Liam Mahedy

Peer victimization during adolescence and risk for anxiety disorders in adulthood: a prospective cohort study.

Peer victimization is ubiquitous across schools and cultures, and has been suggested as one developmental pathway to anxiety disorders. However, there is a dearth of prospective studies examining this relationship. The purpose of this cohort study was to examine the association between peer victimization during adolescence and subsequent anxiety diagnoses in adulthood. A secondary aim was to investigate whether victimization increases risk for severe anxiety presentations involving diagnostic comorbidity.

Common versus psychopathology-specific risk factors for psychotic experiences and depression during adolescence

Background An argument often used to support the view that psychotic experiences (PEs) in general population samples are a valid phenotype for studying the aetiology of schizophrenia is that risk factors for schizophrenia show similar patterns of association with PEs. However, PEs often co-occur with depression, and no study has explicitly tested whether risk factors for schizophrenia are shared between PEs and depression, or are psychopathology specific, while jointly modelling both outcomes. Method We used data from 7030 subjects from a birth cohort study. Depression and PEs at age 18 years were assessed using self-report questionnaires and semi-structured interviews. We compared the extent to which risk factors for schizophrenia across sociodemographic, familial, neurodevelopmental, stress–adversity, emotional–behavioural and substance use domains showed different associations with PEs and depression within bivariate models that allowed for their correlation. Results Most of the exposures examined were associated, to a similar degree, with an increased risk of both outcomes. However, whereas female sex and family history of depression showed some discrimination as potential risk factors for depression and PEs, with stronger associations in the former, markers of abnormal neurodevelopment showed stronger associations with PEs. Conclusions The argument that PEs are valid markers for studying the aetiology of schizophrenia, made simply on the basis that they share risk factors in common, is not well supported. PEs seem to be a weak index of genetic and environmental risk for schizophrenia; however, studies disentangling aetiological pathways to PEs from those impacting upon co-morbid psychopathology might provide important insights into the aetiology of psychotic disorders.

Maternal perinatal mental health and offspring academic achievement at age 16: the mediating role of childhood executive function

Background Elucidating risk pathways for under‐achieving at school can inform strategies to reduce the number of adolescents leaving school without passing grades in core subjects. Maternal depression can compromise the quality of parental care and is associated with multiple negative child outcomes. However, only a few small studies have investigated the association between perinatal maternal depression and poor academic achievement in adolescence. The pathways to explain the risks are also unclear. Method Prospective observational data from 5,801 parents and adolescents taking part in a large UK population cohort (Avon‐Longitudinal‐Study‐of‐Parents‐and‐Children) were used to test associations between maternal and paternal depression and anxiety in the perinatal period, executive function (EF) at age 8, and academic achievement at the end of compulsory school at age 16. Results Adolescents of postnatally depressed mothers were 1.5 times (1.19, 1.94, p = .001) as likely as adolescents of nondepressed mothers to fail to achieve a ‘pass’ grade in math; antenatal anxiety was also an independent predictor of poor math. Disruption in different components of EF explained small but significant proportions of these associations: attentional control explained 16% (4%, 27%, p < .001) of the association with postnatal depression, and working memory explained 17% (13%, 30%, p = .003) of the association with antenatal anxiety. A similar pattern was seen for language grades, but associations were confounded by maternal education. There was no evidence that paternal factors were independently associated with impaired child EF or adolescent exams. Conclusion Maternal postnatal depression and antenatal anxiety are risk factors for adolescents underachieving in math. Preventing, identifying, and treating maternal mental health in the perinatal period could, therefore, potentially increase adolescents’ academic achievement. Different aspects of EF partially mediated these associations. Further work is needed, but if these pathways are causal, improving EF could reduce underachievement in math.

