Retinoic acid and affective disorders: the evidence for an association

All-trans Retinoic Acid-induced Abnormal Hippocampal Expression of Synaptic Genes SynDIG1 and DLG2 is Correlated with Anxiety or Depression-Like Behavior in Mice

Clinical reports suggest a potential link between excess retinoids and development of depression. Although it has been shown that all-trans retinoic acid (ATRA) administration induces behavioral changes, further insight into how ATRA is involved is lacking. The hippocampus seems to be a major target of retinoids, and abnormal synaptic plasticity of the hippocampus is involved in depression. We examined two genes associated with synaptic function, discs large homolog 2 (DLG2), and synapse differentiation-inducing gene protein 1 (SynDIG1) in terms of hippocampal expression and correlation with behavior. Three different doses of ATRA were injected into young mice and 10 mg/kg ATRA was found to induce depression-like behavior. In the hippocampus, DLG2 mRNA was significantly decreased by ATRA. mRNA levels were positively correlated with central area duration and distance in the open-field test. Increased SynDIG1 mRNA levels were observed. There was a negative correlation between SynDIG1 mRNA levels and mobility time in the forced swimming test. Retinoic acid receptor γ mRNA was significantly positively correlated with DLG2 and negatively correlated with SynDIG1. To summarize, ATRA administration induced anxiety- and depression-like behavior accompanied by a decreased expression of DLG2 and an increased expression of SynDIG1. Moreover, DLG2 was correlated with anxiety-like behavior and SynDIG1 was correlated with depression-like behavior. These results might constitute a novel target underlying ATRA-induced anxiety- and depression-like behavior.

The role of the retinoids in schizophrenia: genomic and clinical perspectives

Signalling by retinoid compounds is vital for embryonic development, with particular importance for neurogenesis in the human brain. Retinoids, metabolites of vitamin A, exert influence over the expression of thousands of transcripts genome wide, and thus, act as master regulators of many important biological processes. A significant body of evidence in the literature now supports dysregulation of the retinoid system as being involved in the aetiology of schizophrenia. This includes mechanistic insights from large-scale genomic, transcriptomic and, proteomic studies, which implicate disruption of disparate aspects of retinoid biology such as transport, metabolism, and signalling. As a result, retinoids may present a valuable clinical opportunity in schizophrenia via novel pharmacotherapies and dietary intervention. Further work, however, is required to expand on the largely observational data collected thus far and confirm causality. This review will highlight the fundamentals of retinoid biology and examine the evidence for retinoid dysregulation in schizophrenia.

Challenges and Solutions in Oral Isotretinoin in Acne: Reflections on 35 Years of Experience

Acne vulgaris affects more than 80% of adolescents and young adults and forms a substantial proportion of the dermatologist's and general practitioner's caseload. Severity of symptoms varies but may result in facial scarring and psychological repercussions. Oral isotretinoin is highly effective but can only be prescribed by specialists. Side effects are recognized and mostly predictable, ranging from cosmetic effects to teratogenicity. These can affect patients' quality of life and treatment adherence. This article provides a commentary on 4 key areas: the use of oral isotretinoin vs oral antibiotics, including the importance of early recognition of nonresponse to treatment, the psychological effects of acne and isotretinoin treatment, the side effects of isotretinoin therapy, and cosmetic treatment options that can help alleviate predictable side effects. The authors, who have all participated in various international expert groups, draw on relevant literature and their extensive professional experience with oral isotretinoin in the treatment of acne. The aim of this article is to provide an informative and practical approach to managing oral isotretinoin treatment in patients with acne, to help optimize treatment of this skin disease.

Isotretinoin and risk factors for suicide attempt: a population-based comprehensive case series and nested case-control study using 2010-2014 French Health Insurance Data

BACKGROUND

Although the causal role of isotretinoin in suicidal behaviour is controversial, suicide attempts (SA) do occur among patients taking isotretinoin.

OBJECTIVES

To describe patient profiles and the management of isotretinoin among patients who committed or attempted suicide under treatment. To assess the risk factors for SA under isotretinoin.

METHODS

We performed a comprehensive case series of suicides and SAs under isotretinoin, and a case-control study, using Nationwide French Health Insurance database. The main analysis compared cases (subjects with a SA during a course of isotretinoin) to controls, individually matched for age, gender and rank of the current course; controls were to be exposed to isotretinoin at the index date (date of SA for the corresponding cases). The patients' psychiatric history at isotretinoin initiation was studied. In a secondary analysis, patients who continued their isotretinoin treatment after their SA were compared to patients who discontinued it.

RESULTS

In all, 328 018 subjects started a course of isotretinoin between 1 January 2010 and 31 December 2014 and 184 patients were hospitalized for a SA; half of them had a psychiatric history at initiation. In the multivariate analysis, psychiatric history and history of anxiety alone were risk factors for SA [Odds ratio (OR), 18.21; 95% confidence interval (CI), 9.96-33.30 and 4.78; 95% CI, 2.44-9.33, respectively]. Among 176 cases of SA with sufficient follow-up, 103 (58.5%) carried on with their treatment after their SA. Treatment initiation by a dermatologist was inversely associated with the continuation of the treatment after a SA (OR, 0.38; 95% CI, 0.18-0.80).

CONCLUSIONS

Suicide attempts under isotretinoin are rare events, and our results suggest that most of the patients concerned have a risk-prone profile detectable at the time of treatment initiation. The risk-benefit ratio of continuing isotretinoin after a SA warrants further careful evaluation.

