Gender differences in subtypes of depression by first incidence and age of onset: a follow-up of the Lundby population.

The Lundby Study is a prospective mental health survey in a community population (N = 3563), in which data were collected in 4 waves of field-work between 1947 and 1997. We investigated gender differences during the follow-up in overall first incidence rates, ages of onset, and incidence by age of onset patterns, in different subtypes of depression. The overall incidence rate in females was higher than males for most subtypes of depression. However, for depression with melancholic and/or psychotic features, the overall first incidence rate did not differ significantly between the genders. The mean age of onset did not differ significantly between females and males in any of the depressive subtypes. Nevertheless, females and males had different first incidence rates by age of onset patterns for unipolar non-melancholic DSM-IV mood disorder and major depressive disorder (MDD), with a consistent gender incidence gap across all ages, but with the most conspicuous gender gap in middle age. The first incidence rates by age of onset patterns for DSM-IV MDD with melancholic and/or psychotic features did not differ significantly between the genders. The findings support that females are more prone than males to develop depression with medium severity, but no gender differences were found in melancholic and/or psychotic depression. The findings may support that unipolar non-melancholic depression and melancholic and/or psychotic depression represents different disorders. Tentative explanations for this are discussed.

Long-term suicide risk in no, one or more mental disorders: the Lundby Study 1947-1997.

OBJECTIVE: To investigate long-term suicide risk in individuals with no, one or more mental disorders. METHOD: In the Lundby Study, involving a total population of 3563 subjects, mental health and suicide risk were monitored over 54-64 years. RESULTS: The long-term suicide risk in subjects with no, one, or more mental disorders was 0.3%, 3.4% and 6.2% respectively. For individuals with only depression, the risk was 6.0%, only alcohol use disorder 4.7%, and only psychosis 3.1%. However, when individuals had additional disorders, the suicide risks were 6.6%, 9.4% and 10.4% respectively. Each diagnosis per se was significantly related to increased risk of suicide. Men had a higher suicide risk in depression than women. Men who had alcohol use disorder in addition to depression showed a very high risk of suicide, 16.2%. CONCLUSION: Long-term suicide risk was increased for depression, alcohol use disorder, and psychosis per se. For the latter two the diagnosis alone there may be a lower risk than previously estimated when there is no additional diagnosis. In men, depression in addition to alcohol use disorder should be treated vigorously in the work to prevent suicide.

Loneliness, health and mortality.

AIMS: Literature suggests an association between loneliness and mortality for both males and females. Yet, the linkage of loneliness to mortality is not thoroughly examined, and need to be replicated with a long follow-up time. This study assessed the association between loneliness and mortality, including associations to gender, in 1363 adult swedes. METHODS: This community-based prospective cohort study from the Swedish Lundby Study included 1363 individuals of whom 296 individuals (21.7%) were identified as lonely with use of semi-structured interviews in 1997. The cohort was followed until 2011 and survival analyses were used to estimate the relative risk of death. RESULTS: Death occurred with an incidence rate of 2.63 per 100 person-years and 2.09 per 100 person-years for lonely and non-lonely individuals, respectively. In crude analysis, loneliness was associated with a significant increased mortality risk of 27% compared with non-lonely individuals [hazard ratio (HR) 1.27; 95% CI 1.01-1.60]. Unadjusted, lonely females had a significant increased risk (HR 1.76; 95% CI 1.31-2.34) and adjusted insignificant increased mortality risk of 27% (HR 1.27; 95% CI 0.92-1.74), compared with non-lonely females. Lonely males were found to have an adjusted significant decreased risk of mortality (HR 0.50; 95% CI 0.32-0.80), compared with non-lonely males. CONCLUSIONS: Findings suggest an association between loneliness and increased risk of mortality and that gender differences may exist, which have not been previously reported. If replicated, our results indicate that loneliness may have differential physical implications in some subgroups. Future studies are needed to further investigate the influence of gender on the relationship.

Long-term suicide risk of depression in the Lundby cohort 1947-1997--severity and gender.

OBJECTIVE: The long-term suicide risk of depression was evaluated in a community sample by severity and gender. METHOD: The Lundby study is a prospective, longitudinal cohort study on a population consisting of 3563 subjects. In 1947-1997 medium or severe depression according to the Lundby diagnostic system were registered in 503 subjects. The same subjects were also diagnosed according to DSM-IV showing major depressive disorder (MDD) in 293 and depressive disorder not otherwise specified (DDNOS) in 131 subjects. RESULTS: The overall long-term suicide risk varied from 5.6% to 6.8%. The long-term suicide risk was 3.1% for medium and 11.4% for severe 'Lundby depression', 3.7% for medium and 13.8% for severe MDD + DDNOS, 3.1% for medium and 13.7% for severe MDD. Severity and male sex were risk factors for suicide. CONCLUSION: Males with a severe depression showed a high long-term risk for suicide, around 20%.

Mortality of subjects with mood disorders in the Lundby community cohort: a follow-up over 50 years.