Longitudinal associations between adolescent psychotic experiences and depressive symptoms

Background Psychotic experiences are prevalent in community samples and are highly correlated with depressive symptoms. This study aimed to investigate the longitudinal associations between psychotic experiences and depressive symptoms between adolescence and young adulthood. Method Prospective cohort study with a 6 year follow-up in a community sample of 7632 adolescents and young adults. Depressive symptoms were assessed with the Short Moods and Feelings Questionnaire and psychotic experiences with a semi-structured clinical interview at 12 and 18 years. Longitudinal and cross-sectional associations were investigated with regression and structural equation models. Results Depressive symptoms and psychotic experiences were associated at each time-point (12 years r = 0.486 [95% CI 0.457, 0.515]; 18 years r = 0.286 [95% CI 0.233, 0.339]) and there were longitudinal within-phenotype associations (depressive symptoms r = 0.252 [95% CI 0.205, 0.299]; psychotic experiences r = 0.662 [95% CI 0.595, 0.729]). There was an across-phenotype association between psychotic experiences at 12 and depressive symptoms at 18 r = 0.139 [95% CI 0.086, 0.192; p<0.001], but no association between depressive symptoms at 12 and psychotic experiences at 18 r = −0.022 [95% CI −0.032, 0.077; p = 0.891]. Conclusions Longitudinal across-phenotype associations were substantially weaker than cross-sectional associations or within-phenotype longitudinal associations. Whilst psychotic experiences at 12 years were associated with a small increase in depression at 18 years, depression at 12 years was not associated with psychotic experiences at 18 years once across-phenotype cross-sectional and within-phenotype longitudinal associations were accounted for. This suggests that the biological mechanisms underlying depression at this age do not increase subsequent risk of psychotic experiences once they resolve.

Association between Maternal Depression Symptoms across the First Eleven Years of Their Child’s Life and Subsequent Offspring Suicidal Ideation

Depression is common, especially in women of child-bearing age; prevalence estimates for this group range from 8% to 12%, and there is robust evidence that maternal depression is associated with mental health problems in offspring. Suicidal behaviour is a growing concern amongst young people and those exposed to maternal depression are likely to be especially at high risk. The aim of this study was to utilise a large, prospective population cohort to examine the relationship between depression symptom trajectories in mothers over the first eleven years of their child’s life and subsequent adolescent suicidal ideation. An additional aim was to test if associations were explained by maternal suicide attempt and offspring depressive disorder. Data were utilised from a population-based birth cohort: the Avon Longitudinal Study of Parents and Children. Maternal depression symptoms were assessed repeatedly from pregnancy to child age 11 years. Offspring suicidal ideation was assessed at age 16 years. Using multiple imputation, data for 10,559 families were analysed. Using latent class growth analysis, five distinct classes of maternal depression symptoms were identified (minimal, mild, increasing, sub-threshold, chronic-severe). The prevalence of past-year suicidal ideation at age 16 years was 15% (95% CI: 14-17%). Compared to offspring of mothers with minimal symptoms, the greatest risk of suicidal ideation was found for offspring of mothers with chronic-severe symptoms [OR 3.04 (95% CI 2.19, 4.21)], with evidence for smaller increases in risk of suicidal ideation in offspring of mothers with sub-threshold, increasing and mild symptoms. These associations were not fully accounted for by maternal suicide attempt or offspring depression diagnosis. Twenty-six percent of non-depressed offspring of mothers with chronic-severe depression symptoms reported suicidal ideation. Risk for suicidal ideation should be considered in young people whose mothers have a history of sustained high levels of depression symptoms, even when the offspring themselves do not have a depression diagnosis.