Rapid Action of Retinoic Acid on the Hypothalamic Pituitary Adrenal Axis

Retinoic acid (RA) is the active metabolite of vitamin A but is also used as a medication, primarily for acne in which the treatment regime lasts several months. A number of studies have indicated that treatment with RA over this time period impacts the hypothalamic-pituitary-adrenal (HPA) axis and may contribute to a number of the side-effects of the drug. No studies though have investigated the short-term, early effects RA may have on the HPA axis via the transcriptional pathways activated by the RA receptor. This study investigated the action of RA over 3 days on regulatory components of the HPA axis. Several key genes involved in glucocorticoid feedback pathways in the hippocampus, hypothalamus and pituitary were unchanged after 3-days exposure to RA. Key elements though in the adrenal gland involved in corticosterone and aldosterone synthesis were altered in particular with the Cyp11b2 gene downregulated in vivo and ex vivo. The rapid, 5 h, change in Cyp11b2 expression suggested this activation may be direct. These results highlight the adrenal gland as a target of short-term action of RA and potentially a trigger component in the mechanisms by which the long-term adverse effects of RA treatment occur.

The Synthetic Retinoid Acitretin Increases IL-6 in the Central Nervous System of Alzheimer Disease Model Mice and Human Patients

These days, the important role of retinoids in adult brain functionality and homeostasis is well accepted and has been proven by genomic as well as non-genomic mechanisms. In the healthy brain, numerous biological processes, e.g., cell proliferation, neurogenesis, dendritic spine formation as well as modulation of the immune system, have been attributed to retinoid signaling. This, together with the finding that retinoid metabolism is impaired in Alzheimer's disease (AD), led to preclinical and early clinical testing of natural and synthetic retinoids as innovative pharmaceuticals with multifactorial properties. Acitretin, an aromatic retinoid, was found to exert an anti-amyloidogenic effect in mouse models for AD as well as in human patients by stimulating the alpha-secretase ADAM10. The lipophilic drug was already demonstrated to easily pass the blood brain barrier after i.p. administration and evoked increased nest building capability in the 5xFAD mouse model. Additionally, we analyzed the immune-modulatory capacity of acitretin via a multiplex array in the 5xFAD mouse model and evaluated some of our findings in human CSF derived from a pilot study using acitretin. Although several serum analytes did not display changes, Interleukin-6 (IL-6) was found to be significantly increased in both-mouse and human neural material. This demonstrates that acitretin exerts an immune stimulatory effect-besides the alpha-secretase induction-which could impact the alleviation of learning and memory disabilities observed in the mouse model.

Risk of suicide attempt associated with isotretinoin: a nationwide cohort and nested case-time-control study

Background

Isotretinoin is the only effective treatment for severe acne. An isotretinoin-related suicide risk is still debated and under scrutiny by regulatory agencies. Our objectives were: to assess the risk of suicide attempt before, during and after isotretinoin treatment; to detect any potential triggering effect of isotretinoin initiation on suicide attempt.

Methods

We implemented a cohort and nested case-time-control study of subjects treated with oral isotretinoin (course or initiation) aged 10–50 years, using the Nationwide French Health Insurance data (2009–2016). The main outcome was hospitalized suicide attempt. Standardized incidence ratios for hospitalized suicide attempts were calculated before, during and after isotretinoin treatment. The number of isotretinoin initiations was compared in risk and control periods of 2 months using a case-time-control analysis.

Results

In all, 443 814 patients (median age 20.0 years; interquartile range 17.0–27.0 years) were exposed to isotretinoin, amounting to 244 154 person-years, with a marked seasonality for treatment initiation. Compared with the French general population, the occurrence of suicide attempts under isotretinoin treatment was markedly lower, with a standardized incidence ratio of 0.6 [95% confidence interval (CI) = 0.53–0.67]; the same applied, to a lesser extent, before and after isotretinoin treatment. In the case-time-control analysis, among cases of suicide attempt, 108 and 127 isotretinoin initiations were observed in the risk and control periods respectively (i.e. 0–2 months and 2–4 months before the date of suicide attempt). The comparison with the 1199 and 1253 initiations observed among matched controls in the same two periods yielded a case-time-control odds ratio of 0.89 (95% CI = 0.68–1.16). A sensitivity analysis using three-month periods and a complementary analysis adding completed suicides for case definition showed consistent results.

Conclusion

Compared with the general population, a lower risk of suicide attempt was observed among patients exposed to isotretinoin and there was no evidence for a triggering effect of isotretinoin initiation on suicide attempt. A selection of patients at lower risk for suicidal behaviour and appropriate treatment management could explain these findings. Risk management plans should therefore be maintained.

The Thalamus Regulates Retinoic Acid Signaling and Development of Parvalbumin Interneurons in Postnatal Mouse Prefrontal Cortex

GABAergic inhibitory neurons in the prefrontal cortex (PFC) play crucial roles in higher cognitive functions. Despite the link between aberrant development of PFC interneurons and a number of psychiatric disorders, mechanisms underlying the development of these neurons are poorly understood. Here we show that the retinoic acid (RA)-degrading enzyme CYP26B1 (cytochrome P450 family 26, subfamily B, member 1) is transiently expressed in the mouse frontal cortex during postnatal development, and that medial ganglionic eminence (MGE)-derived interneurons, particularly in parvalbumin (PV)-expressing neurons, are the main cell type that has active RA signaling during this period. We found that frontal cortex-specific Cyp26b1 knock-out mice had an increased density of PV-expressing, but not somatostatin-expressing, interneurons in medial PFC, indicating a novel role of RA signaling in controlling PV neuron development. The initiation of Cyp26b1 expression in neonatal PFC coincides with the establishment of connections between the thalamus and the PFC. We found that these connections are required for the postnatal expression of Cyp26b1 in medial PFC. In addition to this region-specific role in postnatal PFC that regulates RA signaling and PV neuron development, the thalamocortical connectivity had an earlier role in controlling radial dispersion of MGE-derived interneurons throughout embryonic neocortex. In summary, our results suggest that the thalamus plays multiple, temporally separate roles in interneuron development in the PFC.

