Bipolar disorder and comorbidity: increased prevalence and increased relevance of comorbidity for hospital-based mortality during a 12.5-year observation period in general hospital admissions

BACKGROUND

Bipolar disorder (BD) is associated with an increase of psychiatric and physical comorbidities, but the effects of these disorders on general hospital-based mortality are unclear. Consequently, we investigated whether the burden of comorbidity and its relevance on hospital-based mortality differed between individuals with and without BD during a 12.5-year observation period in general hospital admissions.

METHODS

During 1 January 2000 and 30 June 2012, 621 individuals with BD were admitted to three General Manchester Hospitals. All comorbidities with a prevalence ≥1% were compared with those of 6210 randomly selected and group-matched hospital controls of the same age and gender, regardless of priority of diagnoses. Comorbidities that increased the risk for hospital-based mortality (but not mortality outside of the hospitals) were identified using multivariate logistic regression analyses.

RESULTS

Individuals with BD had a more severe course of disease than controls that was associated with a higher total number of in-hospital deaths. Individuals with BD compared to controls had a substantial higher burden of comorbidities, the most frequent comorbidities included asthma, type-2 diabetes mellitus (T2DM), and alcohol dependence. 18 other diseases with a surplus of diabetes related complications were also increased. Fourteen comorbidities contributed to the prediction of hospital-based mortality in univariate analyses. Risk factors for hospital-based mortality in multivariate analyses were ischemic stroke, pneumonia, bronchitis, chronic obstructive pulmonary disease, T2DM, and hypertension. The impact of T2DM on hospital-based mortality was higher in individuals with BD than in controls.

LIMITATIONS

The study design was not assigned to assess the type of BD, the current bipolar status, and if individuals with BD were treated with medication. It was neither possible to compare drug effects, nor to compare the adherence to treatment between samples.

CONCLUSION

In one of the largest samples of individuals with BD in general hospitals, the excess comorbity in individuals with BD compared to controls is in particular caused by asthma and T2DM. T2DM and its complications cause significant excess hospital-based mortality in individuals with BD.

Comorbidity and its relevance on general hospital based mortality in major depressive disorder: a naturalistic 12-year follow-up in general hospital admissions

Major depressive disorder (MDD) is associated with physical comorbidity, but the risk factors of general hospital-based mortality are unclear. Consequently, we investigated whether the burden of comorbidity and its relevance on in-hospital death differs between patients with and without MDD in a 12-year follow-up in general hospital admissions. During 1 January 2000 and 30 June 2012, 9604 MDD patients were admitted to three General Manchester Hospitals. All comorbidities with a prevalence ≥1% were compared with those of 96,040 age-gender matched hospital controls. Risk factors of in-hospital death were identified using multivariate logistic regression analyses. Crude hospital-based mortality rates within the period under observation were 997/9604 (10.4%) in MDD patients and 8495/96,040 (8.8%) in controls. MDD patients compared to controls had a substantial higher burden of comorbidity. The highest comorbidities included hypertension, asthma, and anxiety disorders. Subsequently, twenty-six other diseases were disproportionally increased, many of them linked to chronic lung diseases and to diabetes. In deceased MDD patients, chronic obstructive pulmonary disease and type-2 diabetes mellitus were the most common comorbidities, contributing to 18.6% and 17.1% of deaths. Furthermore, fifteen physical diseases contributed to in-hospital death in the MDD population. However, there were no significant differences in their impact on mortality compared to controls in multivariate logistic regression analyses. Thus in one of the largest samples of MDD patients in general hospitals, MDD patients have a substantial higher burden of comorbidity compared to controls, but they succumb to the same physical diseases as their age-gender matched peers without MDD.

EPA Guidance on Building Trust in Mental Health Services

Purpose

To advance mental health care use by developing recommendations to increase trust from the general public and patients, those who have been in contact with services, those who have never been in contact and those who care for their families in the mental health care system.

Methods

We performed a systematic literature search and the retrieved documents were evaluated by two independent reviewers. Evidence tables were generated and recommendations were developed in an expert and stakeholder consensus process.

Results

We developed five recommendations which may increase trust in mental health care services and advance mental health care service utilization.

