Opal A. McInnis

A paradoxical association of an oxytocin receptor gene polymorphism: early-life adversity and vulnerability to depression.

Several prosocial behaviors may be influenced by the hormone oxytocin. In line with this perspective, the oxytocin receptor (OXTR) gene single nucleotide polymorphism (SNP), rs53576, has been associated with a broad range of social behaviors. In this regard, the G allele of the OXTR SNP has been accompanied by beneficial attributes such as increased empathy, optimism, and trust. In the current study among university students (N = 288), it was shown that early-life maltreatment was associated with depressive symptoms, and that the OXTR genotype moderated this relationship, such that under high levels of childhood maltreatment, only individuals with GG/GA genotype demonstrated increased depressive symptomatology compared to those with the AA genotype. In addition, the role of distrust in mediating the relation between childhood maltreatment and depression seemed to be more important among G allele carriers compared to individuals with the AA genotype. Thus, a breach in trust (i.e., in the case of early-life abuse or neglect) may have a more deleterious effect among G carriers, who have been characterized as more prosocial and attuned to social cues. The data suggested that G carriers of the OXTR might favor social sensitivity and thus might have been more vulnerable to the effects of early-life adversity.

Making room for oxytocin in understanding depression

Depression is accompanied by an array of neurobiological variations, including altered HPA axis activity, monoamine, growth factor and inflammatory immune functioning. In addition, a recent perspective has entertained the possible role for oxytocin in depressive disorders. Given the involvement of oxytocin in prosocial behaviors such as attachment, affiliation, trust, and social support seeking, it is not surprising this neuropeptide might be involved in the development or maintenance of depressive disorders. This view is supported by evidence that oxytocin interacts with various neuroendocrine, neurotransmitter, and inflammatory processes that have previously been implicated in depression. Thus, it might be profitable to consider the contribution of oxytocin in the context of several neurobiological changes provoked by stressors. The current review examines the relation between oxytocin and depression with a specific focus on the interactions between the oxytocinergic system and stressor-provoked biological and psychosocial responses. The possibility is also considered that oxytocin might increase the salience of social cues, such that positive or negative experiences result in exaggerated responses that may influence affective states.

Living with the unexplained: coping, distress, and depression among women with chronic fatigue syndrome and/or fibromyalgia compared to an autoimmune disorder

Chronic fatigue syndrome (CFS) and fibromyalgia are disabling conditions without objective diagnostic tests, clear-cut treatments, or established etiologies. Those with the disorders are viewed suspiciously, and claims of malingering are common, thus promoting further distress. It was hypothesized in the current study that levels of unsupportive social interactions and the coping styles used among those with CFS/fibromyalgia would be associated with perceived distress and depressive symptoms. Women with CFS/fibromyalgia (n = 39), in fact, reported higher depression scores, greater perceived distress and more frequent unsupportive relationships than healthy women (n = 55), whereas those with a chronic, but medically accepted illness comprising an autoimmune disorder (lupus erythematosus, multiple sclerosis, rheumatoid arthritis; n = 28), displayed intermediate scores. High problem-focused coping was associated with low levels of depression and perceived distress in those with an autoimmune condition. In contrast, although CFS/fibromyalgia was also accompanied by higher depression scores and higher perceived distress, this occurred irrespective of problem-focused coping. It is suggested that because the veracity of ambiguous illnesses is often questioned, this might represent a potent stressor in women with such illnesses, and even coping methods typically thought to be useful in other conditions, are not associated with diminished distress among those with CFS/fibromyalgia.

Distress of ostracism: Oxytocin receptor gene polymorphism confers sensitivity to social exclusion

A single-nucleotide polymorphism on the oxytocin receptor gene (OXTR), rs53576, involving a guanine (G) to adenine (A) substitution has been associated with altered prosocial features. Specifically, individuals with the GG genotype (i.e. the absence of the polymorphism) display beneficial traits including enhanced trust, empathy and self-esteem. However, because G carriers might also be more socially sensitive, this may render them more vulnerable to the adverse effects of a negative social stressor. The current investigation, conducted among 128 white female undergraduate students, demonstrated that relative to individuals with AA genotype, G carriers were more emotionally sensitive (lower self-esteem) in response to social ostracism promoted through an on-line ball tossing game (Cyberball). Furthermore, GG individuals also exhibited altered blood pressure and cortisol levels following rejection, effects not apparent among A carriers. The data support the view that the presence of the G allele not only promotes prosocial behaviors but also favors sensitivity to a negative social stressor.

