Cornelia Sindermann

An Affective Neuroscience Framework for the Molecular Study of Internet Addiction

Internet addiction represents an emerging global health issue. Increasing efforts have been made to characterize risk factors for the development of Internet addiction and consequences of excessive Internet use. During the last years, classic research approaches from psychology considering personality variables as vulnerability factor, especially in conjunction with neuroscience approaches such as brain imaging, have led to coherent theoretical conceptualizations of Internet addiction. Although such conceptualizations can be valuable aid, the research field is currently lacking a comprehensive framework for determining brain-based and neurochemical markers of Internet addiction. The present work aims at providing a framework on the molecular level as a basis for future research on the neural and behavioral level, in order to facilitate a comprehensive neurobiological model of Internet addiction and its clinical symptomatology. To help establish such a molecular framework for the study of Internet addiction, we investigated in N = 680 participants associations between individual differences in tendencies toward Internet addiction measured by the Generalized Problematic Internet Use Scale-2 (GPIUS-2) and individual differences in primary emotional systems as assessed by the Affective Neuroscience Personality Scales (ANPS). Regression analysis revealed that the ANPS scales FEAR and SADNESS were the ANPS scales most robustly positively linked to several (sub)scales of the GPIUS-2. Also the scales SEEKING, CARE and PLAY explain variance in some of the GPIUS-2 subscales. As such, these scales are negatively linked to the GPIUS-2 subscales. As the ANPS has been constructed on substantial available brain data including an extensive molecular body with respect to evolutionary highly conserved emotional circuitry in the ancient mammalian brain, the present study gives first ideas on putative molecular mechanisms underlying different facets of Internet addiction as derived from associations between tendencies toward Internet addiction and individual differences in primary emotional systems. For example, as SADNESS is linked to the overall GPIUS-2 score, and the neuropeptide oxytocin is known to downregulate SADNESS, it is conceivable that the neuropeptide might play a role in Internet addition on the molecular level. Our findings provide a theoretical framework potentially illuminating the molecular underpinnings of Internet addiction. Finally, we also present data on the ANPS and smartphone addiction at the end of the paper. Similar to the reported associations between the ANPS and the GPIUS-2, these correlations might provide an initial outline for a framework guiding future studies that aim to address the molecular basis of smartphone addiction.

The 2D:4D-Ratio and Neuroticism Revisited: Empirical Evidence from Germany and China

The 2D:4D-Ratio, as an indirect measure of the fetal testosterone to estradiol ratio, is potentially very important for understanding and explaining different personality traits. It was the aim of the present study to replicate the findings from Fink et al. (2004) about the relation between individual differences in 2D:4D-Ratios and the Five Factor Model in different cultural groups. Therefore a sample of n = 78 Chinese and n = 370 German participants was recruited. Every participant provided hand scans of both hands, from which 2D:4D-Ratios were computed. Moreover, all participants filled in the NEO Five Factor Inventory (NEO-FFI). Significant sex differences were found for ratios of both hands in the expected direction, with females showing higher ratios than males. With respect to links between personality and the digit ratio, a positive association was observed between 2D:4D-Ratio and Neuroticism in females, as shown in the earlier study. These findings were observed in both female subsamples from China and Germany, as well as in the full sample of participants. But in contrast to the results for the whole and the German female sample, where 2D:4D-Ratio of both hands were related to Neuroticism, in the Chinese female sample only left hand 2D:4D-Ratio was significantly and positively related to Neuroticism. There were no significant correlations found in any of the male samples. Thus, prenatal exposure to sex steroids appears to influence the personality factor Neuroticism in females specifically. This finding potentially has implications for mental health, as Neuroticism has been shown to be a risk factor for various forms of psychopathology.

Does acceptance of power distance influence propensities for problematic Internet use? Evidence from a cross-cultural study.

Several studies suggest that Asian countries are particularly afflicted by problematic Internet use (PIU).

