21st Century Early Adult (55-74) Deaths from Brain-Disease-Deaths Compared to All Other Cause Mortality in the Major Western Countries – Exposing a Hidden Epidemic

ABSTRACT

Objectives

To examine early adult deaths (EAD) – people aged 55–74 due to brain disease deaths (BDD) compared to all other causes (AOC) in the 21st century in 21 major Western countries (MWC).

Method

EAD are below MWCc average life expectancy. All mortality drawn from the latest WHO data. The three global BDD categories consist of mental and behaviour disorder, nervous diseases and Alzheimer and other dementias. Mortality rates per million are analysed for people 55–74 years and total age-standardised death rates (ASDR). BDD rates between 2000–2015 compared against AOC of deaths for EAD and ASDR. Confidence Intervals determine any significant difference AOC and BDD over the period 2000–15, plus an examination of EAD in six separate global mortality categories.

Results

EAD: The separate BDD categories for EAD significantly positively correlated, validating their combination as BDD. Every country’s AOC 55–74 rates fell substantially, but fourteen country’s BDD rose substantially (>20%) and all MWC countries BDD rose significantly more than AOC. ASDR: All nations total AOC fell substantially, whereas seventeen BDD rates rose substantially and every country’s BDD significantly increased compared to AOC deaths. Six other EAD mortalities, circulatory, cancer, respiratory, compared to BDD produced Odds Ratios ranging from 1:1.54 to 1:2.36 such were the marked differences over the period.

Discussion

Positive news is that AOC are down across all investigated countries in the 21st century. However, the extent of the EAD rises in just 16 years indicates that these BDD conditions are starting earlier suggesting multiple interactive environmental factors impacting upon brain related diseases.

KEYWORDS:

• Early adult death neurological
• international
• environment

Introduction

The first comparative international study of changing patterns of brain disease deaths (BDD) covered the period 1979–1997 found that 12 of the 21 major Western countries (MWC) had substantially increased rates of BDD [1]. Subsequent studies over the period 1989–2014 reported that all 21 countries had risen substantially (+20%) in the intervening years [2–5]. However, some had argued that these apparent rises were essentially due to demographics, the presence of more elderly (75+) people in the population and better diagnosis [6–8], indeed, they postulated the ‘Gompertzian hypothesis’ was the cause of these increases [7,8]. This theory states that because people were now living longer, they were now living long enough to develop age-related diseases. This was challenged by findings that over 25 years the US BDD rates had jumped from being 15th highest of the 21 MWC to becoming the second highest rate despite every other country also increasing its BDD. Even countries with traditional low levels of BDD, such as Austria, Greece and Japan had seen a doubling of their rates over the same period [4,5]. Furthermore, there has simultaneously been a growing number of Western world studies of rises in cases of early-onset dementia and deaths [9–13].

Nonetheless, it is recognised that many of the BDD conditions are age-related, so it was decided to focus on WHO mortality rates of people aged 55–74 year olds which is well below the current average life expectancy in the 21 MWC – now averaging 82 years [14]. Hence, a death in this age band can be said to be an `early-adult death’ (EAD).

This population-based study examines any changes in EAD from BDD to be compared with EAD from all other cause of death (AOC) during the 21st century. In addition Total BDD and AOC mortality are also analysed based upon the WHO age-standardised death rates (ASDR) [14].

To provide a wider perspective six separate major global mortality categories are also examined for EAD to explore to what extent have these other six mortality categories varied over the period compared to the BDD outcomes.

There is one null hypothesis:

During the 21st century there will be no significant differences in EAD and ASDR BDD compared to AOC for the two age-bands over the period.

Method

The 21 MWCs to be reviewed are Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Japan, Netherlands, New Zealand, Norway, Portugal, Spain, Sweden, Switzerland, the UK and the USA. These countries, it is argued, share broadly the same liberal democratic tradition, having health care systems based on scientific evidence. Life expectancy in these countries ranges from Japan at 84.2 to the USA at 78.5 years. Based upon WHO data [14] we calculated MWC average life expectancy to be 81.98 years (82 years).