The Role of the Val66Met Polymorphism of the Brain Derived Neurotrophic Factor Gene in Coping Strategies Relevant to Depressive Symptoms.

Disturbances of brain derived neurotrophic factor (BDNF) signalling have been implicated in the evolution of depression, which likely arises, in part, as a result of diminished synaptic plasticity. Predictably, given stressor involvement in depression, BDNF is affected by recent stressors as well as stressors such as neglect experienced in early life. The effects of early life maltreatment in altering BDNF signalling may be particularly apparent among those individuals with specific BDNF polymorphisms. We examined whether polymorphisms of the Val66Met genotype might be influential in moderating how early-life events play out with respect to later coping styles, cognitive flexibility and depressive features. Among male and female undergraduate students (N = 124), childhood neglect was highly related to subsequent depressive symptoms. This outcome was moderated by the BDNF polymorphism in the sense that depressive symptoms appeared higher in Met carriers who reported low levels of neglect than in those with the Val/Val allele. However, under conditions of high neglect depressive symptoms only increased in the Val/Val individuals. In effect, the Met polymorphism was associated with depressive features, but did not interact with early life neglect in predicting later depressive features. It was further observed that among the Val/Val individuals, the relationship between neglect and depression was mediated by emotion-focused styles and diminished perceived control, whereas this mediation was not apparent in Met carriers. In contrast to the more typical view regarding this polymorphism, the data are consistent with the perspective that in the presence of synaptic plasticity presumably associated with the Val/Val genotype, neglect allows for the emergence of specific appraisal and coping styles, which are tied to depression. In the case of the reduced degree of neuroplasticity expected in the Met carriers, early life adverse experiences are not tied to coping styles, and hence less likely to be translated into depressive states.

The moderating role of an oxytocin receptor gene polymorphism in the relation between unsupportive social interactions and coping profiles: implications for depression

Oxytocin is a hormone that is thought to influence prosocial behaviors and may be important in modulating responses to both positive and negative social interactions. Indeed, a single nucleotide polymorphism, rs53576, of the oxytocin receptor gene (OXTR) has been associated with decreased trust, empathy, optimism, and social support seeking, which are important components of coping with stressors. In the current study, conducted among undergraduate students (N = 225), it was shown that parental and peer social support was related to fewer depressive symptoms through elevated problem-focused coping and lower emotion-focused coping, and these effects were independent of the OXTR polymorphism. Unsupportive social interactions from parents were associated with more severe depressive symptoms through the greater use of emotion-focused coping, and this relation was moderated by the OXTR genotype. Specifically, individuals who carried the polymorphism on one or both of their alleles demonstrated increased emotion-focused coping following unsupportive responses compared to those without the polymorphism. Likewise, lower problem-focused coping mediated the relation between parental and peer unsupportive responses to depressive symptoms, but this mediated relation was only evident among carriers of the polymorphism. These findings suggest that carrying this OXTR polymorphism might favor disadvantageous coping styles in the face of negative social interactions, which in turn are linked to poor mood. Regardless of genotype, parental, and peer social support are fundamental in determining stress-related coping and well-being.

Relations between plasma oxytocin and cortisol: The stress buffering role of social support.

Stress responses in humans can be attenuated by exogenous oxytocin administration, and these stress-buffering properties may be moderated by social factors. Yet, the influence of acute stressors on circulating endogenous oxytocin levels have been inconsistent, and limited information is available concerning the influence of social support in moderating this relationship. In the current investigation, undergraduate women (N = 67) were assessed in the Trier Social Stress Test (TSST) with either social support available from a close female friend or no social support being available. An additional set of women served as controls. The TSST elicited marked elevations of state anxiety and negative emotions, which were largely attenuated among women who received social support. Furthermore, baseline oxytocin levels were inversely related to womens general feelings of distrust, as well as basal plasma cortisol levels. Despite these associations, oxytocin levels were unaffected by the TSST, and this was the case irrespective of oral contraceptive use or estrogen levels. In contrast, plasma cortisol elevations were elicited by the psychosocial stressor, but only in women using oral contraceptives, an effect that was prevented when social support was available. Taken together, these data provisionally suggest that changes in plasma oxytocin might not accompany the stress attenuating effects of social support on cortisol levels. Moreover, as plasma oxytocin might not reliably reflect brain oxytocin levels, the linkage between oxytocin and prosocial behaviors remains tenuous.

Childhood adversity, perceived discrimination, and coping strategies in relation to depressive symptoms among First Nations adults in Canada: The moderating role of unsupportive social interactions from ingroup and outgroup members.

