Objective The purpose of this study was to clarify the causes of the smoking-schizophrenia association. Method Using Cox proportional hazard and co-relative control models, the authors predicted future risk for a diagnosis of schizophrenia or nonaffective psychosis from the smoking status of 1,413,849 women and 233,879 men from, respectively, the Swedish birth and conscript registries. Results Smoking was assessed in women at a mean age of 27 and in men at a mean age of 18. The mean age at end of follow-up was 46 for women and 26 for men. Hazard ratios for first-onset schizophrenia were elevated both for light smoking (2.21 [95% CI=1.90–2.56] for women and 2.15 [95% CI=1.25–3.44] for men) and heavy smoking (3.45 [95% CI=2.95–4.03] for women and 3.80 [95% CI=1.19–6.60] for men). These associations did not decline when schizophrenia onsets 3–5 years after smoking assessment were censored. When age, socioeconomic status, and drug abuse were controlled for, hazard ratios declined only modestly in both samples. Women who smoked into late pregnancy had a much higher risk for schizophrenia than those who quit early. Hazard ratios predicting nonaffective psychosis in the general population, in cousins, in half siblings, and in full siblings discordant for heavy smoking were, respectively, 2.67, 2.71, 2.54, and 2.18. A model utilizing all relative pairs predicted a hazard ratio of 1.69 (95% CI=1.17–2.44) for nonaffective psychosis in the heavy-smoking member of discordant monozygotic twin pairs. Conclusions Smoking prospectively predicts risk for schizophrenia. This association does not arise from smoking onset during a schizophrenic prodrome and demonstrates a clear dose-response relationship. While little of this association is explained by epidemiological confounders, a portion arises from common familial/genetic risk factors. However, in full siblings and especially monozygotic twins discordant for smoking, risk for nonaffective psychosis is appreciably higher in the smoking member. These results can help in evaluating the plausibility of various etiological hypotheses for the smoking-schizophrenia association.

Objective The authors sought to clarify the relationship between marriage and risk for alcohol use disorder. Method The association between marital status and risk for first registration for alcohol use disorder in medical, criminal, and pharmacy registries was assessed in a population-based Swedish cohort (N=3,220, 628) using longitudinal time-dependent survival and co-relative designs. Results First marriage was associated with a substantial decline in risk for onset of alcohol use disorder in men (hazard ratio=0.41, 95% CI=0.40–0.42) and women (hazard ratio=0.27, 95% CI=0.26–0.28). This association was slightly stronger when the spouse had no lifetime alcohol use disorder, while marriage to a spouse with lifetime alcohol use disorder increased risk for subsequent alcohol use disorder registration in both men (hazard ratio=1.29, 95% CI=1.16–1.43) and women(hazard ratio=1.18, 95% CI=1.06–1.30). In both sexes, the protective effect of marriage was significantly stronger in those with than those without a family history of alcohol use disorder. In both men and women, the associations between marriage and risk for alcohol use disorder in cousins, half siblings, full siblings, and monozygotic twins discordant for marital status were as strong as that seen in the general population. Conclusions First marriage to a spouse with no lifetime alcohol use disorder is associated with a large reduction in risk for alcohol use disorder. This association cannot be explained by standard covariates or, as indicated by co-relative analyses, familial genetic or shared environmental confounders. These results are consistent with the hypothesis that the psychological and social aspects of marriage, and in particular health-monitoring spousal interactions, strongly protect against the development of alcohol use disorder. The protective effects of marriage on risk for alcohol use disorder are increased in those at high familial risk for alcoholism.

BackgroundMedical treatment of hypertension is not always sufficient to achieve blood pressure control. Despite this, previous studies on supplementary therapies, such as yoga, are relatively few. We investigated the effects of two yoga interventions on blood pressure and quality of life in patients in primary health care diagnosed with hypertension.MethodsAdult patients (age 20–80 years) with diagnosed hypertension were identified by an electronic chart search at a primary health care center in southern Sweden. In total, 83 subjects with blood pressure values of 120–179/≤109 mmHg at baseline were enrolled. At baseline, the patients underwent standardized blood pressure measurement at the health care center and they completed a questionnaire on self-rated quality of life (WHOQOL-BREF). There were three groups: 1) yoga class with yoga instructor (n = 28); 2) yoga at home (n = 28); and 3) a control group (n = 27). The participants were matched at the group level for systolic blood pressure. After 12 weeks of intervention, the assessments were performed again. At baseline a majority of the patients (92%) were on antihypertensive medication, and the patients were requested not to change their medication during the study.ResultsThe yoga class group showed no improvement in blood pressure or self-rated quality of life, while in the yoga at home group there was a decline in diastolic blood pressure of 4.4 mmHg (p < 0.05) compared to the control group. Moreover, the yoga at home group showed significant improvement in self-rated quality of life compared to the control group (p < 0.05).ConclusionsA short yoga program for the patient to practice at home seems to have an antihypertensive effect, as well as a positive effect on self-rated quality of life compared to controls. This implies that simple yoga exercises may be useful as a supplementary blood pressure therapy in addition to medical treatment when prescribed by primary care physicians.Trial registrationClinicalTrials.gov (NCT01302535)

Background To clarify the role of genetic and environmental factors in criminal behavior (CB), we examined all CB and violent and non-violent subtypes (VCB and NVCB, respectively) in a Swedish national sample of adoptees and their relatives. Method CB was defined by a conviction in the Swedish Crime Register with standard definitions for VCB and NVCB subtypes. We examined adoptees born 1950–1991 (n=18070) and their biological (n=79206) and adoptive (n=47311) relatives. Results The risk for all CB was significantly elevated in the adopted-away offspring of biological parents of which at least one had CB [odds ratio (OR) 1.5, 95% confidence interval (CI) 1.4–1.6] and in the biological full and half-siblings of CB adoptees (OR 1.4, 95% CI 1.2–1.6 and OR 1.3, 95% CI 1.2–1.3, respectively). A genetic risk index (including biological parental/sibling history of CB and alcohol abuse) and an environmental risk index (including adoptive parental and sibling CB and a history of adoptive parental divorce, death, and medical illness) both strongly predicted probability of CB. These genetic and environmental risk indices acted additively on adoptee risk for CB. Moderate specificity was seen in the transmission of genetic risk for VCB and NVCB between biological parents and siblings and adoptees. Conclusions CB is etiologically complex and influenced by a range of genetic risk factors including a specific liability to CB and a vulnerability to broader externalizing behaviors, and by features of the adoptive environment including parental CB, divorce and death. Genetic risk factors for VCB and NVCB may be at least partially distinct.