Increased analytical thinking in depression

AcknowledgementsThis study was supported by the Faculty of Biology of the University of Warsaw and Rada Konsultacyjna ds. Studenckiego Ruchu Naukowego.

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.

Paweł Mazurkiewicz, Katarzyna Czajkowska, Natalia Bielczyk*, Michał Nowacki

Inter-Faculty Individual Studies in Mathematics and Natural Sciences / Student’s Society of Neurobiology, University of Warsaw, Warsaw

http://www.biol.uw.edu.pl/sknn; *e-mail : sknn@biol.uw.edu.pl

The term ‘depression’, described by Baillarger in 1894, designates a psychiatric affective disorder. Hypotheses about neurochemical basis of depression emphasize the role of dopamine and serotonin. Some theories consider depression to have an adaptive sense. Those theories stress the fact that depressives think in a more analytical manner. From neurobiological point of view, depression is related to increased activation in parietal and frontal lobes of the right hemisphere, decreased volume of brain tissue and decreased activity of sgACC, reduced level of neroglia, altered density of neurons, reduced size of neural soma, increased volume of brain tissue of rACC, difference in cACC.

Aim of study•Does depressive realism phenomenon exist?•Is depressive realism, mainly associated with

mild depression, also connected with severe depression?•Is there a difference in prediction of positive and negative situations?

Subjects- 108 subjects, 62% women / 38% men- students, 19 - 26 years old- classification based on BDI test result:non-depressives (a) 0-5, mild-depressives (b) 10-18, severe-depressives (c) 18-45

Results

MethodsChosen 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).

AnalysisA 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.

Task 1 (based on Weinstein)

Please assess the level of probability, in comparison to other students of the same gender and of the similar age, that the given situation will happen to you, on a scale -7 to +7.(translation only for conference purpose)

Task 2 (based on Cypryańska and Krejtz)

You are presented twelve hypothetical random situations. Please assess the probability of each situation to happen to you / your friend (on a scale -3 to +3). (translation only for conference purpose)

Predicting positive/negative outcome

Fig. 1 Mean absolute evaluation of the possibility of positive (A) and negative (B) situation occurrence for three groups.

Subdepressives are the most accurate in predicting the possibility of positive situation occurrence. After dividing the subjects into three groups there is no significant difference between non-depressives and subjects with severe depression. There is a significant difference between non-depressives and mild-depressive group (p<0.05).

References1.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.Hamann S (2005) Blue genes wiring the brain for depression. Nat Neurosci 8: 701-703.3.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: 830-43.4.Schacter D, Addis DR (2006) The optimistic brain. Nat Neurosci 10: 1345-1347.5.Sharot T, Riccardi AM, Raio C, Phelps EA (2007) Neural mechanisms mediating optimism bias. Nature 450: 102-105.6.Weinstein ND (1980) Unrealistic optimism about future life events. J Personal Soc Psychol 39: 806-820.7.Marquand A, Mourao-Miranda J, Brammer MJ, Cleare AJ, Fu CHY. Neuroanatomy of verbal working memory as a diagnostic biomarker for depression. Neuroreport 2008;19:1507-1511.8.Fu T, Koutstaal W, Fu CHY, Poon L, Cleare AJ. Depression, confidence, and decision: evidence against depressive realism. Journal of Psychopathology and Behavioural Assessment 2005;27:243-252.9.Ingram, R. E., Lumry, A., Cruet, D., & Sieber, W. (1987). Attentional processes in depression disorders. Cognitive Therapy and Research, 11, 351 - 360.10.Kapci, E. G., & Cramer, D. (1999). Judgment of control revisited: Are the depressed realistic or pessimistic? Counselling Psychology Quarterly, 12, 95 - 105.11.Stone, E. R., Dodrill, C. L., & Johnson, N. (2001). Depressive cognition: a test of depressive realism versus negativity using general knowledge questions. Journal of Psychology, 135, 583 - 602.12.Wood, J., Moffoot, A. P. R., & O'Carroll, R. E. (1998). 'Depressive realism' revisited: Depressed patients are realistic when they are wrong but are unrealistic when they are right. Cognitive Neuropsychiatry, 3, 119 - 126.

Experimental plan

Prospective studyWe plan to examine another aspects of analytic thinking. The planned fMRI experiment involves depressive and non-depressive subjects to be presented a crime riddle. Time, accuracy and brain activity during the process of extracting data and determining who is guilty of crime will be recorded and compared between groups. The assumption is that the groups differ in activity patterns during problem solving and the depressive tend to be slower but more accurate than others.

Fig. 2 Mean relative evaluation of the possibility of positive (A) and negative (B) situation occurrence for three groups.

Non-depressives overestimate the probability of positive situation occurrence and underestimate the possibility of negative situation occurrence. Differences between all pairs of groups, except for differences between negative prediction in mild and severe depressives, are significant (p<0.05).

Masculinity/femininity vs Level of depression

Fig. 3 Mean relative evaluation of the possibility of positive (A) and negative (B) situation occurrence for three groups.

Non-depressives overestimate the probability of positive situation occurrence and underestimate the possibility of negative situation occurrence. Differences between all pairs of groups, except for differences between negative prediction in mild and severe depressives, are significant (p<0.05).

Task 1 example questions:

1.I will possess my own house / apartament.2.I will try to commit suicide.3.I will be addicted to alcohol.4.I will have problems with police.5.I will live above 85 years.6.I will visit many interesting places.7.I will suffer from cancer.8.I will lose my job.9.I will appreciate my job after studies.10.I will win a small prize in a lottery. 11.I will be robbed.12.I will build a happy family.

Neurobiology 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 )