Epilepsy and bipolar disorder

The neuropsychological presentation of women with epilepsy: Clinical considerations and future directions

Objective: Cognitive, mood, and behavioral changes are common among persons with epilepsy (PWE), resulting in a complex neuropsychological presentation. Women with epilepsy (WWE) represent a distinct cohort within the broader epilepsy population due to sex and gender-specific factors impacting epilepsy semiology and treatment. However, unique neuropsychological profiles among WWE have not been established. This narrative review aims to further define neuropsychological correlates in WWE and promote meaningful discussion related to enhancing the provision of neuropsychological care within this clinical population. Method: Current literature in PWE examining differences in cognitive function, mental health, and quality of life (QoL) between women and men was critically reviewed, emphasizing considerations for neuropsychological practice. Results: WWE demonstrate a preservation of verbal learning and memory compared to men both pre- and post-surgically, with sex-based, neurobiological mechanisms likely contributing to this association. WWE also have elevated risk for affective disorder psychopathology, suicidality, and traumatic experiences. Epidemiology related to psychotic and bipolar spectrum disorders is less clear, and findings are mixed regarding sex-specific behavioral side effects of antiseizure and psychotropic medication. Finally, hormonal and obstetric factors are highlighted as important contributors to neuropsychological symptoms in WWE, with elevated risk for low QoL and increased stigma associated with greater medical and psychiatric comorbidities compared to men. Conclusions: While emerging literature has begun to characterize the neuropsychological presentation of WWE, future research is needed to define sex and gender differences in neuropsychological sequalae among PWE to ensure consistency and quality of care for WWE.

Bipolar mania and epilepsy pathophysiology and treatment may converge in purine metabolism: A new perspective on available evidence

Decreased ATPergic signaling is an increasingly recognized pathophysiology in bipolar mania disease models. In parallel, adenosine deficit is increasingly recognized in epilepsy pathophysiology. Under-recognized ATP and/or adenosine-increasing mechanisms of several antimanic and antiseizure therapies including lithium, valproate, carbamazepine, and ECT suggest a fundamental pathogenic role of adenosine deficit in bipolar mania to match the established role of adenosine deficit in epilepsy. The depletion of adenosine-derivatives within the purine cycle is expected to result in a compensatory increase in oxopurines (uric acid precursors) and secondarily increased uric acid, observed in both bipolar mania and epilepsy. Cortisol-based inhibition of purine conversion to adenosine-derivatives may be reflected in observed uric acid increases and the well-established contribution of cortisol to both bipolar mania and epilepsy pathology. Cortisol-inhibited conversion from IMP to AMP as precursor of both ATP and adenosine may represent a mechanism for treatment resistance common in both bipolar mania and epilepsy. Anti-cortisol therapies may therefore augment other treatments both in bipolar mania and epilepsy. Evidence linking (i) adenosine deficit with a decreased need for sleep, (ii) IMP/cGMP excess with compulsive hypersexuality, and (iii) guanosine excess with grandiose delusions may converge to suggest a novel theory of bipolar mania as a condition characterized by disrupted purine metabolism. The potential for disease-modification and prevention related to adenosine-mediated epigenetic changes in epilepsy may be mirrored in mania. Evaluating the purinergic effects of existing agents and validating purine dysregulation may improve diagnosis and treatment in bipolar mania and epilepsy and provide specific targets for drug development.

Polymicrogyria: An Unusual Case of Secondary Mania

BACKGROUND

Secondary mania refers to a manic episode that arises during a medical illness other than bipolar disorder or in response to a drug or medication. As the psychopathological features of secondary mania resemble those of mania due to bipolar disorder, misdiagnosis is frequent.

PURPOSE AND BASIC PROCEDURES

We present the case of a 20-year-old woman who developed a manic episode with psychotic symptoms, in whom polymicrogyria, a malformation of the cortical development with abnormal electroencephalographic activity, was documented. After initiating antiepileptic management, the affective symptoms completely subsided.

MAIN FINDINGS

To date, no specific recommendations are available concerning when to perform advanced studies in patients with a manic episode; however, as our case shows, these are much needed.

PRINCIPAL CONCLUSION

Because the treatment of secondary conditions largely depends on finding the underlying cause, patients with a new-onset mania should undergo a thorough assessment for secondary causes.

