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8/3/2019 Mental Fatigue and Attention Problems Due to Brain Injury
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Brain Injury, December 2009; 23(1314): 10271040
Mental fatigue and impaired information processing after mild andmoderate traumatic brain injury
BIRGITTA JOHANSSON, PETER BERGLUND, & LARS RONNBACK
Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, The Sahlgrenska
Academy, University of Gothenburg, Gothenburg, Sweden
(Received 4 March 2009; revised 8 October 2009; accepted 18 October 2009)
AbstractPrimary objective: Mental fatigue is a common symptom after brain injury. Its mechanisms are not fully understood andit has been difficult to find an objective way of measuring it. The aim was to compare cognitive tests with a newself-assessment questionnaire about mental fatigue.
Methods and procedures: Individuals reporting mental fatigue for 6 months or more after mild traumatic brain injury (MTBI)or traumatic brain injury (TBI) and controls were assessed for subjective fatigue, information processing speed, workingmemory and attention. Depression and anxiety were also assessed in the individuals with brain injury.Results: Individuals with MTBI or TBI reported significantly more problems with mental fatigue and related symptoms thancontrols. A significantly decreased information processing speed (digit symbol-coding, reading speed, trail making test) wasfound in those on sick leave due to MTBI or TBI, compared to controls. Divided attention was affected to a lesser extentand no effect was detected on working memory.Conclusion: Mental fatigue after MTBI can last for several years. It can be profoundly disabling and affect working capacityas well as social activities. Subjective mental fatigue following brain injury is suggested to mainly correlate with objectively
measured information processing speed.
Keywords: Mental fatigue, TBI, MTBI, self-assessment questionnaire, information processing speed, working memory, digit
symbol-coding, reading speed, TMT
Introduction
Fatigue is a common symptom after both a mild
traumatic brain injury (MTBI) and traumatic brain
injury (TBI). Mental fatigue is characterized by
concentration and memory difficulties as well as
increased fatigability after mental activities, withdepletion of energy which can take days to recover
from. For most individuals the problem disappears
within a year, but for some, mental fatigue becomes
a chronic problem that affects daily life. The
mechanisms that cause mental fatigue are not fully
understood and no clear treatment guidelines have
been developed. Therefore, it is important to find
appropriate assessment methods to increase knowl-
edge of mental fatigue.
Concern about the different aspects of mental
fatigue has been addressed for neurological diseases
and injuries [1] and an investigation revealed thatit is the most common problem following TBI, as it
can last for many years and influences daily activities
[2]. One third of the patients who suffered from
MTBI complained of severe fatigue at 6 months as
well as a decrease in physical and social activities [3],
while 40% complained of headache and fatigue
Correspondence: Dr Birgitta Johansson, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, The Sahlgrenska
Academy, University of Gothenburg, Per Dubbsgatan 14, 1tr, SE 413 45 Gothenburg, Sweden. Tel: 46-31-34210 00. E-mail: birgitta.johansson2@
vgregion.se
ISSN 02699052 print/ISSN 1362301X online
2009 Informa Healthcare Ltd.DOI: 10.3109/02699050903421099
8/3/2019 Mental Fatigue and Attention Problems Due to Brain Injury
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1 year after concussion [4]. After 5 years, 73%
reported still having a problem with fatigue, which
affected them in everyday life [5]. Even after 10
years, fatigue was still present, irrespective of injury
severity [6]. Improvement was reported during the
first year, after which it was limited [7]. Fatigue after
brain injury has a significant effect on well-being and
quality of life and is suggested to be due to the brain
injury, as it cannot be explained as an effect of
depression, pain or sleep-disturbance [8]. In addi-
tion, the degree of fatigue is not related to the
severity of the injury, age or time since injury [9, 10].