All mortality data is taken from the latest WHO annual statistics report (2020), updated May 2018 for the years 2000 and 2015 [14]. Some countries have earlier index years, which are noted in the tables, e.g. Canada 2013, France 2014. Austria, the Netherlands and Sweden have the later year 2016 but in view of the relative short time period being analysed it was decided to report these country’s most recent year.

In the earlier comparative international studies of BDD [4,5] only the global categories of nervous disease deaths (NDD) and Alzheimer’s and other dementias (Alz) had been used to examine BDD over the years [14]. These global diagnostic categories are based upon the International Statistical Classification of Diagnoses (ICD10th Revision) [15] which are used in the WHO mortality statistics [14]. However, it was realised we had omitted a major global category that includes neurodegeneration conditions that are not reported in the other two neurological categories, which is the mental and behavioural disorder category [15]. To validate combining the three global categories into a total BDD rate, the changing rates of all three categories in all MWC in the 21st-century countries will be examined separately. Spearman rank order correlation tests will be used to determine any statistical congruence between the categories. Theoretically, any general change in overall BDD should be significantly reflected in all three categories. Thus, total rates BDD for both EAD and ASDR age bands will include the three global diagnostic categories to measure BDD rates during the 21st century.

The BDD will be directly compared with AOC for both people aged 55–74 years, the EAD and total mortalities of the ASDR per million (pm), which controls for age, gender and population [14]. To calculate death rates for the 55–74 year olds we examine the numbers of deaths in this age band to be divided by the population of each country’s 55–74 year olds to produce an EAD mortality rate per million (pm). The ASDR data is extrapolated directly from the WHO statistics [14].

The three neurological categories are in chapters five and six of the International Statistical Classification of Diseases 10th revision [15], used by the WHO in the reported data [14,15]. The broad outlines are as follows from chapter five:

1. The Mental and Behavioural Disorder (M&BD) category (coded F00–F99), note the over-lap in coding of the diagnoses, which covers a wide range of conditions, many `psychological’ to include personality disorders, anxiety states, as well as the major psychiatric disorders – the depressions and the schizophrenias. The key neurological conditions not included anywhere else are the organic based mental disorders, systemic brain disease and vascular dementias. In respect to the range of psycho-social diagnoses it is assumed that there will be few death certificates siting the diagnoses such as personality disorders, anxiety disorders, etc., as causes of death. Whilst deaths associated with psychoses and psychological crises mainly result in suicide, found in the Intentional Self-Harm category coded X60-X84 and Y870 outlined in chapter twenty of the ICD [15].

In ICD’s chapter six are the two other global brain disease categories:-

2.Nervous Disease Deaths (coded G00-G99) include a range of conditions such as motor neurone disease, Parkinson’s disease, Huntington’s disease, multiple system atrophy, vascular syndromes of brain in cerebrovascular disease, and extra-pyramidal movements disorders, etc. As we are measuring the total category, there is no need to identify the separate diagnostic categories, which are contained in this WHO omnibus category [15].

3. The Alzheimer’s and Other Dementias (coded F01, 03, G30-31) include Alzheimer’s disease, Pic’s disease and other dementias not classified elsewhere and unspecified dementias, etc. [15]. As the analysis is based upon the total category, specific diagnoses are not an issue.

The three categories together, assuming there will be positive statistical significance, can be combined to become BDD.

For clarity purposes in the tables we first present AOC compared to BDD for the age band 55–74 and total deaths in ASDR [14]. To test for any statistically significant changes between AOC and NDD mortality over the period a series of confidence interval calculations are carried out using SPSS statistical programme.

People with neuro-degenerative diseases often face years of chronic disability, which impacts upon patient’, families and health and social services. To give a more `clinical perspectives we report upon changes in the numbers of BDD and population in four countries to exemplify the practical burden of these conditions.