The Role of the Gut Microbiome in Bipolar Disorder and its Common Comorbidities

Bipolar disorder is a decidedly heterogeneous and multifactorial disease, with significant psychosocial and medical disease burden. Much difficulty has been encountered in developing novel therapeutics and objective biomarkers for clinical use in this population. In that regard, gut-microbial homeostasis appears to modulate several key pathways relevant to a variety of psychiatric, metabolic, and inflammatory disorders. Microbial impact on immune, endocrine, endocannabinoid, kynurenine, and other pathways are discussed throughout this review. Emphasis is placed on this system's relevance to current pharmacology, diet, and comorbid illness in bipolar disorder. Despite the high level of optimism promoted in many reviews on this topic, substantial obstacles exist before any microbiome-related findings can provide meaningful clinical utility. Beyond a comprehensive overview of pathophysiology, this review hopes to highlight several key areas where progress is needed. As well, novel microbiome-associated suggestions are presented for future research.

Mania Following Traumatic Brain Injury: A Systematic Review

OBJECTIVE

Traumatic brain injury (TBI) is a leading cause of mortality and morbidity worldwide. Mania is an uncommon, but debilitating, psychiatric occurrence following TBI. The literature on mania following TBI is largely limited to case reports and case series. In the present review, the investigators describe the clinical, diagnostic, and treatment characteristics of mania following TBI.

METHODS

A systematic search of MEDLINE, EMBASE, and PsycINFO was conducted for English-language studies published from 1980 to July 15, 2021. The included studies provided the required individual primary data and sufficient information on clinical presentation or treatment of manic symptoms. Studies with patients who reported a history of mania or bipolar disorder prior to TBI and studies with patients who sustained TBI before adulthood were excluded.

RESULTS

Forty-one studies were included, which reported information for 50 patients (the mean±SD age at mania onset was 39.1±14.3 years). Patients were more frequently male, aged <50 years, and without a personal or family history of psychiatric disorders. Although 74% of patients reported mania developing within 1 year following TBI, latencies of up to 31 years were observed. Illness trajectory varied from a single manic episode to recurrent mood episodes. Rapid cycling was reported in six patients. Mood stabilizers and antipsychotics were most frequently used to improve symptoms.

CONCLUSIONS

Heterogeneity of lesion locations and coexisting vulnerabilities make causality difficult to establish. Valproate or a second-generation antipsychotic, such as olanzapine or quetiapine, may be considered first-line therapy in the absence of high-level evidence for a more preferred treatment. Early escalation to combined therapy (mood stabilizer and second-generation antipsychotic) is recommended to control symptoms and prevent recurrence. Larger prospective studies and randomized controlled trials are needed to refine diagnostic criteria and provide definitive treatment recommendations.

Causal effect of psychiatric disorders on epilepsy: A two-sample Mendelian randomization study

BACKGROUND

This study aims to explore the relationship between psychiatric disorders and the risk of epilepsy using Mendelian randomization (MR) analysis.

METHODS

We collected summary statistics of seven psychiatric traits from recent largest genome-wide association study (GWAS), including major depressive disorder (MDD), anxiety disorder, autism spectrum disorder (ASD), bipolar disorder (BIP), attention deficit hyperactivity disorder (ADHD), schizophrenia (SCZ), and insomnia. Then, MR analysis estimates were performed based on International League Against Epilepsy (ILAE) consortium data (n_case  = 15,212 and n_control  = 29,677), the results of which were subsequently validated in FinnGen consortium (n_case  = 6260 and n_control  = 176,107). Finally, a meta-analysis was conducted based on the ILAE and FinnGen data.

RESULTS

We found significant causal effects of MDD and ADHD on epilepsy in the meta-analysis of the ILAE and FinnGen, with corresponding odds ratios (OR) of 1.20 (95% CI 1.08-1.34, p = .001) and 1.08 (95% CI 1.01-1.16, p = .020) by the inverse-variance weighted (IVW) method respectively. MDD increases the risk of focal epilepsy while ADHD has a risk effect on generalized epilepsy. No reliable evidence regarding causal effects of other psychiatric traits on epilepsy was identified.

CONCLUSIONS

This study suggests that major depressive disorder and attention deficit hyperactivity disorder may causally increase the risk of epilepsy.

