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53 Physioacta Vol.6-No.2

ATTENTION AND LEARNING IN MEDICAL STUDENTS

WITH DIFFERENT LEVELS OF ANXIETY AND

DEPRESSION

Manchevska S 1, Pluncevic-Gligoroska J

1, Bozhinovska L

2, Tecce J

3

1Department of Physiology with Anthropology, Medical Faculty, Skopje

2 Neuroscience and Electrophysiology Laboratory, Department of Biological and

Physical Sciences, South Carolina State University, Orangeburg, South Carolina,

USA 3

Psychology Department, Boston College of Arts and Sciences, Boston,

Massachusetts, USA

Abstract

The aim of the study was to estimate the speed and the efficiency of cognitive

performance in medical students with different levels of anxiety and depression.

Anxiety and depression were assessed by standardized psychiatric instruments

(Beck Anxiety Inventory - BAI and Beck Depression Inventory - BDI) which were

given to seventy second year medical students, (50 females and 20 males) aged 18-

20 years, in a form of self-rating questionnaires one day prior to examination of

cognitive performance. The subjects performed on two computerized psychological

tests: the Strop Color-Word test (SCWT) for divided attention and the test for

sustained attention, memory and learning. Total number of false recognitions,

number of trials necessary to fulfill the tests and the learning index for the P-R test

were the analyzed parameters of cognitive performance.

Based on the results of BAI and BDI, subjects were divided in three groups: low

anxiety and no depression (LA) (BAI = 4±1; BDI= 3.4±2.5; n=13), moderate

anxiety and no depression (MA) (BAI = 14.2±6.8; BDI= 8.5±6.1; n=44) and high

anxiety and marginal depressive mood (HA) group (BAI = 32.5±5.7; BDI=

17.7±6.5; n=8). The efficiency of attention and learning was highest in subjects

with low anxiety and no depression (total number of false recognitions on P-R test:

8.2±7.91), while with high anxiety and marginal depressive mood performed with

mean number of total false recognitions of 12.5±17.1(p<0.05). Subjects with

moderate anxiety levels and no depression showed worst results on both tests.

The results of our study showed that low levels of anxiety and nonexistence of

depressive symptoms have a positive effect on cognitive performance in medical

students, but high anxiety levels could also have facilitating effects on the learning

process depending on the difficulty of the task. There was no effect of different

levels of depression on attention and learning.

Key words: anxiety, depression, attention, learning, medical students

Manchevska S at al.

Physioacta Vol.6-No.2 54

ВНИМАНИЕ И УЧЕЊЕ КАЈ СТУДЕНТИ ПО МЕДИЦИНА СО

РАЗЛИЧНИ НИВОА НА АНКСИОЗНОСТ И ДЕПРЕСИЈА

Апстракт

Celta na trudot be{e da se proceni brzinata i efikasnosta na kognitivnata izvedba kaj studenti po medicina so razli~ni nivoa na anksioznost i na depresivnost. Anksioznosta i depresivnosta bea proceneti so standardizirani psihijatriski instrumenti (Beck Anxiety

Inventory - BAI i Beck Depression Inventory - BDI), koi vo forma na pra{alnici za samopopolnuvawe, im bea dadeni na 70 studenti po medicina vo vtora godina (50 devojki i 20 mom~iwa), na vozrast od 18 do 20 godini, eden den pred ispituvaweto na kognitivnata izvedba. Ispitanicite bea testirani so dva kompjuterizirani psiholo{ki

testa: Stroop -oviot test za podeleno vnimanie (Strop Color Word test -

SCWT) i testot za prepoznavawe na oblici (Pattern Recognition test- P-R), test za prodol`eno vnimanie, pomnewe i u~ewe. Vkupniot broj na pogre{ni prepoznavawa, brojot na obidi neophodni da se re{at testovite i indeksot na u~ewe za P-R testot bea analiziranite parametri na kognitivnata izvedba.

Vrz osnova na rezultatite na BAI i BDI, ispitanicite bea podelen vo tri grupi: niska anksioznosi i bez depresija (LA) (BAI = 4±1; BDI=

3.4±2.5; n=13), umerena anksioznost i bez depresija (MA) (BAI = 14.2±6.8;

BDI= 8.5±6.1; n=44) i visoka anksioznost i grani~no depresivno

raspolo`enie (HA) group (BAI = 32.5±5.7; BDI= 17.7±6.5; n=8).

