What is the genetic relationship between anxiety and depression?

Anxiety and depression share a long, close history in psychiatric nosology and treatment. The anxiety disorders, individually and as a group, exhibit remarkably high rates of comorbidity with each other and with major depression. Analyses done in large-scale epidemiologic surveys have identified major patterns of phenomenological overlap between these conditions. Researchers have tested hypotheses of shared genetic etiologies as a potential basis of this relationship. In general, available family studies have found mixed evidence for co-aggregation of anxiety and depressive disorders, while twin studies more definitively indicate that shared genetic risk factors largely account for this comorbidity. Some of this appears to be accounted for by genetic variation in personality traits that broadly predispose to anxiety and depression. Molecular genetic studies of these conditions, though too early to draw firm conclusions, thus far provide tentative support for specific genetic loci that may generally influence susceptibility across the anxiety-depressive spectrum.     

Do dysfunctional cognitions mediate the relationship between risk factors and postnatal depression symptomatology?

BACKGROUND: This study investigated the mediating role of general and maternal-specific dysfunctional cognitions, in the relationship between non-cognitive risk factors and postnatal depressive symptomatology. METHODS: An Australian community sample comprising 406 postnatal women responded to the Dysfunctional Attitude Scale (DAS), the Maternal Attitudes Questionnaire (MAQ), the Vulnerable Personality Style Questionnaire (VPSQ) and the Edinburgh Postnatal Depression Scale (EPDS). They also responded to several questions related to perinatal and postnatal experiences. RESULTS: Path analysis demonstrated that different mediational pathways operated for different risk factors. The relationship between having a difficult baby and postnatal depression was fully mediated by maternal-specific dysfunctional cognitions (MAQ scores), whereas the relationship between past history of depression and postnatal depression was partially mediated by general dysfunctional cognitions (DAS scores). Finally, the relationship between a vulnerable personality and depressive symptomatology was mediated by both DAS and MAQ scores. LIMITATIONS: The study employed a correlational design. Thus, all inferences regarding possible causal pathways are tentative. In addition, the generalisability of these findings to other populations needs to be demonstrated in future research. CONCLUSIONS: The results of the study are consistent with the view that risk factors may influence postnatal depression indirectly through at least two distinct cognitive mediators (dysfunctional maternal and general cognitions). It may be possible to target therapies more effectively by identifying the relevant mediating mechanism(s) for individuals with different risk profiles.     

Depression and vascular disease: what is the relationship?

BACKGROUND: the 'vascular depression' hypothesis proposes that vascular disease predisposes to, precipitates or perpetuates depression, and this proposal has stimulated further research into the relationship of depression to vascular disease. METHODS: We investigated the nature of the relationship between depression and vascular diseases by reviewing epidemiological, clinical, neuroimaging and neuropathology studies which have reported on the relationship of depression to coronary artery disease, stroke disease, alterations in blood pressure, vascular dementia, diabetes mellitus and cholesterol levels and by reviewing potential mechanisms by which depression could be associated with vascular diseases. RESULTS: there is abundant and increasing evidence from these different lines of research that depression has a bidirectional association with vascular diseases and plausible mechanisms exist which explain how depression might increase these vascular diseases and vice versa. LIMITATIONS: this was not a systematic review and so not every report of relevance has been included. CONCLUSIONS: depression has a clear bidirectional relationship with vascular diseases. Further study is needed to clarify the mechanisms involved and to investigate the benefits of conventional and novel treatments for vascular diseases in depressive illness.     

Wound-healing and benzodiazepines: does sleep play a role in this relationship?

Patients who have suffered burns frequently experience psychological consequences, among which anxiety disorders are prominent. Benzodiazepines are commonly administered to treat these symptoms. The effects of benzodiazepines on healing may not be direct but rather are modulated by alterations of the sleep architecture. This hypothesis is supported by studies that demonstrate the effects of benzodiazepines on the immune system and the inflammatory profile under both normal sleep conditions and during sleep deprivation, particularly rapid eye movement sleep deprivation.     

Hyperactive and antisocial behaviors: comorbid or two points in the same process?