Response to lithium and anticonvulsants among patients with bipolar disorder with and without comorbid epilepsy - A nation-wide population-based longitudinal study

OBJECTIVE

In a nation-wide population-based longitudinal register linkage study for the first time 1) to investigate long-term response to lithium in patients with bipolar disorder with and without comorbid epilepsy, and 2) within patients with bipolar disorder and comorbid epilepsy to compare differences in responses between lithium, valproate and lamotrigine.

METHODS

We used Danish nation-wide population-based longitudinal register linkage to identify 154 patients with bipolar disorder and comorbid epilepsy and 8381 patients with bipolar disorder without comorbid epilepsy during a study period from 1995 to 2017. Response was defined as continuous monotherapy with lithium, valproate or lamotrigine without switch to or add-on of an antipsychotic drug or an antidepressant or hospitalization during an up to ten-year follow-up period. We calculated standardized absolute risks and differences thereof with respect to age, gender, socioeconomic status and comorbidity with other physical disorders than epilepsy.

RESULTS

Response to lithium was decreased in patients with bipolar disorder with versus without comorbid epilepsy during the ten-year follow-up period and the difference remained after standardization for comorbidity with other physical disorders than epilepsy. Within patients with bipolar disorder and comorbid epilepsy, response to lithium was decreased compared with responses to valproate and lamotrigine.

CONCLUSIONS

The findings suggest that valproate and lamotrigine should be given priority in patients with comorbid bipolar disorder and epilepsy. The study highlights the need for closely clinical monitoring and psychological support for patients with bipolar disorder and comorbid epilepsy and emphasize the need for further long-term studies of effect of interventions.

Validation of a Chromosome 14 Risk Haplotype for Idiopathic Epilepsy in the Belgian Shepherd Dog Found to Be Associated with an Insertion in the RAPGEF5 Gene

An idiopathic epilepsy (IE) risk haplotype on canine chromosome (CFA) 14 has been reported to interact with the CFA37 common risk haplotype in the Belgian shepherd (BS). Additional IE cases and control dogs were genotyped for the risk haplotypes to validate these previous findings. In the new cohort, the interaction between the two regions significantly elevated IE risk. When the haplotypes were analyzed individually, particular haplotypes on both CFA14 (ACTG) and 37 (GG) were associated with elevated IE risk, though only the CFA37 AA was significantly associated (p < 0.003) with reduced risk in the new cohort. However, the CFA14 ACTG risk was statistically significant when the new and previous cohort data were combined. The frequency of the ACTG haplotype was four-fold higher in BS dogs than in other breeds. Whole genome sequence analysis revealed that a 3-base pair predicted disruptive insertion in the RAPGEF5 gene, which is adjacent to the CFA14 risk haplotype. RAPGEF5 is involved in the Wnt-β-catenin signaling pathway that is crucial for normal brain function. Although this risk variant does not fully predict the likelihood of a BS developing IE, the association with a variant in a candidate gene may provide insight into the genetic control of canine IE.

Psychiatric Comorbidities in Epilepsy

BACKGROUND AND PURPOSE

Psychiatric comorbidities (PC) occur more frequently in patients with epilepsy than in the general population. To determine the main PC associated with epilepsy and its association with demographic data and clinical features of epilepsy.

METHODS

A retrospective study was carried out on patients with epilepsy at the Medical Specialties Center of the Municipal Health Department. Demographic data, crisis onset, time range of seizures evolution, type of epileptic seizures, types of epilepsy, etiology, brain injury, topographic location, hemispheric location, type of antiepileptic drugs (AEDs), use of monotherapy or polytherapy, control of epileptic seizures and the PC were recorded.

RESULTS

One hundred forty adult patients were studied 51.4% male, mean age 44.9 years, time of evolution of the crises was 14 years, focal crisis 88.6%, mesial temporal sclerosis 42%, controlled 92.4%, monotherapy 66.1%, and the most used AEDs were carbamazepine (33.1%), valproic acid (28.2%), and phenobarbital (10.4%). The PC present in 67.1% of the patients was depression (22.8%), anxiety disorder (AD) (17.8%), psychosis (10%), dementia (9.2%) and bipolar affective disorder (BAD) (8.5%). The relationship between PC and crisis control was significant (p<0.009).

CONCLUSIONS

Schooling was lower than that reported in the general population in Brazil, and we found a low rate of unemployment or retirement. Epilepsy is associated with PC, the most frequent being depression, AD, psychosis, dementia and BAD. The absence of a relationship between depression and brain damage; anxiety disorder with education, types of epilepsy and etiology; psychosis with sex and time of epilepsy evolution were significant.