Are plasma 25-hydroxyvitamin D and retinol levels and one-carbon metabolism related to metabolic syndrome in patients with a severe mental disorder?

There is a scarcity of studies assessing the influence of biomarkers in metabolic syndrome in psychiatric patients. Our aim was to correlate serum or plasma levels of 25-hydroxyvitamin D (25-OH-VD), retinol, vitamin B12 (VB12), folate and homocysteine (Hcy), with the metabolic status, in a sample of 289 outpatients with Schizophrenia or Bipolar Disorder. Logistic regression and multiple linear regressions were performed to assess the ability of biomarkers to predict the presence of MetS, the number of risk factors for MetS, and insulin resistance indexes (HOMA and QUICKI). Regarding the association between biomarkers and the QUICKI index, the model explained 6.8% of the variance, with folate and 25-OH-VD levels contributing significantly to the model. The model predicting the number of MetS risk factors was significant and explained 21.7% of the variance, being 25-OH-VD and retinol the statistically significant factors. As for the impact of biomarkers on MetS, the model was statistically significant, being 25-OH-VD and retinol levels the significant factors.  We report for the first time an association between MetS and both low 25-OH-VD and high retinol concentrations. Inflammation-related biomarkers may help identify patients with a high risk of MetS who might benefit from healthy lifestyle counselling and early intervention.

Is there an association between isotretinoin therapy and adverse mood changes? A prospective study in a cohort of acne patients

Background: Treatment with isotretinoin has been associated with adverse mood changes. However, even though a number of studies support this association, others refute it, and a concrete causal link has yet to be proven. Acne itself is associated with depressive symptoms, thus making studies on the topic difficult to design and interpret. Objectives and methods: Using validated tools, we performed a prospective study in order to assess the effects of treatment with isotretinoin on the mood of patients with acne vulgaris. Results: Fifty-six patients were included with a mean age of 21 years. At baseline, questionnaire scores for all measured parameters were indicative of lower mood than published norms. During and after treatment, values of either stable or improving mood were displayed across all questionnaires. Three patients developed significantly deteriorating moods, two of whom also experienced severe physical adverse effects. Conclusion: The relationship between isotretinoin and depression is the most debated aspect of isotretinoin therapy. Our results link isotretinoin to an overall improvement in psychological wellbeing, even in patients suffering with stable mental illness. However, we also found that a small minority of patients are susceptible to severe mood deterioration, particularly in conjunction with severe physical side effects.

Psychiatric and Developmental Effects of Isotretinoin (Retinoid) Treatment for Acne Vulgaris

BACKGROUND

An association between isotretinoin (13-cis-retinoic acid, sold under trade names including Accutane [Hoffmann-La Roche Inc, Basel, Switzerland]) and birth defects, depression, and suicide is well documented but controversial. A link to psychosis and exacerbation of bipolar symptoms is less extensively addressed in the literature.

OBJECTIVE

Given recent conceptualization of psychotic disorders as neurodevelopmental, and current interest in possible shared etiology of different neurodevelopmental disorders such as psychosis, autism, and intellectual disability, this review concurrently examines the literature on developmental (primarily teratogenic) and psychiatric side effects of isotretinoin exposure. The goal of concurrent review is to identify shared mechanisms in the literature that may inform future efforts to clarify the neurocognitive and psychiatric effects of isotretinoin exposure at different developmental stages or given different genetic backgrounds.

METHODS

Literature was obtained by PubMed search for the term isotretinoin in combination with each of the terms psychosis, psychiatric, and teratogenic. Resulting articles met inclusion criteria for review if they addressed psychiatric side effects of isotretinoin treatment or the neurobehavioral teratology of isotretinoin.

RESULTS

The association of isotretinoin exposure with prenatal developmental toxicity is well established. Although numerous reports also link isotretinoin treatment with psychiatric side effects, this association remains controversial.

CONCLUSIONS

The extent to which isotretinoin influences pediatric and adult development and cognition, and whether and why certain individuals may be susceptible to psychiatric side effects, remains to be clarified. Curr Ther Res Clin Exp. 2019; 80:XXX-XXX).

Approaches to limit systemic antibiotic use in acne: Systemic alternatives, emerging topical therapies, dietary modification, and laser and light-based treatments

Acne is one of the most common diseases worldwide and affects ∼50 million individuals in the United States. Oral antibiotics are the most common systemic agent prescribed for the treatment of acne. However, their use might be associated with a variety of adverse outcomes including bacterial resistance and disruption of the microbiome. As a result, multiple treatment guidelines call for limiting the use of oral antibiotics in the treatment of acne, although actual prescribing often does not follow these guidelines. In this review, the rationale for concerns regarding the use of oral antibiotics for the management of acne is reviewed. In addition, we will discuss our approach to complying with the intent of the guidelines, with a focus on novel topical agents, dietary modification, laser and light-based modalities, and systemic medications, such as spironolactone, combined oral contraceptives, and oral isotretinoin.

Gulf War Illness: Unifying Hypothesis for a Continuing Health Problem

An estimated 25%⁻32% of veterans of the 1991 Gulf War continue to experience multiple unexplained health problems known as Gulf War Illness (GWI). GWI encompasses chronic pain, musculoskeletal weakness, headache, fatigue, cognitive deficits, alterations in mood, and numerous multi-system complaints. Most potential exposures implicated in GWI were not well documented but included varying levels of several neurotoxicants as well as the anticholinergic drug pyridostigmine bromide (PB), which was routinely taken as prophylaxis against the nerve agent soman. While some veterans also took chloroquine as an antimalarial agent, the literature suggests an association between receipt of multiple vaccinations prior to or during the conflict (perhaps combined with other exposures), and GWI. In-theater exposures may account for any single individual veteran's ill health but many veterans of the same era who were not deployed overseas also suffer the same or similar symptoms. The features of GWI also overlap with those of fibromyalgia, chronic fatigue syndrome and multiple chemical sensitivity, in all of which liver dysfunction has been documented, suggesting a unifying hypothesis. It is proposed that multiple vaccinations, with concurrent or subsequent exposure to PB or additional chemical insults of a liver-damaging nature, plausibly explain the pathogenesis and the observed chronicity of GWI. The suggested mechanism for GWI is thus a chemically-induced impaired liver function, with the spillage of stored vitamin A compounds ("retinoids") into the circulation in toxic concentrations, resulting in an endogenous chronic form of hypervitaminosis A. Implications of the hypothesis are briefly reviewed.