Aboriginal peoples are at greater risk of experiencing early life adversity relative to non-Aboriginal peoples in Canada, and as adults frequently experience high levels of discrimination that act as a further stressor. Although these factors appear to contribute to high rates of depressive disorders and suicidality in Aboriginal peoples, the psychosocial factors that contribute to the relationship between childhood adversity and the development of depressive symptoms have hardly been assessed in this group. The present investigation explored potential mediators to help explain the relation between childhood trauma and depressive symptoms among a sample of First Nations adults from across Canada. These mediated relationships were further examined in the context of unsupportive social interactions from ingroup and outgroup members. In Study 1, (N = 225), the relationship between childhood trauma and depression scores was mediated by perceived discrimination, and this was particularly notable in the presence of unsupportive relations with outgroup members. In Study 2, (N = 134) the relationship between childhood trauma and depressive symptoms was mediated by emotion-focused coping that was specific to coping with experiences of ethnic discrimination, and this mediated effect was moderated by both outgroup and ingroup unsupportive social interactions. Thus, it seems that experiences of discrimination and unsupport might contribute to depressive symptoms among First Nations adults who had experienced early life adverse events.

Oxytocin and Social Sensitivity: Gene Polymorphisms in Relation to Depressive Symptoms and Suicidal Ideation

Although the neuropeptide oxytocin has been associated with enhanced prosocial behaviors, it has also been linked to aggression and mental health disorders. Thus, it was suggested that oxytocin might act by increasing the salience of social stimuli, irrespective of whether these are positive or negative, thus increasing vulnerability to negative mental health outcomes. The current study (N = 243), conducted among white university students, examined the relation of trauma, depressive symptoms including suicidal ideation in relation to a single nucleotide polymorphism (SNP) within the oxytocin receptor gene (OXTR), rs53576, and a SNP on the CD38 gene that controls oxytocin release, rs3796863. Individuals with the polymorphism on both alleles (AA genotype) of the CD38 SNP had previously been linked to elevated plasma oxytocin levels. Consistent with the social sensitivity perspective, however, in the current study, individuals carrying the AA genotype displayed elevated feelings of alienation from parents and peers as well as increased levels of suicidal ideation. Moreover, they tended to report elevated depressive symptoms compared to CC homozygotes. It was also observed that the CD38 genotype moderated the relation between trauma and suicidal ideation scores, such that high levels of trauma were associated with elevated suicidal ideation among all CD38 genotypes, but this relationship was stronger among individuals with the AA genotype. In contrast, there was no relationship between the OXTR SNP, rs53576, depression or suicidal ideation. These findings support a social sensitivity hypothesis of oxytocin, wherein the AA genotype of the CD38 SNP, which has been considered the “protective allele” was associated with increased sensitivity and susceptibility to disturbed social relations and suicidal ideation.

Suicide Ideation and Attempts among First Nations Peoples Living On-Reserve in Canada: The Intergenerational and Cumulative Effects of Indian Residential Schools

Objective: Suicide rates among Indigenous peoples in Canada are at least twice that of their non-Indigenous counterparts. Although contemporary stressors contribute to this increased risk, historical experiences such as the Indian Residential School (IRS) system may also have continuing links with the risk for suicidal thoughts and behaviors. The current investigation examined the intergenerational and cumulative links between familial IRS attendance in relation to lifetime suicide ideation and attempts among First Nations adults living on-reserve. Method: Data from the 2008-2010 First Nations Regional Health Survey were analyzed, and participants comprised a representative sample of First Nations adults older than 18 years (weighted N = 127,338; IRS attendees were excluded). Of those who knew their familial IRS history, 38.0% had no history of attendance, 19.3% had a grandparent who attended, 16.2% had a parent who attended, and 26.5% had a parent and grandparent who attended. Results: Exposure of one previous familial generation to the IRS experience was associated with increased risk for lifetime suicide ideation (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.16 to 1.84; P = 0.001) and attempts (OR, 1.44; 95% CI, 1.07 to 1.94; P < 0.016) compared with those with no IRS history. Having 2 generations of IRS familial history was associated with greater odds of reporting a suicide attempt compared with having one generation (OR, 1.35; 95% CI, 1.05 to 1.75; P = 0.022), which was reduced when current levels of distress and ideation were accounted for. Conclusion: Findings support the existence of linkages between intergenerational exposure to IRS and risk for suicidal ideation and attempts and for a potential cumulative risk in relation to suicide attempts across generations.