Sex differences in the familial transmission of mood disorders

Disentangling the effects of intergenerational transmission of depression from adolescence to adulthood: the protective role of self-esteem

This study aimed to disentangle time-stable and time-varying effects of maternal and paternal depression on trajectories of adolescent depression from ages 13 to 23 and examined whether self-esteem moderates the examined associations. Sex differences in the direct effects of parental depression and its interacted effects with self-esteem were further explored. Data were collected from a sample of 2502 adolescents and their parents participating in a panel study spanning from the year 2000 to 2009 in northern Taiwan. Multilevel modeling was conducted to disentangle the time-stable and time-varying effects of parental depression on adolescent depression. The moderating role of self-esteem and the potential sex differences in the transmission process were tested by adding two- and three-way interactions among parental depression, self-esteem, and sex of adolescents in the models. As predicted, significant time-stable intergenerational transmission of depression was found, indicating that adolescents of parents with higher levels of depression were at increased risks for depression. Self-esteem was further found to buffer the negative effects of maternal depression on development of depression in offspring. No sex-specific intergenerational transmission of depression was observed. In sum, both maternal and paternal depression contributed to elevated levels of adolescent depression. The effects of maternal depression, however, may not be uniform, but depend on levels of self-esteem. Intervention and prevention strategies that enhance self-esteem may help participants withstand the negative effects of maternal depression.

Familiality of Psychiatric Disorders and Risk of Postpartum Psychiatric Episodes: A Population-Based Cohort Study

OBJECTIVE

Postpartum psychiatric disorders are common and morbid complications of pregnancy. The authors sought to evaluate how family history of psychiatric disorders is associated with postpartum psychiatric disorders in proband mothers with and without a prior psychiatric history by assessing degree of relationship, type of disorder, and sex of family members.

METHOD

The authors linked Danish birth and psychiatric treatment registers to evaluate familial risk of postpartum psychiatric episodes in a national population-based cohort. Probands were first-time mothers who were born in Denmark in 1970 or later and who gave birth after age 15 and before Dec. 31, 2012 (N=362,462). The primary exposure was a diagnosed psychiatric disorder in a relative. Cox regression models were used to estimate the hazard ratio of postpartum psychiatric disorders in proband mothers.

RESULTS

The relative risk of psychiatric disorders in the postpartum period was elevated when first-degree family members had a psychiatric disorder (hazard ratio=1.45, 95% CI=1.28-1.65) and highest when proband mothers had a first-degree family member with bipolar disorder (hazard ratio=2.86, 95% CI=1.88-4.35). Associations were stronger among proband mothers with no previous psychiatric history. There were no notable differences by sex of the family member.

CONCLUSIONS

Family history of psychiatric disorders, especially bipolar disorder, is an important risk factor for postpartum psychiatric disorders. To assist in identification of women at risk for postpartum psychiatric disorders, questions related to female and male first-degree relatives with bipolar disorder are of the highest importance and should be added to routine clinical screening guidelines to improve prediction of risk.

Influence of demographic factors and serotonin transporter-linked polymorphic region (5-HTTLPR) variants on major depression in a northeastern Thai population

Background: Several lines of evidence suggest that the serotonergic system may be involved in the etiology of major depressive disorder (MDD). Objective: Investigate a potential association between the functional polymorphism in the serotonin transporter-linked polymorphic region (5-HTTLPR) and MDD in a northeastern Thai population, and explore the involvement of demographic characteristics in this disorder. Methods: One hundred eighty seven patients with MDD and 207 healthy controls were recruited from the same geographical area into the study. The 5-HTTLPR genotypes were determined using polymerase chain reaction (PCR) and analyzed statically. Results: Significant demographic differences between the two groups were observed, which included age, marital status, occupation, educational background, income, and alcohol use. The allele frequencies of the 5- HTTLPR polymorphism in our studied population were relatively near those of Asian populations, especially Chinese, which was regarded as enormously distinct from those of Caucasians. Nevertheless, our present study found no significant association between this polymorphism and MDD with respect to either genotype distributions or allele frequencies. Conclusion: No involvement of the 5-HTTLPR polymorphism was suggested, but demographic features in MDD were highlighted with respect to this studied population.