Mitochondrial Agents for Bipolar Disorder

Background

Bipolar disorder is a chronic and often debilitating illness. Current treatment options (both pharmaco- and psychotherapy) have shown efficacy, but for many leave a shortfall in recovery. Advances in the understanding of the pathophysiology of bipolar disorder suggest that interventions that target mitochondrial dysfunction may provide a therapeutic benefit.

Methods

This review explores the current and growing theoretical rationale as well as existing preclinical and clinical data for those therapies aiming to target the mitochondrion in bipolar disorder. A Clinicaltrials.gov and ANZCTR search was conducted for complete and ongoing trials on mitochondrial agents used in psychiatric disorders. A PubMed search was also conducted for literature published between January 1981 and July 2017. Systematic reviews, randomized controlled trials, observational studies, case series, and animal studies with an emphasis on agents affecting mitochondrial function and its role in bipolar disorder were included. The search was augmented by manually searching the references of key papers and related literature. The results were presented as a narrative review.

Results

Mitochondrial agents offer new horizons in mood disorder treatment. While some negative effects have been reported, most compounds are overall well tolerated and have generally benign side-effect profiles.

Conclusions

The study of neuroinflammation, neurodegeneration, and mitochondrial function has contributed the understanding of bipolar disorder's pathophysiology. Agents targeting these pathways could be a potential therapeutic strategy. Future directions include identification of novel candidate mitochondrial modulators as well as rigorous and well-powered clinical trials.

Relationship between Vitamin Intake and Depressive Symptoms in Elderly Japanese Individuals: Differences with Gender and Body Mass Index

Only a few studies have focused on the relationship between vitamin intake and depressive symptoms in Japanese individuals. This cross-sectional study investigated the relationship between vitamin intake and depressive symptoms in 1634 elderly Japanese individuals (65 years and older). The consumption of fifteen vitamins including retinol, a retinol equivalent, beta-carotene equivalent, vitamin D, alpha-tocopherol, vitamin K, vitamin group B, vitamin C, and cryptoxanthine was analyzed using a brief-type self-administered diet history questionnaire (BDHQ). The short version of the Geriatric Depression Scale (GDS) was used to assess depressive symptoms. The prevalence of participants with depressive symptoms was 26.7%. The consumption of all vitamins, except for retinol and vitamin D, was lower among depressed than non-depressed participants. The consumption of vitamins was significantly less in female and overweight participants with depressive symptoms than in elderly participants without depressive symptoms. After adjustments for potential confounders, none of the fifteen vitamins were correlated with depressive symptoms in male or underweight participants. Associations between vitamin deficiencies and depressive symptoms were observed in female and overweight elderly participants. Our findings demonstrated a relationship between vitamin intake and depressive symptoms.

Association of Isotretinoin With Depression and Suicide: A Review of Current Literature

Acne vulgaris, a condition that can affect people at any age, is the most common cause of referral to a dermatologist. Isotretinoin (ITT) is the most effective treatment available, but serious adverse effects, including a possible association with depression and suicide, limit its use. We review the current literature regarding the association of ITT with depression and suicide. Case reports and database studies show a clear association, and this association is biologically plausible. Although prospective studies have opposite results, limitations make them unsuitable to identify a subgroup of patients who may be at risk of developing depression or suicidal ideation with ITT. Overall, it seems some people might be at risk, particularly those with a personal or family history of mental disorder, but further studies are needed to identify those patients who would benefit from an early referral to a mental health professional when ITT is initiated. Currently, no conclusions can be drawn, and it seems appropriate to regularly screen all patients on ITT for depressive symptoms and suicidal ideation and promptly refer them to a mental health professional if any are found.

Psychiatric disorders, acne and systemic retinoids: comparison of risks

BACKGROUND

The link between isotretinoin, treatment of a severe form of acne, and psychiatric disorders remains controversial, as acne itself could explain the occurrence of psychiatric disorders. This study aims at assessing the disproportionality of psychiatric adverse events reported with isotretinoin in the French National PharmacoVigilance Database, compared with other systemic acne treatments and systemic retinoids.

MATERIALS AND METHODS

Data were extracted from the French National PharmacoVigilance Database for systemic acne treatments, systemic retinoids and drugs used as comparators. Each report was subjected to double-blind analysis by two psychiatric experts. A disproportionality analysis was performed, calculating the number of psychiatric ADRs divided by the total number of notifications for each drug of interest.

RESULTS

Concerning acne systemic treatments: all 71 reports of severe psychiatric disorders involved isotretinoin, the highest proportion of mild/moderate psychiatric adverse events was reported with isotretinoin (14.1%). Among systemic retinoids, the highest proportion of severe and mild/moderate psychiatric events occurred with isotretinoin and alitretinoin.

CONCLUSION

Our study raises the hypothesis that psychiatric disorders associated with isotretinoin are related to a class effect of retinoids, as a signal emerges for alitretinoin. Complementary studies are necessary to estimate the risk and further determine at-risk populations.

Drug-induced panic attacks: Analysis of cases registered in the French pharmacovigilance database

BACKGROUND

The potential role of drugs in the onset of panic attacks (PAs) is poorly understood.