To provide a further perspective we examine changes in six other specific major global mortalities of 55–74 years to compare against the EAD neurological results. These are circulatory diseases (coded I00–I99), cancers (Coo-D48), respiratory (J00–J99), digestive system (K00–K93), diabetic diseases (E10–E14), and genitourinary (N00-N99) [15]. With such broad codes these global categories also include many separate diagnostic conditions within their sphere. In order to avoid repetition, we report only on the ten of largest populated Western countries. We measure any difference via a series of ratios of change 2000–2015 as each country serves as its own control group. We calculate the average EAD ratio of change for each separate mortality category or the ten countries, against average BDD ratio to produce a six other causes to BDD odds ratios. These results are also illustrated in a bar chat of the separate global categories change in the 21st century. The baseline being 1.00 and plus or minus ratios of change.

Results

Congruence of nervous disease and Alzheimer’s and other dementias and mental and behavioural disorders

EADs (55–74): Table 1 presents EAD of the separate three categories changes death rates of all 21 countries. All three mortality categories correlated statistically significant; the nervous disease with Alzheimer (Rho = +0.8893, p < 0.001), the nervous disease and mental & MD deaths (Rho = +0.5808, p < 0.005) and Alzheimer’s and other dementia and mental & BD (Rho = +0.5432, p < 0.01). All three categories now form the BDD global category.

Table 1. Nervous disease deaths (NDD), Alzheimer and other dementia (Alz), mental and behavioural disorder deaths = brain disease deaths (BDD) 55–74 year olds rates per million 2000–2015 Ratio of Change. Ranked by highest BDD

Country and % change	NDD 55–74 2000-2015	Alzh 55–74 2000-2015	BD 55–74 2000–2015	BDD 55–74 2000-2015
1.Finland Ratio change	394–642 1.63	305–364 1.19	225–188 0.84 #	924–1194 1.29
2.Denmark Ratio change	339–398 1.17	115–204 1.77	312–518 1.66	766–1120 1.46
3.USA Ratio change	364–455 1.25	147–255 1.73	119–213 1.79	630–923 1.47
4.Netherlands Ratio change	350–379 1.08	116–223 1.92	151–245 1.62	617–847 1.37
5.UK Ratio change	256–399 1.56	164–254 1.55	106–180 1.70	526–833 1.58
6.Sweden Ratio change	267–387 1.45	157–239 1.52	241–198 0.82 #	665–824 1.24
7.Belgium Ratio change	377–383 1.02	206–172 0.83 #	188–218 1.16	771 773 1.00
8.Switzerland Ratio change	297–356 1.20	141–180 1.28	165–215 1.30	603–751 1.25
9.Norway Ratio change	365–390 1.07	125–176 1.39	161–182 1.13	651–748 1.15
10.Germany Ratio change	254–342 1.35	60–136 2.27	149–271 1.82	463–749 1.62
11.New Zealand 2013 Ratio change	279–314 1.13	129–161 1.25	151–245 1.62	559–720 1.29
12.Canada 2013 Ratio change	376–318 0.85 #	159–168 1.06	1.61–161 1.00	696–647 0.93 #
13.Australia Ratio change	272–335 1.23	105–171 1.63	108–126 1.17	485–632 1.30
14.France Ratio change	397–321 0.81 #	173–119 0.69 #	225–188 0.84 #	795–628 0.79 #
15.Ireland Ratio change	291–345 1.19	174–176 1.01	147–95 0.65 #	612–616 1.01
16.Austria Ratio change	160–286 1.79	74–129 1.74	97–198 2.04	331–613 1.85
17.Spain Ratio change	299–329 1.10	195–179 0.92	116–99 0.85 #	610–607 0.99
18.Italy Ratio change	266–327 1.23	186–143 0.77 #	71–82 1.15	523–552 1.06
19.Portugal Ratio change	230–290 1.26	144–142 0.99	31–88 2.84	405–520 1.28
20.Greece Ratio change	213–279 1.31	121–99 0.82 #	11–84 7.64	345–462 1.34
21.Japan Ratio change	123–180 1.46	28–26 0.93 #	19–28 1.47	170–234 1.38

Notes: # fall of BDD.

Fourteen countries had increased rates in all three separate categories, only France had falls in three and Spain in two. In every country nervous disease rates of people aged 55–74 were higher than the other two categories but mental & BD rates were higher than Alzheimer’s in 10 countries.