Mental fatigue is central to many neurological
disorders and biological models have been proposed
as a means of understanding pathophysiological
mechanisms. Chaudhuri and Behan [1] formulated
a hypothesis suggesting that metabolic and structural
lesions that disrupt the usual process of activation
in pathways interconnecting the basal ganglia,
thalamus, limbic system and higher cortical centreare implicated in the pathophysiological process
of central fatigue. Another hypothesis proposed
that functions of the glial cells in the brain are out
of balance [11, 12]. Inflammatory activity with
microglial activation and the production of cytokines
could be responsible for an attenuated astroglial
fine-tuning and support of the neuronal glutamate
signalling, which is of the utmost importance for
information processing in the brain. In addition,
other systems have been found to be affected.
Recent research results demonstrate that there is
an imbalance in the regulation of the hypothalamus-
hypophysis-adrenal cortex (HPA)-axis, which isunder the control of the excitatory neurotransmitter
glutamate [13]. It was also shown that glutamate can
activate the amygdala to release the corticotropine-
releasing factor [14], which in turn can lead to
increased glucocorticoid levels. Moreover, it has
been suggested that genetic variation is
important [15].
It has proved difficult to relate cognitive functions
such as attention and memory to mental fatigue
[10]. However, mental fatigue theories suggest that
cognitive activities require more resources than
normal [16] and subjective assessment of fatigue
has been found to correlate with complex selectiveattention [9] and information processing speed [17].
Higher neuronal activity compared to controls
during a mental activity may also indicate an
increased cerebral effort after brain injury [18] and
support for the theory above [16].
There are a large number of different scales for
assessing fatigue, of which several were designed
for a specific disease [19] as well as for patients with
brain injury [10]. This means that different scales
report varying effects and accordingly it is difficult
to conduct intervention studies due to the lack of
validated tests [20]. The aim of this project was to
find better ways to determine mental fatigue. Both
subjective and objective measurements were used
with the intention of more clearly identifying
items associated with mental fatigue. A new self-
assessment scale was employed for the subjective
rating of mental fatigue and related symptoms [21]
in combination with objective tests of information
processing speed, working memory and divided
attention.
Method
Participants
The main purpose was to study subjectively reported
mental fatigue and cognitive functions and not the
frequency of mental fatigue. Participants with MTBI
or TBI who were reporting long-term mental fatigue
were recruited by means of an advertisement in alocal newspaper. Some subjects were also recruited
by a Swedish patient association for people with
brain injury and from the department of neurology at
the Sahlgrenska University hospital. The inclusion
criteria were MTBI or TBI with no other neurolog-
ical or psychiatric illnesses, no dyslexia and hav-
ing sustained the injury over 6 months prior to
inclusion. All MTBI participants had been diag-
nosed with commotion/concussion (ICD-10 S06.0).
Participants with TBI were not differentiated
between moderate and severe, but they all described
a moderate-to-severe head trauma and had been
hospitalized for varying lengths of time (months to ayear) and had received rehabilitation in specialized
units. The subjects with MTBI or TBI had no
motor complaints and all were living independently.
Some were working full time, while others were on
sick leave, most of them 100%, but some to a lesser
extent such as 25, 50 and 75%. MTBI working full
time were analysed separately, as it was assumed that
they could give valuable information about working
capacity and about severity of mental fatigue.
Control participants with no history of head injury,
no neurological disturbance or psychiatric illness,
no limitation in working capacity and of similarage, education and gender were recruited from the
general community. The study was approved by
the regional Ethics Committee in Gothenburg. The
participants gave their informed written consent
before the assessment.
Self-assessment of mental fatigue
The self-reported questionnaire contains 15 ques-
tions and was adapted from Rodholm et al. [22].
The questions cover the most common symptoms
occurring after brain injury [23, 24]. Each item
1028 B. Johansson et al.
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comprises examples of common activities to be
related to four response alternatives (see Appendix).
The rating is based on intensity, frequency and
duration. Higher scores reflect more severe symp-
toms. A rating of 0 corresponds to normal function,
1 indicate a problem, 2 a pronounced symptom and
3 a maximal symptom. It is also possible to indicate
a score between the given alternatives (0.5, 1.5, 2.5).
The intention was to construct an assessment scale
with response alternatives that can help the subjects
to be clearer and more consistent in their judgement.
