and illness severity, current staging models integrate multiple levels of information that can help to define each patient's characteristics, severity, and prognosis in a more precise and individualized way. Moreover, staging might serve as the foundation to create a clinical decision-making algorithm on the basis of the patient's stage. In this review we will summarize the evolution of the bipolar disorder staging model in relation to the new discoveries on the neurobiology of bipolar disorder. Furthermore, we will discuss how the latest and future progress in psychiatry might transform current staging models into precision staging models.

Antimanic Efficacy of a Novel Kv3 Potassium Channel Modulator

Kv3.1 and Kv3.2 voltage-gated potassium channels are expressed on parvalbumin-positive GABAergic interneurons in corticolimbic brain regions and contribute to high-frequency neural firing. The channels are also expressed on GABAergic neurons of the basal ganglia, substantia nigra, and ventral tegmental area (VTA) where they regulate firing patterns critical for movement control, reward, and motivation. Modulation of Kv3.1 and Kv3.2 channels may therefore have potential in the treatment of disorders in which these systems have been implicated, such as bipolar disorder. Following the recent development of a potassium channel modulator, AUT1-an imidazolidinedione compound that specifically increases currents mediated by Kv3.1 and Kv3.2 channels in recombinant systems-we report that the compound is able to reverse 'manic-like' behavior in two mouse models: amphetamine-induced hyperactivity and ClockΔ19 mutants. AUT1 completely prevented amphetamine-induced hyperactivity in a dose-dependent manner, similar to the atypical antipsychotic, clozapine. Similar efficacy was observed in Kv3.2 knockout mice. In contrast, AUT1 was unable to prevent amphetamine-induced hyperactivity in mice lacking Kv3.1 channels. Notably, Kv3.1-null mice displayed baseline hyperlocomotion, reduced anxiety-like behavior, and antidepressant-like behavior. In ClockΔ19 mice, AUT1 reversed hyperactivity. Furthermore, AUT1 application modulated firing frequency and action potential properties of ClockΔ19 VTA dopamine neurons potentially through network effects. Kv3.1 protein levels in the VTA of ClockΔ19 and WT mice were unaltered by acute AUT1 treatment. Taken together, these results suggest that the modulation of Kv3.1 channels may provide a novel approach to the treatment of bipolar mania.

The extended evolutionary synthesis and addiction: the price we pay for adaptability

Humans are more likely to become addicted and to stay addicted than are other animals. This chapter is a neurobiological and molecular review of addiction and the cooccurring traits and psychiatric disorders from the perspective of the Extended Evolutionary Synthesis (EES). Addiction is an example of pleiotropy as many common haplotypes that are associated with individual differences in vulnerability to substance dependence express a variety of important brain-based phenotypes such as neuroadaptive processes. The neurochemical mechanisms of addiction are shared with behavioral flexibility and the ability to innovate, which are hallmark features of our species. The dopaminergic system provides a link between addiction and the cooccurring traits and psychiatric disorders evident in the shared genetic profile. A hypofunctioning dopaminergic system is also a common characteristic feature of addiction and the cooccurring traits and psychiatric disorders. Epigenetics allows for environmental factors to create lasting and heritable phenotypic changes enabling rapid adaptation to an environment. Addiction "high-jacks" this system as well as the neurochemical mechanisms that control flexibility and innovation and is, thus, the price we pay for adaptability.

Predictors of a Shorter Time to Hospitalization in Patients with Bipolar Disorder: Medication during the Acute and Maintenance Phases and Other Clinical Factors

Objective

The present study was conducted to compare the effects of pharmacological treatments during the acute and maintenance phases of mood episodes, sociodemographic, and clinical characteristics between a shorter time to hospitalization group (<12 months) and a longer time to hospitalization group (≥12 months).

Methods

The discharge medication for the first hospitalization was considered the acute treatment and the medication used during the week prior to the second hospitalization at the outpatient clinic was considered the maintenance treatment. Additionally, the charts were reviewed to examine a variety of demographic and clinical characteristics.

Results

Patients in the shorter time to hospitalization group were more likely to be unmarried and/or unemployed, have had a previous hospital admission for a mood episode, and have used antidepressant during the acute phase than those in the longer time to hospitalization group. Patients in the shorter time to hospitalization group were also less likely to use olanzapine, serotonin-norepinephrine reuptake inhibitors, or mood stabilizer monotherapy as a maintenance treatment than were patients in the longer time to hospitalization group.

Conclusion

Predictors for shorter time to hospitalization were associated with number of previous hospital admissions for a mood episode, being unmarried and/or unemployed, and antidepressant use during the acute phase.

Bipolar mood state reflected in cortico-amygdala resting state connectivity: A cohort and longitudinal study

BACKGROUND

Using resting-state functional magnetic resonance imaging (rsfMRI), we previously compared cohorts of bipolar I subjects in a manic state to those in a euthymic state to identify mood state-specific patterns of cortico-amygdala connectivity. Our results suggested that mania is reflected in the disruption of emotion regulation circuits. We sought to replicate this finding in a group of subjects with bipolar disorder imaged longitudinally across states of mania and euthymia METHODS: We divided our subjects into three groups: 26 subjects imaged in a manic state, 21 subjects imaged in a euthymic state, and 10 subjects imaged longitudinally across both mood states. We measured differences in amygdala connectivity between the mania and euthymia cohorts. We then used these regions of altered connectivity to examine connectivity in the longitudinal bipolar group using a within-subjects design.

RESULTS

Our findings in the mania vs euthymia cohort comparison were replicated in the longitudinal analysis. Bipolar mania was differentiated from euthymia by decreased connectivity between the amygdala and pre-genual anterior cingulate cortex. Mania was also characterized by increased connectivity between amygdala and the supplemental motor area, a region normally anti-correlated to the amygdala in emotion regulation tasks.

