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Causes of the comorbidity of substance misuse with anxiety-related and depressive disorders (anxiety/depression) remain poorly known. We estimated associations of substance misuse and anxiety/depression in the general population and tested them while accounting for genetic and shared environmental factors.
We studied individuals born in Sweden 1968–1997 (n = 2 996 398) with follow-up in nationwide register data for 1997–2013. To account for familial effects, stratified analyses were conducted within siblings and twin pairs. Substance misuse was defined as ICD-10 alcohol or drug use disorder or an alcohol/drug-related criminal conviction. Three dimensions of ICD-10 anxiety and depressive disorders and a substance misuse dimension were identified through exploratory factor analysis.
Substance misuse was associated with a 4.5-fold (95% CI 4.50–4.58) elevated risk of lifetime generalized anxiety/depression, 4.7-fold (95% CI 4.63–4.82) elevated risk of panic disorder and agora/social phobia, and 2.9-fold elevated risk of phobias/OCD (95% CI 2.82–3.02) as compared to those without substance misuse. The associations were attenuated in within-family analyses but we found elevated risks in monozygotic twin pairs discordant for substance misuse as well as significant non-shared environmental correlations. The association between anxiety/depression and substance misuse was mainly driven by generalized anxiety/depression, whereas other anxiety/depression dimensions had minor or no independent associations with substance misuse.
Substance misuse and anxiety/depression are associated at the population level, and these associations are partially explained by familial liabilities. Our findings indicate a common genetic etiology but are also compatible with a potential partially causal relationship between substance misuse and anxiety/depression.
Studies on the individual gender-specific risk and familial co-aggregation of suicidal behaviour in autism spectrum disorder (ASD) are lacking.
We conducted a matched case-cohort study applying conditional logistic regression models on 54 168 individuals recorded in 1987–2013 with ASD in Swedish national registers: ASD without ID n = 43 570 (out of which n = 19035, 43.69% with ADHD); ASD + ID n = 10 598 (out of which n = 2894 individuals, 27.31% with ADHD), and 270 840 controls, as well as 347 155 relatives of individuals with ASD and 1 735 775 control relatives.
The risk for suicidal behaviours [reported as odds ratio OR (95% confidence interval CI)] was most increased in the ASD without ID group with comorbid ADHD [suicide attempt 7.25 (6.79–7.73); most severe attempts i.e. requiring inpatient stay 12.37 (11.33–13.52); suicide 13.09 (8.54–20.08)]. The risk was also increased in ASD + ID group [all suicide attempts 2.60 (2.31–2.92); inpatient only 3.45 (2.96–4.02); suicide 2.31 (1.16–4.57)]. Females with ASD without ID had generally higher risk for suicidal behaviours than males, while both genders had highest risk in the case of comorbid ADHD [females, suicide attempts 10.27 (9.27–11.37); inpatient only 13.42 (11.87–15.18); suicide 14.26 (6.03–33.72); males, suicide attempts 5.55 (5.10–6.05); inpatient only 11.33 (9.98–12.86); suicide 12.72 (7.77–20.82)]. Adjustment for psychiatric comorbidity attenuated the risk estimates. In comparison to controls, relatives of individuals with ASD also had an increased risk of suicidal behaviour.
Clinicians treating patients with ASD should be vigilant for suicidal behaviour and consider treatment of psychiatric comorbidity.
This paper investigates the California Vowel Shift, previously characterized as a chain shift, in communities across California's Central Valley. An incremental apparent time analysis of 72 Californians’ vowel spaces provides no clear evidence of a gradual chain shift; that is, changes have not unfolded in an order that reflects an implicational chain in chronological time. Instead, we see contemporaneous movements of vowels that work against the phonological tendency of maximal dispersion typically invoked in describing chain shifts. By analyzing change in the size and dispersion of the entire vowel space, we find that ongoing sound change is instead characterized by a holistic compression of the vowel space. This suggests that, in these California communities, the shift's unfolding was driven by articulatory and social, rather than purely phonological, factors. We propose that the analysis of the size and spread of holistic vowel space can help characterize the nature and motivations for vocalic changes.
Maternal polycystic ovary syndrome (PCOS) has been proposed as a model for investigating the role of prenatal androgen exposure in the development of neuropsychiatric disorders. However, women with PCOS are at higher risk of developing psychiatric conditions and previous studies are likely confounded by genetic influences.