A functional polymorphism of the OXTR gene is associated with autistic traits in Caucasian and Asian populations

There is increasing evidence for associations between polymorphisms of the oxytocin receptor (OXTR) gene and autism spectrum disorder, but to date no study has established links with autistic traits in healthy subjects and potential cultural differences. The present research firstly investigated associations between three widely studied OXTR SNPs and autistic and empathic traits (rs53576 (G/A); rs2254298 (G/A); rs2268498 (T/C)) in two independent studies on male and female Caucasian (n = 537) and Chinese students (n = 280). Autistic and empathic traits were measured in all subjects in the two independent groups using the Autism ‐Spectrum Quotient (AQ) and the Interpersonal Reactivity Index (IRI) respectively, together with their sub‐scales. For both sites, genotyping of the OXTR SNPs was conducted on buccal swab samples using a Cobas Z 480 Light Cycler following automated DNA extraction. Associations at the genotype level with autism trait scores were found in Caucasian subjects for rs2268498 only, with TT carriers having the lowest AQ scores compared with those carrying at least one C‐allele. This finding was independently replicated in the Chinese sample although a smaller proportion carried the C‐allele compared with the Caucasian sample. Some minor associations were found between empathy trait scores and the three SNPs but were not consistent between the samples. These findings show for the first time that the rs2268498 SNP localized in the promoter flanking region of the OXTR gene is associated with autistic traits in different ethnic/cultural groups. This provides further support for the role of the OXTR gene in relation to autism.

Internet Communication Disorder and the structure of the human brain: initial insights on WeChat addiction

WeChat represents one of the most popular smartphone-based applications for communication. Although the application provides several useful features that simplify daily life, a growing number of users spend excessive amounts of time on the application. This may lead to interferences with everyday life and even to addictive patterns of use. In the context of the ongoing discussion on Internet Communication Disorder (ICD), the present study aimed to better characterize the addictive potential of communication applications, using WeChat as an example, by examining associations between individual variations in tendencies towards WeChat addiction and brain structural variations in fronto-striatal-limbic brain regions. To this end levels of addictive tendencies, frequency of use and structural MRI data were assessed in n = 61 healthy participants. Higher tendencies towards WeChat addiction were associated with smaller gray matter volumes of the subgenual anterior cingulate cortex, a key region for monitoring and regulatory control in neural networks underlying addictive behaviors. Moreover, a higher frequency of the paying function was associated with smaller nucleus accumbens volumes. Findings were robust after controlling for levels of anxiety and depression. The present results are in line with previous findings in substance and behavioral addictions, and suggest a similar neurobiological basis in ICD.

Investigating the Effect of Personality, Internet Literacy, and Use Expectancies in Internet-Use Disorder: A Comparative Study between China and Germany

Research on Internet-use Disorder (IUD) has increased rapidly, indicating its clinical and global importance. Past studies suggested cultural diversity regarding the prevalence of an IUD, e.g., between Asian and European countries. Additionally, it was found that personality factors, Internet-related cognitions and specific competences seem to influence IUD tendencies, but research lacks in cultural comparative studies regarding these mechanisms. This study focuses on differences between Germany and China regarding the above-mentioned characteristics. German (n = 411; M = 20.70 years, SD = 3.34 years) and Chinese participants (n = 410; M = 20.72 years, SD = 2.65 years) answered the short Internet Addiction Test, Big Five Inventories, the Internet-use Expectancies Scale, as well as the Internet Literacy Questionnaire. The results revealed higher occurrence of IUD symptoms in China. Furthermore, Chinese participants scored significantly higher on neuroticism and agreeableness, whereas German participants scored higher on extraversion and openness. Compared to German participants, Chinese showed higher expectancies to avoid negative feelings online and to be positively reinforced. Regarding Internet literacy, German participants indicated higher skills concerning the reflection and critical analysis of online content, whereas Chinese showed higher expertise in producing and interacting online. Further, simple slope analyses indicated that certain Internet literacy domains were related differentially to IUD symptoms in Germany and China. While Chinese participants with higher reflective skills indicated highest IUD symptoms, reflective skills revealed no effect in Germany. Additionally, higher self-regulative skills correlated with lower IUD symptoms in the German, but not in the Chinese sample. The results give a hint to potential cultural differences regarding IUD, especially on the predictive and protective role of Internet literacy domains.

The Role of Empathy and Life Satisfaction in Internet and Smartphone Use Disorder

Recent studies have yielded initial evidence for an association between Internet Use Disorder (IUD), empathy, and life satisfaction. In the present study we sought to replicate these previous findings, and then to extend this research by also examining the relationship between empathy, life satisfaction, and the related phenomenon of Smartphone Use Disorder (SUD). The present study included independent samples from China (N = 612, 162 females) and Germany (N = 304, 207 females), with the same set of questionnaires administered to both samples. IUD was measured with Pawlikowskis s-IAT and SUD was assessed with the short version of Kwons Smartphone Addiction Scale. The Interpersonal Reactivity Index (IRI) was used to assess individual differences in empathy. Please note that for the German sample data on the empathy quotient (EQ) are also available. Life satisfaction data were collected using items from the SOEP-Questionnaire (Socio-Economic Panel, Germany). In both of our samples we replicated previous findings showing the association between higher IUD, lower empathy, and lower life satisfaction scores. In addition, individuals with higher SUD showed higher scores on the IRI Personal Distress scale in China and Germany, while further associations between IRI dimensions and SUD were only found in the Chinese sample. Personal Distress is known to be highly correlated with the personality trait of Neuroticism, hence higher stress/negative emotionality in tense social situations is related to SUD. In the present study we confirm earlier findings showing the relationship between empathy, life satisfaction, and IUD, and extend some of these findings to SUD. We also emphasize the importance of cross-cultural studies when investigating IUD/SUD in the context of empathy and life satisfaction.