Gender Moderation of the Intergenerational Transmission and Stability of Depressive Symptoms from Early Adolescence to Early Adulthood

Factors that might exacerbate or mitigate the transmission of depressive symptoms from parents to adolescents and the continuity of depressive symptoms into early adulthood are poorly understood. This study tested the hypothesis that the intergenerational transmission and stability of depressive symptoms would be stronger for girls than boys over adolescence and into early adulthood, while considering the possibility that the pattern of gender moderation might vary depending on parent gender and developmental timing. The participants were 667 rural Midwestern adolescents (52 % female) and their parents. Survey data on maternal and paternal depressive symptoms (at youth age 11) and on adolescent and young adult depressive symptoms (at youth ages 11, 18, and 21) were analyzed via multiple group structural equation modeling. Maternal depressive symptoms predicted increased late adolescent depressive symptoms for girls but not boys, and adolescent depressive symptoms were more stable in girls. Paternal depressive symptoms predicted increased late adolescent depressive symptoms for all youth. The findings suggest the need for early, tailored interventions.

Family patterns of psychopathology in psychiatric disorders

OBJECTIVE

Familial loading and crucial outcomes of family history of psychopathology in psychiatric disorders have long been recognized. There has been ample literature providing convincing evidence for the importance of family psychopathology in development of emotional disturbances in children as well as worse outcomes in the course of psychiatric disorders. More often, maternal psychopathology seems to have been an issue of interest rather than paternal psychopathology while effects of second-degree familiality have received almost no attention. In this study, we addressed the relations between affected first- and second-degree relatives of probands and categories of psychiatric disorders.

METHOD

Subjects were 350 hospitalized psychiatric inpatients, consecutively admitted to psychiatry clinics in Van, Turkey. Mean age was 34.16 (SD±12) and 51.4% of the sample consisted of male patients. Assessment of psychopathology in psychiatric probands was conducted based on DSM-IV TR. Familial loading of psychiatric disorders amongst first- and second-degree relatives of patients were initially noted primarily relying on patients' retrospective reports, and confirmed by both phone call and following official health records via the Medical Knowledge System. We analyzed the data using latent class analysis approach.

RESULTS

We found four patterns of familial psychopathology. Latent homogeneous subsets of patients due to familial characteristics were as paternal kinship psychopathology with schizophrenia, paternal kinship psychopathology with mood disorders, maternal kinship psychopathology and core family psychopathology.

CONCLUSION

Family patterns were critical to exerting variation in psychiatric disorders of probands and affected relatives. Probands with a core family pattern of psychopathology exhibited the most colorful clinical presentations in terms of variation in psychopathology. We observed a specificity of intergenerational transmission of psychiatric disorders when family patterns of psychopathology were taken into consideration, even second-degree relatives of psychiatric probands.

Familial risk of early suicide: variations by age and sex of children and parents

To determine familial risk of early suicide, data on cause of death of all Dutch residents aged 20-55 years who died between 1995 and 2001 were linked to data of their parents. Men whose father died by suicide had a higher odds of suicide themselves, relative to men whose father died of other causes (Odds Ratio (OR): 2.5; 95% confidence interval: 1.8-3.6). This effect was slightly stronger in the case of mother's suicide (OR: 3.4; 2.3-5.0). The same effect was observed for women, for suicide by father (OR: 2.2; 1.3-3.7) and mother (OR: 4.6; 2.6-8.0). The odds of suicide increased with decreasing age at death of parent. Parental suicide is predictive for offspring suicide. Our data suggest that the predictive value is higher in case the mother died by suicide, particularly if the mother died by suicide at a young age.

Functional connectivity of the amygdala in early-childhood-onset depression

OBJECTIVE

Adult major depressive disorder (MDD) is associated with reduced cortico-limbic functional connectivity thought to indicate decreased top-down control of emotion. However, it is unclear whether such connectivity alterations are also present in early-childhood-onset MDD.

METHOD

A total of 51 children 7 through 11 years of age who had been prospectively studied since preschool age, completed resting state functional magnetic resonance imaging (fMRI) and were assigned to one of four groups: 1) C-MDD (N = 13), those children with a personal history of early-childhood-onset MDD; 2) M-MDD (N = 11), those with a maternal history of affective disorders; 3) CM-MDD (N = 13), those with both maternal and early-childhood-onset MDD; or 4) CON (N = 14), those without either a personal or maternal history of MDD. We used seed-based resting state functional connectivity (rsfcMRI) analysis in an independent sample of adults to identify networks showing both positive (e.g., limbic regions) and negative (e.g., dorsal frontal/parietal regions) connectivity with the amygdala. These regions were then used in region-of-interest-based analyses of our child sample.

