It is well known from previous research that depressive feelings are more common in persons with dementia. Many have interpreted this association to mean that depressive feelings are part of a dementia syndrome, while others think that the causative link is the opposite: that depressive feelings may contribute to cause the disease.
In a new study at Karolinska Institutet in Stockholm, Sweden and University of Eastern Finland in Kuopio, researchers have demonstrated that feelings of hopelessness indeed are more common among persons with dementia, but that these feelings already existed twenty years before the diagnoses were made (see figure).
The new findings give strong support to the idea that negative feelings already in midlife can affect dementia risk in later life: persons with elevated feelings of hopelessness in midlife had almost a three-fold risk increase of Alzheimers disease, also after consideration of individual differences in age, hypertension, genetic factors, sex, BMI and other factors of relevance for dementia risk. The association for hopelessness in midlife was even significant after additional adjustments for hopelessness and other depressive feelings at follow-up. This study also shows that the increased risk of hopelessness feelings was especially pronounced among persons who also carried the ApoE4 allele, the major genetic risk factor for Alzheimers disease.
The study builds on population data from Eastern Finland with 1409 participants and has a unique follow-up time of twenty years. An important feature is also that hopelessness feelings were measured in later life shortly before, not after, the participants were screened for a possible dementia disease.
Two other population based studies from the US had a similar design, but with several follow-up measurements. These studies also found no noticeable increases of depressive feelings during the follow-up time. Taken together, these studies demonstrate that carrying negative feelings could increase the risk for dementia.
The new study was performed by Krister Håkansson, Hilkka Soinninen, Bengt Winblad and Miia Kivipelto and is published on October 13, in PLOS ONE.
For further information, please contact:
Krister Håkansson
krister.hakansson@ki.se
+46 73 7080 768
The paper is available at: http://dx.plos.org/10.1371/journal.pone.0140261