Interactive genetic association with anxiety was observed such that effects of 5-HTTLPR depended on the BDNF Val66Met polymorphism (rs6265 variant), with higher anxiety scores in short and Met carriers compared to the other allelic groups.
The present findings hint towards distinct mechanisms mediating the influence of 5-HTTLPR/rs25531 genotype on depressive symptoms and anxiety, with negative life events playing a crucial role in both phenotypes.
5-HTT knockout mice, lacking the 5-HTT gene either homo- or heterozygously, provide a widely used model organism for the study of symptoms related to human anxiety disorders.
Antidepressants that block the serotonin transporter, (Slc6a4/SERT), selective serotonin reuptake inhibitors (SSRIs) improve mood in adults but have paradoxical long-term effects when administered during perinatal periods, increasing the risk to develop anxiety and depression.
Polymorphisms in genes coding for the serotonin receptor subtype 1A (HTR1A), the serotonin transporter (SLC6A4), and the serotonin degrading enzyme monoamine oxidase A (MAOA) are associated with anxiety, impulsivity, and neurotic personality in humans.
Previously it was shown that healthy individuals with the short allelic variant ('s-group') of the 5-HTTLPR-polymorphism displayed more anxiety and negative mood, and had a lower transcriptional efficiency compared to individuals who are homozygous for the l-allele ('l-group').
Along with being the main target of many antidepressant medications, the serotonin transporter (5-HTT) is known to be involved in the pathophysiology of depression and anxiety disorders.
We show that 5-HTTLPR predicts higher impulsivity, hostility, and neuroticism, and that impulsivity could serve as a useful independent outcome or intermediary phenotype in genetic studies of anxiety.
Using functional MRI, we investigated whether and how the serotonin transporter promoter polymorphism (5-HTTLPR), which has been associated with mental disorders such as anxiety and depression, moderates the associations between a cultural trait (i.e., interdependence) and self-report of death anxiety/depression and between interdependence and brain responses to mortality threats.
In the present study, the number of 5-HT- and TPH-positive cells, and expression of 5-HT<sub>1A</sub> and 5-HTT protein decreased in dorsal raphe, and depression and anxiety like behavior increased in HFD group compared with the CON group.
This SNP is located within the serotonin transporter gene SLC6A4, which is the primary target of selective-serotonin reuptake inhibitors used for the treatment of depressive and anxiety disorders.
In humans, the short (S) allele in the 5-HTT gene-linked polymorphic region, which decreases 5-HTT expression, has been shown to be associated with behavioral changes including an increased level of anxiety.
The interaction between the serotonin transporter (SERT) linked polymorphic region (5-HTTLPR) and adverse early life stressing (ELS) events is associated with enhanced stress susceptibility and risk to develop mental disorders like major depression, anxiety, and aggressiveness.
We used different statistical analyses to test co-development of cannabis use and symptoms of anxiety throughout adolescence and the possible role of the 5-HTTLPR genotype in this process.
IBS patients with depressive disorders were characterized by higher frequency of 5-HTTLPR L allele in comparison to IBS patients with anxiety disorders.
We explored this issue in 371 preschoolers and their caregivers, examining whether parent characteristics (i.e., overinvolvement or anxiety disorder) and child 5-HTTLPR influenced the continuity of BI between ages 3 and 5.
The study did not demonstrate the relationship between the 5-HTT and MAO-A gene polymorphisms, and the severity of anxiety and mood disorders in healthy late-reproductive-stage women.
The distribution of 5-HTT gene polymorphisms in the healthy group, the group with asthma but without anxiety, and the group with asthma and anxiety had significant differences.
Moreover, the 5-HTTLPR association with RRS was mediated by the RVPFC activity and the 5-HTTLPR association with social interaction anxiety was mediated by both the dorsal-rostral ACC connectivity and RVPFC activity.
The lower-expressing (S') alleles of the serotonin transporter (5-HTT) gene promoter polymorphism (5-HTTLPR) are linked to mood and anxiety related psychopathology.
The serotonin transporter length polymorphism (5-HTTLPR) short allele (5-HTTLPR-s) has been associated with differential susceptibility for anxiety and depression in multiple psychiatric disorders.
Thus, our results provide further evidence that 5-HTTLPR and COMT Val(158)Met genotypes influence the vulnerability for the development of anxiety disorders via different mechanisms.