We hypothesized that hyperactivity defines the first stage and that antisocial problems define a second stage in a progression that leads eventually to early-onset delinquency. As expected, a structural equation model (SEM) showed that a latent construct for hyperactivity was significantly related to a latent construct for antisocial problems. We hypothesized that this path reflected a shared mechanism, disrupted parental discipline. A second SEM showed that the relation between hyperactivity and antisocial behavior really reflected a shared disruption in parental discipline. A third SEM showed that having antisocial parents was uniquely correlated with antisocial children but not with hyperactivity. A fourth SEM showed that early-onset delinquency was predicted by a latent construct for antisocial child; but when this was partialed out, the contribution for hyperactivity was nonsignificant.     

The role of exercise dependence for the relationship between exercise behavior and eating pathology: mediator or moderator?

Our study examined the potential mediating or moderating effect of exercise dependence on the exercise-eating pathology relationship. Female university students (N = 330) completed Internet-based self-report measures of exercise behavior, exercise dependence, and eating pathology. Exercise dependence served as a mediator for the relationship between exercise and eating pathology. This unidirectional causal model suggests that an individual's pathological motivation or compulsion to exercise is the critical mediating component in the exercise-eating pathology relationship. The best target for removing the link between exercise behavior and eating pathology may be reformulating exercise dependence symptoms.     

Does a U-shaped relationship exist between alcohol use and DSM-III-R mood and anxiety disorders?

BACKGROUND: In recent community surveys, abstainers and heavy drinkers of alcohol have reported more mood and anxiety symptoms than moderate drinkers (U-shaped relationship). The present study was aimed at extending this finding by investigating this potential U-shaped relationship using structured diagnostic interviews to assess mood and anxiety disorders. METHODS: Data came from two contemporaneous surveys, the National Comorbidity Survey (NCS; N=6780) and the Mental Health Supplement of the Ontario Health Survey (OHS-MHS; N=7001). The University of Michigan Revision of the Composite International Diagnostic Interview (UM-CIDI) was used to make DSM-III-R psychiatric diagnoses in both surveys. Three mutually exclusive lifetime alcohol use categories were compared: (1) Alcohol abstainers-individuals reporting no alcohol use or less than 12 drinks in any year throughout their life. (2) Moderate drinkers-individuals that did not meet criteria for alcohol abstainers or problem drinkers. (3) Problem drinkers-DSM-III-R lifetime alcohol abuse, dependence or hazardous levels of alcohol use. RESULTS: After controlling for demographic variables, alcohol abstainers were not found to have significantly higher rates of mood and anxiety disorders in comparison with moderate drinkers. However, problem drinking was significantly associated with mood and anxiety disorders. CONCLUSIONS: Across both surveys, there was no evidence of a U-shaped relationship between lifetime alcohol consumption and lifetime mood and anxiety disorders.     

Stress and performance: do service orientation and emotional energy moderate the relationship?

The current study examines the moderating effect of customer service orientation and emotional energy on the stress-performance relationship for 681 U.S. casual dining restaurant employees. Customer service orientation was hypothesized to moderate the stress-performance relationship for Front-of-House (FOH) workers. Emotional energy was hypothesized to moderate stress-performance for Back-of-House (BOH) workers. Contrary to expectations, customer service orientation failed to moderate the effects of stress on performance for FOH employees, but the results supported that customer service orientation is likely a mediator of the relationship. However, the hypothesis was supported for BOH workers; emotional energy was found to moderate stress performance for these employees. This finding suggests that during times of high stress, meaningful, warm, and empathetic relationships are likely to impact BOH workers' ability to maintain performance. These findings have real-world implications in organizational practice, including highlighting the importance of developing positive and meaningful social interactions among workers and facilitating appropriate person-job fits. Doing so is likely to help in alleviating worker stress and is also likely to encourage worker performance.     

Type 1 diabetes and viral infections: What is the relationship?

Type 1 diabetes (T1D) is the most common chronic metabolic disorder in children. Epigenetic and environmental factors capable of altering the penetrance of major susceptibility genes or capable of increasing the penetrance of low-risk genes are currently thought to play a role in triggering autoimmunity and T1D development. This paper discusses the current knowledge of the role of viruses in T1D. Most studies that have evaluated the potential association between viral infections and T1D have indicated that it is highly likely that some of these infectious agents play a role in T1D development. However, most T1D cases are immune-mediated, and it is supposed that the initial viral infection is capable of creating, in genetically predisposed subjects, a particular condition in which chronic local inflammation occurs through the persistence of the infecting virus in pancreatic tissue and the activation of autoimmunity by means of molecular mimicry, bystander activation, or both. Theoretically, this knowledge could lead to possible prophylaxis and therapy for T1D. Further studies devoted to evaluating which infectious agents are linked to T1D and which immune mechanisms induce or protect against the disease are needed before adequate prophylactic and therapeutic measures can be developed.     