AIM

The objective of our study was to characterize drug-induced PAs.

METHOD

We performed an analysis of PAs registered in the French pharmacovigilance database between 01/01/1985 and 05/11/2014.

RESULTS

Among the 163 recorded cases, 136 (83.4%) were directly related to drugs, mainly antidepressants (11.3%, mainly serotonin reuptake inhibitors), mefloquine (7.2%), isotretinoin (5.2%), rimonabant (3.6%) and corticosteroids (4.7%). PAs are labelled in the Summary of Product Characteristics (SmPC) for a minority (8.6%) of these drugs. In 31.4% of these cases, withdrawal of the suspected drug was performed more than a week after the onset of PAs. PAs could also be secondary to another adverse drug reaction (ADR; n = 14, 8.6%), mainly an allergy to antineoplastic or immunomodulating agents. In 13 cases (8.0%), PAs occurred during a drug-withdrawal syndrome, mainly after benzodiazepines or opioids. Most cases (73%) involved patients without any previous psychiatric disorder.

CONCLUSION

This is the first pharmacoepidemiological study about iatrogenic PAs. Beside antidepressants, the most often encountered drugs are not indicated for psychiatric diseases. This study also reveals that iatrogenic PAs mostly occur in patients without any psychiatric medical history and that PAs can be triggered by another ADR. Lastly, the many cases with delayed management underline the need to raise awareness of this relatively unknown ADR among physicians, especially since PAs are generally not labelled in SmPCs of the suspected drugs.

Animal models to improve our understanding and treatment of suicidal behavior

Worldwide, suicide is a leading cause of death. Although a sizable proportion of deaths by suicide may be preventable, it is well documented that despite major governmental and international investments in research, education and clinical practice suicide rates have not diminished and are even increasing among several at-risk populations. Although nonhuman animals do not engage in suicidal behavior amenable to translational studies, we argue that animal model systems are necessary to investigate candidate endophenotypes of suicidal behavior and the neurobiology underlying these endophenotypes. Animal models are similarly a critical resource to help delineate treatment targets and pharmacological means to improve our ability to manage the risk of suicide. In particular, certain pathophysiological pathways to suicidal behavior, including stress and hypothalamic-pituitary-adrenal axis dysfunction, neurotransmitter system abnormalities, endocrine and neuroimmune changes, aggression, impulsivity and decision-making deficits, as well as the role of critical interactions between genetic and epigenetic factors, development and environmental risk factors can be modeled in laboratory animals. We broadly describe human biological findings, as well as protective effects of medications such as lithium, clozapine, and ketamine associated with modifying risk of engaging in suicidal behavior that are readily translatable to animal models. Endophenotypes of suicidal behavior, studied in animal models, are further useful for moving observed associations with harmful environmental factors (for example, childhood adversity, mechanical trauma aeroallergens, pathogens, inflammation triggers) from association to causation, and developing preventative strategies. Further study in animals will contribute to a more informed, comprehensive, accelerated and ultimately impactful suicide research portfolio.

Congenital anomalies following use of isotretinoin: Emphasis on its legal aspects

We described a neonate with severe and multiple abnormalities following use of isotretinoin, in spite of the mother's previous knowledge of drug complications. Initial physical examination after delivery showed congenital absence of both eyes and both auricles as well as anal atresia and a cleft palate. Due to severe respiratory distress and atresia of the anus, the neonate was admitted to a neonatal intensive care unit and underwent reconstructive surgery. The drug should not have been used during pregnancy. Using this drug within pregnancy with awareness of its side effects may have legal consequences.

New Insights Into the Roles of Retinoic Acid Signaling in Nervous System Development and the Establishment of Neurotransmitter Systems

Secreted chiefly from the underlying mesoderm, the morphogen retinoic acid (RA) is well known to contribute to the specification, patterning, and differentiation of neural progenitors in the developing vertebrate nervous system. Furthermore, RA influences the subtype identity and neurotransmitter phenotype of subsets of maturing neurons, although relatively little is known about how these functions are mediated. This review provides a comprehensive overview of the roles played by RA signaling during the formation of the central and peripheral nervous systems of vertebrates and highlights its effects on the differentiation of several neurotransmitter systems. In addition, the evolutionary history of the RA signaling system is discussed, revealing both conserved properties and alternate modes of RA action. It is proposed that comparative approaches should be employed systematically to expand our knowledge of the context-dependent cellular mechanisms controlled by the multifunctional signaling molecule RA.

Neurological and Neuropsychiatric Adverse Effects of Dermatologic Medications

Severe, recalcitrant dermatologic conditions often require systemic treatment. Although efficacious, these medications have been associated with wide-ranging adverse reactions. Some are reversible, predictable, and either dose-dependent or treatment length-dependent, while others are unpredictable, irreversible, and potentially fatal. This review examines the neuropsychiatric adverse effects associated with US FDA-approved medications for treatment of the following dermatologic pathologies that typically require systemic therapy: autoimmune dermatoses, acne, psoriasis, and melanoma. A search of the literature was performed, with adverse effects ranging from mild headaches and neuropathy to severe encephalopathies. The medications associated with the most serious reactions were those used to treat psoriasis, especially the older non-biologic medications such as cyclosporine A and methotrexate. Given the importance of these systemic dermatologic therapies in treating severe, recalcitrant conditions, and the wide variety of potentially serious neuropsychiatric adverse effects of these medications, neurologists, psychiatrists, dermatologists, oncologists, and primary care providers must be aware of the potential for these neuropsychiatric adverse reactions to allow for appropriate counseling, management, and medication withdrawal.

Inhibition of brain retinoic acid catabolism: a mechanism for minocycline's pleiotropic actions?

