P.1.j.010 Neuropsychological impairment: the disturbed effect of self-processing in major depressive disorder

Abstract

Background: Neuropsychological impairment (mainly focus on executive function, attention, verbal and nonverbal learning and memory) has long been established as a fundamental characteristic in major depressive disorder, but a specific pattern of neuropsychological impairment generally accepted has not been summarized. Different studies generally adopted different methodological issues (such as clinical status, samples, the measures of neuropsychological task and statistical methods, etc) to investigate on account of the considerable variability in the heterogeneity of depression. However, compared with other types of cognitive function, self-face recognition was considered as may help us to clearly understand the process of self-related information. Besides, it is always believed that the self-experience ability is unique for human beings, and the self-face symbolizes distinct self-characteristics of humans. The purpose of this research was to explore whether the self was impaired in major depressive disorder with the classic neuropsychological paradigm of self-face recognition (SFR). Methods: A total of 18 depressive patients and 20 healthy subjects participated in this SFR study. Morphed faces were basic materials in this experiment. We presented three types of face stimuli: self-face stimuli, famous-face stimuli (the face of a famous star who was able to be recognized by the participants at first sight), and stranger-face stimuli. Here, we mixed the features of any two of the three types of faces based on a certain proportion and got three serious of morphed faces. We directly tested the bias by instructing participants to recognize the identity of the morphed faces created by blending face features between any of two identities. All the experimental results would be automatically recorded on the computer immediately. Results: RM-ANOVA showed a significant main effect between different test groups [F(1,36) = 7.388, P = 0.01). The independent t-test further revealed that self (t = 2.636, P = 0.012) and selfrecognition bias (t = 2.190, P = 0.035) observed in self-famous task and self-stranger task for depressive patients were significantly greater than that for healthy control. In contrast, there was no significant difference between two groups in famous-stranger task (t = 0.892, P = 0.378), that was to say, there was no impairment on familiarity-processing in depression. Conclusions: The results in SFR study showed that the tendency of both self (self-famous task) and self-recognition (selfstranger task) were impaired in patients with major depressive disorder, i.e., there might be a specific deficit in the effect of selfprocessing, and therefore influencing the ability of face recognition. This kind of self-disturbance is consistent with the clinical phenomenon and the neural basis of depression in some respects. The findings provide a new perspective for our further study on etiology and pathological mechanisms of major depressive disorder. In addition, the study only involves some behavioral levels of data and future empirical research should combine various techniques, such as MRI and ERP, to explore neural basis of self-disturbance in major depressive disorder. P.1.j.011 Synthesis and pharmacological evaluation of irreversible allosteric ligands for the M1 muscarinic acetylcholine receptor B.J. Davie1 °, C. Valant1, B. Capuano2, P.J. Scammells2, A. Christopoulos1 1Monash Institute of Pharmaceutical Sciences, Drug Discovery Biology, Melbourne, Australia; 2Monash Institute of Pharmaceutical Sciences, Medicinal Chemistry, Melbourne, Australia