Vascular risk factors for depression and apathy | Part II 148 Is apathy in remitted depression related to CSVD? Given that the symptoms of the apathy syndrome substantially overlap those of the depressive-executive subtype of depression and the nature and strength of the relationship between CSVD and apathy is being debated, the studies in Chapters 5, 6 and 7 were dedicated to apathy and its relation to CSVD. Chapter 5 examined apathy in remitted depression and its relationship to vascular damage in 663 participants (mean age 46.5 years, range 18-86 years) of the Netherlands Study of Depression and Anxiety (NESDA) and the Netherlands Study of Depression in Older persons (NESDO). To systematically distinguish between residual depressive symptoms and apathy we performed a principal component analysis, which yielded two apathy factors, amotivation and loss of initiative, and one mood factor. When remission of depression was during follow-up, the associations between vascular risk factors or diseases and the two apathy factors was cross-sectionally evaluated by multivariate linear regression analyses in which we corrected for mood. Neither blood pressure nor ankle brachial index, body mass index, smoking, diabetes mellitus, cardiac disease, or cerebrovascular accidents were associated with either of the two apathy factors after mood had been controlled for. This raises the question whether apathy in remitted depression is aetiologically related to the earlier depressive episode and whether it should be regarded as a residual symptom. We were thus unable to establish a vascular pathway to apathy in this mixed-age group having recently recovered from depression, which is in line with the findings in late-life populations with a (severe) previous or current depression 16 17 18, with one exception 19. These results thereby contradict more consistent findings of a CSVD-apathy association in the general and neurodegenerative populations 20 (see Chapters 6 and 7). We suggested that in those who suffer from (severe) depression apathy as a symptom of depression might overshadow other pathways to apathy, where apathy after seemingly successful treatment of depression might in fact be a residual symptom. Can silent CSVD cause apathy and is vascular apathy a clinical syndrome? The hypothesis that CSVD can cause apathy was further examined in Chapters 6 and 7. In chapter 6, 14 general population studies on the relationship between subclinical CSVD and apathy were systematically reviewed. Subclinical CSVD was operationalized as WMH or white matter diffusivity changes, lacunar infarcts, cerebral microbleeds, decreasing cortical thickness, and perivascular spaces. Peripheral proxies for subclinical CSVD were also considered: the ankle brachial index, the intima media thickness, cardio-femoral pulse wave velocity, hypertension, or cardiovascular disease. We found that arterial stiffness and white matter diffusivity were not related to apathy, while the associations with cortical thickness were contradictory. Cross-sectional studies did find evidence of apathy being associated with WMH, cerebral microbleeds, cardiovascular disease, hypertension, and the ankle brachial index. Cardiovascular disease was prospectively associated with apathy. The methodologies of the studies included were too heterogeneous to perform meta-analyses.
RkJQdWJsaXNoZXIy MjY0ODMw