Response to antidepressants among patients with unipolar depression with and without comorbid epilepsy-a nation-wide population-based longitudinal study

OBJECTIVE

In a nation-wide population-based longitudinal register linkage study to investigate long-term response to antidepressants in patients with depression with and without comorbid epilepsy.

METHODS

We used Danish nation-wide population-based longitudinal register linkage to identify 1487 patients with depression and comorbid epilepsy and 71,163 patients with depression without comorbid epilepsy during a study period from 1995 to 2017. Response was defined as continuous monotherapy with an antidepressant drug without switch to or add-on of another antidepressant drug, an antipsychotic drug or lithium or hospitalization during an up to ten-year follow-up period. We calculated standardized absolute risks and differences thereof with respect to age, gender, socioeconomic status and comorbidity with other physical disorders than epilepsy.

RESULTS

In patients with depression, response to antidepressants was decreased with versus without comorbid epilepsy during the ten-year follow-up period. One year after start of antidepressant treatment the proportion of responders was 12% (CI: 10%-14%) lower in patients with versus without comorbid epilepsy in the standardized population. Response to antidepressants were specifically decreased among younger and unemployed patients with depression and comorbid epilepsy.

LIMITATIONS

We did not include sub-analyses according to subtypes of epilepsy.

CONCLUSIONS

Response to antidepressants was decreased in patients with comorbid epilepsy versus without comorbid epilepsy at all time points during a ten-year follow-up period. The study highlights the need for closely clinical monitoring and psychological support for patients with depression and comorbid epilepsy and emphasize the need for further long-term studies of effect of interventions.

Bipolar spectrum disorders in neurologic disorders

Psychiatric symptoms frequently predate or complicate neurological disorders, such as neurodegenerative diseases. Symptoms of bipolar spectrum disorders (BSD), like mood, behavioral, and psychotic alterations, are known to occur - individually or as a syndromic cluster - in Parkinson's disease and in the behavioral variant of frontotemporal dementia (FTD). Nonetheless, due to shared pathophysiological mechanisms, or genetic predisposition, several other neurological disorders show significant, yet neglected, clinical and biological overlaps with BSD like neuroinflammation, ion channel dysfunctions, neurotransmission imbalance, or neurodegeneration. BSD pathophysiology is still largely unclear, but large-scale network dysfunctions are known to participate in the onset of mood disorders and psychotic symptoms. Thus, functional alterations can unleash BSD symptoms years before the evidence of an organic disease of the central nervous system. The aim of our narrative review was to illustrate the numerous intersections between BSD and neurological disorders from a clinical-biological point of view and the underlying predisposing factors, to guide future diagnostic and therapeutical research in the field.

Ouabain inhibitor rostafuroxin attenuates dextromethorphan-induced manic potential

Dextromethorphan (DM) abuse produces mania-like symptoms in humans. ERK/Akt signaling activation involved in manic potential can be attenuated by the inhibition of ouabain-like cardiac steroids. In this study, increased phosphorylations of ERK/Akt and hyperlocomotion induced by DM (30 mg/kg, i.p./day × 7) were significantly protected by the ouabain inhibitor rostafuroxin (ROSTA), suggesting that DM induces the manic potential. ROSTA significantly attenuated DM-induced protein kinase C δ (PKCδ) phosphorylation, GluN2B (i.e., MDA receptor subunit) expression, and phospho-PKCδ/GluN2B interaction. DM instantly upregulated the nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent system. However, DM reduced Nrf2 nuclear translocation, Nrf2 DNA binding activity, γ-glutamylcysteine mRNA expression, and subsequent GSH/GSSG level and enhanced oxidative parameters following 1-h of administration. ROSTA, PKCδ inhibitor rottlerin, and GluN2B inhibitor traxoprodil significantly attenuated DM-induced alterations in Nrf2-related redox parameters and locomotor activity induced by DM in wild-type mice. Importantly, in PKCδ knockout mice, DM failed to alter the above parameters. Further, ROSTA and traxoprodil also failed to enhance PKCδ depletion effect, suggesting that PKCδ is a critical target for the anti-manic potential of ROSTA or GluN2B antagonism. Our results suggest that ROSTA inhibits DM-induced manic potential by attenuating ERK/Akt activation, GluN2B/PKCδ signalings, and Nrf2-dependent system.

