| 1. |
- Pettersson, E., et al.
(författare)
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Common psychiatric disorders share the same genetic origin : a multivariate sibling study of the Swedish population
- 2016
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Ingår i: Molecular Psychiatry. - New York, USA : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 21:5, s. 717-721
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have shown that different mental-health problems appear to be partly influenced by the same set of genes, which can be summarized by a general genetic factor. To date, such studies have relied on surveys of community-based samples, which could introduce potential biases. The goal of this study was to examine whether a general genetic factor would still emerge when based on a different ascertainment method with different biases from previous studies. We targeted all adults in Sweden (n=3 475 112) using national registers and identified those who had received one or more psychiatric diagnoses after seeking or being forced into mental health care. In order to examine the genetic versus environmental etiology of the general factor, we examined whether participants' full- or half-siblings had also received diagnoses. We focused on eight major psychiatric disorders based on the International Classification of Diseases, including schizophrenia, schizoaffective disorder, bipolar disorder, depression, anxiety, attention-deficit/hyperactivity disorder, alcohol use disorder and drug abuse. In addition, we included convictions of violent crimes. Multivariate analyses demonstrated that a general genetic factor influenced all disorders and convictions of violent crimes, accounting for between 10% (attention-deficit/hyperactivity disorder) and 36% (drug abuse) of the variance of the conditions. Thus, a general genetic factor of psychopathology emerges when based on both surveys as well as national registers, indicating that a set of pleiotropic genes influence a variety of psychiatric disorders.
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| 2. |
- Fernández de la Cruz, Lorena, et al.
(författare)
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Suicide in obsessive-compulsive disorder : a population-based study of 36 788 Swedish patients
- 2017
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Ingår i: Molecular Psychiatry. - : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 22:11, s. 1626-1632
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Tidskriftsartikel (refereegranskat)abstract
- The risk of death by suicide in individuals with obsessive-compulsive disorder (OCD) is largely unknown. Previous studies have been small and methodologically flawed. We analyzed data from the Swedish national registers to estimate the risk of suicide in OCD and identify the risk and protective factors associated with suicidal behavior in this group. We used a matched case-cohort design to estimate the risk of deaths by suicide and attempted suicide in individuals diagnosed with OCD, compared with matched general population controls (1:10). Cox regression models were used to study predictors of suicidal behavior. We identified 36 788 OCD patients in the Swedish National Patient Register between 1969 and 2013. Of these, 545 had died by suicide and 4297 had attempted suicide. In unadjusted models, individuals with OCD had an increased risk of both dying by suicide (odds ratio (OR)=9.83 (95% confidence interval (CI), 8.72-11.08)) and attempting suicide (OR=5.45 (95% CI, 5.24-5.67)), compared with matched controls. After adjusting for psychiatric comorbidities, the risk was reduced but remained substantial for both death by suicide and attempted suicide. Within the OCD cohort, a previous suicide attempt was the strongest predictor of death by suicide. Having a comorbid personality or substance use disorder also increased the risk of suicide. Being a woman, higher parental education and having a comorbid anxiety disorder were protective factors. We conclude that patients with OCD are at a substantial risk of suicide. Importantly, this risk remains substantial after adjusting for psychiatric comorbidities. Suicide risk should be carefully monitored in patients with OCD.
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| 3. |
- Mataix-Cols, David, et al.
(författare)
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A total-population multigenerational family clustering study of autoimmune diseases in obsessive-compulsive disorder and Tourette’s/chronic tic disorders
- 2017
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Ingår i: Molecular Psychiatry. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 1359-4184 .- 1476-5578.
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Tidskriftsartikel (refereegranskat)abstract
- The association between obsessive-compulsive disorder (OCD) and Tourette's/chronic tic disorders (TD/CTD) with autoimmune diseases (ADs) is uncertain. In this nationwide study, we sought to clarify the patterns of comorbidity and familial clustering of a broad range of ADs in individuals with OCD, individuals with TD/CTD and their biological relatives. From a birth cohort of 7 465 455 individuals born in Sweden between 1940 and 2007, we identified 30 082 OCD and 7279 TD/CTD cases in the National Patient Register and followed them up to 31 December 2013. The risk of 40 ADs was evaluated in individuals with OCD, individuals with TD/CTD and their first- (siblings, mothers, fathers), second- (half siblings) and third-degree (cousins) relatives, compared with population controls. Individuals with OCD and TD/CTD had increased comorbidity with any AD (43% and 36%, respectively) and many individual ADs. The risk of any AD and several individual ADs was consistently higher among first-degree relatives than among second- and third-degree relatives of OCD and TD/CTD probands. The risk of ADs was very similar in mothers, fathers and siblings of OCD probands, whereas it tended to be higher in mothers and fathers of TD/CTD probands (compared with siblings). The results suggest a familial link between ADs in general (that is, not limited to Streptococcus-related conditions) and both OCD and TD/CTD. Additional mother-specific factors, such as the placental transmission of antibodies, cannot be fully ruled out, particularly in TD/CTD.