The highest EAD total BDD rates were in Finland 1194 per million (pm), then Denmark 1120 pm and the USA 923 pm. Down to lows of 234 pm in Japan, 462 pm Greece and Portugal 520 pm.

In 14 countries total EAD had risen substantially (+20%) over the period but Canada fell equivalent to 7% and France 21%. The average MWC ratio of change was 1.27.

Table 2 present changes in EAD between all other causes and brain disease mortality over the period.

Table 2. EADs (55–74) all other causes vs. BDD rates per million 2000–2015. Confidence intervals AOC vs. BDD. Ranked by highest BDDs

Country and rank	All other EAD 2000–2015	EAD brain 2000 – 2015	Other: brain odds ratio	C.I other: brain low – high
1.Finland Ratio change	13,235–9150 0.68	924–11941.29	1.90	1.71-2.04
2.Denmark Ratio change	15,972–10,752 0.67	766–1120 1.46	2.18	1.97-2.39
3.USA Ratio change	14,603–10,457 0.72	630–923 1.47	2.04	1.84-2.27
4.Netherland Ratio change	13,804–9233 0.67	617–847 1.37	2.04	1.84-2.28
5.UK R change	14,982–9771 0.65	526–833 1.58	2.43	2.17-2.72
6.Sweden 2016 Ratio change	11,389–8838 0.78	665–824 1.24	1.59	1.44-1.78
7.Belgium Ratio change	13,498–9498 0.70	771–771 1.00	1.43	1.28-1.58
8.Germany Ratio change	13,890–10,907 0.79	463–749 1.62	2.05	1.83-2.32
9.Switzerland Ratio change	10,660–7574 0.71	603–751 1.25	1.76	1.57-1.96
10.Norway Ratio change	12,533–8231 0.66	651–748 1.15	1.74	1.57-1.95
11. New Zealand 13 Ratio change	12,847–8281 0.64	559–720 1.29	2.02	1.78-2.24
12.Canada 2013 Ratio change	11,848–8178 0.69	696–644 0.93	1.39	1.20-1.50
13.Australia Ratio change	11,090–7458 0.67	485–632 1.30	1.94	1.72-2.19
14.France 2014 Ratio change	11,698–8156 0.70	795–628 0.79 #	1.13	1.02-1.26
15.Ireland Ratio change	16,021–8843 0.55	612–616 1.01	1.84	1.63-2.05
16.Austria 2016 Ratio change	13,258–9924 0.75	331–613 1.85	2.47	2.16-2.84
17.Spain Ratio change	12,056–8286 0.69	610–607 0.99	1.43	1.29-1.63
18.Italy Ratio change	12,098–8351 0.69	523–542 1.04	1.51	1.33-1.70
19.Portugal Ratio change	14,571–9555 0.66	405–520 1.28	1.94	1.72-2.24
20.Greece Ratio change	13,281–10,032 0.76	345–462 1.34	1.76	1.54-2.04
21.Japan Ratio change	10,453–8238 0.79	170–234 1.38	1.75	1.43-2.13

• Notes: Correlating EAD AOC v BDD Rho = +0.3370 p < 0.1

In every nation AOC of deaths fell substantially ranging from Ireland, with a ratio of change 0.55 to Japan and Germany 0.79, an overall average of 0.71.

A series of confidence intervals found that every country had a statistically significant proportional rises in EAD BDD compared to AOC, even in the outlier France whose C.I was significant (1.02–1.26).

Total ASDR for all other causes vs. brain-disease-deaths: Table 3 lists total AOC and BDD rates.

Table 3. Age-standardised death rates all other cause vs. brain mortality 2000 vs. 2015: confidence intervals. Ranked by highest brain disease deaths