Does Growing up in Urban Compared to Rural Areas Shape Primary Emotional Traits

Growing up in urban areas represents a possible risk factor in the genesis of psychopathologies. The aim of the present study was to investigate the link between urbanicity variables and indicators for psychiatric disorders. We investigated a potential association between primary emotional traits and urbanicity variables in 324 individuals from Germany and 713 individuals from China. Higher scores in the urbanicity index in childhood were inversely associated with FEAR and SADNESS only in adult Chinese females. These effects seemed to be driven by living in Chinese mega-cities, because a parallel sample from Germany and China (contrasting upbringing in cities with the categories <10,000 inhabitants, ≥10,000 inhabitants (but <100,000), and ≥100,000 inhabitants) resulted in weaker, but more similar effects in females in both countries. Additional associations could be observed with higher PLAY and urban upbringing in Chinese males. The results seem surprising, given an expectation of adverse emotional effects from growing up in todays’ mega-cities compared to rural areas. Although we do not want to over-interpret our findings (given rather small correlations and multiple testing issues), they should encourage researchers to consider including urbanicity variables in personality neuroscience and personality oriented clinical psychiatric research.

Personality and Primary Emotional Traits: Disentangling Multiple Sclerosis Related Fatigue and Depression

Objective It remains an unresolved research objective to clarify the overlap/association between fatigue (especially its cognitive facet) and depression in People with MS (PwMS). Therefore, in this study the patterns of personality and primary emotional traits (PETs) associated with each (motoric/cognitive fatigue and depression in PwMS) were investigated and compared in order to disentangle the three constructs in PwMS. Additionally, differences in personality and PETs between PwMS and healthy controls (HC) were examined. Method Associations between motoric/cognitive fatigue, depression, personality and PETs were investigated in 52 PwMS. Personality and PETs were also assessed in a gender matched HC sample (N = 52) and results regarding these were compared between PwMS and HC. Results Low extraversion was the only significant predictor of MS related motoric fatigue (β = -.341, p = .013). High neuroticism was a predictor of both MS related cognitive fatigue (β = .426, p = .002) and depression (β = .443, p < .001). Whereas neuroticism was the only significant predictor for MS related cognitive fatigue, the cluster of (high) neuroticism, (high) SADNESS (β = .273, p = .023), and (low) extraversion (β = -.237, p = .025) predicted MS related depression. PwMS showed significantly higher scores in neuroticism and FEAR compared to HC. Conclusions MS related motoric/cognitive fatigue and depression in PwMS share variance. But the substantial amount of non-shared variance (motoric fatigue, depression: 72%; cognitive fatigue, depression: 66%) together with additional predictors for depression (SADNESS being a predictor of depression only), indicate that MS related motoric/cognitive fatigue and depression are distinguishable. Consequently, we recommend assessing especially SADNESS scores to distinguish between MS related fatigue and depression.

The relationship between Internet Use Disorder, depression and burnout among Chinese and German college students

In the present study, we investigated the relationship between depression and Internet Use Disorder (IUD) and between burnout and IUD among German as well as Chinese college students. Due to cultural differences and their implications for the individuals psychological health, we expected Chinese college students to have in particular higher IUD than German college students. We further expected to find positive relationships between depression and IUD and between burnout and IUD. Furthermore, we believed these relationships to reflect global effects and thus to be present in both samples. The data showed that Chinese college students had higher average burnout scores in the subscales MBI Emotional Exhaustion and MBI Cynicism and also higher IUD scores, but not higher depression scores. As expected, the correlation analysis revealed significant, positive correlations between depression and IUD as well as between burnout and IUD. The results are consistent in both samples, implying that the effect is globally valid. Furthermore, we observed that the relationship between depression and IUD is stronger than the relationship between emotional exhaustion and IUD in both samples, although this effect was not significant. We conclude that burnout and depression are related to IUD and that this relationship is valid independently of the cultural background of an individual.