Efikasnosta na vnimanieto i u~eweto be{e najgolema kaj ispitanicite so niska anksioznost i bez depresija (vkupen broj na

pogre{ni prepoznavawa na P-R testot: 8.2±7.91), dodeka ispitanicite so visoka anksioznost i marginalno depresivno raspolo`enie imaa

prose~no 12.5±17.1 pogre{ni prepoznavawa (p<0.05). Ispitanicite so umerena anksioznost i bez depresija poka`aa najlo{i rezultati na dvata testa. Rezulatite od na{iot trud poka`aa deka niskite nivoa na aksioznost imaat pozitiven efekt na kognitivnata izvedba kaj studentite po medicina, no deka i visokite nivoa na anksioznost mo`at isto taka da imaat pozitivni efekti na procesot na u~ewe vo zavisnost od te`inata na zada~ata. Razli~nite nivoa na depresivnosta nemaa vlijanie vrz vnimanieto i u~eweto kaj studentite po medicina. Klu~ni zborovi: anksioznost, depresija, vnimanie, u~ewe, studenti po

medicina. Introduction

Many studies have recognized university students worldwide as a population, in

which the rates of depression and anxiety are higher than in the general population.

During this period of life, there are many stressors, including low socioeconomic

status, uncompleted processes of separation and individualization of the young

person, lack of social relations, worries about academic achievement and the future

career goals, which can lead to adoption and maintenance of maladaptive

behaviours, such as anxiety and depressive symptoms, and poor academic

achievement in students. Higher rates of high anxiety, depression and other

ATTENTION AND LEARNING IN MEDICAL STUDENTS.....

55 hysioacta Vol.6-No.2

symptoms of psychological distress have been reported for medical students in

countries world wide (1-9).

Effective cognitive performance, especially the learning ability of the student and

his/her motivation are important for their academic achievement (12,13,16).

However many reports suggest that high levels of anxiety have a negative impact

on attention, memory and problem solving (as components of cognitive

performance), whereas low and moderate anxiety levels are related to better

cognitive performance in subjects (12,14,15). It is now commonly accepted that

depression is associated with a number of deficits in episodic memory and learning,

which do not fully recover upon the remission of the episode. The underlying

mechanisms of these effects of mood disorders on cognition are still unknown,

although recent studies suggest that cognitive impairment could be a core

neurobiological feature of these disorders (23).

The aim of the present study was to estimate the speed and the efficiency of

cognitive performance in medical students, with different levels of anxiety and

depression, at the early stage of education.

Material and Methods

The study took place in Skopje, University Ss. Cyril and Methodius, Republic of

Macedonia. It was conducted during the second semester of the 2011-2012

academic year at the second year of Faculty of Medicine. Seventy students, out of a

cohort of 160 second year medical students, volunteered for the study. The

participant’s age ranged from 18 to 20 years. For the purpose of clinical and

psychological evaluation of the levels of anxiety and depression, two standardized

instruments (Beck Anxiety Inventory - BAI and Beck Depression Inventory - BDI)

in a form of self-rating questionnaires, were administered to the subjects, one day

before the psychological testing of the cognitive performance.

The level of anxiety was measured by Macedonian version of Beck Anxiety

Inventory (15). It consists of 21 questions related to various aspects of anxiety. The

intensity of perceived anxiety was rated from 0 to 3, with 0 representing the least

serious and 3 the most serious symptoms. BAI scores from 0-7 were ranked as low

anxiety level, BAI scores from 8-25 as moderate anxiety and BAI scores above 25

as high anxiety levels.

The degree of depression was measured by Macedonian version of 21-item revised

form of Beck Depression Inventory. This instrument is culture free, well-validated

and has firm cut-offs that are strongly predictive of clinical impairment. The BDI

statements were ranked from 0 to 3, with 0 representing the least serious and 3 the

most serious symptoms. BDI scores from 0 to 10 were ranked as “no depression”,

BDI scores from 11-20 as “marginal depressive mood”, and BDI scores from 21 to

63 as “manifest depression”. We used the BDI scores ≥ 21 as a well established

criterion for moderate depression. The participating students gave informed consent

and completed the questionnaire anonymously using code names. Validation of the

responses by objective means was not undertaken.