Discussion

Trust is a mutual, complex, multidimensional and dynamic interrelationship of a multitude of factors. Its components may vary between individuals and over time. They may include, among others, age, place of residence, ethnicity, culture, experiences as a service user, and type of disorder. For mental health care services, issues of knowledge about mental health services, confidentiality, continuity of treatment, dignity, safety and avoidance of stigma and coercion are central elements to increase trust.

Conclusion

Evidence-based recommendations to increase mutual trust of service users and psychiatrists have been developed and may help to increase mental health care service utilization.

Physical comorbidity and its relevance on mortality in schizophrenia: a naturalistic 12-year follow-up in general hospital admissions

Schizophrenia is a major psychotic disorder with significant comorbidity and mortality. Patients with schizophrenia are said to suffer more type-2 diabetes mellitus (T2DM) and diabetogenic complications. However, there is little consistent evidence that comorbidity with physical diseases leads to excess mortality in schizophrenic patients. Consequently, we investigated whether the burden of physical comorbidity and its relevance on hospital mortality differed between patients with and without schizophrenia in a 12-year follow-up in general hospital admissions. During 1 January 2000 and 31 June 2012, 1418 adult patients with schizophrenia were admitted to three General Manchester NHS Hospitals. All comorbid diseases with a prevalemce ≥1% were compared with those of 14,180 age- and gender-matched hospital controls. Risk factors, i.e. comorbid diseases that were predictors for general hospital mortality were identified using multivariate logistic regression analyses. Compared with controls, schizophrenic patients had a higher proportion of emergency admissions (69.8 vs. 43.0%), an extended average length of stay at index hospitalization (8.1 vs. 3.4 days), a higher number of hospital admissions (11.5 vs. 6.3), a shorter length of survival (1895 vs. 2161 days), and a nearly twofold increased mortality rate (18.0 vs. 9.7%). Schizophrenic patients suffered more depression, T2DM, alcohol abuse, asthma, COPD, and twenty-three more diseases, many of them diabetic-related complications or other environmentally influenced conditions. In contrast, hypertension, cataract, angina, and hyperlipidaemia were less prevalent in the schizophrenia population compared to the control population. In deceased schizophrenic patients, T2DM was the most frequently recorded comorbidity, contributing to 31.4% of hospital deaths (only 14.4% of schizophrenic patients with comorbid T2DM survived the study period). Further predictors of general hospital mortality in schizophrenia were found to be alcoholic liver disease (OR = 10.3), parkinsonism (OR = 5.0), T1DM (OR = 3.8), non-specific renal failure (OR = 3.5), ischaemic stroke (OR = 3.3), pneumonia (OR = 3.0), iron-deficiency anaemia (OR = 2.8), COPD (OR = 2.8), and bronchitis (OR = 2.6). There were no significant differences in their impact on hospital mortality compared to control subjects with the same diseases except parkinsonism which was associated with higher mortality in the schizophrenia population compared with the control population. The prevalence of parkinsonism was significantly elevated in the 255 deceased schizophrenic patients (5.5 %) than in those 1,163 surviving the study period (0.8 %, OR = 5.0) and deceased schizophrenic patients had significantly more suffered extrapyramidal symptoms than deceased control subjects (5.5 vs. 1.5 %). Therefore patients with schizophrenia have a higher burden of physical comorbidity that is associated with a worse outcome in a 12-year follow-up of mortality in general hospitals compared with hospital controls. However, schizophrenic patients die of the same physical diseases as their peers without schizophrenia. The most relevant physical risk factors of general hospital mortality are T2DM, COPD and infectious respiratory complications, iron-deficiency anaemia, T1DM, unspecific renal failure, ischaemic stroke, and alcoholic liver disease. Additionally, parkinsonism is a major risk factor for general hospital mortality in schizophrenia. Thus, optimal monitoring and management of acute T2DM and COPD with its infectious respiratory complications, as well as the accurate detection and management of iron-deficiency anaemia, of diabetic-related long-term micro- and macrovascular complications, of alcoholic liver disease, and of extrapyramidal symptoms are of utmost relevance in schizophrenia.

The efficacy of agomelatine in elderly patients with recurrent major depressive disorder: a placebo-controlled study

OBJECTIVE

The present placebo-controlled study evaluated the efficacy, tolerability, and safety of 8-week treatment with agomelatine (25-50 mg/d by mouth) in elderly patients with major depressive disorder (MDD).