Exploring the mechanisms of action of the antidepressant effect of the ketogenic diet

The ketogenic diet (KD) is characterized by a diet ratio of 4:1 fat to non-fat energy sources. For decades KD has been successfully used to control seizures in epilepsy patients. Investigations into its mechanism of action suggest that it may have an effect on the metabolic, nervous, immune, and digestive systems. In this review, we postulate that KD may also improve depressive symptoms - for that, we highlight the similarities between depression and epilepsy, describe the extent to which body systems involved in both conditions are affected by the KD, and ultimately hypothesize how KD could improve MDD outcomes. Research into animal models and human patients have reported that KD can increase mitochondrial biogenesis and increase cellular resistance to oxidative stress both at the mitochondrial and genetic levels. Its effect on neurotransmitters alters cell-to-cell communication in the brain and may decrease hyperexcitability by increasing Gamma Aminobutyric Acid (GABA) and decreasing excitatory neurotransmitter levels. Its anti-inflammatory effects are mediated by decreasing chemo- and cytokine levels, including TNF-alpha and IL-1 levels. Finally, KD can alter gut microbiota (GM). Certain strains of microbiota predominate in major depressive disorder (MDD) when compared to healthy individuals. Recent evidence points to Bacteroidetes as a potential treatment predictor as it seems to increase in KD treatment responders for epilepsy. Each of these observations contributes to the presumed modulatory effects of KD on mood and supports its potential role as antidepressant.

Lithium as a Neuroprotective Agent for Bipolar Disorder: An Overview

Lithium (Li⁺) is a first option treatment for adult acute episodes of Bipolar Disorder (BD) and for the prophylaxis of new depressed or manic episodes. It is also the preferred choice as maintenance treatment. Numerous studies have shown morphological abnormalities in the brains of BD patients, suggesting that this highly heritable disorder may exhibit progressive and deleterious changes in brain structure. Since treatment with Li⁺ ameliorates these abnormalities, it has been postulated that Li⁺ is a neuroprotective agent in the same way atypical antipsychotics are neuroprotective in patients diagnosed with schizophrenia spectrum disorders. Li⁺'s neuroprotective properties are related to its modulation of nerve growth factors, inflammation, mitochondrial function, oxidative stress, and programmed cell death mechanisms such as autophagy and apoptosis. Notwithstanding, it is not known whether Li⁺-induced neuroprotection is related to the inhibition of its putative molecular targets in a BD episode: the enzymes inositol-monophosphatase, (IMPase), glycogen-synthase-kinase 3β (GSK3), and Protein kinase C (PKC). Furthermore, it is uncertain whether these neuroprotective mechanisms are correlated with Li⁺'s clinical efficacy in maintaining mood stability. It is expected that in a nearby future, precision medicine approaches will improve diagnosis and expand treatment options. This will certainly contribute to ameliorating the medical and economic burden created by this devastating mood disorder.

Differences in course of illness between patients with bipolar II disorder with and without epileptiform discharges or other sharp activity on electroencephalograms: a cross-sectional study

BACKGROUND

A diagnosis of bipolar II disorder requires that the symptoms cannot be better explained by a medical condition. Epilepsy is in some cases associated with an affective syndrome mimicking an unstable bipolar II disorder. Epileptiform discharges on electroencephalograms (EEGs) are typical, but not pathognomonic, for epilepsy. A previous study has found a high frequency of epileptiform discharges and other sharp activity among patients with bipolar disorder. The aim of the study was to identify if epileptic discharges or other sharp activity per se are associated with an altered course of illness among patients with bipolar II disorder.

METHODS

Eighty six patients diagnosed with bipolar II disorder at two psychiatric departments were interviewed about prior course of illness and assessed with EEGs. The patients were split into two groups based on the presence (n = 12) or absence (n = 74) of epileptiform discharges or other sharp activity. Wilcoxon rank sum test, Fisher's exact test, and Pearson's chi squared test were used to assess differences between the groups on six variables of course of illness.

RESULTS

Patients with epileptiform discharges or other sharp activity had a history of more hypomanic episodes per year (median (interquartile range (IQR)) 1.5 (3.2) vs. 0.61 (1.1), p = 0.0090) and a higher hypomania:depression ratio (median (IQR) 3.2 (16) vs. 1.0 (1.0), p = 0.00091) as compared to patients without. None of the patients with epileptiform discharges or other sharp activity had self-reported epileptic seizures in their history.

