Anticonvulsant drugs in bipolar disorder

The relationship between familial-genetic risk and pharmacological treatment in a Swedish national sample of patients with major depression, bipolar disorder, and schizophrenia

Using Swedish registers, we examine whether the prescription of and the response to antidepressants (AD), mood stabilizers (MS), and antipsychotics (AP) in the treatment of, respectively, major depression (MD), bipolar disorder (BD), and schizophrenia (SZ), are influenced by familial-genetic risk. We examined individuals born in Sweden 1960-1995 with a first diagnosis of MD (n = 257,177), BD (n = 23,032), and SZ (n = 4248) from 2006 to 2018. Drug classes and Defined Daily Dose (DDD) were obtained from the Pharmacy register using the Anatomical Therapeutic Chemical system. We utilized the Familial Genetic Risk Scores (FGRS) calculated from morbidity risks in first- through fifth degree relatives. Treatment with antidepressants (AD) in MD, mood-stabilizers (MS) in BD, and antipsychotics (AP) in SZ were associated with significantly higher disorder-specific familial-genetic risks. Using dosage trajectory analysis of AD, MS, and AP treatment for MD, BD, and SZ, respectively, familial-genetic risk was positively associated with higher and/or increasing drug dosages over time. For MD and BD, examining cases started on the most common pharmacologic treatment class (SSRIs for MD and "other anti-epileptics" for BD), familial-genetic risks were significantly lower in those who did not versus did later receive treatment from other AD and MS classes, respectively. Higher familial-genetic risk for BD predicted switching AD medication in cases of MD. Among pharmacologically treated cases of BD, familial-genetic risk was significantly higher for those treated with lithium. In a large population-based patient cohort, we found evidence of a wide-spread association between higher familial-genetic risk and i) increased likelihood of receiving pharmacologic treatment but 2) responding more poorly to it-as indicated by a switching of medications -- and/or requiring higher doses. Further investigations into the clinical utility of genetic risk scores in the clinical managements of MD, BD, and SZ are warranted.

Antiepileptics in Electroconvulsive Therapy: A Mechanism-Based Review of Recent Literature

ABSTRACT

Although prior conventional wisdom strongly recommended complete discontinuation of medications increasing the seizure threshold before electroconvulsive therapy (ECT), more recent literature suggests that anticonvulsants should be considered a relative rather than an absolute contraindication to proceeding with therapy. Most literature regarding the use of use antiepileptic drugs in ECT focuses on antiepileptic mood stabilizers with which most psychiatrists are familiar. However, there is considerably less information available about the use of newer antiepileptics in conjunction with ECT, which may be prescribed to a patient with epilepsy or off-label for psychiatric reasons.In this article, we provide a mechanism-based review of recent available literature concerning the use of antiepileptics during ECT and discuss which medications have the most robust evidence supporting their continued use in select patients. Finally, we highlight important considerations for psychiatrists when deciding how to proceed with patients on antiepileptics who require ECT.

Anticonvulsant use and bone health in a population-based study of men and women: cross-sectional data from the Geelong Osteoporosis Study

Background

Anticonvulsant use has been linked to bone deficits in specific patient populations. We studied the association between anticonvulsant use and bone health in a population-based sample of men and women.

Methods

Data from 926 men (24-73 yr) and 1070 women (21-94 yr) participating in the Geelong Osteoporosis Study were included. Bone mineral density (BMD, g/cm²) of the PA-spine and total hip was measured using dual-energy X-ray absorptiometry (Lunar). Bone quality was determined using quantitative heel ultrasound (QUS). Anthropometry was conducted and socioeconomic status was determined. Medication and lifestyle information was obtained via questionnaire. Linear regression was used to test associations between anticonvulsant use and bone health before and after adjustment for potential confounders.

Results

Seventeen (1.8%) men and 20 (1.9%) women reported anticonvulsant use. In men, anticonvulsant users had 9.1% lower adjusted mean BMD at the spine and hip compared to non-users. Body mass index was an effect modifier at the spine. Anticonvulsant users also had 1.8% lower speed of sound (SOS), 10.6% lower broadband ultrasound attenuation (BUA) and 13.7% lower stiffness index (SI) compared to non-users. In women, BMD tended to be lower at the hip compared to non-users as with the bone quality measure, BUA. No significant associations were observed at the spine or the other bone quality measures, SOS and SI.

Conclusion

Our data suggest that bone quantity and quality, assessed using BMD and QUS, are lower for men and possibly women who use anticonvulsants. While further exploration into potential mechanisms is needed, our findings suggest that monitoring bone health among users of anticonvulsants is warranted.

Prevalence and correlates of diagnosed and undiagnosed epilepsy and migraine headache among people with severe psychiatric disorders in Ethiopia

BACKGROUND

There is a paucity of research on the prevalence of diagnosed as well as undiagnosed neurological disorders with episodic manifestations such as epilepsy and migraine headaches in people with severe psychiatric disorders (SPD). To the best of our knowledge, this is the first study analyzing and comparing the prevalence of diagnosed and undiagnosed chronic neurological disorders with episodic manifestations including epilepsy and migraine headache in people with SPD.

METHOD

This quantitative cross-sectional survey was undertaken among 309 patients with SPD selected by a systematic random sampling technique. The Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) was used to confirm SPD among the participants. The International Classification of Headache Disorders (ICHD-3) and International League Against Epilepsy (ILAE) were used to define migraine headache and epilepsy, respectively]. Risk factors for chronic neurologic disorders were explored by using logistic regression models.

