Molecular genetic associations between a prominent serotonin transporter gene polymorphism (5‐HTTLPR/rs25531) and individual differences in tendencies toward autistic traits and generalized internet use disorder in China and Germany

Abstract

Background The serotonin transporter polymorphism 5‐HTTLPR is an extensively investigated genetic marker of autistic traits or autism spectrum disorder, and recently has also been studied in the realm of internet use disorder (IUD), yet the findings remain controversial. Therefore, the present study aimed to explore associations between 5‐HTTLPR (also including SNP rs25531) and autistic traits/IUD tendencies and to assess whether the relationship between autistic traits and IUD tendencies varies by this genetic marker in participants from China and Germany. Methods A total of 540 Chinese and 563 German subjects were genotyped for 5‐HTTLPR/rs25531 and completed the Adult Autism Spectrum Quotient questionnaire and the short version of the Internet Addiction Test. Results Carriers of the low expressing S'S’ genotype (S, L G ) showed significantly higher levels of autistic traits than the high expressing allele (e.g. L A ) carriers in both samples. There was no significant effect of 5‐HTTLPR/rs25531 on IUD either in the Chinese or Germany samples, whereas positive correlations between autistic traits and IUD varied by 5‐HTTLPR/rs25531 genotypes and also differed between Chinese and German samples. In the Chinese sample, positive correlations were mainly driven by S'S’ and S'L' carriers, while they were mainly determined by S'L’ and L'L' carriers in the German sample. Further analyses revealed that the associations between autistic traits and IUD tended in parts to be more strongly pronounced in the complete German sample compared to the complete Chinese sample, and also varied depending on 5‐HTTLPR/rs25531 genotypes (in S'S’ carriers: China > Germany; in S'L’ and L'L’ carriers: China < Germany; both in terms of more positive associations). Conclusions Our findings suggest carriers of low expressing alleles (S, L G ) are more likely to show higher autistic traits in both Chinese and German samples. Furthermore, the present work shows that both 5‐HTTLPR/rs25531 and cultural differences might be of relevance to understand associations between autistic traits and IUD tendencies, but this needs to be further backed up.

Investigating autistic traits, social phobia, fear of COVID-19, and internet use disorder variables in the context of videoconference fatigue

“…These results are, at least in part, further supported by a recent study showing that the level of fear experienced by individuals with higher autistic traits was significantly more pronounced compared to individuals with lower autistic traits during the COVID-19 pandemic [34] . Second , we observed a positive association between autistic traits and IUD tendencies [50] , [51] , [52] , and the relationship between autistic traits and VC fatigue was mediated by IUD tendencies. Third , a chain-mediating mechanism via Fear of COVID-19 and IUD tendencies in the relationship between autistic traits and VC fatigue was identified in the present work.…”

“…Although existing research has not yet explicitly linked these vulnerability factors with the experience of VC fatigue, it might be plausible that autistic traits mark the beginning of the causal chain-mediation mechanism as these traits are known to be rather stable [ 80 , 81 ]. As previously pointed out, individuals with higher autistic traits are more prone to experience higher levels of negative emotionality, such as fear, especially during the COVID-19 pandemic [33] , and also show higher tendencies towards IUD [50] , [51] , [52] . It is noteworthy that the positive relationship between Fear of COVID-19 and IUD tendencies was also observed in the multiple mediation model, which is consistent with the growing body of research [ 49 , 82 , 83 ] and might be explained by the idea that individuals being stressed out due to the pandemic might seek distraction online, which – with excessive use patterns – can result in IUD tendencies.…”

“…It is not surprising that recent studies observed a positive relationship between Fear of COVID-19 and IUD tendencies [ 48 , 49 ]. As the present study focuses on VC fatigue, we also highlight recent works that established links between autistic traits and IUD tendencies [50] , [51] , [52] , and between IUD and fatigue including physical and mental health symptoms [ 53 , 54 ]. Therefore, we investigated these vulnerability factors in one study and explored the possible relationships between these vulnerability factors (autistic traits, Fear of COVID-19, and IUD tendencies) and VC fatigue as the exploratory nature of the study.…”