LIMITATIONS

Stringent controls for movement effects limited the number of subjects in the longitudinal sample.

CONCLUSIONS

In this first report of rsfMRI conducted longitudinally across mood states, we find that previously observed between-group differences in amygdala connectivity are also found longitudinally within subjects. These results suggest resting state cortico-amygdala connectivity is a biomarker of mood state in bipolar disorder.

Mood Disorder as an Early Presentation of Epidermoid of Quadrigeminal Cistern

Intracranial epidermoids are space-occupying lesions of rare variant. Although cerebropontine angle and parasellar region are common sites of occurrence, it has been reported in various other parts of the intracranial cavity. Headache and features of increased intracranial tension are the common clinical manifestation. Report of psychiatric symptoms as the initial presentation of epidermoid is not known in literature except a single case report, which describes mutism to be the manifestation of intracranial epidermoid. We present here the case of a young male, who presented with long depressive episode persisting for 3 years with subsequent switch to mania, which persisted for more than 3 years. An episode of unconsciousness warranted neuroimaging, which revealed a large epidermoid of the quadrigeminal cistern. Surgical resection of the epidermoid was done. Persisting mood symptoms had responded to mood stabilizer and antipsychotic treatment.

A Brain on a Roller Coaster: Can the Dopamine Reward System Act as a Protagonist to Subdue the Ups and Downs of Bipolar Disorder?

One of the most interesting but tenebrous parts of the bipolar disorder (BD) story is the switch between (hypo)mania and depression, which can give bipolar patients a thrilling, but somewhat perilous, ‘ride’. Numerous studies have pointed out that there are some recognizable differences (either state-dependent or state-independent) in several brain regions of people with BD, including components of the brain’s reward system. Understanding the underpinning mechanisms of high and low mood statuses in BD has potential, not only for the development of highly specific and selective pharmaceutical agents, but also for better treatment approaches and psychological interventions to manage BD and, thus, give patients a safer ride. Herein, we review evidence that supports involvement of the reward system in the pathophysiology of mood swings, with the main focus on the mesocorticolimbic dopaminergic neural circuitry. Principally using findings from neuroimaging studies, we aim to signpost readers as to how mood alterations may affect different areas of the reward system and how antipsychotic drugs can influence the activity of these brain areas. Finally, we critically evaluate the hypothesis that the mesocorticolimbic dopamine reward system may act as a functional rheostat for different mood states.

Circuits Regulating Pleasure and Happiness in Bipolar Disorder

According to our model, the motivation for appetitive-searching vs. distress-avoiding behaviors is regulated by two parallel cortico-striato-thalamo-cortical (CSTC) re-entry circuits that include the core and the shell parts of the nucleus accumbens, respectively. An entire series of basal ganglia, running from the caudate nucleus on one side to the centromedial amygdala on the other side, control the intensity of these reward-seeking and misery-fleeing behaviors by stimulating the activity of the (pre)frontal and limbic cortices. Hyperactive motivation to display behavior that potentially results in reward induces feelings of hankering (relief leads to pleasure); while, hyperactive motivation to exhibit behavior related to avoidance of aversive states results in dysphoria (relief leads to happiness). These two systems collaborate in a reciprocal fashion. We hypothesized that the mechanism inducing the switch from bipolar depression to mania is the most essential characteristic of bipolar disorder. This switch is attributed to a dysfunction of the lateral habenula, which regulates the activity of midbrain centers, including the dopaminergic ventral tegmental area (VTA). From an evolutionary perspective, the activity of the lateral habenula should be regulated by the human homolog of the habenula-projecting globus pallidus, which in turn might be directed by the amygdaloid complex and the phylogenetically old part of the limbic cortex. In bipolar disorder, it is possible that the system regulating the activity of this reward-driven behavior is damaged or the interaction between the medial and lateral habenula may be dysfunctional. This may lead to an adverse coupling between the activities of the misery-fleeing and reward-seeking circuits, which results in independently varying activities.

Emergence of mania in two middle-aged patients with a history of unipolar treatment-refractory depression receiving vagus nerve stimulation

OBJECTIVES

We report on two patients who experienced emergence of full manic symptoms while receiving vagal nerve stimulation (VNS).

METHODS

Two patients, both with a well-documented and verified history of longstanding unipolar depression, were initiated on VNS for treatment of their severe major depressive episodes.

RESULTS

The two patients had emergence of full manic symptoms after 8 and 9 months of VNS, respectively. Manic symptoms were adequately managed with standard treatments (mood stabilizer and electroconvulsive therapy) and VNS was continued in the two subjects for up to 5 years without any further occurrences of manic/hypomanic episodes.

CONCLUSIONS

These cases suggest that some patients with treatment-resistant depression may have a previously unrecognized bipolar disorder, triggered only by VNS. This report also provides evidence that VNS-induced manic switches, however serious and troubling to patients, can be managed safely, and that VNS maintenance can be continued for an extended period of time without manic relapses. Although the mechanism of action of VNS is not known, emerging evidence supports central nervous system dopaminergic and possibly cholinergic system involvement.