Country rank and year	All other	Ratio change	Total brain	Ratio change	Other: brain odds ratio	C.I. low – high
1.Finland 2015	4704 3368	0.72	543 617	1.14	1.58	1.40 -	1.80
2. UK 2015	4998 3527	0.71	234 517	2.21	3.11	2.67 -	3.68
3. Netherlands 2014–16	4885 3373	0.69	312 498	1.60	2.32	1.99 -	2.68
4. USA 2015	5259 4315	0.82	265 471	1.78	2.17	1.85 -	2.53
5. Denmark 2015	5455 3771	0.69	270 443	1.64	2.38	2.03 -	2.78
6 = Sweden 2014–16	4224 3206	0.76	321 411	1.28	1.68	1.45 -	1.97
6 =  Switzerland 2015 21	3983 2915	0.73	310 411	1.33	1.82	1.55 -	2.12
8. Canada 2011–13	4246 3286	0.71	290 377	1.30	1.83	1.43 -	1.97
9. Norway 2015	4633 3321	0.72	289 376	1.30	1.81	1.55 -	2.13
10. Germany 2015 2	5469 3803	0.70	195 370	1.90	2.71	2.28 -	3.26
11. Ireland 2012–14	5573 3713	0.70	209 352	1.68	2.40	2.12 -	3.01
12. Belgium 2015	4942 3732	0.76	287 349	1.22	1.61	1.37 -	1.89
13. Australia 2015 19	4067 3075	0.76	223 345	1.55	2.04	1.72 -	2.44
14. New Zealand 2011–13	4644 3564	0.77	223 315	1.41	1.83	1.54 -	2.20
15. Spain 2015 18	4325 3110	0.72	270 312	1.16	1.61	1.36 -	1.90
16. France 2012–14	4406 3313	0.75	286 291	1.02	1.36	1.14 -	1.60
17. Italy 2015	4296 3238	0.75	181 217	1.20	1.60	1.30 -	1.95
18. Austria 2014–66	4879 3219	0.66	103 201	1.95	2.95	2.32 -	3.77
19. Portugal 2012–14	5549 3944	0.71	97 192	1.98	2.79	2.17 -	3.57
20. Greece 2015	5145 3892	0.76	57 103	1.81	2.38	1.72 -	3.31
21. Japan 2015 20	3691 3007	0.81	44 77	1.75	2.16	1.48 -	3.12

Notes: AOC vs. BDD Rho = +0.1354 n.sig.

Every Western country’s total ASDR AOC fell substantially (>20%) except the USA (18%), with an overall average 27% fall.

The highest total BDD rates were in Finland 617 pm, the UK at 517 pm and the Netherlands 498 pm, down to the lowest countries Japan 77 pm, Greece 103 pm and Portugal 192 pm. Seventeen countries rates increased substantially (>1.20) over the period the exceptions being France (1.02), Finland (1.14) and Spain (1.16).

Notable (>50%) AOC to BDD odds ratio occurred in Australia 1.54, Austria 1.95, Denmark 1.64, Germany 1.90, Greece 1.81, Ireland 1.68, Japan 1.75, the Netherlands 1.60, the UK 2.21 and the USA 1.78.

Again every country’s total BDD was statistically significantly greater than AOC, which of course had fallen, in contrast to BDD rises, including the relative outliers for EAD in Spain (C.I. 1.36–1.90), Canada (C.I 1.43–1.97) and France (C.I, 1.14 − 1.60).

Examples of EAD other global mortalities. Table 4 presents six separate global mortality rates of EAD between 2000 and 2015 in the 10 biggest population MWC. The average ratio of reduced mortality for these conditions over the period was circulatory 0.53; cancer 0.81, respiratory 0.76. digestive 0.72, diabetes 0.60 and genitourinary 0.77 showing a welcome reduction in EAD in these conditions. Conversely, the average BDD ratio of change was 1.25 producing an AOC to BDD odds ratios ranging from 1.54 to 2.26. To illustrate these difference EAD of the BDD to these six other categories, Figure 1 graphically highlights the changes over the period.