The questions concern fatigue in general, lack of
initiative, mental fatigue, mental recovery, concen-
tration difficulties, memory problems, slowness of
thinking, sensitivity to stress, increased tendency to
become emotional, irritability, sensitivity to light and
noise, decreased or increased sleep as well as 24-hour
variations. The construction of the questionnaire
resemble the Comprehensive Psychopathological
Rating Scale (CPRS) designed to measure changesin psychopathology over a short period [25].
A clinical interview was performed based on the
questions from the self-assessment scale as well as
the CPRS to measure the presence of depression
and anxiety. Participants with brain injury were
also asked about changes in their leisure and social
activities, both at home and outside the home
according to the structured interview for the
Glasgow Coma Scale [26].
Neuropsychological tests
The neuropsychological tests measured informationprocessing speed (the time required to execute
a cognitive task within a finite time period) [27],
attention, working memory, verbal fluency and
reading speed, which are common problems after
MTBI. The tests included were digit symbol-coding
from the WAIS-III NI [28], measuring information
processing speed. Attention and working memory,
both auditory and visual, were measured by means
of the digit span and spatial span [28]. Both tests
included repetition of forward series of random
numbers or blocks in order as well as in reverse.
The verbal fluency test (FAS) measures the ability to
generate as many words as possible beginning witha specific letter within 1 minute [29]. Parts A and B
of the Trail Making Test (TMT) were administered
according to the published guidelines [30] in order
to measure visual scanning, divided attention and
motor speed [31]. The test consists of a series of
connect-the-circle tasks, part A with a numerical
order of 125 and part B comprising letters and
digits in alternating numerical and alphabetical
order, which have to be completed as quickly as
possible. In order to evaluate higher demands such
as dual tasks, a series of new tests was constructed
with three and four factors, respectively. The same
number of circles (25) was used in all parts. The
alternation between factors was similar to part B
except for the fact that months were added in part C
and both months and days of the week in chrono-
logical order in part D. In the latter, the order of
letters and digits was changed (A: 125, B: 1-A-2-
B-3-C, C: 1-A-January-2-B-February-3-C-March,
D: A-1-January-Monday-B-2-February-Tuesday).
The reading speed was measured using the DLS
reading speed test [32]. The participants were
instructed to read the text silently and mark the
correct word that corresponded to the meaning of
the sentence from 36 evenly distributed parentheses
containing three words, which serves as a check of
reading comprehension. The whole text contains
887 words and the time taken to read each page was
recorded. The average number of words per second
and page was measured. The native language of the
healthy controls was Swedish, with the exceptionof one individual whose first language was English,
but who had lived in Sweden for 10 years and
spoke Swedish fluently. None of the healthy controls
reported any reading problems or dyslexia. One
MTBI participant reported dyslexia and was
excluded from the analysis of reading speed.
The assessment was made in the following order:
self-assessment of fatigue, Trail Making Test, assess-
ment by the examiner, i.e. a neuropsychologist or
psychiatrist, of subjective fatigue, depression and
anxiety, digit symbol-coding, digit span, spatial span,
verbal fluency, reading speed and social function.
The instruments were administered according to therespective published guidelines.
Statistical analysis
The self-assessment questions and binominal data
were analysed by the non-parametric Kruskal-
Wallis, Mann-Whitney and Chi-squared tests.
Bonferroni adjustment was used after multiple
comparisons. ANOVA, ANCOVA and regression
analysis were employed for the parametric data and
Bonferroni served as a post-hoc test. Spearmans
rank correlation was used for the analysis of the
subjective assessments and cognitive tests. Theinternal consistency reliability of the self-assessment
questions was analysed by means of Cronbachs
alpha. SPSS 16.0 for Windows was used for data
analysis.