Biological hypotheses and biomarkers of bipolar disorder

The most common mood disorders are major depressive disorders and bipolar disorders (BD). The pathophysiology of BD is complex, multifactorial, and not fully understood. Creation of new hypotheses in the field gives impetus for studies and for finding new biomarkers for BD. Conversely, new biomarkers facilitate not only diagnosis of a disorder and monitoring of biological effects of treatment, but also formulation of new hypotheses about the causes and pathophysiology of the BD. BD is characterized by multiple associations between disturbed brain development, neuroplasticity, and chronobiology, caused by: genetic and environmental factors; defects in apoptotic, immune-inflammatory, neurotransmitter, neurotrophin, and calcium-signaling pathways; oxidative and nitrosative stress; cellular bioenergetics; and membrane or vesicular transport. Current biological hypotheses of BD are summarized, including related pathophysiological processes and key biomarkers, which have been associated with changes in genetics, systems of neurotransmitter and neurotrophic factors, neuroinflammation, autoimmunity, cytokines, stress axis activity, chronobiology, oxidative stress, and mitochondrial dysfunctions. Here we also discuss the therapeutic hypotheses and mechanisms of the switch between depressive and manic state.

Are major depression and bipolar disorder neuropsychologically distinct? A meta-analysis of comparative studies

BACKGROUND

Neuropsychological deficits are present in both major depression and bipolar disorder. So far, however, reports directly comparing these mood disorders with regard to cognitive outcomes have been scant and yielded inconsistent results. This work aims to combine the findings of comparative studies of cognition in major depression and bipolar disorder in order to explore whether these neuropsychiatric conditions present with distinct cognitive features.

METHODS

The main online databases were extensively searched to retrieve reports assessing neurocognitive functioning in two groups of mood disorder patients, one with major depressive disorder and another with bipolar disorder, both in the same phase of illness. Between-group effect sizes for cognitive variables were obtained from selected studies and pooled by means of meta-analytic procedures.

RESULTS

During euthymia, a significant overall effect size (Hedges'g=0.64, P<0.001) favoring major depressive disorder was found for verbal memory as assessed with list learning tests, whereas no significant between-group differences were found for the remaining variables analyzed. During depressive episodes, similar cognitive outcomes were observed between groups.

CONCLUSION

At present, it is not possible to postulate specific neuropsychological profiles for major depression and bipolar disorder in light of available evidence. It remains to be ascertained whether the differences found for verbal memory constitute an expression of distinct underlying mechanisms or whether they are best explained by sample characteristics or differential exposure to variables with a negative impact on cognition.

The Inositol Trisphosphate/Calcium Signaling Pathway in Health and Disease

Many cellular functions are regulated by calcium (Ca2+) signals that are generated by different signaling pathways. One of these is the inositol 1,4,5-trisphosphate/calcium (InsP3/Ca2+) signaling pathway that operates through either primary or modulatory mechanisms. In its primary role, it generates the Ca2+ that acts directly to control processes such as metabolism, secretion, fertilization, proliferation, and smooth muscle contraction. Its modulatory role occurs in excitable cells where it modulates the primary Ca2+ signal generated by the entry of Ca2+ through voltage-operated channels that releases Ca2+ from ryanodine receptors (RYRs) on the internal stores. In carrying out this modulatory role, the InsP3/Ca2+ signaling pathway induces subtle changes in the generation and function of the voltage-dependent primary Ca2+ signal. Changes in the nature of both the primary and modulatory roles of InsP3/Ca2+ signaling are a contributory factor responsible for the onset of a large number human diseases.

Cycles of insanity and creativity within contemplative neural systems

Random connection weight disturbances within an assembly of artificial neural networks (ANN) drive a progression of activation patterns that are tantamount to the memories and ideas nucleating within the brain's cortex. The numerical evaluation of these pattern-based notions by another, more placid system of ANNs governs the magnitude of weight disturbances administered to the former assembly, that perturbative intensity in turn controlling the novelty of the resulting ideational stream as well as the retention of newly formed concepts. In search of solution patterns to posed problems, such collaborating neural systems autonomously cycle between two extremes in mean synaptic perturbation level. The higher limit, characterized by chaos and inattentiveness to exogenous input patterns, is the regime in which ideas first form and incubate. The lower bound, marked by relative synaptic tranquility, is favorable to the reactivation and reinforcement of concepts first seeded during heightened perturbation. When considering this synthetic neural architecture as a cognitive model, the proposed source of such synaptic fluctuations is volume neurotransmitter release within cortex where both ideational and critic nets are commingled. As a result of their overlap, not only are the generative cortical networks suffused with neurotransmitters, but also those functioning in a critic role, leading to altered 'opinions' about the perturbation-driven stream of consciousness that then govern the injection of neurotransmitters into cortex. The likely effect of such chemical feedback is that the brain constantly cycles between states of idea generating chaos and perception stabilizing tranquility in much the same way that creative artificial neural systems do. Postulating that ideas are potentially useful or interesting false memories born within such turmoil, creativity appears to take place through a cyclic process consisting of alternating phases of (1) cognitive incapacitation, during which confabulatory notions incubate, and (2) synaptic calm when these incubated thoughts reemerge and reinforce themselves as they are then recognized for their value by a lucid perceptual apparatus. Extremes in such cycling, especially within the former dysfunctional phase, would be problematic from a mental health perspective. Whereas the literature is replete with findings linking creativity and various psychopathologies, the main hypothesis advanced herein is that the neurodynamics of both phenomena are the same. If vindicated, this theory may lead to advanced treatments that could potentially boost creativity as well as safeguard against the associated cognitive and psychological disorders, all through control of just one parameter, the difference between cortical concentrations of excitatory and inhibitory neurotransmitters.

Blue-blocking glasses as additive treatment for mania: a randomized placebo-controlled trial

OBJECTIVES

The discovery of the blue lightsensitive retinal photoreceptor responsible for signaling daytime to the brain suggested that light to the circadian system could be inhibited by using blue-blocking orange tinted glasses. Blue-blocking (BB) glasses are a potential treatment option for bipolar mania. We examined the effectiveness of BB glasses in hospitalized patients with bipolar disorder in a manic state.

