سطوح اکسی توسین پلاسما شناسایی نشانه های اجتماعی در افراد مبتلا به اسکیزوفرنی پیش بینی می کند

Lower endogenous levels of the neuropeptide oxytocin may be an important biological predictor of social cognition impairments in schizophrenia (SZ). Prior studies have demonstrated that lower-level social cognitive processes (e.g., facial affect perception) are significantly associated with reduced plasma oxytocin levels in SZ; however, it is unclear whether higher-level social cognition, which requires inferential processes and knowledge not directly presented in the stimulus, is associated with endogenous oxytocin. The current study explored the association between endogenous oxytocin levels and lower- and higher-level social cognition in 40 individuals diagnosed with SZ and 22 demographically matched healthy controls (CN). All participants received the Social Cue Recognition Test (SCRT), which presents participants with videotaped interpersonal vignettes and subsequent true/false questions related to concrete or abstract aspects of social interactions in the vignettes. Results indicated that SZ had significantly higher plasma oxytocin concentrations than CN. SZ and CN did not differ on SCRT hits, but SZ had more false positives and lower sensitivity scores than CN. Higher plasma oxytocin levels were associated with better sensitivity scores for abstract items in CN and fewer false positives for concrete items in individuals with SZ. Findings indicate that endogenous oxytocin levels predict accurate encoding of lower-level socially relevant information in SZ.

Although social cognition has been defined in several ways, it typically refers to the ability to perform mental processes that underlie social interactions, including interpreting, perceiving, and generating appropriate responses to the behaviors, dispositions, and intentions of others (Green et al., 2008). Individuals with schizophrenia (SZ) display impairments in multiple aspects of social cognition, and these deficits predict community-based social and vocational outcome (Horan et al., 2012 and Couture et al., 2006). Impairments in social cognition have been found to load onto two distinct factors: lower-level and higher-level processes (Sergi et al., 2007). Lower-level social cognition involves evaluating and accurately encoding objective, socially relevant information from an immediately available stimulus (e.g., facial affect perception). Higher-level social cognition requires inferential processing and the ability to use knowledge not directly presented in a stimulus to make judgments about the thoughts, emotions, and intentions of others (e.g., theory of mind). In mammals, there is evidence that the neuropeptide oxytocin plays a critical role in various aspects of social cognition and social interaction (Dantzer et al., 1990, Dickinson and Keverne, 1988, Dluzen et al., 1998 and Wacker and Ludwig, 2012). Relatively few studies have examined whether endogenous oxytocin levels are abnormal in people with SZ. Those studies that have been conducted have yielded inconsistent results, with the majority indicating no group differences (Rubin et al., 2010, Rubin et al., 2011, Rubin et al., 2013 and Rubin et al., 2014) and some reporting lower (Goldman et al., 2008 and Goldman et al., 2011) or higher endogenous oxytocin concentrations in people with SZ compared to controls (Beckmann et al., 1985). Inconsistencies in endogenous oxytocin levels among studies may reflect differences in evaluating peripheral vs. cerebrospinal fluid levels, sample-related differences in demographics (e.g., sex, age, race), the proportion of participants taking different antipsychotics, differences in disease chronicity, and the proportion of participants displaying neuroendocrine dysfunction (e.g., polydipsia). Despite these inconsistencies regarding group-level differences among studies, lower endogenous oxytocin has consistently been associated with impairments in social cognition, especially lower-level processes such as facial affect perception (Goldman et al., 2008 and Rubin et al., 2011). Lower endogenous oxytocin also predicts poor social functioning and greater severity of positive and negative symptoms (Goldman et al., 2008, Keri et al., 2009, Rubin et al., 2010, Rubin et al., 2011, Walss-Bass et al., 2013 and Strauss et al., 2015). Intranasal administration of oxytocin has generally shown beneficial effects on social cognition, with many studies showing effects on lower-level social cognitive processes and several on higher-order social cognition (Feifel et al., 2010, Pedersen et al., 2011, Averbeck et al., 2012, Davis et al., 2013, Davis et al., 2014, Fischer-Shofty et al., 2013a, Fischer-Shofty et al., 2013b, Gibson et al., 2014 and Woolley et al., 2014); however, not all studies have reported significant improvements on social cognition (Lee et al., 2013 and Horta de Macedo et al., 2014). Furthermore, one study comparing differential effects of oxytocin on higher- and lower-level social cognition demonstrated improvements specific to higher-order processes (Woolley et al., 2014). Thus, oxytocin may be critically linked to impairments in social cognition and social functioning in people with SZ; however, additional work is needed to determine whether lower- or higher-level social cognition is most highly associated with oxytocin. In the current study, we extended the literature on social cognition and oxytocin by administering a well-validated measure, the Social Cue Recognition Test (SCRT: Corrigan and Green, 1993), which requires participants to watch brief video-taped vignettes of social interactions and then respond to a series of questions pertaining to concrete or abstract aspects of the interaction. Importantly, the SCRT's use of concrete items allowed us to replicate prior associations between lower-level social cognition and endogenous oxytocin (Goldman et al., 2008 and Rubin et al., 2011), and extend prior findings by also examining higher-level social cognition (abstract items). The SCRT is ideal for evaluating differential associations between oxytocin and lower- and higher-level social cognition because it evaluates these processes within a single paradigm that uses identical stimulus presentation and response formats across conditions. In line with prior studies, we hypothesized that people with SZ would have lower plasma oxytocin levels than healthy controls (CN) (Goldman et al., 2008 and Goldman et al., 2011), and that lower endogenous oxytocin would be associated with poorer SCRT performance for both concrete and abstract items.