Relationship Between OCD and Myasthenia Gravis
There is no established direct pathophysiological relationship between Obsessive-Compulsive Disorder (OCD) and Myasthenia Gravis (MG), but depression and anxiety disorders—not OCD—are the most common psychiatric comorbidities in MG patients.
Psychiatric Comorbidities in Myasthenia Gravis
The psychiatric landscape in MG is dominated by mood and anxiety disorders, not obsessive-compulsive symptoms:
Depression and anxiety are the primary psychiatric comorbidities found in MG patients, with higher incidence rates compared to both healthy controls and patients with other comparable chronic conditions 1, 2.
MG patients experience depressive symptoms including sad mood, anhedonia, fatigue, insomnia, and feelings of hopelessness, typically developing as comorbidity during the disease course 1.
Psychopathological disturbances in MG are often temporary and completely reversible after adequate somatic therapy, distinguishing them from primary psychiatric disorders 3.
Why OCD Is Not Linked to MG
The available evidence does not support any association between OCD and MG:
OCD is a distinct neuropsychiatric disorder mediated by cortico-striato-thalamo-cortical circuits, with specific brain pathology involving sensorimotor, cognitive, and affective processes 4, 5.
OCD has a lifetime prevalence of 2-3% in the general population and typically starts early in life (often before age 10 in males, during adolescence in females), with no evidence of increased prevalence in autoimmune or neuromuscular disorders 4.
The psychiatric manifestations in MG are reactive to the physical burden of the disease and psychosocial stressors (unemployment, disability, declining health), rather than representing primary obsessive-compulsive pathology 1, 2.
Clinical Implications for MG Patients
When evaluating psychiatric symptoms in MG patients, focus on:
Screen specifically for depression and anxiety, not OCD, as these are the documented psychiatric comorbidities requiring treatment 1.
Consider that depressive and anxiety symptoms have a negative impact on quality of life beyond motor symptoms in MG 1.
Recognize that psychopathological symptoms may be stress-dependent and fluctuate with MG disease severity, potentially being misdiagnosed as primary psychiatric disorders 3.
Treatment with SSRIs (such as sertraline 50 mg daily) and anxiolytics shows good response for comorbid depression and anxiety in MG patients 1.
Important Caveat
If a patient has both OCD and MG, these are coincidental conditions occurring at their expected population prevalence rates, not causally related. Treat each condition according to its respective evidence-based guidelines: serotonin reuptake inhibitors and cognitive-behavioral therapy with exposure and response prevention for OCD 4, 6, and standard immunosuppressive therapy for MG with appropriate psychiatric management of any comorbid mood or anxiety symptoms 1.