METHODS

In a single-blinded, randomized, placebo-controlled trial (RCT), eligible patients (with bipolar mania; age 18-70 years) were recruited from five clinics in Norway. Patients were assigned to BB glasses or placebo (clear glasses) from 6 p.m. to 8 a.m. for 7 days, in addition to treatment as usual. Symptoms were assessed daily by use of the Young Mania Rating Scale (YMRS). Motor activity was assessed by actigraphy, and compared to data from a healthy control group. Wearing glasses for one evening/night qualified for inclusion in the intention-to-treat analysis.

RESULTS

From February 2012 to February 2015, 32 patients were enrolled. Eight patients dropped out and one was excluded, resulting in 12 patients in the BB group and 11 patients in the placebo group. The mean decline in YMRS score was 14.1 [95% confidence interval (CI): 9.7-18.5] in the BB group, and 1.7 (95% CI: -4.0 to 7.4) in the placebo group, yielding an effect size of 1.86 (Cohen's d). In the BB group, one patient reported headache and two patients experienced easily reversible depressive symptoms.

CONCLUSIONS

This RCT shows that BB glasses are effective and feasible as add-on treatment for bipolar mania.

Increased sleep duration precedes the improvement of other symptom domains during the treatment of acute mania: a retrospective chart review

BACKGROUND

Understanding trajectories of symptom changes may help gauge treatment response and better identify therapeutic targets in treatment of acute mania. We examined how symptoms of sleep disturbance, mania, and psychosis resolved in a naturalistic treatment setting, hypothesizing that improvement in sleep would precede improvement in manic and psychotic symptoms.

METHODS

Charts of 100 patients with admitting diagnoses of bipolar mixed or manic episode were retrospectively reviewed. Medications and demographic variables were recorded, and the Clinician-Administered Rating Scale for Mania (CARS-M) mania and psychosis ratings and sleep hours were determined for 8 observation points. Times to minimum symptom level in each domain were compared via Wilcoxon signed-rank tests. Symptom correlations and trajectories and medication effects were explored using repeated measures ANOVA and regression models.

RESULTS

Manic and psychotic symptom resolution was linear over the time of hospitalization. In contrast, sleep showed a slow initial response, followed by rapid increase to peak, preceding peak improvement in mania and psychosis (p < 0.001). Rate of sleep restoration was a predictor of rate but not of magnitude of treatment response for symptoms mania and psychosis. Patterns of medication use did not affect symptom trajectories.

CONCLUSIONS

In acute mania, improvement in sleep with treatment is dissociable from resolution in symptoms of mania and psychosis, but there appears to be no therapeutic advantage to patient oversedation. Sleep improves first and may be both a predictor of the rate of treatment response and a useful therapeutic target.

Role of Pharmacogenetics in Improving the Safety of Psychiatric Care by Predicting the Potential Risks of Mania in CYP2D6 Poor Metabolizers Diagnosed With Bipolar Disorder

One of the main concerns in psychiatric care is safety related to drug management. Pharmacogenetics provides an important tool to assess causes that may have contributed the adverse events during psychiatric therapy. This study illustrates the potential of pharmacogenetics to identify those patients for which pharmacogenetic-guided therapy could be appropriate. It aimed to investigate CYP2D6 genotype in our psychiatric population to assess the value of introducing pharmacogenetics as a primary improvement for predicting side effects.A broad series of 224 psychiatric patients comprising psychotic disorders, depressive disturbances, bipolar disorders, and anxiety disorders was included. The patients were genotyped with the AmpliChip CYP450 Test to analyzing 33 allelic variants of the CYP2D6 gene.All bipolar patients with poor metabolizer status showed maniac switching when CYP2D6 substrates such as selective serotonin reuptake inhibitors were prescribed. No specific patterns were identified for adverse events for other disorders.We propose to utilize pharmacogenetic testing as an intervention to aid in the identification of patients who are at risk of developing affective switching in bipolar disorder treated with selective serotonin reuptake inhibitors, CYP2D6 substrates, and inhibitors.

Decreased serum zinc concentration during depressive episode in patients with bipolar disorder

OBJECTIVES

Zinc may be involved in the pathophysiology and treatment of depressive disorder. However, data on this issue in bipolar disorder (BD) are limited. The aim of the study was to assess zinc concentrations in the blood serum of patients at various phases and stages of bipolar disorder.

METHODS

The study included 129 patients with a diagnosis of bipolar disorder type I (n=69) or type II (n=60). Fifty-eight were in a depressive episode, 23 in a manic episode and 48 in remission. Fifty healthy volunteers made a control group. Zinc concentration was measured using flame atomic absorption spectrometry.

RESULTS

Serum zinc level in patients diagnosed with BD type I in the depressive phase was significantly reduced as compared with mania, remission and healthy subjects. In the BD type II, serum zinc level in hypomania, depression or remission phase was not significantly different from the control group. In the whole group, lower level of zinc in depression compared to remission and control subjects was found during late stage of the illness but not in the early stage. Zinc concentration was not dependent on the severity of manic or depressive symptoms and subtype of depression but correlated positively with the number of manic/hypomanic relapses in the past year.

LIMITATIONS

Lack of prospective model, heterogeneity of pharmacological treatment, small number of subgroups presenting specified clinical features.

CONCLUSIONS

Decreased serum zinc concentration occurs in depression in BD type I and probably in depression in the late stage of BD.