OBJECTIVES

Minocycline is a tetracycline antibiotic increasingly recognized in psychiatry for its pleiotropic anti-inflammatory and neuroprotective potential. While underlying mechanisms are still incompletely understood, several lines of evidence suggest a relevant functional overlap with retinoic acid (RA), a highly potent small molecule exhibiting a great variety of anti-inflammatory and neuroprotective properties in the adult central nervous system (CNS). RA homeostasis in the adult CNS is tightly controlled through local RA synthesis and cytochrome P450 (CYP450)-mediated inactivation of RA. Here, we hypothesized that minocycline may directly affect RA homeostasis in the CNS via altering local RA degradation.

METHODS

We used in vitro RA metabolism assays with metabolically competent synaptosomal preparations from murine brain and human SH-SY5Y neuronal cells as well as viable human SH-SY5Y neuroblastoma cell cultures.

RESULTS

We revealed that minocycline potently blocks RA degradation as measured by reversed-phase high-performance liquid chromatography and in a viable RA reporter cell line, even at low micromolar levels of minocycline.

CONCLUSIONS

Our findings provide evidence for enhanced RA signalling to be involved in minocycline's pleiotropic mode of action in the CNS. This novel mode of action of minocycline may help in developing more specific and effective strategies in the treatment of neuroinflammatory or neurodegenerative disorders.

Affective disorders as potential complication of anti-acne treatment with isotretinoin: A case series

OBJECTIVE

To analyse cases of 9 patients (18-27 yo) who were consequently admitted to our department and treated with affective disorders (AD) while undergoing isotretinoin (INN) therapy.

METHODS

A semi-structured questionnaire designed by the authors was used to analyse many variables related to demographic characteristics, dermatologic and psychiatrics symptoms, AD course and treatment, family history of mental disorders, building on medical histories of patients and their families, and available medical records.

RESULTS

Patients were diagnosed (DSM-IV-TR) with: a major depressive episode (4 patients), a recurrent major depressive episode (3), a bipolar mixed episode (1), and rapid cycling bipolar I disorder (1). The mean time from the first use of INN to: I. the onset of mental disorders was approximately 2 months (1-6 months), II. a visit with a psychiatrist was about 12 months (1-38 months). The predictors of occurrence of AD included a family history of AD and a prior episode of mental disorders. The onset of AD was in most cases preceded by prodromal symptoms such as headaches, sleep disorders, fatigue, drowsiness, or general weakness. Five patients reported suicidal ideation, four patients showed suicidal tendencies, and two persons attempted to commit suicide during the treatment.

CONCLUSIONS

Psychiatrists should pay special attention to isotretinoin as a drug that may trigger episodes of AD, particularly in patients with a family history of AD or prior episodes of mental disorders. Isotretinoin therapy of patients with acne and a family history of AD or prior episodes of mental disorders requires special care and, if symptoms of depression develop or worsen during the INN treatment, collaboration between a dermatologist and a psychiatrist is needed.

The effect of abscisic acid chronic treatment on neuroinflammatory markers and memory in a rat model of high-fat diet induced neuroinflammation

Background

Western diet and lifestyle are associated with overweight, obesity, and type 2 diabetes, which, in turn, are correlated with neuroinflammation processes. Exercise and a healthy diet are important in the prevention of these disorders. However, molecules inhibiting neuroinflammation might also be efficacious in the prevention and/or treatment of neurological disorders of inflammatory etiology. The abscisic acid (ABA) is a phytohormone involved in hydric-stress responses. This compound is not only found in plants but also in other organisms, including mammals. In rodents, ABA can play a beneficial role in the regulation of peripheral immune response and insulin action. Thus, we hypothesized that chronic ABA administration might exert a protective effect in a model of neuroinflammation induced by high-fat diet (HFD).

Methods

Male Wistar rats were fed with standard diet or HFD with or without ABA in the drinking water for 12 weeks. Glucose tolerance test and behavioral paradigms were performed to evaluate the peripheral and central effects of treatments. One-Way ANOVA was performed analyzed statistical differences between groups.

Results

The HFD induced insulin resistance peripherally and increased the levels of proinflammatory markers in in the brain. We observed that ABA restored glucose tolerance in HFD-fed rats, as expected. In addition, chronic ABA treatment rescued cognitive performance in these animals, while not affecting control diet fed animals. Moreover, it counteracted the changes induced by HFD in the hypothalamus; microglia activations and TNFα mRNA levels.

Conclusion

These results suggest that ABA might become a new therapeutic molecule improving the neuroinflammatory status and insulin resistance.

Developmental Neurotoxic Effects of Percutaneous Drug Delivery: Behavior and Neurochemical Studies in C57BL/6 Mice

Dermatosis often as a chronic disease requires effective long-term treatment; a comprehensive evaluation of mental health of dermatology drug does not receive enough attention. An interaction between dermatology and psychiatry has been increasingly described. Substantial evidence has accumulated that psychological stress can be associated with pigmentation, endocrine and immune systems in skin to create the optimal responses against pathogens and other physicochemical stressors to maintain or restore internal homeostasis. Additionally, given the common ectodermal origin shared by the brain and skin, we are interested in assessing how disruption of skin systems (pigmentary, endocrine and immune systems) may play a key role in brain functions. Thus, we selected three drugs (hydroquinone, isotretinoin, tacrolimus) with percutaneous excessive delivery to respectively intervene in these systems and then evaluate the potential neurotoxic effects. Firstly, C57BL/6 mice were administrated a dermal dose of hydroquinone cream, isotretinoin gel or tacrolimus ointment (2%, 0.05%, 0.1%, respectively, 5 times of the clinical dose). Behavioral testing was performed and levels of proteins were measured in the hippocampus. It was found that mice treated with isotretinoin or tacrolimus, presented a lower activity in open-field test and obvious depressive-like behavior in tail suspension test. Besides, they damaged cytoarchitecture, reduced the level of 5-HT-5-HT1A/1B system and increased the expression of apoptosis-related proteins in the hippocampus. To enable sensitive monitoring the dose-response characteristics of the consecutive neurobehavioral disorders, mice received gradient concentrations of hydroquinone (2%, 4%, 6%). Subsequently, hydroquinone induced behavioral disorders and hippocampal dysfunction in a dose-dependent response. When doses were high as 6% which was 3 times higher than 2% dose, then 100% of mice exhibited depressive-like behavior. Certainly, 6% hydroquinone exposure elicited the most serious impairment of hippocampal structure and survival. The fact that higher doses of hydroquinone are associated with a greater risk of depression is further indication that hydroquinone is responsible for the development of depression. These above data demonstrated that chronic administration of different dermatology drugs contributed into common mental distress. This surprising discovery of chemical stressors stimulating the hippocampal dysfunction, paves the way for exciting areas of study on the cross-talk between the skin and the brain, as well as is suggesting how to develop effective and safe usage of dermatological drugs in daily practice.