RESULTS

We found a significant interaction between maternal affective disorder history and the child's MDD history for both positive and negative rsfcMRI networks. Specifically, when compared with CON, we found reduced connectivity between the amygdala and the "negative network" in children with C-MDD, M-MDD, and CM-MDD. Children with either C-MDD or a maternal history of MDD (but not CM-MDD) displayed reduced connectivity between the amygdala and the "positive network."

CONCLUSIONS

Our finding of an attenuated relationship between the amygdala, a region affected in MDD and involved in emotion processing, and cognitive control regions is consistent with a hypothesis of altered regulation of emotional processing in C-MDD, suggesting developmental continuity of this alteration into early childhood.

The Moderating Effects of Mother-Adolescent Relations on the Longitudinal Association between Father and Offspring Depressive Symptoms

Little theoretical or empirical attention has been given to factors associated with better or worse outcomes in offspring of depressed fathers. Drawing from interpersonal models of intergenerational depression transmission in children of depressed mothers, the present investigation of adolescents and their families (N = 424) examined maternal warmth and hostility as moderators of the longitudinal association between paternal and adolescent depressive symptoms. Controlling for family demographic variables, previous adolescent depressive symptoms, and maternal depressive symptoms, fathers' depressive symptoms predicted offspring depressive symptoms among adolescents experiencing low maternal warmth or high maternal hostility. Adolescent girls reporting adversity in their relationships with their mothers were the most vulnerable to risk associated with paternal depressive symptoms. These findings highlight the implications of fathers' mental health for adolescent psychological well-being and add to the growing evidence that family relationships play a crucial role in the transmission of depression from one generation to the next.

Paternal Depressive Symptoms and Adolescent Functioning: The Moderating Effect of Gender and Father Hostility

This study examined the longitudinal relationship between paternal depressive symptoms, paternal hostility, and adolescent functioning in a community sample of 451 families. Paternal depressive symptoms were a strong predictor of adolescent outcome, even after controlling for family demographic variables, maternal depressive symptoms, and previous adolescent symptoms. Adolescent gender and perception of paternal hostility moderated this association such that females reporting high paternal hostility were particularly vulnerable to the adverse effects of paternal depressive symptoms. Maternal and paternal depressive symptoms had an additive, rather than interactive, effect on adolescent functioning. These results contribute to our knowledge of the interpersonal processes by which depression runs in families and highlight the importance of including fathers in developmental research on adolescent internalizing problems.

Mechanisms of sex difference: a historical perspective

OBJECTIVE

The history of the discovery of mechanisms contributing to sex difference helps to better appreciate gender factors in a variety of disease states. The objective of this article is to illustrate four mechanisms of sex differences in disease incidence: X-linkage (including inactivation, escape from inactivating, skewed inactivation), sex-specific exposure to disease-producing pathogens, fetal microchimerism, and iron depletion.

METHODS

This is a historic review.

RESULTS

An emphasis on sex difference led to the uncovering of four different mechanisms by which illness rates differ in men and women.

CONCLUSIONS

Research into many disease states can benefit from a focus on potential mechanisms that yield sex differences in illness susceptibility, progression, and outcome.

Translin-associated factor X gene (TSNAX) may be associated with female major depressive disorder in the Japanese population

Several investigations have reported that the translin-associated factor X gene (TSNAX)/disrupted-in-schizophrenia-1 gene (DISC1) was associated with major psychiatric disorders including schizophrenia, bipolar disorder (BP), and major depressive disorder (MDD). TSNAX is located immediately upstream of DISC1, and has been shown to undergo intergenic splicing with DISC1. It thus may also be influenced by translocation. To our knowledge, there are no reported gene-based association analyses between TSNAX and mood disorders in the Japanese population. We conducted a case-control study of Japanese samples (158 bipolar patients, 314 major depressive disorder patients, and 811 controls) with three tagging SNPs in TSNAX, selected using HapMap database. In addition, we performed an association analysis between TSNAX and the efficacy of fluvoxamine treatment in 120 Japanese patients with MDD. The MDD patients in this study had scores of 12 or higher on the 17 items of the Structured Interview Guide for Hamilton Rating Scale for Depression (SIGH-D). We defined a clinical response as a decrease of more than 50% in baseline SIGH-D within 8 weeks, and clinical remission as an SIGH-D score of less than 7 at 8 weeks. We found an association between rs766288 in TSNAX and female MDD in the allele/genotype analysis. However, we did not find any association between TSNAX and BP or the fluvoxamine therapeutic response in MDD in the allele/genotype analysis or haplotype analysis. Our results suggest that rs766288 in TSNAX may play a role in the pathophysiology of female MDD in the Japanese population. A replication study using larger samples may be required for conclusive results, since our sample size was small.