Possible relationship between amino acids, aggression and psychopathy

OBJECTIVE

Aggressive behaviour is associated with reduced serotonin metabolism in the brain, but there is not enough knowledge on potential changes of the serotonin precursor levels among violent offenders. In this study, we aimed to evaluate the relationships among the tendency of psychopathy, anger and the basic amino acids.

METHODS

Fifty-two young adult male patients with antisocial personality disorder (APD) and 30 healthy men included the study. Serum amino acid levels were measured by HPLC method. Aggression questionnaire and Hare Psychopathology Scale were used for all participants.

RESULTS

Blood levels of phosphoserine, aspartic acid, glutamic acid, aminoadipic acid and 1-methylhistidine in group of patients with APD were significantly higher than the control group. Blood levels of TRP, asparagine, citrulline, cystine, isoleucine, tyrosine, histidine, hydroxylysine, lysine, ethanolamine and arginine in the group of patients were found lower than the control group. A significant positive correlation between anger scores and histidine, methionine and GABA was found. GABA and methionine showed a significant correlation with the indirect aggression score.

CONCLUSION

Our study showed a relationship between serum amino acid levels and the scores of aggression and psychopathy. We think that this is a productive research area for understanding the relationship among biochemical factors, aggression and psychopathy.

Ketamine and other glutamate receptor modulators for depression in bipolar disorder in adults

BACKGROUND

There is emerging evidence that glutamatergic system dysfunction might play an important role in the pathophysiology of bipolar depression. This review focuses on the use of glutamate receptor modulators for depression in bipolar disorder.

OBJECTIVES

1. To assess the effects of ketamine and other glutamate receptor modulators in alleviating the acute symptoms of depression in people with bipolar disorder.2. To review the acceptability of ketamine and other glutamate receptor modulators in people with bipolar disorder who are experiencing acute depression symptoms.

SEARCH METHODS

We searched the Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Register (CCDANCTR, to 9 January 2015). This register includes relevant randomised controlled trials (RCTs) from: the Cochrane Library (all years), MEDLINE (1950 to date), EMBASE (1974 to date), and PsycINFO (1967 to date). We cross-checked reference lists of relevant papers and systematic reviews. We did not apply any restrictions to date, language or publication status.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing ketamine, memantine, or other glutamate receptor modulators with other active psychotropic drugs or saline placebo in adults with bipolar depression.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected studies for inclusion, assessed trial quality and extracted data. Primary outcomes for this review were response rate and adverse events. Secondary outcomes included remission rate, depression severity change scores, suicidality, cognition, quality of life, and dropout rate. We contacted study authors for additional information.

MAIN RESULTS

Five studies (329 participants) were included in this review. All included studies were placebo-controlled and two-armed, and the glutamate receptor modulators - ketamine (two trials), memantine (two trials), and cytidine (one trial) - were used as add-on drugs to mood stabilisers. The treatment period ranged from a single intravenous administration (all ketamine studies), to repeated administration for memantine and cytidine (8 to 12 weeks, and 12 weeks, respectively). Three of the studies took place in the USA, one in Taiwan, and in one, the location was unclear. The majority (70.5%) of participants were from Taiwan. All participants had a primary diagnosis of bipolar disorder, according to the DSM-IV or DSM-IV-TR, and were in a current depressive phase. The severity of depression was at least moderate in all but one study.Among all glutamate receptor modulators included in this review, only ketamine appeared to be more efficacious than placebo 24 hours after the infusion for the primary outcome, response rate (odds ratio (OR) 11.61, 95% confidence interval (CI) 1.25 to 107.74; P = 0.03; I² = 0%, 2 studies, 33 participants). This evidence was rated as low quality. The statistically significant difference disappeared at three days, but the mean estimate still favoured ketamine (OR 8.24, 95% CI 0.84 to 80.61; 2 studies, 33 participants; very low quality evidence). We found no difference in response between ketamine and placebo at one week (OR 4.00, 95% CI 0.33 to 48.66; P = 0.28, 1 study; 18 participants; very low quality evidence).There was no significant difference between memantine and placebo in response rate one week after treatment (OR 1.08, 95% CI 0.06 to 19.05; P = 0.96, 1 study, 29 participants), two weeks (OR 4.88, 95% CI 0.78 to 30.29; P = 0.09, 1 study, 29 participants), four weeks (OR 5.33, 95% CI 1.02 to 27.76; P = 0.05, 1 study, 29 participants), or at three months (OR, 1.66, 95% CI 0.69 to 4.03; P = 0.26, I² = 36%, 2 studies, 261 participants). These findings were based on very low quality evidence.There was no significant difference between cytidine and placebo in response rate at three months (OR, 1.13, 95% CI 0.30 to 4.24; P = 0.86, 1 study, 35 participants; very low quality evidence).For the secondary outcome of remission, no significant differences were found between ketamine and placebo, nor between memantine and placebo. For the secondary outcome of change scores from baseline on depression scales, ketamine was more effective than placebo at 24 hours (MD -11.81, 95% CI -20.01 to -3.61; P = 0.005, 2 studies, 32 participants) but not at one or two weeks after treatment. There was no difference between memantine and placebo for this outcome.We found no significant differences in terms of adverse events between placebo and ketamine, memantine, or cytidine. There were no differences between ketamine and placebo, memantine and placebo, or cytidine and placebo in total dropouts. No data were available on dropouts due to adverse effects for ketamine or cytidine; but no difference was found between memantine and placebo.