Results
Demographics
The participants were divided into four groups;
controls (Group 1), persons with MTBI in full time
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employment (Group 2), persons with MTBI who
were on sick leave (Group 3) and persons with TBI
who were on sick leave (Group 4). As no statistical
difference was found between the groups with
different degrees of sick leave (25, 50, 75 or
100%), they were therefore combined. Sick leaveof 100% was the most common. Demographic data
are presented in Table I. More women than men
participated in the study, but there was no significant
difference in number of men and women between
the healthy control and brain injured groups.
A significant age difference emerged (F9.01,
p
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injury were found for reading speed, where group 2
was faster than group 4, and for the TMT D, where
group 2 was faster than group 3. Reading speed and
digit symbol-coding were maintained at almost the
same speed in both tests.
No significant difference in auditory (digit span)and visual (spatial span) working memory for total
and backward scores or visual span forward were
detected between groups. The only significant
difference was that group 3 scored fewer digits
forward compared to the control group (p
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significantly decreased their outdoor physical activ-
ity, activity at home and even social life outside and
in the home compared to MTBI working full time
(all questions, p
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one participant was assessed as being depressed.
Aches and pain from the CPRS was above 0.5 in
groups 3 and 4 and both increased and decreased
sleep was reported (Figure 5).
Discussion
Mental fatigue after MTBI is a common problem
and it often limits working capacity as well as the
ability to participate in social activities. The present
study aimed at investigating mental fatigue after
MTBI or TBI and examining whether it can be
related to cognitive functions. The authors wereunable to draw any conclusion about frequency,
as the participants were recruited on the basis of
reporting mental fatigue following brain injury.
Subjective effects
Subjects with MTBI and TBI, irrespective of work-
ing capacity and severity, reported significantly more
problems, both for total sum of scores and for all
separate items in the self-assessment questionnaire
compared to controls. In particular, mental fatig-
ability, mental recovery and stress sensitivity were
rated as high. The self-assessment scale includeditems with a high internal consistency and the
questions also correlated significantly with each
other. The scale was also relevant for different
diseases [21]. This indicates that the core problem
with mental fatigue comprise a broader spectrum
of relevant items with either primary or secondary
symptoms. The response alternatives may also make
the self-reports more consistent and might have
resulted in a more definite deviation from the healthy
controls. Social and leisure activities were also
affected and many of the participants had reported
mental fatigue for many years. This is in agreement
with other studies reporting that fatigue plays aprominent role in the lives of many people a long
time after a TBI [25].
Individuals with MTBI who were working full
time did not change their leisure and social activities,
although they rated their mental fatigue and related
items on the same level as the participants with
MTBI and TBI who were on sick leave. This may
appear strange but, depending on their mental load
during the day, subjects working full time might
need to devote more attention to mental work and
use more energy than is normal.
Figure 3. The figure shows the significant negative correlation for
the total sum score and digit symbol-coding (scale score used here
is adjusted for age in accordance with the WAIS-III manual).
Figure 4. Changes in leisure and social activities. Participants
with MTBI who were on sick leave had significantly decreased
their leisure and social activities both outside the home and at
home compared to those with MTBI who were working full time
(yesdecreased activity).
Figure 5. Selected items from the expert assessment with CPRS
and the self-assessment scale, showing median rating of depres-
sion, anxiety, pain, sleep, mental fatigue and sensitivity of stress.
Mental fatigue, TBI and information processing 1033
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If they had the same mental effort, those on sick
leave might become more easily fatigued, but sick
leave or part time work probably helps them to
conserve their energy, which is crucial, as today rest
is the most important restorative factor for indivi-
duals who suffer from mental fatigue. If, as
suggested, mental activities require more cognitive
or cerebral effort than normal [16, 18, 34], this
would explain the similar subjective ratings among
individuals with brain injury. Unlike in the case of
those on sick leave, objective cognitive tests did not
differ between healthy subjects and those with
MTBI who were working full time and individuals
with MTBI who were working full time read faster
than both the MTBI group on sick leave and the TBI
group and were faster in the TMT D than the MTBI
group on sick leave, indicating a difference in injury
severity.