CONCLUSIONS

Epileptiform discharges or other sharp activity on EEGs are associated with more hypomanic episodes and an increased hypomania:depression ratio. Our results warrant replication in prospective studies, but suggest that EEG findings could be of prognostic importance for patients diagnosed with bipolar II disorder in psychiatric care.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT00201526 ).

Prolonged functional cerebral asymmetry as a consequence of dysfunctional parvocellular paraventricular hypothalamic nucleus signaling: An integrative model for the pathophysiology of bipolar disorder

Approximately 45 million people worldwide are diagnosed with bipolar disorder (BD). While there are many known risk factors and models of the pathologic processes influencing BD, the exact neurologic underpinnings of BD are unknown. We attempt to integrate the existing literature and create a unifying hypothesis regarding the pathophysiology of BD with the hope that a concrete model may potentially facilitate more specific diagnosis, prevention, and treatment of BD in the future. We hypothesize that dysfunctional signaling from the parvocellular neurons of the paraventricular hypothalamic nucleus (PVN) results in the clinical presentation of BD. Functional damage to this nucleus and its signaling pathways may be mediated by myriad factors (e.g. immune dysregulation and auto-immune processes, polygenetic variation, dysfunctional interhemispheric connections, and impaired or overactivated hypothalamic axes) which could help explain the wide variety of clinical presentations along the BD spectrum. The neurons of the PVN regulate ultradian rhythms, which are observed in cyclic variations in healthy individuals, and mediate changes in functional hemispheric lateralization. Theoretically, dysfunctional PVN signaling results in prolonged functional hemispheric dominance. In this model, prolonged right hemispheric dominance leads to depressive symptoms, whereas left hemispheric dominance correlated to the clinical picture of mania. Subsequently, physiologic processes that increase signaling through the PVN (hypothalamic-pituitaryadrenal axis, hypothalamic- pituitary-gonadal axis, and hypothalamic-pituitary-thyroid axis activity, suprachiasmatic nucleus pathways) as well as, neuro-endocrine induced excito-toxicity, auto-immune and inflammatory flairs may induce mood episodes in susceptible individuals. Potentially, ultradian rhythms slowing with age, in combination with changes in hypothalamic axes and maturation of neural circuitry, accounts for BD clinically presenting more frequently in young adulthood than later in life.

Orthosiphon stamineus Proteins Alleviate Pentylenetetrazol-Induced Seizures in Zebrafish

The anticonvulsive potential of proteins extracted from Orthosiphon stamineus leaves (OSLP) has never been elucidated in zebrafish (Danio rerio). This study thus aims to elucidate the anticonvulsive potential of OSLP in pentylenetetrazol (PTZ)-induced seizure model. Physical changes (seizure score and seizure onset time, behavior, locomotor) and neurotransmitter analysis were elucidated to assess the pharmacological activity. The protective mechanism of OSLP on brain was also studied using mass spectrometry-based label-free proteomic quantification (LFQ) and bioinformatics. OSLP was found to be safe up to 800 µg/kg and pre-treatment with OSLP (800 µg/kg, i.p., 30 min) decreased the frequency of convulsive activities (lower seizure score and prolonged seizure onset time), improved locomotor behaviors (reduced erratic swimming movements and bottom-dwelling habit), and lowered the excitatory neurotransmitter (glutamate). Pre-treatment with OSLP increased protein Complexin 2 (Cplx 2) expression in the zebrafish brain. Cplx2 is an important regulator in the trans-SNARE complex which is required during the vesicle priming phase in the calcium-dependent synaptic vesicle exocytosis. Findings in this study collectively suggests that OSLP could be regulating the release of neurotransmitters via calcium-dependent synaptic vesicle exocytosis mediated by the "Synaptic Vesicle Cycle" pathway. OSLP's anticonvulsive actions could be acting differently from diazepam (DZP) and with that, it might not produce the similar cognitive insults such as DZP.

Predictive factors of diagnostic conversion from major depressive disorder to bipolar disorder in young adults ages 19-34: A nationwide population study in South Korea

BACKGROUND

Predicting patients who convert to bipolar disorder is important for deciding appropriate treatment for young adults with major depressive disorder (MDD). We focused on the predictive factors of bipolar conversion in a large population of young adults.