AUTHORS' CONCLUSIONS

Reliable conclusions from this review are severely limited by the small amount of data usable for analysis. The body of evidence about glutamate receptor modulators in bipolar disorder is even smaller than that which is available for unipolar depression. Overall, we found limited evidence in favour of a single intravenous dose of ketamine (as add-on therapy to mood stabilisers) over placebo in terms of response rate up to 24 hours; ketamine did not show any better efficacy in terms of remission in bipolar depression. Even though ketamine has the potential to have a rapid and transient antidepressant effect, the efficacy of a single intravenous dose may be limited. Ketamine's psychotomimetic effects could compromise study blinding; this is a particular issue for this review as no included study used an active comparator, and so we cannot rule out the potential bias introduced by inadequate blinding procedures.We did not find conclusive evidence on adverse events with ketamine. To draw more robust conclusions, further RCTs (with adequate blinding) are needed to explore different modes of administration of ketamine and to study different methods of sustaining antidepressant response, such as repeated administrations. There was not enough evidence to draw meaningful conclusions for the remaining two glutamate receptor modulators (memantine and cytidine). This review is limited not only by completeness of evidence, but also by the low to very low quality of the available evidence.

Investigating the underlying mechanisms of aberrant behaviors in bipolar disorder from patients to models: Rodent and human studies

Psychiatric patients with bipolar disorder suffer from states of depression and mania, during which a variety of symptoms are present. Current treatments are limited and neurocognitive deficits in particular often remain untreated. Targeted therapies based on the biological mechanisms of bipolar disorder could fill this gap and benefit patients and their families. Developing targeted therapies would benefit from appropriate animal models which are challenging to establish, but remain a vital tool. In this review, we summarize approaches to create a valid model relevant to bipolar disorder. We focus on studies that use translational tests of multivariate exploratory behavior, sensorimotor gating, decision-making under risk, and attentional functioning to discover profiles that are consistent between patients and rodent models. Using this battery of translational tests, similar behavior profiles in bipolar mania patients and mice with reduced dopamine transporter activity have been identified. Future investigations should combine other animal models that are biologically relevant to the neuropsychiatric disorder with translational behavioral assessment as outlined here. This methodology can be utilized to develop novel targeted therapies that relieve symptoms for more patients without common side effects caused by current treatments.

Predictors of switch from depression to mania in bipolar disorder

Manic switch is a relevant issue when treating bipolar depression. Some risk factors have been suggested, but unequivocal findings are lacking. We therefore investigated predictors of switch from depression to mania in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) sample. Manic switch was defined as a depressive episode followed by a (hypo)manic or mixed episode within the following 12 weeks. We assessed possible predictors of switch using generalized linear mixed models (GLMM). 8403 episodes without switch and 512 episodes with switch (1720 subjects) were included in the analysis. Several baseline variables were associated with a higher risk of switch. They were younger age, previous history of: rapid cycling, severe manic symptoms, suicide attempts, amphetamine use and some pharmacological and psychotherapeutic treatments. During the current depressive episode, the identified risk factors were: any possible mood elevation, multiple mania-associated symptoms with at least moderate severity, and comorbid panic attacks. In conclusion, our study suggests that both characteristics of the disease history and clinical features of the current depressive episode may be risk factors for manic switch.

Distinct effects of the serotonin-noradrenaline reuptake inhibitors milnacipran and venlafaxine on rat pineal monoamines

Monoamine systems are involved in the pathology and therapeutic mechanism of depression. The pineal gland contains large amounts of serotonin as a precursor for melatonin, and its activity is controlled by noradrenergic sympathetic nerves. Pineal diurnal activity and its release of melatonin are relevant to aberrant states observed in depression. We investigated the effects on pineal monoamines of serotonin-noradrenaline reuptake inhibitors, which are widely used antidepressants. Four days of milnacipran treatment led to an increase in noradrenaline and serotonin levels, whereas 4 days of venlafaxine treatment reduced 5-hydroxyindoleacetic acid levels; both agents induced an increase in dopamine levels. Our data suggest that milnacipran increases levels of the precursor for melatonin synthesis by facilitating the noradrenergic regulation of pineal activity and that venlafaxine inhibits serotonin reuptake into noradrenergic terminals on the pineal gland.

Investigating the mechanism(s) underlying switching between states in bipolar disorder

Bipolar disorder (BD) is a unique disorder that transcends domains of function since the same patient can exhibit depression or mania, states with polar opposite mood symptoms. During depression, people feel helplessness, reduced energy, and risk aversion, while with mania behaviors include grandiosity, increased energy, less sleep, and risk preference. The neural mechanism(s) underlying each state are gaining clarity, with catecholaminergic disruption seen during mania, and cholinergic dysfunction during depression. The fact that the same patient cycles/switches between these states is the defining characteristic of BD however. Of greater importance therefore, is the mechanism(s) underlying cycling from one state - and its associated neural changes - to another, considered the 'holy grail' of BD research. Herein, we review studies investigating triggers that induce switching to these states. By identifying such triggers, researchers can study neural mechanisms underlying each state and importantly how such mechanistic changes can occur in the same subject. Current animal models of this switch are also discussed, from submissive- and dominant-behaviors to kindling effects. Focus however, is placed on how seasonal changes can induce manic and depressive states in BD sufferers. Importantly, changing photoperiod lengths can induce local switches in neurotransmitter expression in normal animals, from increased catecholaminergic expression during periods of high activity, to increased somatostatin and corticotrophin releasing factor during periods of low activity. Identifying susceptibilities to this switch would enable the development of targeted animal models. From animal models, targeted treatments could be developed and tested that would minimize the likelihood of switching.

Alcohol withdrawal delirium manifested by manic symptoms in an elderly patient

Alcohol withdrawal syndrome is a commonly seen problem in psychiatric practice. Alcohol withdrawal delirium is associated with significant morbidity and mortality. Withdrawal symptoms usually include tremulousness, psychotic and perceptual symptoms, seizures, and consciousness disturbance. Herein, we report a case involving a 63-year-old man who had alcohol withdrawal delirium that was manifested mainly by manic symptoms.

