T T Saari1, I Hallikainen2, T Hintsa3, A M Koivisto4. 1. Department of Neurology, University of Eastern Finland, Kuopio, Finland; School of Educational Sciences and Psychology, University of Eastern Finland, Joensuu, Finland. Electronic address: toni.saari@uef.fi. 2. Department of Neurology, University of Eastern Finland, Kuopio, Finland. 3. School of Educational Sciences and Psychology, University of Eastern Finland, Joensuu, Finland. 4. Department of Neurology, University of Eastern Finland, Kuopio, Finland; Department of Neurology, Kuopio University Hospital, Kuopio, Finland; Department of Neurosciences, University of Helsinki, Helsinki, Finland; Department of Internal Medicine and Rehabilitation, Helsinki University Hospital, Helsinki, Finland.
Abstract
BACKGROUND: Affective symptoms in Alzheimer's disease (AD) can be rated with both informant- and self-ratings. Information from these two modalities may not converge. We estimated network structures of affective symptoms in AD with both rating modalities and assessed the longitudinal stability of the networks. METHODS: Network analyses combining self-rated and informant-rated affective symptoms were conducted in 3198 individuals with AD at two time points (mean follow-up 387 days), drawn from the NACC database. Self-rated symptoms were assessed by Geriatric Depression Scale, and informant-rated symptoms included depression, apathy and anxiety questions from Neuropsychiatric Inventory Questionnaire. RESULTS: Informant-rated symptoms were mainly connected to symptoms expressing lack of positive affect, but not to the more central symptoms of self-rated worthlessness and helplessness. Networks did not differ in structure (p = .71), or connectivity (p = .92) between visits. Symptoms formed four clinically meaningful clusters of depressive symptoms and decline, lack of positive affect, informant-rated apathy and anxiety and informant-rated depression. LIMITATIONS: The symptom dynamics in our study could have been present before AD diagnosis. The lack of positive affect cluster may represent a methodological artefact rather than a theoretically meaningful subgroup. Requiring follow-up lead to a selection of patients with less cognitive decline. CONCLUSIONS: Informant rating may only capture the more visible affective symptoms, such as not being in good spirits, instead of more central and severe symptoms, such as hopelessness and worthlessness. Future research should continue to be mindful of differences between self- and informant-rated symptoms even in earlier stages of AD.
BACKGROUND: Affective symptoms in Alzheimer's disease (AD) can be rated with both informant- and self-ratings. Information from these two modalities may not converge. We estimated network structures of affective symptoms in AD with both rating modalities and assessed the longitudinal stability of the networks. METHODS: Network analyses combining self-rated and informant-rated affective symptoms were conducted in 3198 individuals with AD at two time points (mean follow-up 387 days), drawn from the NACC database. Self-rated symptoms were assessed by Geriatric Depression Scale, and informant-rated symptoms included depression, apathy and anxiety questions from Neuropsychiatric Inventory Questionnaire. RESULTS: Informant-rated symptoms were mainly connected to symptoms expressing lack of positive affect, but not to the more central symptoms of self-rated worthlessness and helplessness. Networks did not differ in structure (p = .71), or connectivity (p = .92) between visits. Symptoms formed four clinically meaningful clusters of depressive symptoms and decline, lack of positive affect, informant-rated apathy and anxiety and informant-rated depression. LIMITATIONS: The symptom dynamics in our study could have been present before AD diagnosis. The lack of positive affect cluster may represent a methodological artefact rather than a theoretically meaningful subgroup. Requiring follow-up lead to a selection of patients with less cognitive decline. CONCLUSIONS: Informant rating may only capture the more visible affective symptoms, such as not being in good spirits, instead of more central and severe symptoms, such as hopelessness and worthlessness. Future research should continue to be mindful of differences between self- and informant-rated symptoms even in earlier stages of AD.
Authors: Lilah Besser; Walter Kukull; David S Knopman; Helena Chui; Douglas Galasko; Sandra Weintraub; Gregory Jicha; Cynthia Carlsson; Jeffrey Burns; Joseph Quinn; Robert A Sweet; Katya Rascovsky; Merilee Teylan; Duane Beekly; George Thomas; Mark Bollenbeck; Sarah Monsell; Charles Mock; Xiao Hua Zhou; Nicole Thomas; Elizabeth Robichaud; Margaret Dean; Janene Hubbard; Mary Jacka; Kristen Schwabe-Fry; Joylee Wu; Creighton Phelps; John C Morris Journal: Alzheimer Dis Assoc Disord Date: 2018 Oct-Dec Impact factor: 2.703