Risk of self-harm and nonfatal suicide attempts, and completed suicide in patients with psoriasis: a population-based cohort study

BACKGROUND

Psoriasis is a common inflammatory skin disease, and inflammation may affect suicidal behaviour. Current data on the incidence and risk of suicidal behaviour in patients with psoriasis are scarce.

OBJECTIVES

We investigated the association between psoriasis and the risk of self-harm and suicide attempts and suicides.

METHODS

All Danish patients aged ≥ 18 years with mild or severe psoriasis (cases) from 1 January 1997 to 31 December 2011 were matched on age, sex and calendar time 1 : 5 with healthy controls. The outcome was a diagnosis of self-harm or a nonfatal suicide attempt, or completed suicide. Incidence rates per 10 000 person-years were calculated, and incidence rate ratios (IRRs) and confidence intervals (CIs) were estimated by Poisson regression models.

RESULTS

The study cohort comprised 408 663 individuals, including 57 502 and 11 009 patients with mild and severe psoriasis, respectively. In total 280 cases of self-harm or suicide attempts, and 574 suicides occurred during follow-up. There was no increased risk of self-harm or suicide attempts in patients with mild psoriasis (IRR 1·01, 95% CI 0·17-2·01), but this risk was significantly increased in severe psoriasis (IRR 1·69, 95% CI 1·00-2·84). There was no increased risk of suicides in mild (IRR 1·05, 95% CI 0·84-1·32) or severe psoriasis (IRR 0·78, 95% CI 0·45-1·36). Similar results were found when suicides were confirmed by official forensic investigations, and when psoriasis was compared with atopic dermatitis.

CONCLUSIONS

We found limited evidence to suggest an increased risk of self-harm and nonfatal suicide attempts in patients with psoriasis. Importantly, after adjustment for psoriatic arthritis this risk was no longer significantly increased. The risk of completed suicide was also not increased, regardless of psoriasis severity.

Translational research on cognitive and behavioural disorders in neurological and psychiatric diseases

The important medical and social burden of nervous system diseases contrasts with the currently limited therapeutic armamentarium and with the difficulty encountered in developing new therapeutic options. These failures can be explained by the conjunction of various phenomena related to the limitations of animal models, the narrow focus of research on precise pathophysiological mechanisms, and methodological issues in clinical trials. It is perhaps the paradigm itself of the way research is conducted that may be the real reason for our incapacity to find effective strategies. The purpose of this workshop was to define overall lines of research that could lead to the development of effective novel therapeutic solutions. Research has long focused on diseases per se rather than on cognitive and behavioural dimensions common to several diseases. Their expression is often partial and variable, but can today be well-characterised using neurophysiological or imaging methods. This dimensional or syndromic vision should enable a new insight to the question, taking a transnosographic approach to re-position research and to propose: translational models exploring the same functions in animal models and in humans; identification of homogeneous groups of patients defined according to the clinical, anatomico-functional and molecular characteristics; and preclinical and clinical developments enriched by the use of cognitive-behavioural, biological neurological, and imaging biomarkers. For this mutation to be successful, it must be accompanied by synchronised action from the public authorities and by ad hoc measures from the regulatory agencies.

Isotretinoin was not associated with depression or anxiety: A twelve-week study

AIM: To investigate the frequency and severity of depression and/or anxiety in isotretinoin (ITT)-treated subjects and in a non-ITT control group.

METHODS: Sixty consecutively-admitted non-psychiatric outpatients with acne were assigned to either ITT at a fixed dose of 30 mg/d (n = 36) or “other treatment” group (OT; n = 24). The Zung depression or anxiety scales (with cut-off points), two locally developed scales for depression (GeDepr) and anxiety (Ansilet) (without cut-off points) and clinical global impression scales of acne severity were administered at baseline and at weeks 6 and 12 of treatment. Data was analyzed with the chi-squared test and covariance analysis.

RESULTS: Gender distribution, age, marital status and education level did not differ between both treatment groups. The frequency of depression, as defined by the Zung scale cut-off points was similar in the ITT and in the non-ITT groups: Weeks 6 and 12: 8.3% in both groups, P = 0.9. The frequency of anxiety was similar in the groups as well: Week 6: ITT = 8.3%; OT = 0.0%, P > 0.05; week 12: ITT = 11.1%, OT = 4.2%, P > 0.05. The scores in both scales’ sets did not differ between the treatment groups at any evaluation time point (P > 0.05). Five ITT-treated subjects (13.8%) and two from the OT-treated group (8.3%) developed clinically significant anxiety and/or depression during treatment (P > 0.05).

CONCLUSION: Our study confirms the safety of ITT regarding psychological side effects in regular dermatological patients. Susceptible subjects may exist but their identification requires additional strategies.