A Swedish nationwide register-based cohort study was conducted to disentangle the influence of prenatal androgen exposure from familial confounding in the association between maternal PCOS and offspring attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASD), and Tourette's disorder and chronic tic disorders (TD/CTD). PCOS-exposed offspring (n = 21 280) were compared with unrelated PCOS-unexposed offspring (n = 200 816) and PCOS-unexposed cousins (n = 17 295). Associations were estimated with stratified Cox regression models.
PCOS-exposed offspring had increased risk of being diagnosed with ADHD, ASD, and TD/CTD compared with unrelated PCOS-unexposed offspring. Associations were stronger in girls for ADHD and ASD but not TD/CTD [ADHD: adjusted hazard ratio (aHR) = 1.61 (95% confidence interval (CI) 1.31–1.99), ASD: aHR = 2.02 (95% CI 1.45–2.82)] than boys [ADHD: aHR = 1.37 (95% CI 1.19–1.57), ASD: aHR = 1.46 (95% CI 1.21–1.76)]. For ADHD and ASD, aHRs for girls were stronger when compared with PCOS-unexposed cousins, but slightly attenuated for boys.
Estimates were similar when accounting for familial confounding (i.e. genetics and environmental factors shared by cousins) and stronger in girls for ADHD and ASD, potentially indicating a differential influence of prenatal androgen exposure v. genetic factors. These results strengthen evidence for a potential causal influence of prenatal androgen exposure on the development of male-predominant neuropsychiatric disorders in female offspring of women with PCOS.
This paper explores the relation between controlled and automatic perceptions of a sociolinguistic variable that yields no metalinguistic commentary—a marker (Labov, 1972). Two experiments examine links between the backed trap vowel and its social meanings. The first, a matched guise task, measures social evaluations of the feature in a relatively controlled, introspective task. In the second, two measures are used that access different points in online processing and different degrees of listener control: (a) lexical categorization of an ambiguous stimulus, measured by a mouse click, and (b) automatic, early responses to this ambiguous stimulus, measured by eye movements. While listeners perceptually link trap-backing with social information in all three measures, specific social effects differ across the measures. Findings illustrate that the task and time course of a response influence how listeners link a linguistic marker with social information, even when this sociolinguistic knowledge is below the level of conscious awareness.
Social meaning-based approaches to linguistic variation treat variation as a semiotic system, in which sociolinguistic signs—indexical links between linguistic forms and social meanings—serve as interactional resources that individuals use to project personae. This article explores the perceptual nature of the links between social personae and linguistic forms, examining how information about a speaker's persona can influence a listener's linguistic perceptions of a continuous phonetic feature. Using a phoneme categorization task, this study examines associations between gradient phonetic manifestations on a continuum from /æ/ to /ɑ/ and three social personae. Findings illustrate that the social persona made relevant for a listener influences the ways in which points on this phonetic continuum are categorized phonemically as either trap or lot. Overall, this shows that the social constructs of personae influence phonetically detailed perceptions of linguistic material. (Sociolinguistic perception, personae, indexicality, sociophonetics, sociolinguistic signs)*
This article explores the intertwining semiotics of language and embodiment in performances of Californian personae. We analyze two actors’ performances of Californian characters in parodic skits, comparing them to the same actors’ performances of non-Californian characters. In portraying their Californian characters, the actors use particularized jaw settings, which we link to embodied stereotypes from earlier portrayals of the Valley Girl and Surfer Dude personae. Acoustic analysis demonstrates that both actors also produce features of the California Vowel Shift in their Californian performances, aligning their linguistic productions with sound changes documented in California. We argue that these embodied stereotypes and phonetic realizations not only co-occur in parodic styles, but are in fact semiotically and corporeally intertwined, one occasioning the other. Moreover, the performances participate in the broader process of enregisterment, packaging these semiotic resources with other linguistic and extralinguistic features to recontextualize Californian personae in the present day. (Parody, performance, California, California Vowel Shift, embodiment, embodied stereotype, enregisterment)*
Knowledge about the association between alcohol and Barrett’s oesophagus and reflux oesophagitis is conflicting. In this case–control study we evaluated the role of specific alcoholic beverages (red and white wine, beer and liquors) in 339 Barrett’s oesophagus and 462 oesophagitis patients compared with 619 endoscopic controls with other disorders, recruited in twelve Italian endoscopic units. Data on alcohol and other individual characteristics were obtained from structured questionnaires. No clear, monotonic significant dose–response relationship was pointed out for red wine. However, a generalised U-shaped trend of Barrett’s oesophagus/oesophagitis risk due to red wine consumption particularly among current drinkers was found. Similar results were also found for white wine. Liquor/spirit consumption seemed to bring about a 1·14–2·30 risk excess, although statistically non-significant, for current Barrett’s oesophagus/oesophagitis drinkers. Statistically significant decreasing dose–response relationships were found in Barrett’s oesophagus for frequency and duration of beer consumption. Similar, but less clear downward tendencies were also found for oesophagitis patients. In conclusion, although often not statistically significant, our data suggested a reduced risk of Barrett’s oesophagus and oesophagitis with a low/moderate intake of wine and beer consumption. A non-significant increased risk of Barrett’s oesophagus/oesophagitis was observed with a higher intake of any type of heavy alcohol consumption, but no conclusion can be drawn owing to the high number of non-spirit drinkers and to the small number of drinkers at higher alcohol intake levels.
