Depression

Depressive realism in neurobiological context
Paweł Mazurkiewicz*, Małgorzata Zarzycka, Sylwia Purchla, Michał Denkiewicz, Dominika Nowicka
Katarzyna Czajkowska, Anna Karcz, Michał Chiliński, Aleksandra Klemba, Halszka Kwiatkowska
Student’s Society of Neurobiology, Warsaw University, Faculty of Biology, Warsaw
http://www.biol.uw.edu.pl/sknn; *e-mail : [email protected]
Depression – what is it?
The term ”depression” dates from 1854. Jules Gabriel Francis Baillarger, a French psychiatrist, was the first to employ this term to designate
a psychiatric affective disorder. The most common depression symptoms are: low mood, frequent anxiety attacks, negative self-image, lack of
motivation and circadian rhythm disorders lasting more than two weeks. Hypotheses about neurochemical basis of depression emphasize the
role of dopamine and serotonin. Decrease in the level of these two biogenic amines may result in loss of motivation. According to the World
Health Organization, depression is the fourth major health problem in the world. About 17% of adults aged 35-50 suffer from this disease. Some
theories consider depression to have an adaptative sense. Those theories stress the fact that depressives think in a more analytical manner.
Aim of work
* Does depressive realism phenomenon exist?
*Is depressive realism, mainly associated with mild-depression,
also connected with severe depression?
*Is unrealistic optimism correlated with depression level?
*Are positive and negative situations assessed similarly?
Materials
Chosen subjects underwent a Beck Depression Inventory test, Bem Sex
Role Inventory test (IPP, polish version), NEO-Five Factor Inventory test
(NEO-FFI) and an authorial realism-assessment tests based on
Weinstein (1980) and Cypryańska and Krejtz (2005).
Task 1
(based on Weinsteun)
Proszę
ocenić,
z
jakim
prawdopodobieństwem, w stosunku
do innych studentów tej samej płci
w podobnym wieku, dana sytuacja
może się Tobie przydarzyć, w skali
od -7 do 7.
Sample collection
-108 subjects, 62% women and 38% men
-students, from 19 to 26 years old
Fig 1
Task 2
(based on Cypryańska and Krejtz)
Masz
przed
sobą
dwanaście
hipotetycznych sytuacji losowych.
Oceń prawdopodobieństwa w jakim te
sytuacje mogą spotkać
Ciebie /
Twojego kolegę (w skali -3:+3)
Fig 2
Fig.1. BDI test results. Goups chosen to
further tests: nondepressives (a) 0-5 and
depressives (b) 10-45 .
Fig.2. BDI test results. Goups chosen to further
tests: nondepressives: nondepressives (a) 0-5
[47,2%], mild depression (b) 10-16 [22,2%]
and severe depression (c) 18-45 [15,7%].
Statistic work
A Kruskal-Wallis one-way ANOVA was used to compare study groups
and find statistically significant differences. In cases where KW ANOVA
revealed the presence of between-groups differences,
Mann-Whitney U-test was used to break down this general effect.
Results
Depressive realism
Unrealistic optimism
3.1
p<0,001
Fig.3.1. Mean absolute evaluation of the
possibility of positive situation occurence.
7.
6.
p<0,05
Fig.3.2. Mean absolute evaluation of the
possibility of negative situation occurence.
B
A
3.2
purple – depressives (realists/nonrealists)
yellow – nondepressives (realists/nonrealists)
arrows – mean results for realists/nonrealists.
p<0,05
4.
Fig. 6. Mean relative evaluation of the possibility of
positive (A) and negative (B) situation occurence.
Nondepressives overestimate the possibility of positive
situation occurence and underestimate the possibility of
negative situation occurence.
5.
p<0,05
Fig.7. Mean relative evaluation of the possibility of positive (A)
and negative (B) situation occurence for three groups.
Nondepressives overestimate the possibility of positive situation
occurence and underestimate the possibility of negative
situation occurence.
p<0,05
Neurobiology of depression
A
Fig.4. Mean absolute evaluation of the possibility of
positive (A) and negative (B) situation occurence.
Depressives are more accurate in predicting the
possibility of positive and negative situation
occurence.
B
Fig.5. Mean absolute evaluation of the possibility of positive
(A) and negative (B) situation occurence for three groups.
Subdepressives are the most accurate in predicting the
possibility of positive situation occurence. After dividing the
subjects into three groups there is no significant difference
between nondepressives and subjects with severe
depression. There is significant difference between
nondepressives and mild-depressive group.
Conclusions:
1. The results confirm the existence of depressive realism phenomenon.
2. The results suggest that depressive realism is related to mild depression.
3. Unrealistic optimism negatively correlates with the level of depression.
* Functional asymmetry in parietal and frontal lobes in
electroencephalography: increased activation in right
hemisphere
* sgACC (subgenual anterior cingulated cortex) :
decreased volume of brain tissue, decreased activity of
sgACC , reduced level of neroglia, altered density of
neurons, reduced size of neural soma
* rACC (rostral anterior cingulated cortex): increased
volume of brain tissue
* cACC (caudal anterior cingulated cortex )
References
1. Boes AD, McCormick LM, Coryell WH, Nopoulus N (2008) Rostral anterior cingulate cortex volume correlates with depressed mood in normal healthy children. Biol Psychiatry 63: 391-397.
2. Cypryańska M, Krejzt I (2005) Nierealistyczny optymizm - optymizm przewidywań czy zniekształcenia poznawcze przypadkiem optymistyczne? Studia Psychologiczne, tom 43: 37-48.
3. Hamann S (2005) Blue genes wiring the brain for depression. Nat Neurosci 8: 701-703.
4. Mayberg HS, Brannan SK, Tekell JL, Silva JA, Mahurin RK, McGinnis S, Jerabek PA (2000) Regional metabolic effects of fluoxetine in major depression: serial changes and relationship to clinical
response. Biol Psychiatry 48: 830-43.
5. Schacter D, Addis DR (2006) The optimistic brain. Nat Neurosci 10: 1345-1347.
6. Sharot T, Riccardi AM, Raio C, Phelps EA (2007) Neural mechanisms mediating optimism bias. Nature 450: 102-105.
7. Weinstein ND (1980) Unrealistic optimism about future life events. J Personal Soc Psychol 39: 806-820.
Acknowledgements
This study was supported by the Faculty of Biology of the University of Warsaw
and Rada Konsultacyjna ds. Finansowania Kół Naukowych UW. The realization
of the project wouldn’t be possible without the support of Aneta Brzezicka,
PhD, from the Warsaw School of Social Sciences and Humanities.