Psychiatric disorders and risk of subsequent dementia: Systematic review and meta‐analysis of longitudinal studies

Abstract

Objectives Although psychiatric disorders have been found to be associated with increased risk of dementia, previous findings are mixed, and the nature of these relationships remains poorly understood. We examined longitudinal associations between depression, anxiety, post‐traumatic stress disorders (PTSD), bipolar disorder (BPD), psychotic disorders and subsequent dementia. Methods We searched three databases for longitudinal, population‐based studies investigating associations between psychiatric disorders and dementia (PROSPERO registration: CRD42020209638). We conducted narrative synthesis, and random‐effects meta‐analyses to obtain pooled estimates. We used meta‐regression and stratified analyses to examine variation by sex, age‐at‐onset and follow‐up time. Results Fifty‐seven citations met eligibility criteria. Most studies focussed on depression (n = 33), which was associated with subsequent all‐cause dementia (pooled relative risk [RR]: 1.96, 95% confidence interval [CI]: 1.59–2.43; I2 = 96.5%), Alzheimer's Disease (pooled RR: 1.9, 95% CI: 1.52–2.38; I2 = 85.5%), and Vascular Dementia (pooled RR: 2.71, 95% CI: 2.48–2.97; I2 = 0). Associations were stronger in studies with shorter follow‐up periods and for severe and late‐onset depression. Findings regarding anxiety were mixed, and we did not find evidence of an overall association (pooled RR: 1.18, 95% CI: 0.96–1.45; I2 = 52.2%, n = 5). Despite sparse evidence, psychotic disorders (pooled RR: 2.19, 95% CI: 1.44–3.31; I2 = 99%), PTSD and BPD were associated with subsequent dementia. Conclusions People with psychiatric disorders represent high‐risk groups for dementia, highlighting the importance of ongoing symptom monitoring in these groups. Findings regarding temporality and age‐at‐onset indicate that depression symptoms could reflect prodromal dementia for some individuals. Further longitudinal research is required to determine whether psychiatric disorders represent causal risk factors or early markers of dementia neuropathology.

Anti-seizure medication exposure and the risk of dementia: A meta-analysis of observational studies

“…In addition to epilepsy, ASMs are commonly prescribed to treat bipolar disorder, depression, and other mental disorders ( 6 ). Previous meta-analysis have demonstrated that bipolar disorder is associated with an increased risk of dementia ( 30 ). Three included studies ( 11 , 12 , 17 ) focused on patients with bipolar disorder and used non-exposed patients as negative controls to minimize the effects of indication.…”

Alpha-Synuclein at the Interface between Depression, Parkinson’s Disease and Dementia: Evidence from Epidemiology, Population Genetics and Gene-Environment Interactions

“…The most recent data (2019) was used for the current study. Though there is significant evidence for an association between MDD and both Parkinson's and Alzheimer's disease [37][38][39], dysthymia was also included in the analysis in view of older data suggesting that it may be associated with both these disorders [86]. Data on the estimated prevalence of Parkinson's disease, and of Alzheimer's and related dementias, was obtained from the same source.…”

“…In a study of patients with severe depression and no signs of parkinsonism, 6.5% of patients developed Parkinson's disease when followed up over 9 years [37], and a meta-analysis of eleven studies found that, regardless of age, a diagnosis of depression was associated with at least a two-fold increase in the risk of subsequent Parkinsonism; these results remained significant even after adjusting for potential confounders [38]. Likewise, a meta-analysis of longitudinal studies found a significant association between depression and the subsequent risk of Alzheimer's disease, with stronger effects noted for severe-or late-life depression [39], and a review of six meta-analyses found that syndromal depression was associated with a 1.5-fold increase in rates of subsequent Alzheimer's disease [40]. The exact mechanism underlying these associations is unknown, but various mechanisms have been suggested to account for this link.…”

Zehn Jahre Digitale Demenz

“…Der Zusammenhang zwischen dem Bestehen nicht dementieller psychiatrischer Erkrankungen in der Jugend bis ins mittlere Erwachsenenalter und der Entwicklung einer Demenz im Alter ist nachgewiesen. Daher ist es von großer Bedeutung, dass zu hoher Bildschirmmedienkonsum das Risiko von psychischen Störungen wie Depression einschließlich Suizidalität 2 , 56 , 57 , Angst 4 , 25 , 31 und Sucht (sowohl stoffgebundene als auch nicht stoffgebundene Suchterkrankungen, d. h. Alkohol, Nikotin und Drogen als auch Medien, Computerspiele, Smartphones und Facebook 9 , 17 , 19 erhöht, die als Risikofaktoren für Demenz bekannt sind 21 , 51 , 63 . Betrachten wir einige Beispiele etwas genauer.…”