مقایسه ظرفیت برای شناخت اجتماعی و فراشناخت در اپیزود اول و افسردگی طولانی مدت

There is a growing awareness that social cognition is a valuable construct for understanding the psycho-social disabilities in depressive illness. Numerous studies have linked affective disorders to impairments in social cognition and specifically the processing of discrete emotional stimuli. Only few studies have investigated the relation between the burden of depressive illness and social cognitive ability. To study these issues, we compared a group of first-episode depressed patients with a group of chronically depressed patients (duration >2 years) on a broad array of higher-order social cognitive measures including the metacognition assessment scale abbreviated. Contrary to prediction, deficits in social cognition were roughly equivalent between the two groups and there was no significant link between symptom severity and social cognitive ability. Having moderate to severe major depressive disorder (MDD) could be sufficient to predict the presence of deficits in social cognitive ability.

Major depressive disorder (MDD) is a serious and common mental disorder that profoundly affects an individual׳s quality of life. Depression is the most prevalent psychiatric disorder in the western world (Kessler et al., 2011) and is estimated to have a point prevalence of around 4% in the Danish population (Olsen et al., 2004). A central trait of MDD is a marked impairment in social functioning (Joiner and Coyne, 1999 and Segrin, 2010). Depressed individuals lead less active and satisfying social lives than never depressed persons and frequently report difficulties in their relationships with their spouse, children, and friends (Hirschfeld et al., 2000). There is a growing interest in the possibility that deficits in social cognition may be a contributory factor to the psycho-social disabilities so common in MDD. Social cognition is a multifaceted construct concerned with the cognitive processes required by people to come to know themselves and understand other people׳s behavioral intentions (Fiske and Taylor, 1991 and Ochsner, 2008). It is meaningful to place social cognitive capacities along a continuum of increasing complexity and synthesis (Adolphs, 2001 and Adolphs, 2010). Lower-order social cognitive ability encompasses the ability to identify and categorize and manifest affective stimuli, e.g. facial display of basic emotions, biological motion and speech prosody. Processing at this level is characterized by being fast, implicit and domain specific. At an intermediate level, the abilities are to make inferences about the mental states of conspecifics including their beliefs, desires and intentions, commonly known as theory of mind (ToM) and perspective taking (Premack, 1978 and Brüne, 2003). There are numerous tests developed to access different levels of ToM; one is the Sally–Anne test which taps ToM by assessing the ability to attribute false beliefs to others (Wimmer and Perner, 1983). Also present at this level is social perception which draws on multiple abilities including emotional social perception decoding, ToM, and social knowledge in the form of identifying social and societal rules (Lipton and Nowicki, 2009). Social perceptual tests put demand on subjects to make inferences about complex or ambiguous social situations. Recently, video-based tests have been introduced (Dziobek et al., 2006) encompassing ToM-tasks into a social perceptual paradigm putting real-time demand on subjects to infer meaning from the multimodal behavior of others (e.g. facial display of basic emotions or speech prosody) (Lipton and Nowicki, 2009). Finally, higher-order social cognition captures the ability to reflect and reason about the mental and affective states of oneself and others, moreover, utilizing such understanding to solve problems and master subjective suffering (Semerari et al., 2003 and Dimaggio and Lysaker, 2010). This level is often referred to as mentalization (Choi-Kain and Gunderson, 2008) or metacognition (Dimaggio et al., 2009), which compared to lower-order abilities is a more controlled, creative and imaginative process rendering it more sensitive to contextual influences. Metacognition is usually accessed via the coding of a person׳s discourse when thinking and relating to others events and experiences which are personally relevant. Research has suggested that depressed patients are burdened with social cognitive impairment in the areas of ToM (Inoue et al., 2004, Zobel et al., 2010 and Cusi et al., 2012) and in the decoding of affective stimuli (e.g. identifying emotions displayed by faces) (Leppänen, 2006 and Stuhrmann et al., 2011). In case of the latter, mood congruent biases have consistently been documented. Only few studies have investigated higher-order social cognition in MDD. Recently, we documented metacognitive impairments in first-episode depressed patients as assessed by the Abbreviated Metacognitive Assessment Scale (Semerari et al., 2003). Our results were in line with Fischer-Kern et al. (2013) who utilizing the Reflective Functioning Scale (Fonagy et al., 1998) found female depressed patients to be impaired in their mentalizing capacity. The reflective functioning scale is an instrument developed to assess individual differences in the ability to mentalize attachment relationships. Conversely, in an earlier study by Taubner et al., 2011, no difference was documented between chronic depressed patients and their matched healthy controls using the same assessment methods as Fischer-Kern et al. (2013). Notably, in a single case study, Carcione et al. (2008) documented how the metacognitive capabilities, operationalized by the Metacognitive Assessment Scale (MAS), of a young depressed woman improved parallel to the time she began to recover from her depression. Overall, evidence suggests that MDD is associated with wide-ranging impairments in social cognition in the acute state. Less is known about the developmental trajectory of social cognitive capacities or the association between symptom severity and social cognitive ability in the case of MDD. For instance, is impairment present in both the early and the later phases of illness? Does social cognitive ability deteriorate beyond the initial impact of the illness or not? One possible mechanism of change could be that longer duration of depression and the subsequent social disengagement may lead to an atrophy of the metacognitive system. Another possibility is that poorer social cognitive skills may be a liability that increase the risk of more severe depression or even certain types of depression. A few studies have targeted chronic depression with an idea that this subgroup would perform particularly below the norm (Wilbertz et al., 2010, Zobel et al., 2010 and Taubner et al., 2011), they have however used healthy controls as reference group, whereby not allowing them to inquire specifically into the implications of prolonged or multiple exposure to MDD. In a notable exception, van Randenborgh et al. (2012) compared chronically the episodic depressed patients on ToM and alexithymia, the latter designating the inability to identify and describe personal emotions. The research group reported higher scores on alexithymia in the chronically depressed group, while no group differences were found in the domain of ToM. Understanding how the burden of depressive illness is related to social cognition has important clinical implications for both intervention and treatment. To explore these issues, we compared a group of first-episode depressed patients with a group of chronically depressed patients (duration >2 years) on a broad array of intermediate and higher-order social cognitive measures including ToM and metacognition. We expected to find chronically depressed patients less able than first-episode depressed patients in their social cognitive ability as a consequence of their longer exposure to depression. Also, we expected to find a link between increasing symptom severity and social cognitive impairment as documented in much non-social cognitive research (McDermott and Ebmeier, 2009).