Pathways to Suicide-Related Behavior in Offspring of Mothers With Depression: The Role of Offspring Psychopathology

Objective Offspring of mothers with depression are a high-risk group for the development of suicide-related behavior. These offspring are therefore a priority for preventive interventions; however, pathways contributing to risk, including specific aspects of offspring psychopathology, remain unclear. The aim of this study was to examine whether offspring symptoms of major depressive disorder (MDD), generalized anxiety disorder (GAD), disruptive behavior disorder (DBD), attention-deficit/hyperactivity disorder (ADHD), and alcohol abuse independently mediate the association between maternal depression and offspring suicide-related behavior. Method Data were used from a population-based birth cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC). Three distinct classes of depression symptoms across the mothers’ first 11 years of their child’s life were identified (minimal, moderate, chronic-severe). Offspring psychopathology was assessed at age 15 years and suicide-related behavior at age 16 years. Data were analyzed using structural equation modeling. Results There was evidence for increased risk of suicidal ideation in offspring of mothers with chronic-severe depression symptoms in comparison to offspring of mothers with minimal symptoms (odds ratio = 3.04, 95% CI = 2.19, 4.21). This association was independently mediated by offspring MDD, GAD, and DBD symptoms. The same mechanisms were found for offspring of mothers with moderate depression symptoms over time. Results were similar for offspring suicide attempt except for additional evidence of an indirect effect through offspring ADHD symptoms. Conclusion Findings highlight that suicide prevention efforts in offspring of mothers with depression should not only be targeted at offspring with MDD; it is also important to consider offspring with other forms of psychopathology.

Cognitive styles and future depressed mood in early adulthood: The importance of global attributions

Background Cognitive theories of depression suggest that beliefs of low self-worth and the tendency to attribute negative events to causes that are global (widespread rather than specific) and stable (will persist rather than change in the future) are associated with the development of depressed mood. Such theories are supported by evidence from prospective studies and have guided the development of successful treatment and prevention strategies such as CBT. However, the relative importance of different psychological constructs within cognitive theories is unknown. This is important to refine cognitive theories and develop more efficient prevention strategies. Method We used prospective data from over 3500 young adults from the Avon Longitudinal Study for Parents and Children (ALSPAC) cohort in the UK to investigate the association between cognitive style, measured by short forms of the Dysfunctional Attitudes Scale (DAS) and Cognitive Styles Questionnaire-Short Form (CSQ-SF) at age 18, and future depressed mood at age 19. Structural equation modelling techniques were used to separate cognitive style constructs. Results Cognitive styles were associated with future depressed mood, independently of baseline mood, both as measured by the DAS-SF and the CSQ-SF. Of the different CSQ-SF constructs, only global attributions were associated with both baseline and future mood independently of other constructs. Limitations The study was subject to attrition and the follow-up was relatively short (10 months). Conclusion The findings suggest that the tendency to attribute negative events specifically to global causes could be particularly important for depression. Reducing global attributions is potentially important in the prevention and treatment of depression.

Examining whether offspring psychopathology influences illness course in mothers with recurrent depression using a high-risk longitudinal sample

Depression is known to be influenced by psychosocial stressors. For mothers with recurrent depressive illness, the presence of psychopathology in their children may have important effects on their own mental health. Although the impact of maternal depression on child mental health is well-established, no study to date, as far as we are aware, has examined the extent to which offspring psychopathology influences the course of depression in mothers with a history of recurrent depressive illness, what types of child psychopathology impact maternal mental health, or whether risks vary by child gender. Aims were to (a) Use a longitudinal design to examine whether adolescent psychopathology (depression, disruptive behavior disorder; DBD) predicts recurrence of a depressive episode and depression symptom course in women with a history of recurrent depression; and (b) To test if observed effects vary by child gender. 299 mothers with recurrent major depressive disorder and their adolescent offspring were assessed on 2 occasions, 29 months apart. Maternal depression and offspring psychopathology were assessed using semistructured interview measures. Cross-generational links across time were assessed using structural equation modeling. Analyses were adjusted for past severity of maternal depression. Offspring depression symptoms but not DBD symptoms at baseline predicted future episode recurrence in mothers. Depression symptoms in daughters (β = .16, p = .039) but not sons (β = −.07, p = .461), predicted an increase in maternal depression symptoms across time. Psychopathology in daughters is associated with long-term depressive symptoms in women (mothers) with a history of recurrent depression. Findings highlight the importance of careful assessment and management of mental health problems in adolescents for more effective management of maternal depression. This study suggests that offspring symptoms of depression may be important for the recurrence of maternal depression episodes. Girls’ symptoms of depression may be a particularly important psychosocial stressor for the development of depressive symptoms in mothers with a history of recurrent depression.