Objective effects
Objective tests dependent on information processing
speed were significantly impaired in the participants
with MTBI on sick leave and the TBI group
compared to controls. The working memory tests
were not affected, with the exception of a significant
decrease in group 3 on digit forward. Age correlated
with digit symbol-coding [28] as well as with TMT
A and B [35] and also with the total sum score for
the self-assessment scale. However, after controlling
for age (ANCOVA), significant differences remained
for information processing speed. Regression analy-
sis also indicated that age contributed to the varia-tion in self-assessment, but to a lesser extent than
information processing speed. It is therefore sug-
gested that information processing speed is a signif-
icant factor related to mental fatigue in persons with
MTBI and TBI, even when taking account of age.
Age is thus significant in the self-assessment of
fatigue and comparison between groups or interven-
tion studies must control for age. The order of the
tests cannot explain the slower information process-
ing speed as due to fatigability during the test
session, as the TMT, which was administered at the
beginning of the assessment, was also characterized
by decreased speed.The result is in agreement with studies that
describe information processing speed as the most
prominent function to be affected after brain injury
[27, 36] and other neurological diseases [37, 38].
Martin et al. [39] reported decreased information
processing speed, but no effect on working memory
after TBI. Reaction time increased when a more
difficult information processing test was used [40].
Spatial and digit span were in accordance with
previous reports and spatial span forward and
backward were on nearly the same level, while digit
span forward was higher than backward among
both healthy controls [41] and participants with mild
injury [42]. The TMT results of parts A and B were,
in the case of the control participants, close to the
normative data presented by Tombaugh [35]. When
compared with the WISC-III manual, the control
group accords well with what is expected for a
healthy group.
Reading is a complex activity, involving automa-
ticity, information processing speed and working
memory. It is also an important activity in daily life
and the most realistic test used in the present study.
Reading is also commonly reported as tiresome and
slow by patients after brain injury. However, it is
usually employed for assessing dyslexia and not for
testing cognitive disorders after brain injury or
neurological diseases. This study demonstrates that
reading speed can be a useful test for further
exploration of the mechanisms involved in mental
fatigue. TMT C and D, requiring a high load oninformation processing and divided attention, may
also be valuable as this more complex and sensitive
test makes it possible to capture milder cognitive
deficits after brain injury with co-occurring mental
fatigue.
Aspects on mental fatigue and cognitive function
A multi-factorial approach is most often used to
describe the occurrence of mental fatigue. DeLuca
et al. [43] discussed the problem of relating cognitive
tests to fatigue and demonstrated increased neuronal
activity after mental activity in patients with multiplesclerosis (MS). Similar results were also reported by
Kohl et al. [18] for patients with TBI. Furthermore,
a working memory task after brain injury was
associated with increased neuronal activity [44].
Azouvi et al. [16] proposed that mentally tiresome
activities after brain injury were related to reduced
resources and that patients with brain injury also
described mental activity as more energy demanding
than healthy persons. The same was reported after a
divided attention task [34]. Moreover, a simultane-
ous load on working memory that demands total
control of the situation was more tiresome than an
automatic activity [45]. The participants with MTBIwho were working full time also had a significantly
higher total sum score of the self-reporting items
than the controls, thus indicating that mental activity
is more energy demanding than normally expected.
The correlation here between mental fatigue and
information processing speed is also in agreement
with other studies [17, 46, 47]. Thumb pressing as
an objective test of speed did not differ between
control and TBI groups but was correlated with
subjective fatigue [46]. Ziino and Ponsford [47]
reported significantly slower performance on a
1034 B. Johansson et al.
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complex selective attention task and suggested an
association with subjective fatigue. Furthermore,
information processing improved after a repeated
computerized test for healthy controls, something
not found in the subjects with brain injury [17].
Information processing speed is known to have an
important influence on higher order cognitive func-
tions such as working memory, episodic memory,
executive function, reasoning, problem-solving,
visual spatial as well as academic skills [27]. It is
also important for many jobs due to the high
demand on efficiency. A combination of subjective
and objective measures is suggested for assessing
mental fatigue, as it can provide a more specific
assessment of the level of mental fatigue and also be
of great value for estimating working capacity and
the need for rest and rehabilitation.