METHOD

Elderly outpatients aged ≥ 65 years with a primary diagnosis of moderate to severe episode of recurrent MDD (DSM-IV-TR) were recruited in 27 clinical centers in Argentina, Finland, Mexico, Portugal, and Romania from November 2009 to October 2011. The primary outcome measure was the 17-item Hamilton Depression Rating Scale (HDRS17) total score.

RESULTS

A total of 222 elderly patients entered the study (151 in the agomelatine group, 71 in the placebo group), including 69 patients aged 75 years and older. Agomelatine improved depressive symptoms in the elderly population, as evaluated by the HDRS17 total score, in terms of last postbaseline value (agomelatine-placebo difference: mean estimate [standard error] = 2.67 [1.06] points; P = .013) and response to treatment (agomelatine, 59.5%; placebo, 38.6%; P = .004). The agomelatine-placebo difference according to the Clinical Global Impressions-Severity of Illness scale (CGI-S) score was 0.48 (0.19). The agomelatine-placebo difference (estimate [standard error]) for remission on the HDRS17 was 6.9% (4.7%) and did not achieve statistical significance (P = .179, post hoc analysis). Clinically relevant effects of agomelatine were confirmed on all end points in the subset of severely depressed patients (HDRS17 total score ≥ 25 and CGI-S score ≥ 5 at baseline). Agomelatine was well tolerated by patients, with only minimal distinctions from placebo.

CONCLUSIONS

The present study provides the first evidence that an 8-week treatment with agomelatine 25-50 mg/d efficiently relieves depressive symptoms and is well tolerated in elderly depressed patients older than 65 years.

TRIAL REGISTRATION

Controlled-Trials.com identifier: ISRCTN57507360.

Cardiovascular Risk Profiles amongst Women in a Multiethnic Population in Inner City Britain: A Potential Impact of Anaemia

The risk of diabetes is markedly reduced in men with iron deficiency anaemia (IDA). The nature of this relationship in women is not clear, nor is there information about the influence of ethnicity, given the increased susceptibility of diabetes amongst South Asians and Afro-Caribbeans. We reviewed 3563 patients with a diagnosis of anaemia from 2000 to 2007. The age-adjusted prevalence of vitamin B12 deficiency and IDA was calculated, together with cardiovascular comorbidities amongst Caucasians, South Asians, and Afro-Caribbeans. The prevalence of vitamin B12 deficiency (women only) or IDA was markedly higher in South Asians compared to Caucasians and Afro-Caribbeans. Among women with IDA, diabetes was more prevalent among South Asians (45%, 95% CI 39.0-51.0) compared to Caucasians (3.0%, 2.1-4.0); P < 0.001. Among South Asian women with vitamin B12 deficiency, the prevalence of diabetes was reduced 8.5% (5.2-12.0). South Asian women with vitamin B12 deficiency had a higher prevalence of myocardial infarction (MI) and ischemic heart disease (IHD), but this relationship was reversed in IDA. IDA is associated with a greater prevalence of diabetes in South Asian women, but it is not coordinated by a greater risk of macrovascular complications. Given the cardiovascular impact of diabetes in South Asians, this association merits further study in relation to its pathophysiological implication.

Discovery by the Epistasis Project of an epistatic interaction between the GSTM3 gene and the HHEX/IDE/KIF11 locus in the risk of Alzheimer's disease

Despite recent discoveries in the genetics of sporadic Alzheimer's disease, there remains substantial "hidden heritability." It is thought that some of this missing heritability may be because of gene-gene, i.e., epistatic, interactions. We examined potential epistasis between 110 candidate polymorphisms in 1757 cases of Alzheimer's disease and 6294 control subjects of the Epistasis Project, divided between a discovery and a replication dataset. We found an epistatic interaction, between rs7483 in GSTM3 and rs1111875 in the HHEX/IDE/KIF11 gene cluster, with a closely similar, significant result in both datasets. The synergy factor (SF) in the combined dataset was 1.79, 95% confidence interval [CI], 1.35-2.36; p = 0.00004. Consistent interaction was also found in 7 out of the 8 additional subsets that we examined post hoc: i.e., it was shown in both North Europe and North Spain, in both men and women, in both those with and without the ε4 allele of apolipoprotein E, and in people older than 75 years (SF, 2.27; 95% CI, 1.60-3.20; p < 0.00001), but not in those younger than 75 years (SF, 1.06; 95% CI, 0.59-1.91; p = 0.84). The association with Alzheimer's disease was purely epistatic with neither polymorphism showing an independent effect: odds ratio, 1.0; p ≥ 0.7. Indeed, each factor was associated with protection in the absence of the other factor, but with risk in its presence. In conclusion, this epistatic interaction showed a high degree of consistency when stratifying by sex, the ε4 allele of apolipoprotein E genotype, and geographic region.