Table 4. Early adult deaths (EAD) (55–74) separate global categories in 10 MWC and average other categories to average BDD odds ratios

Country EAD	Circ	Can	Resp	Dig	Diab	Geni	BDD
Australia 2015 Ratio	3545 1676 0.47	5112 3821 0.75	939 636 0.68	371 338 0.91	349 246 0.71	123 89 0.72	485 632 1.30
Canada 2013 Ratio	3893 2056 0.53	5719 4310 0.75	827 673 0.81	532 463 0.87	451 291 0.65	180 105 0.58	696 644 0.93 #
France 2014 Ratio	3033 1479 0.49	5910 4617 0.78	622 386 0.62	711 510 0.72	295 175 0.59	121 72 0.60	795 628 0.79 #
Germany 2015 Ratio	5142 2991 0.58	5557 4767 0.86	795 853 1.07	849 673 0.79	319 252 0.79	143 164 1.15	463 749 1.62
Italy 2015 Ratio	3943 2114 0.54	5706 4438 0.78	589 410 0.70	712 389 0.55	419 311 0.74	139 109 0.78	523 542 1.04
Japan 2015 Ratio	2644 1828 0.69	4864 4071 0.84	858 710 0.83	473 363 0.77	168 108 0.64	156 141 0.90	170 234 1.38
Netherland 2016 Ratio	4632 1885 0.41	6003 5089 0.85	1094 730 0.67	463 333 0.72	337 186 0.55	148 98 0.66	617 847 1.37
Spain 2015 Ratio	3631 1897 0.52	5300 4289 0.91	1058 674 0.64	745 499 0.67	295 154 0.52	202 113 0.56	610 607 0.99
UK 2015 Ratio	5727 2557 0.45	5941 4733 0.80	1842 1228 0.67	684 642 0.94	183 102 0.56	131 103 0.79	526 833 1.58
USA 2016 Ratio	5508 3485 0.63	5893 4224 0.72	1470 1257 0.86	614 649 1.06	606 499 0.82	296 294 0.99	630 923 1.47
Average MWC ratios	0.53	0.81	0.76	0.72	0.60	0.77	1.25
Average other: BDD odds ratios	2.36	1.54	1.64	1.74	2.08	1.62	1.00

Notes: # BDD fall.

Abbreviations: Circ = circulatory; Can = cancer; Resp = respiratory; Dig = digestive; Diab = diabetes; Genit = genitourinary; BDD = brain disease deaths.

short-legendFigure 1.

Examples of EAD, ASDR and population numbers. (MWC full numbers of BDD and population are given in a supplementary table.)

Practice perspective in numbers: To give brief examples of the extent of changes in EAD (55–74) BDD, we present numbers of BDD against changes in numbers of population. These countries are Japan, France, the UK and the USA.

French brain EAD numbers went from 8,631 to 8617, down 1% whilst its 55–74 years population rose 31%. UK BDD went from 5,821 to 11,499 up 98%, whilst this population rose 25%. In America EAD went from 26,909 to 62,413, a rise of 132%, with this population up 58%.

Total BDD numbers in France rose from 57,914 to 93,640 up 62%, whilst its total population rose 9%. Britain’s numbers went from 38,083 to 157,623 a rise of 314% with a population rise of 9%. American numbers rose from 220,723 to 573,094 up 160% against a rise in total population of 14% in just 16 years.

Even in the country with the lowest rate of BDD Japan their total numbers increased from 17,943 to 69,217, equivalent to a rise of 286%, whilst its population fell 1% over the period.

Discussion

The study’s limitations are that although the analysis is of global mortality categories, we know nothing about possible variations within these categories. Whilst mental and behaviour disorder deaths correlated positively with the other two categories, they include many psycho-social diagnoses within the codes than the other organic brain conditions [15] and all three BDD EAD categories rose considerably and are positively correlated over the period . This was the direct opposite of EAD in respect to the other categories such as circulatory, cancer and respiratory deaths, etc., which supports the rational for combing the three global BDD categories.

Whilst most countries BDD rose, the slight outliers, like Canada and Spain, but especially, France, cannot readily be explained. Nonetheless, French total BDD mortality rose over the period and significantly more than its all other cause mortality. This might suggest that people in these countries lived to reach the older (75+) age-band before death. Only country-specific research could provide the answers to these questions, and the extent of such changes need to be investigated further, not least to explain the changes within each separate country.