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| 4. |
- Brander, Gustaf, et al.
(författare)
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Perinatal risk factors in Tourette's and chronic tic disorders : a total population sibling comparison study
- 2018
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Ingår i: Molecular Psychiatry. - : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 23:5, s. 1189-1197
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Tidskriftsartikel (refereegranskat)abstract
- Adverse perinatal events may increase the risk of Tourette's and chronic tic disorders (TD/CTD), but previous studies have been unable to control for unmeasured environmental and genetic confounding. We aimed to prospectively investigate potential perinatal risk factors for TD/CTD, taking unmeasured factors shared between full siblings into account. A population-based birth cohort, consisting of all singletons born in Sweden in 1973-2003, was followed until December 2013. A total of 3 026 861 individuals were identified, 5597 of which had a registered TD/CTD diagnosis. We then studied differentially exposed full siblings from 947 942 families; of these, 3563 families included siblings that were discordant for TD/CTD. Perinatal data were collected from the Medical Birth Register and TD/CTD diagnoses were collected from the National Patient Register, using a previously validated algorithm. In the fully adjusted models, impaired fetal growth, preterm birth, breech presentation and cesarean section were associated with a higher risk of TD/CTD, largely independent from shared family confounders and measured covariates. Maternal smoking during pregnancy was associated with risk of TD/CTD in a dose-response manner but the association was no longer statistically significant in the sibling comparison models or after the exclusion of comorbid attention-deficit/hyperactivity disorder. A dose-response relationship between the number of adverse perinatal events and increased risk for TD/CTD was also observed, with hazard ratios ranging from 1.41 (95% confidence interval (CI): 1.33-1.50) for one event to 2.42 (95% CI: 1.65-3.53) for five or more events. These results pave the way for future gene by environment interaction and epigenetic studies in TD/CTD.
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| 5. |
- Borg, J., et al.
(författare)
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Contribution of non-genetic factors to dopamine and serotonin receptor availability in the adult human brain
- 2016
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Ingår i: Molecular Psychiatry. - London, United Kingdom : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 51, s. 879-879
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Tidskriftsartikel (refereegranskat)abstract
- The dopamine (DA) and serotonin (5-HT) neurotransmission systems are of fundamental importance for normal brain function and serve as targets for treatment of major neuropsychiatric disorders. Despite central interest for these neurotransmission systems in psychiatry research, little is known about the regulation of receptor and transporter density levels. This lack of knowledge obscures interpretation of differences in protein availability reported in psychiatric patients. In this study, we used positron emission tomography (PET) in a twin design to estimate the relative contribution of genetic and environmental factors, respectively, on dopaminergic and serotonergic markers in the living human brain. Eleven monozygotic and 10 dizygotic healthy male twin pairs were examined with PET and [(11)C]raclopride binding to the D2- and D3-dopamine receptor and [(11)C]WAY100635 binding to the serotonin 5-HT1A receptor. Heritability, shared environmental effects and individual-specific non-shared effects were estimated for regional D2/3 and 5-HT1A receptor availability in projection areas. We found a major contribution of genetic factors (0.67) on individual variability in striatal D2/3 receptor binding and a major contribution of environmental factors (pairwise shared and unique individual; 0.70-0.75) on neocortical 5-HT1A receptor binding. Our findings indicate that individual variation in neuroreceptor availability in the adult brain is the end point of a nature-nurture interplay, and call for increased efforts to identify not only the genetic but also the environmental factors that influence neurotransmission in health and disease.
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| 6. |
- Cortese, Samuele, et al.