Selective pharmacological blockade of the 5-HT7 receptor attenuates light and 8-OH-DPAT induced phase shifts of mouse circadian wheel running activity

Recent reports have illustrated a reciprocal relationship between circadian rhythm disruption and mood disorders. The 5-HT7 receptor may provide a crucial link between the two sides of this equation since the receptor plays a critical role in sleep, depression, and circadian rhythm regulation. To further define the role of the 5-HT7 receptor as a potential pharmacotherapy to correct circadian rhythm disruptions, the current study utilized the selective 5-HT7 antagonist JNJ-18038683 (10 mg/kg) in three different circadian paradigms. While JNJ-18038683 was ineffective at phase shifting the onset of wheel running activity in mice when administered at different circadian time (CT) points across the circadian cycle, pretreatment with JNJ-18038683 blocked non-photic phase advance (CT6) induced by the 5-HT1A/7 receptor agonist 8-OH-DPAT (3 mg/kg). Since light induced phase shifts in mammals are partially mediated via the modulation of the serotonergic system, we determined if JNJ-18038683 altered phase shifts induced by a light pulse at times known to phase delay (CT15) or advance (CT22) wheel running activity in free running mice. Light exposure resulted in a robust shift in the onset of activity in vehicle treated animals at both times tested. Administration of JNJ-18038683 significantly attenuated the light induced phase delay and completely blocked the phase advance. The current study demonstrates that pharmacological blockade of the 5-HT7 receptor by JNJ-18038683 blunts both non-photic and photic phase shifts of circadian wheel running activity in mice. These findings highlight the importance of the 5-HT7 receptor in modulating circadian rhythms. Due to the opposite modulating effects of light resetting between diurnal and nocturnal species, pharmacotherapy targeting the 5-HT7 receptor in conjunction with bright light therapy may prove therapeutically beneficial by correcting the desynchronization of internal rhythms observed in depressed individuals.

Protein kinase C inhibition rescues manic-like behaviors and hippocampal cell proliferation deficits in the sleep deprivation model of mania

BACKGROUND

Recent studies revealed that bipolar disorder may be associated with deficits of neuroplasticity. Additionally, accumulating evidence has implicated alterations of the intracellular signaling molecule protein kinase C (PKC) in mania.

METHODS

Using sleep deprivation (SD) as an animal model of mania, this study aimed to examine the possible relationship between PKC and neuroplasticity in mania. Rats were subjected to SD for 72 h and tested behaviorally. In parallel, SD-induced changes in hippocampal cell proliferation were evaluated with bromodeoxyuridine (BrdU) labeling. We then examined the effects of the mood stabilizer lithium, the antipsychotic agent aripiprazole, and the PKC inhibitors chelerythrine and tamoxifen on both behavioral and cell proliferation impairments induced by SD. The antidepressant fluoxetine was used as a negative control.

RESULTS

We found that SD triggered the manic-like behaviors such as hyperlocomotion and increased sleep latency, and reduced hippocampal cell proliferation. These alterations were counteracted by an acute administration of lithium and aripiprazole but not of fluoxetine, and only a single administration of aripiprazole increased cell proliferation on its own. Importantly, SD rats exhibited increased levels of phosphorylated synaptosomal-associated protein 25 (SNAP-25) in the hippocampus and prefrontal cortex, suggesting PKC overactivity. Moreover, PKC inhibitors attenuated manic-like behaviors and rescued cell proliferation deficits induced by SD.

CONCLUSIONS

Our findings confirm the relevance of SD as a model of mania, and provide evidence that antimanic agents are also able to prevent SD-induced decrease of hippocampal cell proliferation. Furthermore, they emphasize the therapeutic potential of PKC inhibitors, as revealed by their antimanic-like and pro-proliferative properties.

The noradrenaline metabolite MHPG is a candidate biomarker between the depressive, remission, and manic states in bipolar disorder I: two long-term naturalistic case reports

BACKGROUND

Treatment of the depressive and manic states in bipolar disorder I (BDI) is a challenge for psychiatrists. Despite the recognized importance of the switch phenomenon, the precise mechanisms underlying this process are yet to be shown. We conducted a naturalistic study in two BDI patients to determine whether biological markers (monoamine metabolites and brain-derived neurotrophic factor [BDNF]) are associated with the switch between depressive and manic states.

CASE PRESENTATION AND METHODS

Blood sampling and mood assessments were performed at 2-week intervals over a period of 2 (Case 1, n=72) and 6 (Case 2, n=183) years. Plasma concentrations of 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were analyzed by high-performance liquid chromatography with electrochemical detection. Plasma BDNF was assayed by sandwich ELISA (enzyme-linked immunosorbent assay).

RESULTS

MHPG had the highest standardized coefficient (β) in the multiple regression analysis. We found a significant positive correlation between Young Mania Rating Scale scores and plasma MHPG levels (Case 1: ρ=0.429; Case 2: ρ=0.488), and a significant negative correlation between Montgomery-Asberg Depression Rating Scale scores and MHPG levels (Case 1: ρ=-0.542; Case 2: ρ=-0.465). Conversely, no significant correlation was found between the level of BDNF and the presence of a manic or depressive state, and although HVA had a slightly stronger correlation than MHPG, the levels of neither of these were found to significantly correlate with the symptoms.

CONCLUSION

These data suggest that peripheral MHPG levels (which is related to noradrenaline levels in the brain) could be used as a biomarker of mood states in BDI. The noradrenaline level in the brain is likely to reflect the clinical characteristics of the switch process in BDI, and has prognostic significance for the treatment of both manic and depressive states.