Paternal psychiatric disorders and children's psychosocial development

Psychiatric disorders of parents are associated with an increased risk of psychological and developmental difficulties in their children. Most research has focused on mothers, neglecting psychiatric disorders affecting fathers. We review findings on paternal psychiatric disorders and their effect on children's psychosocial development. Most psychiatric disorders that affect fathers are associated with an increased risk of behavioural and emotional difficulties in their children, similar in magnitude to that due to maternal psychiatric disorders. Some findings indicate that boys are at greater risk than girls, and that paternal disorders, compared with maternal disorders, might be associated with an increased risk of behavioural rather than emotional problems. Improved paternal mental health is likely to improve children's wellbeing and life course.

Possible association of prokineticin 2 receptor gene (PROKR2) with mood disorders in the Japanese population

Several investigations have suggested that disruption of circadian rhythms may provide the foundation for the development of mood disorders such as bipolar disorder (BP) and major depressive disorder (MDD). Recent animal studies reported that prokineticin 2 or prokineticin 2 receptor gene deficient mice showed disruptions in circadian and homeostatic regulation of sleep. This evidence indicates that prokineticin 2 gene (PROK2) and prokineticin 2 receptor gene (PROKR2) are good candidate genes for the pathogenesis of mood disorders. To evaluate the association between PROK2, PROKR2, and mood disorders, we conducted a case-control study of Japanese samples (151 bipolar patients, 319 major depressive disorder patients, and 340 controls) with four and five tagging SNPs in PROK2 or PROKR2, respectively, selected by HapMap database. We detected a significant association between PROKR2 and major depressive disorder and bipolar disorder in the Japanese population. In conclusion, our findings suggest that PROKR2 may play a role in the pathophysiology of mood disorders in the Japanese population. However, because our samples were small, it will be important to replicate and confirm these findings in other independent studies using larger samples.

Intergenerational transmission of internalising and externalising behaviours across three generations: gender-specific pathways

BACKGROUND

Few studies have examined gender-specific pathways in the intergenerational transmission of internalising and externalising behaviours across three generations.

AIM

The current study considered both parental figures' internalising and externalising symptoms simultaneously and tested path models of the transmission of internalising and externalising symptoms from Generation 1 (G1) to Generation 2 (G2) and from G2 to Generation 3 (G3) by focusing on gender-specific pathways.

METHOD

The study used data from the Oregon Youth Study of 206 young men and two associated studies of their intimate partners (Couples Study) and children (Three-Generational Study) over 20 years.

RESULTS

Findings indicated that, in general, mothers' internalising behaviour showed robust influence on offspring's internalising symptoms across three generations, regardless of gender of the child. G2 men's externalising behaviour was further predicted by G1 mothers' internalising as well as externalising behaviour, albeit the latter was only marginally significant. G3 girls' internalising and externalising behaviour was predicted by their fathers' corresponding behaviour. Overall, fathers' influence on their sons was limited.

CONCLUSION

The findings shed important light on potential gender-specific mechanisms of intergenerational transmission of internalising and externalising behaviour.

The End of Behavioral Genetics?

Although genetic models were in the ascendance within psychology during the early 20(th) century, the association of early behavioral genetic research with the eugenics movement served to discredit the field in the eyes of many. Twin and adoption studies throughout the latter half of the 20(th) century helped to reestablish the importance of behavioral genetic models and set the stage for the current focus of the field on developing and testing models of gene-environment interplay. Research findings on developmental behavioral genetic research, gene-environment interaction, and the use of behavioral genetic models to test causal hypotheses are used to highlight the contributions of contemporary behavioral genetic research to psychological research. It is argued that future efforts to investigate models of gene-environment interplay will depend heavily of the field's ability to identify the specific genetic variants that contribute to individual differences in behavior. The anticipated yield from genome-wide association studies gives much reason to be optimistic about the future vitality of behavior genetics.