Similarities in genetic mental retardation and neuroteratogenic syndromes

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

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Isotretinoin teratogenicity well established; psychiatric effects documented, controversial

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Disturbed retinoid signaling implicated in isotretinoin teratogenic and psychiatric effects

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Effect of genetics on susceptibility to psychiatric side effects is possible, not yet known

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Postnatal neurocognitive effects of isotretinoin not yet established

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)

Hindbrain and cranial nerve dysmorphogenesis result from acute maternal ethanol administration

Acute exposure of mouse embryos to ethanol during stages of hindbrain segmentation results in excessive cell death in specific cell populations. This study details the ethanol-induced cell loss and defines the subsequent effects of this early insult on rhombomere and cranial nerve development. Ethanol at a teratogenic dosage (2.9 g/kg) or a comparable volume of vehicle was administered in each of two intraperitoneal injections to pregnant C57BL/6J mice on gestational day (GD) 8, 8 h, and GD 8, 12 h (defined hereafter as GD 8.5). Ethanol-exposed GD 9 embryos, visualized in three dimensions using laser scanning confocal microscopy of LysoTracker Red fluorescence or Nile blue sulphate vital staining, displayed excessive apoptosis in the rostral hindbrain, specifically within rhombomeres 1-3, as well as in cranial neural crest cells and ectodermal placodes. Comparably treated embryos examined on GD 10.5-11 illustrated a disproportionate reduction in the length of the rostral hindbrain. Examination of plastic histological sections of GD 9 embryos and via scanning electron microscopy on GD 10 revealed deficiencies in the hindbrain, with a phenotype including abnormal rhombomere segmentation and an extremely small fourth ventricular roofplate. Whole-mount antineurofilament immunohistochemistry on GD 10.5 and GD 11 illustrated a variety of cranial nerve abnormalities ranging from fused or absent ganglia to ectopic or disorganized fibers. In addition, a delay in the development of the glossopharyngeal (IX) nerve/ganglia complex was observed. These hindbrain and cranial nerve abnormalities are discussed in the context of the genesis of human alcohol-related birth defects and neurodevelopmental disorder.

Safety issues in isotretinoin therapy

Isotretinoin (Accutane, Roche Laboratories Inc, Nutley, NJ) is an important drug, not only for the treatment of severe acne, but also for other diagnoses and in chemoprevention settings. Because the use of isotretinoin is increasing, it is important for physicians to be aware of the adverse events, toxicities, and management issues related to its use. The most important issue is that of congenital defects, which has resulted in new pregnancy prevention policies and programs implemented by the manufacturer. A relatively new concern is that of depression associated with isotretinoin use, also resulting in new policies placed by the manufacturer and the FDA. The most common adverse effects observed during treatment are mucocutaneous and ocular in nature, but laboratory abnormalities and effects in the nervous, musculoskeletal, gastrointestinal, pulmonary, hematologic, and other systems are also described. Additionally, potential drug interactions, follow-up, and toxicity prevention measures are discussed.