METHODS

A nationwide, population-based electronic medical records database from the Health Insurance Review & Assessment service of South was used to investigate adjusted hazard ratio (HR) of each potential predictor of the bipolar converter group compared to the non-converter group using Cox regression analysis including age of onset, medication use, clinical features, comorbid disorders, admission, self-harm, and negative life events in childhood.

RESULTS

Among 291,721 subjects who were initially diagnosed with MDD in young adults, 12,376 subjects experienced diagnostic conversion to bipolar disorder. The cumulative incidence was 6.46% during the average 3.26 years of follow-up. Among the predictive factors during diagnosis of MDD, antipsychotic use (HR 3.12, 95%CI, 2.99-3.26, p < 0.0001) and mood stabilizers (HR 2.45, 95%CI, 2.35-2.55, p < 0.0001) showed the strongest association with diagnostic conversion to bipolar disorder. In addition, female sex, younger age of onset, mood stabilizer use, recurrent depression, psychotic symptoms, and admission to a psychiatric ward during diagnosis of MDD were also associated with diagnostic conversion to bipolar disorder.

CONCLUSION

In young adults with MDD, antipsychotic and mood stabilizer use during diagnosis of MDD were the strongest predictive factors with diagnostic conversion to bipolar disorder during follow-up. If young adults with MDD need antipsychotics or mood stabilizer, patients should be carefully evaluated for possibility of bipolar disorder.

Bridging the divide between epilepsy and mental health to drive solutions

Since its establishment in 2000, Epilepsy & Behavior has published more than 1000 papers on mental health issues among people with epilepsy, including about 200 reviews. These studies on prevalence, treatment, and guidance for future research are important contributions to the field, and they offer great promise. Yet these papers and the multitude published in other journals over the years have failed to result in systematic, scaled changes in how the epilepsy field in the United States addresses mental health issues. The mental health assessment and management gap is especially notable given decades-old, as well as more recent, recommendations from national initiatives on epilepsy, consensus statements, and other expert appeals to reduce psychiatric burden. Selected or comprehensive elements of emerging models and latest approaches from behavioral health (e.g., peer support) and public health (e.g., community-clinical linkages) highlight current opportunities to engage multiple community partners and sectors to bridge the epilepsy and behavioral health fields to implement solutions for improved mental healthcare for people with epilepsy. In honor of the 20th anniversary of Epilepsy & Behavior and its contribution to the literature and the field, we seek to build public health roadmaps to bridge the epilepsy and behavioral health divide-with new epilepsy partners who can expand community-based partnerships that may help facilitate systematic changes to close mental health treatment gaps. Special Issue: Epilepsy & Behavior's 20th Anniversary.

A genome wide association study suggests the association of muskelin with early onset bipolar disorder: Implications for a GABAergic epileptogenic neurogenesis model

BACKGROUND

Although multiple genes have been implicated in bipolar disorder (BD), they explain only a small proportion of its heritability. Identifying additional BD risk variants may be impaired by phenotypic heterogeneity, which is usually not taken into account in genome-wide association studies (GWAS). BD with early age at onset is a more homogeneous familial form of the disorder associated with greater symptom severity.

METHODS

We conducted a GWAS of early-onset BD (onset of mania/hypomania ≤19 years old) in a discovery sample of 419 cases and 1034 controls and a replication sample of 181 cases and 777 controls. These two samples were meta-analyzed, followed by replication of one signal in a third independent sample of 141 cases and 746 controls.

RESULTS

No single nucleotide polymorphism (SNP) associations were genome-wide significant in the discovery sample. Of the top 15 SNPs in the discovery analysis, rs114034759 in the muskelin (MKLN1) gene was nominally significant in the replication analysis, and was among the top associations in the meta-analysis (p=2.63E-06, OR=1.9). In the third sample, this SNP was again associated with early-onset BD (p=0.036, OR=1.6). Gene expression analysis showed that the rs114034759 risk allele is associated with decreased hippocampal MKLN1 expression.

LIMITATIONS

The sample sizes of the early-onset BD subgroups were relatively small.

