ALS/Motor Neuron Disease May Increase Anxiety and Depression

A large-sample study investigating a possible association between anxiety-depressive disorders in amyotrophic lateral sclerosis/motor neuron disease (ALS/MND) in the People’s Republic of China was recently conducted. The study, entitled “Frequency and risk factor analysis of cognitive and anxiety-depressive disorders in patients with amyotrophic lateral sclerosis/motor neuron disease,” was published in Neuropsychiatric Disease and Treatment journal.

Motor neuron diseases (MNDs) are a group of neurodegenerative disorders that involve death of motor neurons of the central nervous system. Amyotrophic lateral sclerosis (ALS, or classical MND) is frequently employed interchangeably with MND. Deterioration and loss of motor neurons in MND/ALS patients leads to progressive wasting of muscle tissues, which in turn results in difficulties in speaking, swallowing, and eventually breathing.

Some studies have suggested that anxiety is a common manifestation at the diagnostic stage of patients with ALS. Once diagnosed, the majority of MND/ALS patients present anxiety-depressive disorders and even suicidal reflections. These symptoms negatively affect their quality of life, and higher depressive scores have been associated with accelerated disease progression.

In Western studies, the link between ALS and depression varies between studies and remains controversial. A study from South Korean researchers illustrated a link between reduced physical function and depressive symptoms. However, no large-sample studies on a possible association between anxiety-depressive disorders in ALS/MND had been conducted.

In this study, the researchers assessed the frequency and characteristics of cognitive impairments and anxiety-depression in Chinese patients with MND/ALS, evaluating a total of 100 ALS/MND patients treated between January 2009 and April 2010 and 100 healthy controls. The patients were screened according to particular criteria such as history of sedatives, psychotropic drugs, or presence of other diseases that may induce emotional expression of anxiety-depressive disorders, among others. They were then examined by means of various psychological test tools like Mini Mental State Examination (MMSE), Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale (SDS), and ALS Functional Rating Scale (ALSFRS).

The results suggested that when compared to controls, MND/ALS patients have extremely reduced MMSE. Within this group of patients, MMSE scores did not vary by sex or age, but higher education, shorter disease course, and a lower ALSFRS were associated with substantial MMSE scores. Also, MND/ALS patients depicted important mean SAS and SDS when compared to controls, a sign of increased anxiety and depression. Finally, very high SAS and SDS scores were correlated with female sex, higher education and important ALSFRS, but factors like age, occupation, diagnostic classification, disease duration, and disease awareness did not account for these scores.

Overall, these findings highlight the higher frequency of anxiety-depression symptoms in Chinese patients with ALS/MND. Factors like higher education, short course of disease, and lower ALSFRS were linked with stable cognitive function. On the other hand, female sex, higher education, and lower ALSFRS scores resulted in a substantial risk of anxiety and depression. The latter could be reduced with proper therapies and psychological interventions.