Depression
Depression is common after brain injury but, withthe exception of one individual, the participants who
voluntarily took part in this study were not found to
be depressed. Furthermore, the results were not
controlled for depression, as very low clinical ratings
close to normal (0 or 0.5) of core items of depression
were found for the participants with brain injury.
As questions overlap between CPRS and the
self-assessment of mental fatigue and related symp-
toms, it was decided to show the depression and
anxiety items separately in Figure 5. In the figure are
also some of the symptoms from the clinical rating
shown for a comparison with depression symptoms.
Depression is more common among MTBI and
TBI, but the inclusion criteria to this study and also
the subjects being recruited voluntarily may have
resulted in fewer depressed patients than would have
been found in an epidemiological study. A mixture
of fatigue, cognitive and depression items are often
included in different depression scales and, together
with other methodological discrepancies between
studies, can explain some of the variation in depres-
sion (from 677%) after brain injury [10]. Many
studies report increased susceptibility to depression
after brain injury, but the connection with mental
fatigue is less clear. Fatigue after brain injury wassuggested to be an effect of the brain injury itself and
not a result of pain, depression or sleep-deprivation
[8]. Therefore, the authors hold that mental fatigue
must be assessed thoroughly and needs to be
separated from depression, as both symptoms are
common and can co-occur but require different
intervention strategies [48].
Consideration of the study group and tests
Time since injury varied between participants,
but no significant correlation between cognitive
function, subjective assessment and years since
injury was found. In the case of 20 participants
(34%), mental fatigue remained for more than
10 years after the injury. This is in accordance with
other studies, reporting long-term visual spatial and
academic skill problems associated with fatigue after
brain injury [24, 7, 49, 50], for up to 10 years,
irrespective of injury severity [5]. Cognitive impair-
ments are also common 10 years after brain injury
[50].
A high proportion of the participants in group 3
had suffered two MTBI. Although it cannot be ruled
out that their problems were worse, no significant
difference was found when those reporting one
and two brain injuries in group 3 were compared.
No significant difference emerged between males
and females for the included items in the subjective
self-assessment scale for mental fatigue or in the
cognitive tests. There were, however, more female
participants in this study. One cannot draw anyconclusions about why more females volunteered
but, in other studies, more women than men
have reported subjective complaints after brain
injury [8, 51].
Limitations of the study
The differentiation of brain injury was not based on
commonly used classification systems, at it was
not possible to collect case records from different
hospitals. Furthermore, mental fatigue has not been
related to severity of the injury and it was therefore
decided to make this division into groups based onthe subjects description of the injury, if it has been
classified as a MTBI or a more severe injury and also
due to hospitalization. The estimation of depression
and anxiety is based on a clinical interview according
to CPRS and a self-assessment of depression
and anxiety is not done here, but would have been
valuable for adjustments and comparisons in statis-
tical analyses. The items included in the self-
assessment scale cover different areas such as sleep,
sensory, emotional and cognitive domains, which
all fit well together. Whether they are primary or
secondary effects to the brain injury is unknown
today, but will be important to explore in the future.In conclusion, mental fatigue after MTBI or TBI
remains in many cases for a very long time and can
be profoundly disabling, affecting working capacity
as well as recreation and social activities. It is
proposed that the self-assessment scale used here
in combination with tests that primarily measure
information processing speed and a high cognitive
load on attention might make it possible to capture
problems described by patients with mental fatigue
such as reading, participating in discussions and
activities involving an environment containing a
Mental fatigue, TBI and information processing 1035
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large amount of stimuli. Subjective mental fatigue
after MTBI and TBI is thus suggested to primarily
correlate with objectively measured information
processing speed.
Acknowledgements
This work was supported by grants from The Health
& Medical Care Committee of the Region Vastra
Gotaland, Swedish Research Council, 21X-13015
and from Fyrbodalinstitutet.
Declaration of interest: The authors report no
conflicts of interest. The authors alone are respon-
sible for the content and writing of the paper.