To assess cognitive performance we used the Stroop Color Word Test and the

Pattern-Recognition memory and learning test. SCWT was originally developed in

1935 (Stroop, 1935) and is one of most frequently used reliable tests for divided

attention and cognitive inhibition (the ability to inhibit an over-learned (i.e.,

dominant) response in favour of an unusual one (22). Our version of the test

consisted of two subtasks. The stimulus material of each of these subtasks was

Manchevska S at al.

Physioacta Vol.6-No.2 56

shown on the computer monitor. The 25 stimuli for each subtask were distributed

evenly in a 5x5 matrix. The first subtask showed colour words in random order

(red, blue, yellow, green) displayed in congruous ink colour (for example: the

word red was displayed in red colour). The second subtask contained colour words

displayed in incongruous ink colour (for example the word red was displayed in

green colour). The participants were instructed to read the words (subtask 1) and to

name the colour of the displayed words (subtask 2) as quickly and as accurately as

possible. There was no time limit to complete a subtask. The times needed to

complete each subtask were analyzed parameters. The Stroop interference effect

was calculated by the difference between times needed to complete the subtask 2

and subtask 1, divided by the time necessary to complete the subtask 1.

The computerized pattern recognition (P-R) test of memory and learning consisted

of 8 test objects - patterns represented with different combinations of binary

numbers 1 and 0, divided into two classes (A and B). Each pattern was shown on

the computer monitor during the time interval of 5 seconds. The subject had to

memorise all of them for correct classification of patterns during a training period.

During the subsequent testing period each pattern of binary numbers was shown

on the monitor along with two keys labelled with the letters A and B. The subjects

had to choose the correct answer in a period of 5 seconds. If the answer was

correct, the sign “correct” appeared, if it was not the sign “not correct” appeared.

The appearance of the patterns was random. The test was completed when all eight

test patterns were correctly recognised and classified by the subject.

Total number of false recognitions (total number of mistakes - TM), number of

trials necessary to fulfill the tests (TT), total duration of the test (TD) and the

learning index (LI) for the P-R test were the analyzed parameters of cognitive

performance.

The Student t-test was used for the analysis of continuous variables. A p- value of ≤

0.05 for two-tailed test was considered significant.

Results

In the next tables and figures we show the results of the study.

Demographic variables, mean values of BAI and BDI scores and the distribution of

different levels of anxiety and depression of the participants in the study are shown

in table 1.

As can be seen in table 1, the mean BAI score in medical students was 14.4 ±9.4,

with a range between 2 and 41, and median = 11,5. Out of all participants (n=70),

12.9 % (n= 9) had a BAI score 26 or higher. Seven female students (7/50) showed

high anxiety symptoms vs. two male students (2/20). The mean BAI score in

female students was not higher than the one in male students (p=0.07) (Table 1).

The mean BDI score in medical students was 9 ±6.6, with a range between 0 and

26, and median = 7. Out of all participants, 8% (n= 6) had a BDI score 21 or

higher. The prevalence of depressive symptoms in female students was 7.8 % (n=4)

vs. 10% (n=2) in male students. The mean BDI score in female students was not

higher than the one in male students (p=0.5) (Table 1).

Based on the results of BAI and BDI, the participants were divided in three groups:

low anxiety and no depression group (LA) (BAI = 4±1; BDI= 3.4±2.5; n=13),

moderate anxiety and no depression (MA) (BAI = 14.2±6.8; BDI= 8.5±6.1; n=44)

and high anxiety and marginal depressive mood (HA) group (BAI = 32.5±5.7;

BDI= 17.7±6.5; n=8). The three groups of students did not differ on academic

achievement. The results of the Stroop test are shown on table 2 (Table 2). The

ATTENTION AND LEARNING IN MEDICAL STUDENTS.....

57 hysioacta Vol.6-No.2

mean values and the standard deviations of the parameters of pattern recognition

(P-R) test: total number of mistakes (TM), total duration (seconds) (TD), total

number of trials (TT), the learning index (LI %), are also shown on table 2 (Table

2).