CONCLUSIONS

Our results suggest MKLN1 is associated with early-onset BD. MKLN1 regulates cellular trafficking of GABA-A receptors, which is involved in synaptic transmission and plasticity, and is implicated in the mechanism of action of a group of antiepileptic mood stabilizers. These results therefore indicate that GABAergic neurotransmission may be implicated in early-onset BD. We propose that an increase in GABA-A receptors in the hippocampus in BD patients due to lower MKLN1 expression might increase the excitability during the GABA-excited early phase of young neurons, leading to an increased risk of developing a manic/hypomanic episode. Further studies are needed to test this model.

Generating Gene Ontology-Disease Inferences to Explore Mechanisms of Human Disease at the Comparative Toxicogenomics Database

Strategies for discovering common molecular events among disparate diseases hold promise for improving understanding of disease etiology and expanding treatment options. One technique is to leverage curated datasets found in the public domain. The Comparative Toxicogenomics Database (CTD; http://ctdbase.org/) manually curates chemical-gene, chemical-disease, and gene-disease interactions from the scientific literature. The use of official gene symbols in CTD interactions enables this information to be combined with the Gene Ontology (GO) file from NCBI Gene. By integrating these GO-gene annotations with CTD’s gene-disease dataset, we produce 753,000 inferences between 15,700 GO terms and 4,200 diseases, providing opportunities to explore presumptive molecular underpinnings of diseases and identify biological similarities. Through a variety of applications, we demonstrate the utility of this novel resource. As a proof-of-concept, we first analyze known repositioned drugs (e.g., raloxifene and sildenafil) and see that their target diseases have a greater degree of similarity when comparing GO terms vs. genes. Next, a computational analysis predicts seemingly non-intuitive diseases (e.g., stomach ulcers and atherosclerosis) as being similar to bipolar disorder, and these are validated in the literature as reported co-diseases. Additionally, we leverage other CTD content to develop testable hypotheses about thalidomide-gene networks to treat seemingly disparate diseases. Finally, we illustrate how CTD tools can rank a series of drugs as potential candidates for repositioning against B-cell chronic lymphocytic leukemia and predict cisplatin and the small molecule inhibitor JQ1 as lead compounds. The CTD dataset is freely available for users to navigate pathologies within the context of extensive biological processes, molecular functions, and cellular components conferred by GO. This inference set should aid researchers, bioinformaticists, and pharmaceutical drug makers in finding commonalities in disease mechanisms, which in turn could help identify new therapeutics, new indications for existing pharmaceuticals, potential disease comorbidities, and alerts for side effects.

Hypothyroidism risk compared among nine common bipolar disorder therapies in a large US cohort

OBJECTIVES

Thyroid abnormalities in patients with bipolar disorder (BD) have been linked to lithium treatment for decades, yet other drugs have been less well studied. Our objective was to compare hypothyroidism risk for lithium versus the anticonvulsants and second-generation antipsychotics commonly prescribed for BD.

METHODS

Administrative claims data on 24,574 patients with BD were analyzed with competing risk survival analysis. Inclusion criteria were (i) one year of no prior hypothyroid diagnosis nor BD drug treatment, (ii) followed by at least one thyroid test during BD monotherapy on lithium carbonate, mood-stabilizing anticonvulsants (lamotrigine, valproate, oxcarbazepine, or carbamazepine) or antipsychotics (aripiprazole, olanzapine, risperidone, or quetiapine). The outcome was cumulative incidence of hypothyroidism per drug, in the presence of the competing risk of ending monotherapy, adjusted for age, sex, physician visits, and thyroid tests.

RESULTS

Adjusting for covariates, the four-year cumulative risk of hypothyroidism for lithium (8.8%) was 1.39-fold that of the lowest risk therapy, oxcarbazepine (6.3%). Lithium was non-statistically significantly different from quetiapine. While lithium conferred a higher risk when compared to all other treatments combined as a group, hypothyroidism risk error bars overlapped for all drugs. Treatment (p = 3.86e-3), age (p = 6.91e-10), sex (p = 3.93e-7), and thyroid testing (p = 2.79e-87) affected risk. Patients taking lithium were tested for hypothyroidism 2.26-3.05 times more frequently than those on other treatments.

CONCLUSIONS

Thyroid abnormalities occur frequently in patients with BD regardless of treatment. Therefore, patients should be regularly tested for clinical or subclinical thyroid abnormalities on all therapies and treated as indicated to prevent adverse effects of hormone imbalances on mood.