Advanced paternal age at childbirth is associated with psychiatric disorders in offspring, including schizophrenia, bipolar disorder and autism. However, few studies have investigated paternal age's relationship with eating disorders in offspring. In a large, population-based cohort, we examined the association between paternal age and offspring eating disorders, and whether that association remains after adjustment for potential confounders (e.g. parental education level) that may be related to late/early selection into fatherhood and to eating disorder incidence.
Data for 2 276 809 individuals born in Sweden 1979–2001 were extracted from Swedish population and healthcare registers. The authors used Cox proportional hazards models to examine the effect of paternal age on the first incidence of healthcare-recorded anorexia nervosa (AN) and all eating disorders (AED) occurring 1987–2009. Models were adjusted for sex, birth order, maternal age at childbirth, and maternal and paternal covariates including country of birth, highest education level, and lifetime psychiatric and criminal history.
Even after adjustment for covariates including maternal age, advanced paternal age was associated with increased risk, and younger paternal age with decreased risk, of AN and AED. For example, the fully adjusted hazard ratio for the 45+ years (v. the 25–29 years) paternal age category was 1.32 [95% confidence interval (CI) 1.14–1.53] for AN and 1.26 (95% CI 1.13–1.40) for AED.
In this large, population-based cohort, paternal age at childbirth was positively associated with eating disorders in offspring, even after adjustment for potential confounders. Future research should further explore potential explanations for the association, including de novo mutations in the paternal germline.
Highly accreting quasars are possible cosmological probes, as their Eddington ratio is expected to saturate toward values of order unity. We present preliminary estimates of redshift- independent source luminosities and the Hubble diagram for quasars in the redshift range 0.1 ≲ z ≲ 2.6.
We analyzed the light curves (LCs) of several radio-quiet and radio-loud quasars belonging to the same parameter space volume in the 4D Eigenvector 1 (4DE1) quasar sequence, using data from the Catalina Real-time Transient Survey (CRTS). We report preliminary results on detected variability pattern, and discuss possible cases of periodic variability.
Given the frequency with which families change residences, the effects of childhood relocations have gained increasing research attention. Many researchers have demonstrated that childhood relocations are associated with a variety of adverse outcomes. However, drawing strong causal claims remains problematic due to uncontrolled confounding factors.
We utilized longitudinal, population-based Swedish registers to generate a nationally representative sample of offspring born 1983–1997 (n = 1 510 463). Using Cox regression and logistic regression, we examined the risk for numerous adverse outcomes after childhood relocation while controlling for measured covariates. To account for unmeasured genetic and environmental confounds, we also compared differentially exposed cousins and siblings.
In the cohort baseline model, each annual relocation was associated with risk for the adverse outcomes, including suicide attempt [hazard ratio (HR) 1.19, 95% confidence interval (CI) 1.19–1.20]. However, when accounting for offspring and parental covariates (HR 1.08, 95% CI 1.07–1.09), as well as genetic and environmental confounds shared by cousins (HR 1.07, 95% CI 1.05–1.09) and siblings (HR 1.00, 95% CI 0.97–1.04), the risk for suicide attempt attenuated. We found a commensurate pattern of results for severe mental illness, substance abuse, criminal convictions, and low academic achievement.
Previous research may have overemphasized the independent association between relocations and later adverse outcomes. The results suggest that the association between childhood relocations and suicide attempt, psychiatric problems, and low academic achievement is partially explained by genetic and environmental confounds correlated with relocations. This study demonstrates the importance of using family-based, quasi-experimental designs to test plausible alternate hypotheses when examining causality.