One feature, linked to the USA, is that during the period they were involved in military activities and over 350,000 US military personnel had sustained a traumatic brain injury, which of course is related to later neurodegenerative conditions [16,17], though this is not without controversy [18]. However, other countries have also reported higher than expected neurological conditions in their former military personnel, whose environment often carries a range of various occupational hazards [19–23]

There is the issue of possible better diagnosis of early-onset-dementia and the Gompertzian hypothesis that states people are now living longer to develop age-related diseases [6–8]. This may be a partial explanation, but it is doubtful whether it could explain the extent of the changes over such a short period. Clearly, more targeted country-specific research is needed to explain each country’s results. However, despite these limitations, the extent of the widening gap between 2000 and 2015 of brain disease to all other cause of deaths indicates something is happening far, far faster than any possible artefact of population demographics could explain. It must be stressed that these changes have occurred in just the last 16 years, strongly suggesting the changes are accelerating when compared to the late 20th century [1],

As both 55–74 years and total BDD were significantly increased compared to AOC, we can reject the null hypothesis. The speed and extent of BDDs especially in the EAD, strongly indicates that brain disease morbidity is beginning earlier and incident rates appear to be accelerating. What can be said with confidence, is that the demographic and Gompertzian hypothesis cannot account for the size and speed of these changes of EAD during this century. Such increased numbers are reflected in the need for a British charity `Young Dementia UK” and the Parkinson’s Disease Society developing a `young persons’ section, whilst in America there is now a training scheme for young caregivers for family members with amyotrophic lateral sclerosis [24].

Nonetheless, the BDDs rates must not disguise the good news that except for rises in BDD, general mortality rates have substantially fallen across most of the 21 MWCs. Yet, the remarkable, almost hidden epidemic rise in brain-related disease needs to be confronted. It is the rises in EADs that are the most worrying especially considering the differences between all other cause and the six separate other global categories.

We can only speculate on the underlying reasons for these profound changes other than to say it appears there must be strong environmental elements. This is seen in examples of studies that have found environmental factors associated with different neurological diseases, though not without controversy. These include links with certain occupations [21–23], endocrine disruptive chemicals [25], rises in background electromagnetism [26–30] and the influence of the one of the most frequent chemical in the human environment, organophosphates [31–33]. Thus, these multiple, possibly, interactive environmental factors impact upon individuals with underlying genetic predisposition. This may account for why oxidative stress is linked to both neurological and cancer syndromes, as the environmental factors are not linier but rather as people respond depending upon their individual genetic predisposition [34–39].

When we recall other environmental impacts upon human health such as DDT, smoking, lead in petrol and asbestos, all had ‘early warning’ indications but slow governmental reaction [40]. This can be seen today in relation to asbestos, which usually takes two decades to manifest itself before serious symptoms emerged, exemplified by the current cohort of Western people dying from asbestosis [41–43]. Further research is needed to explain our results in order to avoid a possible repetition of the unacceptable delays from past health-environmental crises. Such numbers of people and rates dying of brain related diseases in the most advanced countries is a major concern. Urgent answers are needed to explain this `hidden epidemic’. Hopefully finding measures that can redress the underlying environmental factors impacting upon human health.

Acknowledgements

None of the authors have any vested or conflict of interest in this study. Nor was there any external funding for the study. All authors contributed to the development, design and analysis of the study and in the final write-up of the paper.

Additional information

Notes on contributors

Colin Pritchard

Professor Colin Pritchard, crosses many disciplinary boundaries having the advantage of being able to look back more than 50 clinical year and see the bigger picture.  His comparative international studies have ranged from child-abuse-related-deaths, child mortality and poverty, suicides, truancy an delinquency, and was amongst the first to note substantial changes in brain-related-diseases in the Western world.

Lars Hansen

Dr. Lars Hansen, Consultant Psychiatrist has shared with Professor Pritchard in their suicide studies, as he is a specialist in early onset psychosis and problems a pyramidal side affects.

Anne Silk

Dr. Anne Silk, Senior Research Fellow in Public Health, has a long research career, especially interested in possible contributory factors that has led to the accelerating of neurological morbidity, especially with its earlier onsets, as she too benefits from longevity that facilitates lateral thinking.

Emily Rosenorn-Lanng

Emily Rosenorn-Lanng, Senior Statistical Research Officer, who has been in a long collaborator in the team and also shares a particular interest in possible environmental factors.