Table 1 Demographic variables and the distribution of BAI and BDI

scores in subjects.

Subjects

Variables

Males

N=20

Females

N=50

P

Age (Mean and SD) 20.4±1.4 20.5±0.5 0.8

Average grades (Mean and SD) 8.2±1.05 8.42±0.64 0.29

BAI scores (Mean and SD) 11.16±8.01 15.69±9.72 0.07

BAI= 0-7

BAI= 8-25

BAI>25

26.3 %

63.1%

10.5%

15.7%

70.6%

13.7%

BDI scores (Mean and SD) 7.9 ±7.1 9.02 ±6.57 0.5

BDI<11

BDI = 11-20

BDI>20

70%

20%

10%

66.7%

25.5%

7.8%

Table 2 Mean values and standard deviations of analyzed parameters

of cognitive performance in medical students with different

levels of state anxiety and depression

Parameters Stroop test Pattern Recognition Test

Subjects Subtask1

(sec)

Subtask2

(sec)

Stroop

effect

TM TD (sec) TT LI%

LA 12.2±1.96 26.4±9.1 1.15±0.6 8.2±7.9* 166.7±102.5 58.5±38.7 92.5±4.8

MA 14.2±6.8 24.5±6.5 1.09±0.5 21.9±22 257±157 93.8±53.5 85.6±12.7

HA 13.4±2.7 26.7±5.6 1.08±0.7 12.5±17.1 187.4±152.1 75.2±64.8 91.2±9.4

*p<0.05

As can be seen in table 2, the total number of false recognitions (mistakes made

during pattern recognition) in LA subjects (8.2 ± 7.9) was significantly lower than

the one in MA group (21.9 ± 21.7) (p<0.05). The mean number of false pattern

Manchevska S at al.

Physioacta Vol.6-No.2 58

recognitions was 12.5 ± 17.1 in HA group. Other P-R parameters showed no

difference between groups (p>0.05), although LA and HA subjects showed better

results on all parameters than MA subjects.

Discussion

Our results suggest that the prevalence of high levels of anxiety estimated with BAI

in medical students in the second year of their education is 12,9%. These results are

consistent with our earlier findings of 15% prevalence of high anxiety in second

year medical students and 19.6% in first year medical students (7) . The Beck

Anxiety Inventory has widely been used for evaluation of anxiety, manifested by

cognitive, vegetative and panic symptoms in clinical and non-clinical populations.

It can be used for the evaluation of anxiety symptoms related to state anxiety (ref.

http://dx.doi.org/10.1016/j.bbr.2011.03.031

In contrast to trait anxiety concept, the state anxiety is a condition in which

vegetative, cognitive and panic symptoms have already been developed during a

certain period of time as a consequence of a certain situation or stressor. The

concept of high trait anxiety, on the other hand, refers to a habitual tendency to be

anxious over a long period of time, which implies a higher vulnerability and

development of state anxiety during stressful life events.

The prevalence of 8 % of moderate depression ((BDI ≥21) in second year medical

students is consistent with our previous findings of prevalence of 8.6% of second

year medical students (in 2008 year) who showed symptoms of moderate

depression (7). Several studies report that entering medical students show low

prevalence (0.5%-2%) of depressive symptoms (BDI ≥ 21) (11, 19) and low

anxiety symptoms (8, 9, 11, 12, 19). The increment of depressive symptoms

reaches a peak of intensity during second year (8, 9, 10, 11) and third year (19),

while anxiety reaches its’ peak in the fifth year of the training (4, 22). There are

also reports on higher prevalence of depressive symptoms (23%) in eastern

countries (25). Our results confirm our earlier findings (7) and suggest that the

prevalences of moderate depression and high levels of anxiety are stabile features

across several generations of medical students in Macedonia. Medical students

suffer from high psychological distress even on the onset of classes as well as

during the second year of training.

During this period of life, there are many stressors, including low socioeconomic

status, uncompleted processes of separation and individualization, lack of social

relations, worries about academic achievement and the future career goals, for the

young person to cope with, which can lead to adoption and maintenance of

maladaptive behaviours (anxiety, depression, substance use) and poor academic

achievement. It is, therefore, necessary to carefully monitor the students with high

(state and trait) anxiety levels and manifest symptoms of depression during their

education in order to prevent a development of clinically manifested anxiety

disorder and an episode of depression during stressful events which are an

inevitable part of life.