Parental alcohol use and risk of behavioral and emotional problems in offspring

Objective The majority of studies that have examined parental alcohol use and offspring outcomes have either focused on exposure in the antenatal period or from clinical populations. This study sought to examine proximal and distal associations between parental alcohol use and offspring conduct problems and depressive symptoms in a population birth cohort. Methods We used prospective data from a large UK based population cohort (ALSPAC) to investigate the association between parental alcohol use, measured in units, (assessed at ages 4 and 12 years) with childhood conduct trajectories, (assessed on six occasions from 4 to 13.5 years, n = 6,927), and adolescent depressive symptoms (assessed on four occasions from ~13 to ~18 years, n = 5,539). Heavy drinking was defined as ≥21 units per week in mothers and partners who drank 4+ units daily. Results We found little evidence to support a dose response association between parental alcohol use and offspring outcomes. For example, we found insufficient evidence to support an association between maternal alcohol use at age 4 years and childhood conduct problems (childhood limited: OR = 1.00, 95% CI = .99, 1.01; adolescent onset: OR = 0.99, 95% CI = .98, 1.00; and early-onset persistent: OR = 0.99, 95% CI = .98, 1.00) per 1-unit change in maternal alcohol use compared to those with low levels of conduct problems. We also found insufficient evidence to support an association between maternal alcohol use at age 4 years and adolescent depressive symptoms (intercept: b = .001, 95% CI = -.01, .01, and slope: b = .003, 95% CI = -.03, .03) per 1-unit change in maternal alcohol use. Results remained consistent across amount of alcohol consumed (i.e., number of alcohol units or heavy alcohol use), parent (maternal self-reports or maternal reports of partner’s alcohol use), and timing of alcohol use (assessed at age 4 or age 12 years). Conclusions There is no support for an association between parental alcohol use during childhood and conduct and emotional problems during childhood or adolescence.

Low resting heart rate, sensation seeking and the course of antisocial behaviour across adolescence and young adulthood

Background Low resting heart rate (RHR) is a consistent biological correlate of antisocial behaviour (ASB), however potential mechanisms have been largely unexplored. We hypothesise that lower RHR will be associated with higher ASB levels in mid-adolescence and persistence into adulthood, and that these associations will be explained, in part, by sensation seeking and callous-unemotional traits. Methods ASB was assessed repeatedly with young people from ages 15 to 21 years in a population-based birth cohort (ALSPAC). A longitudinal trajectory was derived and showed ASB decreasing across adolescence before stabilising in early adulthood. RHR was recorded at age 12 years, and mediators were assessed at age 14 years. Results After adjusting for socio-demographic confounders, there was evidence for a total effect of RHR on ASB levels in mid-adolescence [b(95% CI) = −0.08 (−0.14 to −0.02)], reflecting 0.08 more types of antisocial activity in the last year per 10 fewer heart beats per minute. This effect was almost entirely explained through sensation seeking [b(95% CI) = −0.06 (−0.08 to −0.04)]. After additionally adjusting for child and parent-related confounders, all effects weakened; however, there was still evidence of an indirect effect of RHR, via sensation seeking, on ASB levels in mid-adolescence [b(95% CI) = −0.01 (−0.03 to −0.003)]. There was no evidence for a total effect of RHR on ASB levels in early adulthood, and weak evidence of an indirect effect, via sensation seeking [b(95% CI) = −0.01 (−0.01 to −0.00)]. Conclusions Lower RHR in childhood was associated with higher ASB levels in mid-adolescence, indirectly via sensation seeking.