Interplay between anorexia nervosa, anxiety and myasthenia gravis in adolescence: a case report

Myasthenia Gravis (MG) is a chronic antibody-mediated autoimmune disorder affecting the neuromuscular junction and is increasingly recognized as a systemic condition with potential non-motor and psychiatric manifestations [1]. Psychiatric comorbidity, particularly anxiety and depressive symptoms, is common in MG and has been associated with increased disease burden, poorer quality of life and variability in symptom severity [2]. Emerging evidence supports a bidirectional interaction between psychological stress and immune function, mediated by neuroendocrine and inflammatory pathways [3]. However, the role of psychopharmacology in patients with MG remains insufficiently studied, particularly in pediatric populations, where both safety data and evidence-based guidance are limited.

We report a single observational case across pediatric, psychiatric and neurological settings, highlighting potential interactions between anxiety, anorexia nervosa and MG in an adolescent patient.

The case involves a 15-year-old girl initially evaluated by liaison psychology during a pediatric admission for MG. After discharge, she developed corticosteroid-induced weight gain, followed by the onset of Anorexia Nervosa and was subsequently referred to Child and Adolescent Psychiatry. Although neurological status remained initially stable, her clinical course was characterized by progressive dietary restriction, intense fear of weight gain, severe body image distortion, escalating anxiety and recurrent panic attacks. Symptoms progressively worsened, culminating in psychiatric hospitalization due to complete refusal of oral intake, with significant medical risk.

During inpatient treatment, Risperidone was initiated and titrated up to 2 mg/day, with additional as-needed dosing, targeting severe ruminative thinking and cognitive rigidity associated with body image distortion. Partial clinical improvement was observed, with gradual re-establishment of oral intake and nutritional stabilization, allowing discharge. However, clinically significant anxiety symptoms persisted after discharge and progressively became the dominant clinical feature, with ongoing functional impairment.

Over the course of follow-up, a relapse of MG symptoms was observed, associated with the marked increase in anxiety and psychological stress. Psychiatric comorbidity in MG has been described as potentially influencing disease course and symptom fluctuations [2,3]. This temporal association raised the hypothesis of stress-related modulation of autoimmune activity. Given persistent anxiety and panic symptoms, treatment with Sertraline was initiated and titrated to 50 mg/day. Following this intervention, progressive stabilization of both psychiatric and neurological status was observed over subsequent months.

This case supports a psychoneuroimmunological framework in which anxiety may act as a clinically relevant modulator of autoimmune disease activity. Stress-related immune mechanisms have been proposed as pathways linking psychological distress and autoimmune exacerbation [2,3]. Importantly, evidence regarding the safety and impact of psychopharmacological treatments in patients with MG remains limited, particularly in children and adolescents, and potential interactions between serotonergic agents and immune modulation are not fully understood.

An integrated multidisciplinary approach is essential in these cases as it may have meaningful implications for both mental health outcomes and the clinical course of autoimmune disease. Further research is needed to clarify psychoneuroimmunological mechanisms and to inform targeted therapeutic strategies in this underexplored clinical population.

References

Gilhus, N.E., 2019. Myasthenia gravis. Nat. Rev. Dis. Primers 5, 30.
Ybarra, M.I., et al., 2020. Psychiatric comorbidity in myasthenia gravis: a review. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC7425828/. [Accessed: 05 May 2026]
Messina, C., 2025. The overlooked side of myasthenia gravis: the non-motor manifestations—a comprehensive review. J Neurol 272, 764. https://doi.org/10.1007/s00415-025-13504-3.