Anxiety and dissection of the human cadaver: an unsolvable relationship?

Anxiety is an emotional reaction frequently shown by students when a human cadaver is being dissected. Nonetheless, few studies analyze the nature of the anxiety response in this situation and the ones that do exist are mainly limited to English-speaking countries. Our research has three aims: to study the characteristic anxiety reaction to dissection practices, to determine the weight exerted by internal and environmental variables on this anxiety reaction, and to design practices aimed at reducing the state of anxiety experienced by pupils in their human anatomy practices. The studies were carried out in the dissection room of the Department of Human Anatomy and Embryology II at the Faculty of Medicine of the Complutense University, Madrid, during the 3 academic years 2000-2003. The anxiety response to the first dissection of a human cadaver is mainly determined by a situation considered to be threatening, with novelty as its main characteristic. The students' anxiety response is first determined by the situation itself and reactions depend on individual differences. Repeated or gradual exposure (detailed verbal information on the situation, visits to dissecting rooms when no cadaver is present, videos showing pictures of human dissections, etc.) before carrying out the first dissection reduce the students' anxiety response.     

The development of antisocial behavior: what can we learn from functional neuroimaging studies?

The recent development of low-risk imaging technologies, such as functional magnetic resonance imaging (fMRI), have had a significant impact on the investigation of psychopathologies in children and adolescents. This review considers what we can infer from fMRI work regarding the development of conduct disorder (CD) and oppositional defiant disorder (ODD). We make two central assumptions that are grounded in the empirical literature. First, the diagnoses of CD and ODD identify individuals with heterogeneous pathologies; that is, different developmental pathologies can receive a CDD or ODD diagnosis. This is indicated by the comorbidities associated with CD/ODD, some of which appear to be mutually exclusive at the biological level (e.g., posttraumatic stress disorder [PTSD] and psychopathic tendencies). Second, two populations of antisocial individuals can be identified: those that show an increased risk for only reactive aggression and those that show an increased risk for both reactive and instrumental aggression. We review the fMRI data indicating that particular comorbidities of CD/ODD (i.e., mood and anxiety conditions such as childhood bipolar disorder and PTSD) are associated with either increased responsiveness of neural regions implicated in the basic response to threat (e.g., the amygdala) or decreased responsiveness in regions of frontal cortex (e.g., ventromedial frontal cortex) that are implicated in the regulation of the basic threat response. We suggest why such pathology would increase the risk for reactive aggression and, in turn, lead to the association with a CD/ODD diagnosis. We also review the literature on psychopathic tendencies, a condition where the individual is at significantly elevated risk for both reactive and instrumental aggression. We show that in individuals with psychopathic tendencies, the functioning of the amygdala in stimulus-reinforcement learning and of the ventromedial frontal cortex in the representation of reinforcement expectancies is impaired. We suggest why such pathology would increase the risk for reactive and instrumental aggression and thus also lead to the association with a CD/ODD diagnosis.     

Does social support mediate the moderating effect of intrinsic religiosity on the relationship between physical health and depressive symptoms among Jews?

Previous research in the general population suggests that intrinsic religiosity moderates (mitigates) the effect of poor physical health on depression. However, few studies have focused specifically on the Jewish community. We therefore examined these variables in a cross-sectional sample of 89 Orthodox and 123 non-Orthodox Jews. Based on previous research suggesting that non-Orthodox Judaism values religious mental states (e.g., beliefs) less and a collectivist social religiosity more, as compared to Orthodox Judaism, we hypothesized that the moderating effect of intrinsic religiosity would mediated by social support among non-Orthodox but not Orthodox Jews. As predicted, results indicated that the relationship between physical health and depression was moderated by intrinsic religiosity in the sample as a whole. Furthermore, this effect was mediated by social support among non-Orthodox Jews, but not among the Orthodox. The importance of examining religious affiliation and potential mediators in research on spirituality and health is discussed.