RESULT

In this study, the prevalence of overall neurological disorders, epilepsy, and migraine headache among people with SPD were found to be 5.2% (95%CI 3.2-8.3), 1.6% (95%CI 0.7-3.9), and 3.9% (95%CI 2.2-6.7), respectively. We found that a considerably higher proportion of people with SPD had undiagnosed overall neurological disorder (87.5%; 14/16), epilepsy (60%; 3/5), as well as migraine headaches (100%; 12/12). On the other hand, in this study, 12.5%, 40%, and 0% of patients with overall neurologic disorder, epilepsy, and migraine headaches respectively were diagnosed by the professionals. Higher disability score (WHODAS score) was associated with increased odds of having neurological disorders compared with the lower WHODAS score [OR = 1.30 (95% CI 1.02-1.66)].

CONCLUSION

Whilst the prevalence estimates of neurological disorders with episodic manifestations including epilepsy and migraine headache was high among people with SPD, the vast majority of them remained undiagnosed. The diagnosis rates of those disorders were significantly low, perhaps surprisingly zero for migraine headache. High WHODAS score was associated with increased odds of having neurological disorders. Routine screening and management of epilepsy and migraine headache are imperative among people with SPD.

A proof of concept study demonstrating that environmental levels of carbamazepine impair early stages of chick embryonic development

Carbamazepine (CBZ) is an anticonvulsant drug used for epilepsy and other disorders. Prescription of CBZ during pregnancy increases the risk for congenital malformations. CBZ is ubiquitous in effluents and persistent during wastewater treatment. Thus, it is re-introduced into agricultural ecosystems upon irrigation with reclaimed wastewater. People consuming produce irrigated with reclaimed wastewater were found to be exposed to CBZ. However, environmental concentrations of CBZ (μgL^-1) are magnitudes lower than its therapeutic levels (μgml^-1), raising the question of whether and how environmental levels of CBZ affect embryonic development. The chick embryo is a powerful and highly sensitive amniotic model system that enables to assess environmental contaminants in the living organism. Since the chick embryonic development is highly similar to mammalians, yet, it develops in an egg, toxic effects can be directly analyzed in a well-controlled system without maternal influences. This research utilized the chick embryo to test whether CBZ is embryo-toxic by using morphological, cellular, molecular and imaging strategies. Three key embryonic stages were monitored: after blastulation (st.1HH), gastrulation/neurulation (st.8HH) and organogenesis (st.15HH). Here we demonstrate that environmental relevant concentrations of CBZ impair morphogenesis in a dose- and stage- dependent manner. Effects on gastrulation, neural tube closure, differentiation and proliferation were exhibited in early stages by exposing embryos to CBZ dose as low as 0.1μgL^-1. Quantification of developmental progression revealed a significant difference in the total score obtained by CBZ-treated embryos compared to controls (up to 5-fold difference, p<0.05). Yet, defects were unnoticed as embryos passed gastrulation/neurulation. This study provides the first evidence for teratogenic effect of environmental-relevant concentrations of CBZ in amniotic embryos that impair early but not late stages of development. These findings call for in-depth risk analysis to ensure that the environmental presence of CBZ and other drugs is not causing irreversible ecological and public-health damages.

Kava pyrones exert effects on neuronal transmission and transmembraneous cation currents similar to established mood stabilizers--a review

1. Antiepileptic drugs that are successful as mood stabilizers, e.g. carbamazepine, valproate and lamotrigine, exhibit a characteristic pattern of action on ion fluxes. As a common target, they all affect Na+- and Ca2+ inward and K+ outward currents. 2. Furthermore, they have a variety of interactions with the metabolism and receptor occupation of biogenic amines and excitatory and inhibitory amino acids, and, by this, also influence long- term potentiation (LTP) to different degrees. 3. The kava pyrones (+/-)-kavain and dihydromethysticin are constituents of Piper methysticum. Anticonvulsant, analgesic and anxiolytic properties have been described in small open trials. 4. In the studies summarized in this article the effects mainly of (+/-)-kavain were tested on neurotransmission and especially on voltage gated ion channels. It is assumed that effects on ion channels may significantly contribute to clinical efficacy. 5. Experimental paradigms included current and voltage clamp recordings from rat hippocampal CA 1 pyramidal cells and dorsal root ganglia as well as field potential recordings in guinea pig hippocampal slices. 6. The findings suggest that (i) kava pyrones have a weak Na+ antagonistic effect that may contribute to their antiepileptic properties (ii) that they have pronounced L- type Ca2+ channel antagonistic properties and act as an positive modulator of the early K+ outward current. These two actions may be of importance for mood stabilization. (iii) Furthermore, kava pyrones have additive effects with the serotonin-1A agonist ipsapirone probably contributing to their anxiolytic and sleep- inducing effects. (iv) Finally, they show a distinct pattern of action on glutamatergic and GABAergic transmission without affecting LTP. The latter, however, seems not to be true for the spissum extract of Kava where suppression of LTP was observed. 7. In summary, kava pyrones exhibit a profile of cellular actions that shows a large overlap with several mood stabilizers, especially lamotrigine.

Dysregulation of ion fluxes in bipolar affective disorder

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