This article presents some observations on “public happiness” in order to clarify the idea’s meaning in the eighteenth-century Italian context. It examines Lugino Bruni’s interpretation of this concept, and criticizes his understanding of public happiness as the continuation of Artistotle’s eudaimonia. Bruni stresses the social and collective nature of happiness in the civil economy of the Italian eighteenth century. By examining the works of Ludovico Antonio Muratori and Antonio Genovesi, this article addresses instead the political meaning of public happiness for absolute monarchies, and underlines its origins in the German tradition of natural law.
Addressing the dearth of variation research in nonurban, noncoastal regions of California, this study examines the extent to which speakers in Redding, an inland community just north of the Central Valley, participate in the California Vowel Shift (CVS). We acoustically analyze the fronting of the back vowels boot and boat, the raising of ban and backing of bat, and the merger of bot and bought, in sociolinguistic interviews with 30 white lifelong residents. Results reveal a change in apparent time for all analyzed variables, indicating the CVS's progression through the community, though not as robust as in urban, coastal areas. Additionally, we provide evidence that shifting patterns for different vowels are structured by the ideological divide between town and country. Thus, as the CVS spreads through Redding, speakers utilize particular features of the shift differently, negotiating identities relevant in California's nonurban locales.
It is unclear whether associations between fetal growth and psychiatric
and socioeconomic problems are consistent with causal mechanisms.
To estimate the extent to which associations are a result of unmeasured
confounding factors using a sibling-comparison approach.
We predicted outcomes from continuously measured birth weight in a
Swedish population cohort (n = 3 291 773), while
controlling for measured and unmeasured confounding.
In the population, lower birth weight (⩽2500 g) increased the risk of all
outcomes. Sibling-comparison models indicated that lower birth weight
independently predicted increased risk for autism spectrum disorder
(hazard ratio for low birth weight = 2.44, 95% CI 1.99–2.97) and
attention-deficit hyperactivity disorder. Although attenuated,
associations remained for psychotic or bipolar disorder and educational
problems. Associations with suicide attempt, substance use problems and
social welfare receipt, however, were fully attenuated in sibling
Results suggest that fetal growth, and factors that influence it,
contribute to psychiatric and socioeconomic problems.
Low socioeconomic status in childhood is a well-known predictor of subsequent criminal and substance misuse behaviours but the causal mechanisms are questioned.
To investigate whether childhood family income predicts subsequent violent criminality and substance misuse and whether the associations are in turn explained by unobserved familial risk factors.
Nationwide Swedish quasi-experimental, family-based study following cohorts born 1989–1993 (ntotal = 526 167, ncousins = 262 267, nsiblings = 216 424) between the ages of 15 and 21 years.
Children of parents in the lowest income quintile experienced a seven-fold increased hazard rate (HR) of being convicted of violent criminality compared with peers in the highest quintile (HR = 6.78, 95% CI 6.23–7.38). This association was entirely accounted for by unobserved familial risk factors (HR = 0.95, 95% CI 0.44–2.03). Similar pattern of effects was found for substance misuse.
There were no associations between childhood family income and subsequent violent criminality and substance misuse once we had adjusted for unobserved familial risk factors.
No prior twin study has explored the heritability of clinically diagnosed attention deficit hyperactivity disorder (ADHD). Such studies are needed to resolve conflicting results regarding the importance of genetic effects for ADHD in adults. We aimed to estimate the relative contribution of genetic and environmental influences for clinically diagnosed ADHD across the lifespan with a specific focus on ADHD in adults.
Information on zygosity and sex was obtained from 59514 twins born between 1959 and 2001 included in the nationwide population-based Swedish Twin Registry. Clinical data for ADHD diagnoses (i.e. stimulant or non-stimulant medication for ADHD) were obtained from the Swedish Prescribed Drug Register (PDR) and from the National Patient Register (i.e. ICD-10 diagnosis of ADHD). Twin methods were applied to clinical data of ADHD diagnoses using structural equation modeling with monozygotic (MZ) and dizygotic (DZ) twins.
The best-fitting model revealed a high heritability of ADHD [0.88, 95% confidence interval (CI) 0.83–0.92] for the entire sample. However, shared environmental effects were non-significant and of minimal importance. The heritability of ADHD in adults was also substantial (0.72, 95% CI 0.56–0.84).
This study shows that the heritability of clinically diagnosed ADHD is high across the lifespan. Our finding of high heritability for clinically diagnosed ADHD in adults indicates that the previous reports of low heritability are best explained by rater effects, and that gene-identification studies of ADHD in adults need to consider pervasiveness (e.g. multiple raters) and developmentally (e.g. childhood-onset criteria) informative data.