There are many studies which report that stress can have helpful as well as harmful

effects on behavioural and cognitive functioning in people. Recent research has

suggested that exposure to moderate, controllable stress benefits cognitive

performance, but exposure to uncontrollable stress or having a more extreme

subjective response to stress tends to harm the performance (24).

In our study, subjects with low levels of anxiety and with no depression performed

best on the both tests of cognitive performance although there was not any

significant difference between groups on any parameter of the SCWT. Alanshari,

ATTENTION AND LEARNING IN MEDICAL STUDENTS.....

59 hysioacta Vol.6-No.2

2004, also didn’t find any difference on the Stroop test between subjects with

different levels of anxiety. Our version of the SCWT consisted of 25 congruent and

25 incongruent words, which could be insufficient for the Stroop interference effect

to be shown in different groups. The small size of the stimuli (50), compared to the

size of 200 words in other studies could be one of the reasons that our participants

performed equally on this test.

The results on P-R memory and learning test show that the subjects with low

anxiety levels and no depression made significantly smaller number of false

recognitions than the students with moderate anxiety levels. The results of the

subjects with high state anxiety levels were closer to the ones of the LA group than

the ones of the MA group. There was no significant difference between groups on

other parameters of P-R test (total duration of the test, the learning index and total

number of trials). Our findings are not in accordance with many reports which

suggest that high levels of anxiety have negative impact on attention, memory and

problem solving, whereas low and moderate anxiety levels are related to better

cognitive performance in subjects, based on the recruitment of person’s

motivational capacities. In our previous study we estimated the cognitive

performance on P-R test in 30 second year medical students with low trait anxiety

levels and in 30 subjects with high trait anxiety levels. Subjects with high trait

anxiety levels showed significantly worse results on all P-R parameters than the

low trait anxiety students (25). Beside the small number of subjects with high state

anxiety levels in this study (8 students), one of the possible explanation for these

findings is that state anxiety is a condition which does not last for a prolonged

period of time, and can be generated on basic low levels of trait anxiety, so the

harmful effects of anxiety on cognition might have not been shown yet. The biggest

surprise in our study was the worst performance of the subjects with moderate

anxiety, which could be discussed in terms of insufficient motivation in these

participants. Many studies point out that besides motivation, subject’s intelligence

is a factor that strongly influences performance on tests of executive functions

(Stroop test, memory tests). In our study we didn’t measure subjects’ intelligence.

Many studies have suggested that high intensity of depression has an adverse effect

on cognition, particularly on executive functions (working memory) which are

directly related to attention and learning process (23). This effect could also be a

result of the loss of motivation, as one of core symptoms of depression, especially

in elderly patients with major depression (26). The comorbid anxiety worsens this

effect of depression on cognition (27). In our study, the levels of BDI scores in

medical students were relatively low (the highest BDI score was 26 out of maximal

63 points), which suggests that the depressive symptoms were more a manifestation

of a depressive reaction associated with higher anxiety levels as a maladaptive

reaction on stress, than a manifestation of clinical depression as an affective

disorder. That could be the reason why we found no effect of different levels of

BDI on the investigated variables, although the subjects with BDI scores ≥21

showed insignificantly worse results than the subjects with lower levels of

depression. The small number of subjects with high anxiety and moderate

depression (8 subjects) does not allow inference about causal associations between

the investigated issues and generalisation (although almost one half of the second

year medical students cohort participated in the study). However, it still provides

important information about emotional states and cognitive performance in medical

students at a specific (early) point in their carrier. Further investigation of these

relations needs to be undertaken. In this way, preventive education and therapeutic

Manchevska S at al.

Physioacta Vol.6-No.2 60

programs can be designed to promote the personal development of each student and

increment of his/her academic achievement.

Conclusions: The results of our study showed that medical students with low levels

of state anxiety and no depression have an efficient cognitive performance, but high

state anxiety levels could also have facilitating effects on the cognitive performance

depending on the difficulty of the task. There was no effect of different levels of

depression on attention and learning.

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