Chronic retinoic acid treatment suppresses adult hippocampal neurogenesis, in close correlation with depressive-like behavior

Clinical studies have highlighted an association between retinoid treatment and depressive symptoms. As we had shown before that chronic application of all-trans retinoic acid (RA) potently activated the hypothalamus-pituitary-adrenal (HPA) stress axis, we here questioned whether RA also induced changes in adult hippocampal neurogenesis, a form of structural plasticity sensitive to stress and implicated in aspects of depression and hippocampal function. RA was applied intracerebroventricularly (i.c.v.) to adult rats for 19 days after which animals were subjected to tests for depressive-like behavior (sucrose preference) and spatial learning and memory (water maze) performance. On day 27, adult hippocampal neurogenesis and astrogliosis was quantified using BrdU (newborn cell survival), PCNA (proliferation), doublecortin (DCX; neuronal differentiation), and GFAP (astrocytes) as markers. RA was found to increase retinoic acid receptor-α (RAR-α) protein expression in the hippocampus, suggesting an activation of RA-induced signaling mechanisms. RA further potently suppressed cell proliferation, newborn cell survival as well as neurogenesis, but not astrogliosis. These structural plasticity changes were significantly correlated with scores for anhedonia, a core symptom of depression, but not with water maze performance. Our results suggest that RA-induced impairments in hippocampal neurogenesis correlate with depression-like symptoms but not with spatial learning and memory in this design. Thus, manipulations aimed to enhance neurogenesis may help ameliorate emotional aspects of RA-associated mood disorders. © 2016 Wiley Periodicals, Inc.

Sensitivity during the forced swim test is a key factor in evaluating the antidepressant effects of abscisic acid in mice

Abscisic acid (ABA), a crucial phytohormone, is distributed in the brains of mammals and has been shown to have antidepressant effects in the chronic unpredictable mild stress test. The forced swim test (FST) is another animal model that can be used to assess antidepressant-like behavior in rodents. Here, we report that the antidepressant effects of ABA are associated with sensitivities to the FST in mice. Based on mean immobility in the 5-min forced swim pre-test, ICR mice were divided into short immobility mice (SIM) and long immobility mice (LIM) substrains. FST was carried out 8 days after drug administration. Learned helplessness, as shown by increased immobility, was only observed in SIM substrain and could be prevented by an 8-day ABA treatment. Our results show that ABA has antidepressant effects in SIM substrain and suggest that mice with learned helplessness might be more suitable for screening potential antidepressant drugs.

Recognizing off-target drug effects in the gut and brain: revisiting isotretinoin and depression

Clinicians often face complex decisions regarding off-target drug effects, both in diagnosis and treatment. A key component in the formulation of the correct diagnosis is the temporal relationship between drug introduction and adverse effect. The sentinel injury may target the gut and brain. The description of the complaint may vary among providers. Modeling Information visualization for clinicians in real time will require the integration of time-stamped data with organ-specific complaints.

Inter-relationships between isotretinoin treatment and psychiatric disorders: Depression, bipolar disorder, anxiety, psychosis and suicide risks

Isotretinoin (Accutane) is a treatment for severe acne that is resistant to other forms of treatment, including antibiotics and topical treatments. The prescription of this drug has been controversial ever since its initial marketing in 1982. It is the only non-psychotropic drug in the Food and Drug Administration top 10 drugs found to be associated with depression. Recently, Bremner et al published an extensive review (until 2010) of the evidence for the association of retinoic acid (RA) with depression and suicide. Some patients who are admitted in psychiatric hospitals report a history of present or past treatment with isotretinoin. Then, the imputability of the molecule in the occurrence of disorders represents necessarily an important question for both professionals and their patients. This paper aims to specify the links between the drug and specific psychiatric disorders. A review of the literature related to isotretinoin, RA, vitamin A, depression, suicide, anxiety, bipolar disorder, psychosis, schizophrenia was performed. Many studies demonstrated an increased risk of depression, attempted suicide and suicide following isotretinoin treatment. However, isotretinoin may have an antidepressant impact, according to some dermatological papers. They consider treating acne with this efficient treatment could improve self-image and make the patient feel better. Several studies showed that patients with bipolar disorder had an increased risk for a clinical exacerbation of symptoms undergoing treatment with isotretinoin. A few studies also seem to suggest a possible link between isotretinoin and psychosis. Nonetheless, studies point out a link between retinoid dysregulation and schizophrenia through modulation of dopamine receptors. From this review, we propose guidelines for isotretinoin prescription to healthcare professionals.

Direct inhibition of retinoic acid catabolism by fluoxetine

Recent evidence from animal and human studies suggests neuroprotective effects of the SSRI fluoxetine, e.g., in the aftermath of stroke. The underlying molecular mechanisms remain to be fully defined. Because of its effects on the cytochrome P450 system (CYP450), we hypothesized that neuroprotection by fluoxetine is related to altered metabolism of retinoic acid (RA), whose CYP450-mediated degradation in brain tissue constitutes an important step in the regulation of its site-specific auto- and paracrine actions. Using traditional pharmacological in vitro assays, the effects of fluoxetine on RA degradation were probed in crude synaptosomes from rat brain and human-derived SH-SY5Y cells, and in cultures of neuron-like SH-SY5Y cells. Furthermore, retinoid-dependent effects of fluoxetine on neuronal survival following glutamate exposure were investigated in rat primary neurons cells using specific retinoid receptor antagonists. Experiments revealed dose-dependent inhibition of synaptosomal RA degradation by fluoxetine along with dose-dependent increases in RA levels in cell cultures. Furthermore, fluoxetine's neuroprotective effects against glutamate excitotoxicity in rat primary neurons were demonstrated to partially depend on RA signaling. Taken together, these findings demonstrate for the first time that the potent, pleiotropic antidepressant fluoxetine directly interacts with RA homeostasis in brain tissue, thereby exerting its neuroprotective effects.