Applications of the Neonatal Quinpirole Model to Psychosis and Convergence upon the Dopamine D2 Receptor

This mini review focuses on the importance of the dopamine D₂-like receptor family and its importance in psychosis. Past findings from this laboratory along with collaborators have been that neonatal quinpirole (a dopamine D₂-like receptor agonist) results in increases in dopamine D₂ receptor sensitivity that persists throughout the animal's lifetime. Findings from this model have been shown to have particular application and validity to schizophrenia, but may have broader implications toward other psychoses, which is reviewed in the present manuscript. In the present review, we also highlight other models of psychoses that have been centered on the subchronic administration of quinpirole to rats in order to model certain psychoses, which has uncovered some interesting and valid behavioral findings. This review highlights the importance of the combination of behavioral findings and neurobiological mechanisms focusing on neural plasticity in discovering underlying pathologies in these disorders that may lead to treatment discoveries, as well as the value of animal models across all psychoses.

Hypothalamic-pituitary-adrenocortical axis: neuropsychiatric aspects

Evidence of aberrant hypothalamic-pituitary-adrenocortical (HPA) activity in many psychiatric disorders, although not universal, has sparked long-standing interest in HPA hormones as biomarkers of disease or treatment response. HPA activity may be chronically elevated in melancholic depression, panic disorder, obsessive-compulsive disorder, and schizophrenia. The HPA axis may be more reactive to stress in social anxiety disorder and autism spectrum disorders. In contrast, HPA activity is more likely to be low in PTSD and atypical depression. Antidepressants are widely considered to inhibit HPA activity, although inhibition is not unanimously reported in the literature. There is evidence, also uneven, that the mood stabilizers lithium and carbamazepine have the potential to augment HPA measures, while benzodiazepines, atypical antipsychotics, and to some extent, typical antipsychotics have the potential to inhibit HPA activity. Currently, the most reliable use of HPA measures in most disorders is to predict the likelihood of relapse, although changes in HPA activity have also been proposed to play a role in the clinical benefits of psychiatric treatments. Greater attention to patient heterogeneity and more consistent approaches to assessing treatment effects on HPA function may solidify the value of HPA measures in predicting treatment response or developing novel strategies to manage psychiatric disease.

Risk of manic switch associated with antidepressant therapy in pediatric bipolar depression

OBJECTIVE

The purpose of this study was to assess the risk of manic switch associated with antidepressants in Medicaid-enrolled pediatric patients with bipolar depression.

METHODS

This retrospective cohort study involved 2003-2007 Medicaid Analytic eXtract (MAX) data from four geographically diverse states. The study sample included children and adolescents (ages 6-18 years) who had received a diagnosis of bipolar disorder on two or more separate occasions or during a hospital discharge, followed by a diagnosis of depression. According to the pharmacotherapy received by these patients in the 30 days around the index bipolar depression diagnosis, patients were categorized into five mutually exclusive groups. Manic switch was defined as having received a diagnosis of mania within 6 weeks after the initiation of bipolar depression treatment. Relative risks of manic switch between antidepressant monotherapy/polytherapy and their alternatives were assessed using Cox proportional hazards model. The robustness of the conventional Cox proportional hazards model toward possible bias caused by unobserved confounders was tested using instrumental variable analysis, and the uncertainty regarding manic switch definition was tested by altering the duration of follow-up.

RESULTS

After applying all the selection criteria, 179 antidepressant monotherapy, 1047 second-generation antipsychotic (SGA) monotherapy, 570 mood stabilizer monotherapy, 445 antidepressant polytherapy, and 1906 SGA-mood stabilizer polytherapy users were identified. In Cox proportional hazard analyses, both antidepressant monotherapy and polytherapy exhibited higher risk of manic switch than their alternatives (antidepressant monotherapy vs. SGA monotherapy, hazard ratio [HR]=2.87 [95% CI: 1.10-7.49]; antidepressant monotherapy vs. mood stabilizer monotherapy, HR=1.41 [95% CI: 0.52-3.80); antidepressant polytherapy vs. SGA-mood stabilizer polytherapy, HR=1.61 [95% CI: 0.90-2.89]). However, only the comparison between antidepressant monotherapy and SGA monotherapy was statistically significant. The instrumental variable analysis did not detect endogeneity of the treatment variables. Extending the follow-up period from 6 weeks to 8 and 12 weeks generated findings consistent with the main analysis.

CONCLUSIONS

Study findings indicated a higher risk of manic switch associated with antidepressant monotherapy than with SGA monotherapy in pediatric patients with bipolar depression. The finding supported the clinical practice of cautious prescribing of antidepressants for brief periods.

Adrenal Clocks and the Role of Adrenal Hormones in the Regulation of Circadian Physiology

The mammalian circadian timing system consists of a master pacemaker in the suprachiasmatic nucleus (SCN) and subordinate clocks that disseminate time information to various central and peripheral tissues. While the function of the SCN in circadian rhythm regulation has been extensively studied, we still have limited understanding of how peripheral tissue clock function contributes to the regulation of physiological processes. The adrenal gland plays a special role in this context as adrenal hormones show strong circadian secretion rhythms affecting downstream physiological processes. At the same time, they have been shown to affect clock gene expression in various other tissues, thus mediating systemic entrainment to external zeitgebers and promoting internal circadian alignment. In this review, we discuss the function of circadian clocks in the adrenal gland, how they are reset by the SCN and may further relay time-of-day information to other tissues. Focusing on glucocorticoids, we conclude by outlining the impact of adrenal rhythm disruption on neuropsychiatric, metabolic, immune, and malignant disorders.