(författare)
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Incidence, prevalence, and global burden of ADHD from 1990 to 2019 across 204 countries : data, with critical re-analysis, from the Global Burden of Disease study
- 2023
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Ingår i: Molecular Psychiatry. - : Springer Nature. - 1359-4184 .- 1476-5578. ; 28:11, s. 4823-4830
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Tidskriftsartikel (refereegranskat)abstract
- Data on incidence, prevalence and burden of ADHD are crucial for clinicians, patients, and stakeholders. We present the incidence, prevalence, and burden of ADHD globally and across countries from 1990 to 2019 from the Global Burden of Disease (GBD) study. We also: (1) calculated the ADHD prevalence based on data actually collected as opposed to the prevalence estimated by the GBD with data imputation for countries without prevalence data; (2) discussed the GBD estimated ADHD burden in the light of recent meta-analytic evidence on ADHD-related mortality. In 2019, GBD estimated global age-standardized incidence and prevalence of ADHD across the lifespan at 0.061% (95%UI = 0.040-0.087) and 1.13% (95%UI = 0.831-1.494), respectively. ADHD accounted for 0.8% of the global mental disorder DALYs, with mortality set at zero by the GBD. From 1990 to 2019 there was a decrease of -8.75% in the global age-standardized prevalence and of -4.77% in the global age-standardized incidence. The largest increase in incidence, prevalence, and burden from 1990 to 2019 was observed in the USA; the largest decrease occurred in Finland. Incidence, prevalence, and DALYs remained approximately 2.5 times higher in males than females from 1990 to 2019. Incidence peaked at age 5-9 years, and prevalence and DALYs at age 10-14 years. Our re-analysis of data prior to 2013 showed a prevalence in children/adolescents two-fold higher (5.41%, 95% CI: 4.67-6.15%) compared to the corresponding GBD estimated prevalence (2.68%, 1.83-3.72%), with no significant differences between low- and middle- and high-income countries. We also found meta-analytic evidence of significantly increased ADHD-related mortality due to unnatural causes. While it provides the most detailed evidence on temporal trends, as well as on geographic and sex variations in incidence, prevalence, and burden of ADHD, the GBD may have underestimated the ADHD prevalence and burden. Given the influence of the GBD on research and policies, methodological issues should be addressed in its future editions.
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| 7. |
- Ghirardi, L., et al.
(författare)
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The familial co-aggregation of ASD and ADHD : a register-based cohort study
- 2018
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Ingår i: Molecular Psychiatry. - London, United Kingdom : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 23:2, s. 257-262
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Tidskriftsartikel (refereegranskat)abstract
- Autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (ADHD) frequently co-occur. The presence of a genetic link between ASD and ADHD symptoms is supported by twin studies, but the genetic overlap between clinically ascertained ASD and ADHD remains largely unclear. We therefore investigated how ASD and ADHD co-aggregate in individuals and in families to test for the presence of a shared genetic liability and examined potential differences between low- and high-functioning ASD in the link with ADHD. We studied 1 899 654 individuals born in Sweden between 1987 and 2006. Logistic regression was used to estimate the association between clinically ascertained ASD and ADHD in individuals and in families. Stratified estimates were obtained for ASD with (low-functioning) and without (high-functioning) intellectual disability. Individuals with ASD were at higher risk of having ADHD compared with individuals who did not have ASD (odds ratio (OR)=22.33, 95% confidence interval (CI): 21.77-22.92). The association was stronger for high-functioning than for low-functioning ASD. Relatives of individuals with ASD were at higher risk of ADHD compared with relatives of individuals without ASD. The association was stronger in monozygotic twins (OR=17.77, 95% CI: 9.80-32.22) than in dizygotic twins (OR=4.33, 95% CI: 3.21-5.85) and full siblings (OR=4.59, 95% CI: 4.39-4.80). Individuals with ASD and their relatives are at increased risk of ADHD. The pattern of association across different types of relatives supports the existence of genetic overlap between clinically ascertained ASD and ADHD, suggesting that genomic studies might have underestimated this overlap.
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| 8. |
- Kuja-Halkola, Ralf, et al.