Interactions between PPAR-α and inflammation-related cytokine genes on the development of Alzheimer's disease, observed by the Epistasis Project

OBJECTIVE

Neuroinflammation contributes to the pathogenesis of sporadic Alzheimer's disease (AD). Variations in genes relevant to inflammation may be candidate genes for AD risk. Whole-genome association studies have identified relevant new and known genes. Their combined effects do not explain 100% of the risk, genetic interactions may contribute. We investigated whether genes involved in inflammation, i.e. PPAR-α, interleukins (IL) IL- 1α, IL-1β, IL-6, and IL-10 may interact to increase AD risk.

METHODS

The Epistasis Project identifies interactions that affect the risk of AD. Genotyping of single nucleotide polymorphisms (SNPs) in PPARA, IL1A, IL1B, IL6 and IL10 was performed. Possible associations were analyzed by fitting logistic regression models with AD as outcome, controlling for centre, age, sex and presence of apolipoprotein ε4 allele (APOEε4). Adjusted synergy factors were derived from interaction terms (p<0.05 two-sided).

RESULTS

We observed four significant interactions between different SNPs in PPARA and in interleukins IL1A, IL1B, IL10 that may affect AD risk. There were no significant interactions between PPARA and IL6.

CONCLUSIONS

In addition to an association of the PPARA L162V polymorphism with the AD risk, we observed four significant interactions between SNPs in PPARA and SNPs in IL1A, IL1B and IL10 affecting AD risk. We prove that gene-gene interactions explain part of the heritability of AD and are to be considered when assessing the genetic risk. Necessary replications will require between 1450 and 2950 of both cases and controls, depending on the prevalence of the SNP, to have 80% power to detect the observed synergy factors.

Completed suicide, ideation and attempt in attention deficit hyperactivity disorder

OBJECTIVE

  Attention deficit hyperactivity disorder (ADHD) and suicidal behaviour are common conditions with significant social and emotional morbidity. Although completed suicide in ADHD has been assessed in a previous meta-analysis, other domains of suicidal behaviour such as attempts and ideation have been documented only in individual studies. This review provides a comprehensive summary of the relationship between attention-deficit and suicidality.

METHOD

  Electronic and manual literature search of MEDLINE, EMBASE and PSYCHINFO, using a range of search terms around suicidality, attention-deficit and hyperactivity.

RESULTS

  Twenty five papers were identified describing a relationship between ADHD and suicide. ADHD occurred more frequently in suicidal groups than controls, with most differences being statistically significant. The direction of results was consistent, with only one sample showing equivocal findings and one showing a reverse pattern. Attempts and ideation were more common in prediagnosed ADHD samples than controls. Three studies showed significant results only for men. Comorbidity had a large influence including delinquency and substance misuse.

CONCLUSION

  There is a positive relationship between ADHD and risk to self. More focussed research needs to take place on younger populations and those without comorbidity. This review highlights the importance of thorough risk assessment in the attention-deficit population.

The role of variation at AβPP, PSEN1, PSEN2, and MAPT in late onset Alzheimer's disease

Rare mutations in AβPP, PSEN1, and PSEN2 cause uncommon early onset forms of Alzheimer's disease (AD), and common variants in MAPT are associated with risk of other neurodegenerative disorders. We sought to establish whether common genetic variation in these genes confer risk to the common form of AD which occurs later in life (>65 years). We therefore tested single-nucleotide polymorphisms at these loci for association with late-onset AD (LOAD) in a large case-control sample consisting of 3,940 cases and 13,373 controls. Single-marker analysis did not identify any variants that reached genome-wide significance, a result which is supported by other recent genome-wide association studies. However, we did observe a significant association at the MAPT locus using a gene-wide approach (p = 0.009). We also observed suggestive association between AD and the marker rs9468, which defines the H1 haplotype, an extended haplotype that spans the MAPT gene and has previously been implicated in other neurodegenerative disorders including Parkinson's disease, progressive supranuclear palsy, and corticobasal degeneration. In summary common variants at AβPP, PSEN1, and PSEN2 and MAPT are unlikely to make strong contributions to susceptibility for LOAD. However, the gene-wide effect observed at MAPT indicates a possible contribution to disease risk which requires further study.

