The purpose of this study was to determine the relationship between personality, the serotonin transporter (5HTT) polymorphisms and the occurrence of anxiety and depressive symptoms in elite athletes. 133 healthy participants completed the NEO Five-Factor Inventory (NEO-FFI). The mood states were assessed using the Profile of Mood States (POMS) questionnaire. The athlete’s mental skills were assessed through the Sport Performance Psychological Inventory (IPPS-48). The occurrence of psychiatric and personality disorders was assessed using the Clinical Interview for DSM-IV Disorders. A polymerase chain reaction was employed to identify genotypes at the 5HTTLPR polymorphism. The 5HTTLPR s/s genotype was associated with both neuroticism (p< 0.001) and tension/anxiety symptoms according to the POMS (p<0.02), cognitive anxiety and emotional arousal control according to the IPPS-48 (p<0.01). Significant correlations were proved between neuroticism and symptoms of anxiety and depression (p<0.05). Neuroticism mediates the association between the 5HTTLPR polymorphism and symptoms of cognitive anxiety and emotional arousal control (p<0.05). These results suggest a significant interaction between the 5HTTLPR polymorphism, neuroticism and sport related stress that predict adverse mental health outcomes in athletes. Identification of homogeneous groups of athletes having predispositions to anxiety and depressive symptoms may help to implement early prevention programs.
Citation: Petito A, Altamura M, Iuso S, Padalino FA, Sessa F, D'Andrea G, et al. (2016) The Relationship between Personality Traits, the 5HTT Polymorphisms, and the Occurrence of Anxiety and Depressive Symptoms in Elite Athletes. PLoS ONE 11(6): e0156601. https://doi.org/10.1371/journal.pone.0156601
Editor: Graham R. Wallace, University of Birmingham, UNITED KINGDOM
Received: December 30, 2015; Accepted: May 17, 2016; Published: June 3, 2016
Copyright: © 2016 Petito et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper.
Funding: The authors have no support or funding to report.
Competing interests: The authors have declared that no competing interests exist.
Many studies investigating the relationship between sport participation and mental health have suggested that participation in sport is associated with psychological benefits including higher levels of self-esteem and lower levels of depression [1, 2]. However, recently, a significant body of research has found evidence of mental health problems associated with sport participation as a result of sport-related significant stressors [3, 4]. A wide range of psychiatric disorders has been reported in the athletic population including depression, anxiety, disordered eating, bipolar disorders and substance abuse [5, 6]. In recent years, the prevalence of depression and anxiety disorders has been reported as increasing in this population [7, 8, 9]. However, the mechanisms leading to both depression and anxiety disorders among athletes are mostly unknown.
Many risk factors have been proposed, such as competition-related stress ; ineffective coping strategies [11, 12] overtraining [13, 14]; negative group dynamics/peer interaction [15,16, 17] and negative interactions with leaders [18,19]. Besides the above-mentioned factors, individual aspects should be considered. In this regard, specific personality traits that might have an influence on the development of depressive and anxiety symptoms are of interest.
Personality is a multidimensional structure that is created by both environmental and genetic factors. According to twin and family studies, individual variation of the heritable component is estimated to account for 30–60% of variance in personality traits [20, 21]. Serotonin (5-HT) neurotransmission has a key role in the regulation of the activity of the central nervous and influences a wide variety of physiological and psychological processes including individual differences in personality traits [22, 23].
The serotonin transporter gene (SLC6A4) encodes the serotonin transporter protein (5-HTT), which acts as a key regulator by removing serotonin from the synaptic cleft. The promoter region of the SLC6A4 gene contains a polymorphism with short (s) and long (l) repeats in a region: 5-HTT-linked polymorphic region (5-HTTLPR). The long form was shown to be associated with higher and the short form with lower expression of the gene product . Several studies have provided strong evidence for an association between the 5-HTTLPR short allele and neuroticism, defined as proneness to negative emotionality, including depression and anxiety. Individual with either one or two copies of the short allele had significantly greater levels of neuroticism than those homozygous for the long allele .
The analysis of the association between the 5-HTTLPR polymorphism and neuropsychiatric disorders, including anxiety and depressive syndromes, has shown some positive but contradictory findings. Significant associations between the short variant and susceptibility for mood disorders have been reported [26, 27, 28] but other studies did not confirm these findings . The original results of Caspi et al.  suggested that individuals carrying the short (s) allele are more likely to develop major depression following exposure to early life stress (e.g., childhood maltreat