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Appendix: Adjusted version
Self report of mental fatigue and related symptoms
This questionnaire will help us to find out how you perceive your health.
We are interested in your present condition, that is how you have felt during the past month.
Each question below is followed by four statements that describe: No (0), Slight (1), Fairly serious (2) and
Serious (3) problems.
We would like you to place a circle around the figure before the statement that best describes your problems.
Should you find that your problem falls between two statements, there are also figures to indicate this.
1. Fatigue
Have you felt fatigued during the past month? It does not matter if the fatigue is physical (muscular) or mental.
If you recently experienced something unusual (for example an accident or short illness) you should try to
disregard it when assessing your fatigue.0 I do not feel fatigued at all. (No abnormal fatigue, do not need to rest more than usual).
0.5
1 I feel fatigued several times every day but I feel more alert after a rest.
1.5
2 I feel fatigued for most of the day and taking a rest has little or no effect.
2.5
3 I feel fatigued all the time and taking a rest makes no difference.
2. Lack of initiative
Do you find it difficult to start things? Do you experience resistance or a lack of initiative when you have to start
something, no matter whether it is a new task or part of your everyday activities?
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0 I have no difficulty starting things.
0.5
1 I find it more difficult starting things than I used to. Id rather do it some other time.
1.5
2 It takes a great effort to start things. This applies to everyday activities such as getting out of bed, washing myself and eating.
2.5
3 I cant do the simplest of everyday tasks (eating, getting dressed). I need help with everything.
3. Mental fatigue
Does your brain become fatigued quickly when you have to think hard? Do you become mentally fatigued from
things such as reading, watching TV or taking part in a conversation with several people? Do you have to take
breaks or change to another activity?
0 I can manage in the same way as usual. My ability for sustained mental effort is not reduced.
0.5
1 I become fatigued quickly but am still able to make the same mental effort as before.
1.5
2 I become fatigued quickly and have to take a break or do something else more often than before.
2.5
3 I become fatigued so quickly that I can do nothing or have to abandon everything after a short period ($5 minutes).
4. Mental recoveryIf you have to take a break, how long do you need to recover after you have worked until you drop or are no
longer able to concentrate on what you are doing?
0 I need to rest for less than an hour before continuing whatever I am doing.
0.5
1 I need to rest for more than an hour but do not require a nights sleep.
1.5
2 I need a nights sleep before I can continue whatever I am doing.
2.5
3 I need several days rest in order to recover.
5. Concentration difficulties
Do you find it difficult to gather your thoughts and concentrate?
0 I can concentrate as usual.0.5
1 I sometimes lose concentration, for example when reading or watching TV.
1.5
2 I find it so difficult to concentrate that I have problems, for example reading a newspaper or taking part in a conversation with
a group of people.
2.5
3 I always have such difficulty concentrating that it is almost impossible to do anything.
6. Memory problems
Do you forget things more often than before, do you need to make notes or do you have to search for things
at home or at work?
0 I h ave no memory p roblems.
0.51 I forget things slightly more often than I should, but I am able to manage by making notes.
1.5
2 My poor memory causes frequent problems (for example forgetting important meetings or turning off the cooker).
2.5
3 I can hardly remember anything at all.
7. Slowness of thinking
Do you feel slow or sluggish when you think about something? Do you feel that it takes an unusually long time
to conclude a train of thought or solve a task that requires mental effort?
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0 My thoughts are neither slow nor sluggish when it comes to work involving mental effort.
0.5
1 My thoughts are a bit slow one or a few times each day when I have to do something that requires serious mental effort.
1.5
2 My thoughts often feel slow and sluggish, even when carrying out everyday activities, for example a conversation with a person or
when reading the newspaper.
2.5
3 My thoughts always feel very slow and sluggish.
8. Sensitivity to stress
Do you find it difficult to cope with stress, that is doing several things at the same time while under time
pressure?
