Spectrum of optic neuromyelitis: psychiatric disorders and suicide risk

We read with great interest the detailed systematic review “Do patients diagnosed with a neurological disease present increased risk of suicide?” by Alejos et al.,¹ recently published in Neurología, which addresses the hypothesis that the prevalence of suicide is higher among patients with different neurological diseases, especially those of neurodegenerative origin.

The authors contribute evidence supporting the increased risk of suicide in patients with such neurological diseases as epilepsy, migraine, multiple sclerosis, Alzheimer disease, Huntington disease, and Parkinson’s disease. However, neuromyelitis optica spectrum disorders (NMOSD), which have been shown to be strongly associated with the risk of suicide in several communications,^2–5 were not included among the diseases analysed. We recently conducted a prospective study that found a surprisingly high rate of suicide attempts among patients with NMOSD. Six in every 20 patients with NMOSD (30% in our cohort) had attempted suicide at least once over the course of the disease. This rate was significantly higher than in healthy controls.³

We showed not only that patients with NMOSD presented more suicide attempts, but also that the risk of suicide itself was greater in this patient group. We believe that suicide should be considered a continuum, from the risk of suicide, including ideation, to planning and finally attempting suicide.

In our study, we detected current risk of suicide in 8 in every 20 patients with NMOSD. We would like to underscore the need to dedicate greater effort to identifying the risk of suicide at the time of diagnosis or of severe relapses with residual disability, since we found that most suicide attempts were made in specific situations over the course of NMOSD progression. However, we did not find a significant association between the risk of suicide and the classification of disability as measured by the Expanded Disability State Scale in our sample of patients with NMOSD.

Assessment of the risk of suicide is well developed in the Mini-International Neuropsychiatric Interview (MINI), a simple, semi-structured interview. We found that current risk of suicide, as measured with the MINI, was positively correlated with current depression, as measured with the Beck Depression Inventory (BDI), but was not always associated with major depressive disorder or another psychiatric diagnosis. Therefore, while suicidal tendencies seem not always to be related with a comorbid psychiatric condition, we believe that the BDI may be a useful tool for detecting depression and current risk of suicide in patients with NMOSD and probably other neurological conditions. The presence of psychiatric comorbidities and suicidal tendencies among patients with NMOSD has been assessed by other researchers, who have obtained similar results to our own.^1,3,4 Like the authors of the study,¹ we would like to highlight the need to evaluate suicidal tendencies in patients with neurological diseases, including NMOSD.