P.2.028 - Neuropharmacological effects of chronic opioid analgesic use on social cognition

• Published in: European neuropsychopharmacology Vol. 28; pp. S40 - S41
• Main Authors: Kroll, S.L., Bieri, F., Baumgartner, M., Soyka, M., Quednow, B.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2018
• ISSN: 0924-977X; 1873-7862
• DOI: 10.1016/j.euroneuro.2017.12.067

Based on an increased public health concern regarding the misuse of opioid analgesics especially in the United States (U.S.) but also in Europe, non-medical prescription opioid use (NMPOU) has become an emerging field in addiction research [1]. Although misuse of opioid analgesics (e.g., morphine, oxycodone, fentanyl, etc.) has reached epidemic dimensions in the U.S., little is known about its neuropsychological sequelae. Social cognition such as empathy and emotion perception is an essential component for prosocial and interpersonal behaviour and is crucial for a positive therapy outcome in substance users. Studies with heroin users and opioid-substituted patients have shown deficits in emotion perception [2,3]. However, in this population, it is difficult to attribute postulated findings only to neuropharmacological effects because of confounding factors such as comorbid physical and psychiatric diseases. The purpose of the present project is to investigate social cognition in relatively pure non-medical prescription opioid users to generate an improved model of chronic opioid effects on socio-cognitive functions and to perform a better calculation of opioid dose-response effects with less confounded factors mentioned before. We compared 23 individuals with NMPOU with 29 matched healthy and drug-naïve controls. Participants conducted the Comprehensive Affect Test System, investigating emotion perception including two channels of communication: affect recognition in faces (ARQ) and prosodic recognition (PRQ). The Multifaceted Empathy Test was used, measuring cognitive (CE) and emotional empathy (EE). Trait empathy was assessed using the German version of the interpersonal reactivity index (IRI). Additionally, screening questionnaires and interviews were conducted. Statistical analyses were performed with SPSS 23.0 using independent t-tests to determine quantitative differences between groups. The analysis of covariance (ANCOVA) was conducted to control for co-factors. Individuals with NMPOU showed reduced emotion perception in both channels of communication ARQ [t(50)=2.62, p=0.012] and PRQ [t(50)=3.34, p<0.01] and reduced CE in comparison to controls [t(50)=2.06, p<0.045] but no differences in EE. These results remain significant even after correcting for age and verbal IQ [F(1,48)=4.88-11.68, p=0.001-0.032]. Pearson’s correlations revealed dose-dependent deficits in emotion perception (r’s=-0.38, p=0.035-0.039). In contrast, the IRI showed no significant differences in trait empathy between both groups. This is the first study investigating social cognition in individuals with NMPOU. Contrary to cocaine and alcohol users displaying deficits mainly in EE, individuals with NMPOU show selective impairments in CE, indicating that the opioid system might be involved in CE processing. Similar deficits were also found in autistic patients supporting Panksepp’s neurochemical theory of autism [4]. Additionally, subjective self-ratings on cognitive and emotional trait empathy of the IRI demonstrated no differences between both groups, assuming that individuals with NMPOU are not aware of their deficits. Furthermore, the present study results indicate inferior social cognition especially in recognising and decoding emotions in faces but also in prosody. These deficits could lead to severe impairments in daily life interactions particularly in social relationships but also in physician-patient communications. Therefore, future interventions of opioid dependence should target deficits in social cognition to improve social interaction and consequently enhance therapy outcome and prevent relapse.