Cognitive complaints in multiple sclerosis:Relationship with objective cognitive functioning, mood, fatigue, and coping style

Introduction: Both self-reported cognitive complaints and objectively measured cognitive impairments are common in multiple sclerosis (MS). Whereas some studies demonstrate that cognitive complaints are associated with a decline in cognitive functioning, others state that cognitive complaints may be better explained by other factors, such as mood and fatigue. Further knowledge on this topic is of relevance in order to decide on appropriate treatment options for PwMS with cognitive complaints in clinical care. <br/>Objectives: To examine associations between cognitive complaints and cognitive functioning, as well as associations of both cognitive complaints and cognitive functioning with anxiety, depression and fatigue in PwMS. <br/>Methods: PwMS (n=87) and healthy controls (HCs; n=82) were included, aged 18-70 (M = 51.4, SD = 11.8 and M = 51.7, SD = 10.6, respectively), well-matched on age, gender, and education. Assessment consisted of neuropsychological tests for memory, processing speed/attention, and executive functioning, as well as questionnaires on cognitive complaints, anxiety, depression, and fatigue. <br/>Results: PwMS showed significantly lower performance on neuropsychological tests for memory, processing speed/attention, and executive functioning compared to HCs. In the group of PwMS, lower performance on one test for processing speed/attention was associated with higher levels of cognitive complaints, r = .36, p &lt; .001. No further associations were found between cognitive complaints and cognitive functioning. Cognitive functioning was not related to anxiety, depression, mental fatigue, or physical fatigue in PwMS. Cognitive complaints, however, did relate to higher levels of self-reported anxiety, r = .33, p &lt; .01, depression, r = .47, p &lt; .001, mental fatigue, r = .59, p &lt; .001 and physical fatigue, r = .40, p &lt; .001. <br/>Conclusion: Although PwMS presented with lower cognitive performance on several neuropsychological tests compared to HCs, little association was found between cognitive functioning and cognitive complaints in PwMS. Cognitive complaints did moderately to strongly relate to anxiety, depression, and fatigue, substantiating the suggestion that PwMS who report cognitive complaints might not necessarily be the ones cognitively impaired. There may consequently be a group of PwMS with cognitive impairments going unnoticed in clinical practice. This underscores the importance of the role of the neuropsychologist, allowing accurate identification of cognitive impairments, complaints and its underlying factors, in PwMS.<br/>