(författare)
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Do borderline personality disorder and attention-deficit/hyperactivity disorder co-aggregate in families? : A population-based study of 2 million Swedes
- 2021
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Ingår i: Molecular Psychiatry. - : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 26:1, s. 341-349
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale family studies on the co-occurrence of attention-deficit/hyperactivity disorder (ADHD) and borderline personality disorder (BPD) are lacking. Thus, we aimed to estimate the co-occurrence and familial co-aggregation of clinically ascertained ADHD and BPD diagnoses using the entire Swedish population. In a register-based cohort design we included individuals born in Sweden 1979-2001, and identified their diagnoses during 1997-2013; in total, 2,113,902 individuals were included in the analyses. We obtained clinical diagnoses of ADHD and BPD from inpatient and outpatient care. Individuals with an ADHD diagnosis had an adjusted (for birth year, sex, and birth order) odds ratio (aOR) of 19.4 (95% confidence interval [95% CI] = 18.6-20.4) of also having a BPD diagnosis, compared to individuals not diagnosed with ADHD. Having a sibling with ADHD also increased the risk for BPD (monozygotic twins, aOR = 11.2, 95% CI = 3.0-42.2; full siblings, aOR = 2.8, 95% CI = 2.6-3.1; maternal half-siblings, aOR = 1.4, 95% CI = 1.2-1.7; paternal half-siblings, aOR = 1.5, 95% CI = 1.3-1.7). Cousins also had an increased risk. The strength of the association between ADHD and BPD was similar in females and males, and full siblings showed similar increased risks regardless of sex. Among both males and females, ADHD and BPD co-occur within individuals and co-aggregate in relatives; the pattern suggests shared genetic factors and no robust evidence for etiologic sex differences was found. Clinicians should be aware of increased risks for BPD in individuals with ADHD and their relatives, and vice versa.
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| 9. |
- Liu, Yangjun, et al.
(författare)
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Exploring the genetic etiology across the continuum of the general psychopathology factor : a Swedish population-based family and twin study
- 2024
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Ingår i: Molecular Psychiatry. - : Springer Nature. - 1359-4184 .- 1476-5578.
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Tidskriftsartikel (refereegranskat)abstract
- Psychiatric comorbidity can be accounted for by a latent general psychopathology factor (p factor), which quantifies the variance that is shared to varying degrees by every dimension of psychopathology. It is unclear whether the entire continuum of the p factor shares the same genetic origin. We investigated whether mild, moderate, and extreme elevations on the p factor shared the same genetic etiology by, first, examining the linearity of the association between p factors across siblings (N = 580,891 pairs). Second, we estimated the group heritability in a twin sample (N = 17,170 pairs), which involves testing whether the same genetic variants influence both extreme and normal variations in the p factor. In both samples, the p factor was based on 10 register-based psychiatric diagnoses. Results showed that the association between siblings' p factors appeared linear, even into the extreme range. Likewise, the twin group heritabilities ranged from 0.42 to 0.45 (95% CI: 0.33-0.57) depending on the thresholds defining the probands (2-3.33 SD beyond the mean; >2 SD beyond the mean; >4.33 SD beyond the mean; and >5.33 SD beyond the mean), and these estimates were highly similar to the estimated individual differences heritability (0.41, 95% CI: 0.39-0.43), indicating that scores above and below these thresholds shared a common genetic origin. Together, these results suggest that the entire continuum of the p factor shares the same genetic origin, with common genetic variants likely playing an important role. This implies, first, genetic risk factors for the aspect that is shared between all forms of psychopathology (i.e., genetic risk factors for the p factor) might be generalizable between population-based cohorts with a higher prevalence of milder cases, and clinical samples with a preponderance of more severe cases. Second, prioritizing low-cost genome-wide association studies capable of identifying common genetic variants, rather than expensive whole genome sequencing that can identify rare variants, may increase the efficiency when studying the genetic architecture of the p factor.
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| 10. |
- Ronald, A., et al.
(författare)
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A twin study of autism symptoms in Sweden
- 2011
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Ingår i: Molecular Psychiatry. - London, United Kingdom : Nature Publishing Group. - 1359-4184 .- 1476-5578. ; 16:10, s. 1039-1047
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to identify empirically the number of factors underlying autism symptoms-social impairments, communication impairments, and restricted repetitive behaviors and interests-when assessed in a general population sample. It also investigated to what extent these autism symptoms are caused by the same or different genetic and environmental influences. Autistic symptoms were assessed in a population-based twin cohort of >12,000 (9- and 12-year-old) children by parental interviews. Confirmatory factor analyses, principal component analyses and multivariate structural equation model fitting were carried out. A multiple factor solution was suggested, with nearly all analyses pointing to a three-factor model for both boys and girls and at both ages. A common pathway twin model fit the data best, which showed that there were some underlying common genetic and environmental influences across the different autism dimensions, but also significant specific genetic effects on each symptom type. These results suggest that the autism triad consists of three partly independent dimensions when assessed in the general population, and that these different autism symptoms, to a considerable extent, have partly separate genetic influences. These findings may explain the large number of children who do not meet current criteria for autism but who show some autism symptoms. Molecular genetic research may benefit from taking a symptom-specific approach to finding genes associated with autism.
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