0 I am able to cope with stress in the same way as usual.
0.5
1 I become more easily stressed, but only in demanding situations that I was previously able to manage.
1.5
2 I become stressed more easily than before. I feel stressed in situations that previously did not bother me.
2.5
3 I become stressed very easily. I feel stressed in unfamiliar or trying situations.
9. Increased tendency to become emotionalDo you find that you cry more easily than previously? Do you often burst into tears when, for example, you
watch a sad film or talk with your family members? If you recently experienced something unusual (for example
an accident or short illness) you should try to disregard it in your assessment.
0 I am not more emotional than I used to be.
0.5
1 I am more emotional than other people but it is something that is natural for me. I start to cry or my eyes fill with tears easily,
but only in relation to things that affect me deeply.
1.5
2 My emotions are problematic or embarrassing. I sometimes even start to cry about things that mean nothing to me. I try to avoid
certain situations because of this.
2.5
3 My emotions cause me great problems. They disturb my day-to-day relationship with members of my immediate family and
make it difficult for me to cope outside the home.
10. Irritability or a short fuse
Are you unusually short-tempered or irritable about things that previously did not bother you?
0 I am not more short-tempered or irritable than I used to be.
0.5
1 I become more easily irritated, but it does not last very long.
1.5
2 I become irritated very quickly about small things or things that do not bother other people.
2.5
3 I react with extreme anger or rage, which I find very difficult to control.
11. Sensitivity to light
Are you sensitive to strong light?0 I have no increased sensitivity to light.
0.5
1 I sometimes experience problems with strong light such as sunlight reflected by snow, water or glass, or strong lights at home,
but I am able to cope with it, for example by wearing sunglasses.
1.5
2 I am so sensitive to light that I prefer to carry out my daily activities in dim light. I find it difficult to leave the house without
sunglasses.
2.5
3 My sensitivity to light is so strong that I am unable to leave the house without sunglasses. I keep the blinds (or equivalent) drawn
at all times.
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12. Sensitivity to noise
Are you sensitive to noise?
0 I do not suffer from increased sensitivity to noise.
0.5
1 I sometimes have difficulty with loud noise (for example music, noise from the TV or radio or sudden, unexpected sounds),
but I can deal with it easily by turning down the volume. My sensitivity to noise does not disturb my everyday life.
1.5
2 I have a marked over-sensitivity to noise. I have to avoid loud noise or reduce it (for example by means of ear plugs) in order
to cope with everyday life.
2.5
3 My sensitivity to noise is so great that I find it difficult to manage at home, despite sound insulation.
13. Decreased sleep at night
Do you sleep badly at night? If you are sleeping more than before at night, please place a circle around the 0.
If you are taking sleeping tablets and sleep normally, please place a circle around the 0.
0 I do not sleep less than before.
0.5
1 I have slight problems falling asleep or my sleep is shorter, lighter or more restless than before.
1.5
2 I sleep at least 2 hours less than before and wake up frequently during the night without anything disturbing me.
2.53 I sleep less than 23 hours per night.
14. Increased sleep
Do you sleep longer and/or more deeply than before? If you are sleeping less than before, please place a circle
around the 0. NB: Please take account of time spent sleeping during the day.
0 I do not sleep more than usual
0.5
1 I sleep longer or deeper, but less than 2 hours more than usual, including naps during the day.
1.5
2 I sleep longer or deeper. At least 2 hours more than usual, including naps.
2.5
3 I sleep longer or deeper. At least 4 hours more than usual, and in addition I need to take a nap during the day.
15. 24-hour variations
Do you find that at certain times of the day or night the problems we asked about (for example tiredness, lack of
concentration) are better or worse? In the statements below, regularly means at least 34 days of the week.
0 I have not noticed that my problems are regularly better or worse at certain times, or I do not have any specific problems.
1 There is a clear difference between certain times of the day. I can predict that I will feel better at certain times and worse at other
times.
2 I feel unwell at all times of the day and night.
If you experience 24-hour variations:
When do you feel at your best? Morning Afternoon Evening Night
When do you feel at your worst? Morning Afternoon Evening Night
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