Genome-wide association study of vascular dementia

BACKGROUND AND PURPOSE

Most studies investigating the genetics of dementia have focused on Alzheimer disease, but little is known about the genetics of vascular dementia. The aim of our study was to identify new loci associated with vascular dementia.

METHODS

We performed a genome-wide association study in the Rotterdam Study, a large prospective population-based cohort study in the Netherlands. We sought to replicate genome-wide significant loci in 2 independent replication samples.

RESULTS

In the discovery analysis of 5700 dementia-free individuals, 67 patients developed incident vascular dementia over a mean follow-up time of 9.3 ± 3.2 years. We showed genome-wide significance for rs12007229, which is located on the X chromosome near the androgen receptor gene (OR, 3.7; 95% CI, 2.3-5.8, per copy of the minor allele; P=1.3 × 10(-8)). This association was further confirmed in 2 independent populations (probability value of combined replication samples=0.024).

CONCLUSIONS

Our study shows a novel genetic locus for vascular dementia on the X chromosome. Further replication of this finding is required.

Interaction of insulin and PPAR-α genes in Alzheimer's disease: the Epistasis Project

Altered glucose metabolism has been described in Alzheimer's disease (AD). We re-investigated the interaction of the insulin (INS) and the peroxisome proliferator-activated receptor alpha (PPARA) genes in AD risk in the Epistasis Project, including 1,757 AD cases and 6,294 controls. Allele frequencies of both SNPs (PPARA L162V, INS intron 0 A/T) differed between Northern Europeans and Northern Spanish. The PPARA 162LL genotype increased AD risk in Northern Europeans (p = 0.04), but not in Northern Spanish (p = 0.2). There was no association of the INS intron 0 TT genotype with AD. We observed an interaction on AD risk between PPARA 162LL and INS intron 0 TT genotypes in Northern Europeans (Synergy factor 2.5, p = 0.016), but not in Northern Spanish. We suggest that dysregulation of glucose metabolism contributes to the development of AD and might be due in part to genetic variations in INS and PPARA and their interaction especially in Northern Europeans.

Alzheimer's disease and co-morbidity: increased prevalence and possible risk factors of excess mortality in a naturalistic 7-year follow-up

BACKGROUND

Subjects with late-onset Alzheimer's disease (AD) have to be sufficiently healthy to live long enough to experience and to be diagnosed with dementia in later life. In contrast, neurodegeneration and cognitive deficits in AD may increase the frequency of co-morbid disorders and their possible influence on mortality. Consequently, we investigated whether the pattern of co-morbidity and its relevance for later death differed between hospitalized AD and age-matched controls subjects.

METHODS

Co-morbid diseases with a prevalence of more than 1% at hospital admission were compared between 634 hospitalized AD and 72,244 control subjects aged above 70 years admitted to the University of Birmingham NHS Trust between 1 January 2000 to 31 December 2007. Risk factors, i.e. co-morbid diseases that were predictors of mortality within the 7-year follow-up, were identified and compared.

RESULTS

Subjects with AD suffer more eating disorders, infections, brain diseases and neck of femur fractures than other hospitalized elderly patients. In contrast, some cardiovascular diseases and diabetes mellitus were less prevalent in AD subjects in comparison with hospitalized controls. Diseases that might have contributed to later mortality in AD were pneumonia, ischemic heart disease and gastroenteritis, but there were no significant differences in their impact on mortality compared to other hospitalized elderly subjects with the same co-morbidities in multivariate logistic regression analyses.

CONCLUSION

Patients with AD have a different pattern of co-morbidity, but die from the same diseases as other hospitalized patients. Infections including pneumonia and diseases that may occur secondary to neurodegeneration and cognitive decline may need special attention in patients with AD who may not be able to identify or report the early symptoms. Preventive measures may be helpful to reduce the high risk and fatal consequences of undetected disease in AD.

