In a recent study published in the journal PLOS ONE, a team of scientists from France investigated the association between depression, anxiety, endothelial function, and cognitive functions in young adults of both sexes.
Mental health disorders such as depression and anxiety are becoming more prevalent in society, and the frequency is thought to be higher among women than men.
Mental health disorders are also linked to deleterious physiological and cognitive changes, with longitudinal studies reporting an increasing risk of cardiovascular disease and cognitive impairments associated with emotional disorders in the later stages of life. However, the development of cognitive impairments due to emotional disorders remains poorly understood.
Recent studies have reported that individuals with depression and anxiety disorders have a higher risk of cardiovascular diseases, which is independent of traditional risk factors for cardiovascular disease. Furthermore, impaired cardiovascular function associated with emotional disorders is believed to mediate cognitive alterations.
Studies among older adults and adolescent females have shown that endothelial function, a marker for cardiovascular health, is altered in association with anxiety.
Other longitudinal studies have also indicated that cardiovascular disease among adults increases the risk of dementia and cognitive decline. However, the inter-relationships between emotional disorders, cardiovascular health, and cognitive impairments remain unclear.
About the study
In the present study, the team conducted an ancillary study to the Better Life by Nutrition During Adulthood (BELINDA) study and examined young adults of both sexes from the general population to determine the association between emotional disorders, endothelial function, and cognitive functions.
Based on existing evidence, they hypothesized that high levels of depression or anxiety would be linked to altered endothelial function and low cognitive scores.
The participants were young adults between the ages of 21 and 32, and individuals who were pregnant or breastfeeding, had been incarcerated, or were unable to provide informed consent were excluded from the study.
All participants underwent endothelial function measurements, neuropsychological assessments based on self-reported responses to questionnaires on depression and anxiety, and an evaluation of cognitive function.
Endothelial function was measured using peripheral pulse tonometry, where a plethysmographic device non-invasively measures the change in blood volume brought about by transient forearm ischemia. The pulse wave amplitude changes were used to calculate the reactive hyperemia index, which was then normalized against the contralateral arm to account for the systemic neurovegetative vasomotor effect.
Two validated, self-reported questionnaires — the State-Trait Anxiety Inventory and the Beck Depression Inventory-II — were used to assess emotional disorders. Cognitive function was evaluated using the Cambridge Neuropsychological Test Automated Battery, which consists of validated neurocognitive tests to measure visuospatial memory, visuospatial working memory, and sustained attention.
The sex of the participants was transformed into binary data, and linear correlation analyses were used to investigate the association between depression, anxiety, endothelial function, and cognitive abilities. The analyses were conducted for the study population on the whole and separately for each sex.
The results suggested that anxiety was linked to a low reactive hyperemia index across sexes, indicating that emotional disorders directly impacted endothelial function.
Furthermore, among females, depression scores were positively correlated to poor performance on visuospatial and working memory tasks. However, among men, high levels of depression or anxiety were negatively correlated with performance on the visuospatial memory tasks.
Furthermore, the association between reactive hyperemia index and cognitive function was insignificant, indicating that emotional disorders independently correlate to endothelial function and cognitive function.
The different associations based on sex between anxiety and depression and cognitive functions could be related to the differences between sexes in processing visuospatial memory. Additionally, the higher cognitive performance could also result from more anxious individuals overcompensating by being hyper-focused.
The anxiety questionnaire evaluated both state and trait anxieties, and it was found that in males, low endothelial function was linked to high-trait anxiety, but among women, poor endothelial function was linked to high state anxiety but not high trait anxiety.
While the results reported no significant correlations between depression scores and endothelial function, other studies have shown that autonomic impairments in cases of depression with concomitant anxiety have been linked to nervous system disturbances.
To summarize, the findings indicated that anxiety was independently linked to poor performance in cognitive tasks and low endothelial function.
Furthermore, the association between anxiety and cognitive impairments varied based on sex, with women with anxiety exhibiting lower performance on visuospatial memory tasks, but the converse is observed in men with anxiety. Depression scores did not have any significant correlations with endothelial function.
The overall results suggested that anxiety is negatively but independently associated with cardiovascular and cognitive functions among non-clinical populations of young adults. However, further research is required to understand the pathophysiological mechanisms of these associations.