Functional neuroanatomy of sustained memory encoding performance in healthy aging and in Alzheimer's disease

The aim of our study was to examine brain networks involved with sustaining memory encoding performance in healthy aging and in Alzheimer's disease (AD). Since different brain regions are affected by degradation in these two conditions, it might be conceivable that different compensation mechanisms occur to keep up memory performance in aging and in AD. Using an event-related functional magnetic resonance imaging (FMRI) design and a correlation analysis, 8 patients suffering from AD and 29 elderly control subjects were scanned while they studied a list of words for a subsequent memory test. Individual performance was assessed on the basis of a subsequent recognition test, and brain regions were identified where functional activations during study correlated with memory performance. In both groups, successful memory encoding performance was significantly correlated with the activation of the right frontal cortex. Furthermore, in healthy controls, there was a significant correlation of memory performance and the activation of the left medial and lateral temporal lobe. In contrast, in AD patients, increasing memory performance goes along with increasing activation of the hippocampus and a bilateral brain network including the frontal and temporal cortices. Our data show that in healthy aging and in AD, common and distinct compensatory mechanisms are employed to keep up a certain level of memory performance. Both in healthy aging and in patients with AD, an increased level of monitoring and control processes mediated by the (right) frontal lobe seems to be necessary to maintain a certain level of memory performance. In addition, memory performance in healthy older subjects seems to rely on an increased effort in encoding item-specific semantic and contextual information in lateral areas of the (left) temporal lobe. In AD patients, on the other hand, the maintenance of memory performance is related to an increase of activation of the (left) hippocampus in conjunction with a bilateral network of cortical areas that might be involved with phonological and visual rehearsal of the incoming information.

A multi-center study of ACE and the risk of late-onset Alzheimer's disease

A key pathological feature of late-onset Alzheimer's disease (LOAD) is the abnormal extracellular accumulation of the amyloid-β (Aβ) peptide. Thus, altered Aβ degradation could be a major contributor to the development of LOAD. Variants in the gene encoding the Aβ-degrading enzyme, angiotensin-1 converting enzyme (ACE) therefore represent plausible candidates for association with LOAD pathology and risk. Following Alzgene meta-analyses of all published case-control studies, the ACE variants rs4291 and rs1800764 showed significant association with LOAD risk. Furthermore ACE haplotypes are associated with both plasma ACE levels and LOAD risk. We tested three ACE variants (rs4291, rs4343, and rs1800764) for association with LOAD in ten Caucasian case-control populations (n = 8,212). No association was found using multiple logistic models (all p > 0.09). We found no population heterogeneity (all p > 0.38) or evidence for association with LOAD risk following meta-analysis of the ten populations for rs4343 (OR = 1.00), rs4291 (OR = 0.97), or rs1800764 (OR = 0.99). Although we found no haplotypic association in our complete dataset (p = 0.51), a significant global haplotypic p-value was observed in one population (p = 0.007) due to an association of the H3 haplotype (OR = 0.72, p = 0.02) and a trend towards an association of H4 (OR = 1.38, p = 0.09) and H7 (OR = 2.07, p = 0.08) although these did not survive Bonferroni correction. Previously reported associations of ACE variants with LOAD will be diminished following this study. At best, ACE variants have modest effect sizes, which are likely part of a complex interaction between genetic, phenotypic and pharmacological effects that would be undetected in traditional case-control studies.

Transferrin and HFE genes interact in Alzheimer's disease risk: the Epistasis Project

Iron overload may contribute to the risk of Alzheimer's disease (AD). In the Epistasis Project, with 1757 cases of AD and 6295 controls, we studied 4 variants in 2 genes of iron metabolism: hemochromatosis (HFE) C282Y and H63D, and transferrin (TF) C2 and -2G/A. We replicated the reported interaction between HFE 282Y and TF C2 in the risk of AD: synergy factor, 1.75 (95% confidence interval, 1.1-2.8, p = 0.02) in Northern Europeans. The synergy factor was 3.1 (1.4-6.9; 0.007) in subjects with the APOEε4 allele. We found another interaction, between HFE 63HH and TF -2AA, markedly modified by age. Both interactions were found mainly or only in Northern Europeans. The interaction between HFE 282Y and TF C2 has now been replicated twice, in altogether 2313 cases of AD and 7065 controls, and has also been associated with increased iron load. We therefore suggest that iron overload may be a causative factor in the development of AD. Treatment for iron overload might thus be protective in some cases.