AIMS: To compare causes of death and mortality among subjects with and without mood disorder in the Lundby Cohort and to analyse additional mental disorders as risk factors for mortality in subjects with mood disorders. BACKGROUND: The Lundby study is a longitudinal study that investigated mental health in an unselected population. The study commenced in 1947; the population was further investigated in 1957, 1972, and 1997. METHODS: Experienced psychiatrists performed semi-structured diagnostic interviews, and best estimate consensus diagnoses of mental disorders were assessed at each field investigation. Subjects with mood disorder (n=508, 195 males, 313 females) were identified until 1997. Causes and dates of death between 1947 and 2011 were obtained from the Swedish cause of death register and were compared between subjects diagnosed with mood disorder and other participants. Mortality was compared between those with mood disorders and the remaining cohort with Cox regression analyses. Other mental disorders were considered as risk factors for death for subjects with mood disorders. RESULTS: The hazard ratio for mortality in mood disorders was HR=1.18. However, the mortality was elevated only for males, HR=1.5. Comorbid anxiety disorders, organic disorders, dementia and psychotic disorders were significant risk factors for death. A total of 6.3% of the participants with mood disorder and 1.2% of the remaining participants committed suicide. CONCLUSIONS: As expected, the suicide rate was higher among participants with mood disorders. Only males with mood disorders had elevated mortality. The impact on mortality from other mental disorders seems to vary between the genders.

Mortality in alcohol use disorder in the Lundby Community Cohort--a 50 year follow-up.

AIMS: To describe the mortality and causes of death among subjects with alcohol use disorder in comparison with those without alcohol disorder and to study whether mental disorders increase mortality in alcoholics. DESIGN AND SETTING: Data were analysed from the database of the Lundby Study, comprising 3563 subjects followed from 1947 to 1997. METHOD: A community-based sample was investigated in 1947 with follow-ups in 1957, 1972 and 1997. Best-estimate consensus diagnoses of mental disorders, including alcohol use disorder, were assessed. In the total cohort, 427 cases of alcohol use disorders were identified. Differences in mortality between subjects with alcohol use disorders and non-alcoholics were studied using Cox regression models and causes of death were compared between alcoholic subjects and other participants. Risk factors for mortality among the 348 individuals with alcohol use disorders and known age-of-onset were analysed by means of Cox regression analyses. RESULTS: The hazard ratio for mortality was higher for alcoholics compared to other subjects in the cohort. A substantial proportion of the causes of death among the alcoholics was suicide N=27 (6.3%) (26 males, 1 female). In the multivariate models of risk factors in alcohol use disorders, anxiety disorders, psychotic disorders, alcohol induced psychotic disorders and dementia were risk factors for premature death. CONCLUSION: The mortality risk for subjects with alcohol use disorder was increased, females were especially vulnerable. The risk for suicide was high among males with alcohol problems. Anxiety disorders and severity of alcohol use disorder turned out as risk factors for premature death.

Does it make sense to do repeated surveys?--the Lundby Study, 1947-1997.

OBJECTIVE: To describe the Lundby Study and the difficulties in doing repeated surveys. METHOD: Best-estimate consensus diagnoses have been used since 1957 together with DSM-IV and ICD-10 in 1997. RESULTS: The Lundby population consisting of 3563 probands was investigated in 1947, 1957 and 1972. Sufficient information was available for 98-99%. In 1997-2000 a fourth field investigation was carried out. Attrition rate for the interviews was 13% (238/1797). About 36% (1030/2827) had died between 1972 and 1997, but data from registers, case notes and key-informants for the period 1972 and 1997 completed the information for 94% (2659/2827). The population has followed the same pattern of development as many rural populations in Sweden since the 1940s. Multiple sources of information are preferable in longitudinal studies in order to tackle the problem of changing diagnostic systems. CONCLUSION: Low attrition rates over 50 years and reasonable diagnostic uniformity make comparisons over time justifiable.

Use of holographic laser interferometry to study the diffusion of polymers in gels.

The aim of this study was to demonstrate the potential for holographic interferometry to be used for diffusion studies of large molecules in gels. The diffusion and partitioning of BSA (67,000 g/mol) and pullulans (5,900-112,000 g/mol) in agarose gel were investigated. The gel diffusion coefficients obtained for BSA were higher when distilled water was used as a solvent compared to those obtained with 0.1 M NaCl as the solvent. Furthermore, the gel diffusion coefficient increased with increasing BSA concentration. The same trend was found for liquid BSA diffusion coefficients obtained by DLS. BSA partition coefficients obtained at different agarose gel concentrations (2-6%, w/w) decreased slightly with increasing gel concentration. However, all BSA gel diffusion coefficients measured were significantly lower than those in pure solvent and they decreased with increasing agarose concentration. The gel diffusion coefficients obtained for pullulans decreased with increasing pullulan molecular weight. The same effect from increased molecular weight was seen in the liquid diffusion coefficients measured by DLS. The pullulan partition coefficients obtained decreased with increasing molecular weight. However, pullulans with a larger Stokes' radius than BSA had partition coefficients that were higher or approximately the same as BSA. This implied that the pullulan molecules were more flexible than the BSA molecules. The results obtained for BSA in this study agreed well with other experimental studies. In addition, the magnitude of the relative standard deviation was acceptable and in the same range as for many other methods. The results thereby obtained showed that holographic interferometry is a suitable method for studying diffusion of macromolecules in gels.

Diffusion of lysozyme in gels and liquids. A general approach for the determination of diffusion coefficients using holographic laser interferometry.

A study on diffusion measurements of the protein lysozyme in liquids and agarose gels, at different pH and ionic strengths, has been performed using holographic laser interferometry. The measurements showed that the diffusive flux was very dependent on pH and ionic strength when the protein was not at its isoelectric point or when the charge of the lysozyme molecules was not screened by ions in the solution. Evaluation of the experimental data with Fick's law, resulted in diffusion coefficients for lysozyme that are strongly dependent on pH and ionic strength. Evaluation of the experimental data using a more general transport model, based on chemical potential gradients instead of concentration gradients resulted in lysozyme diffusion coefficients that are independent of pH and ionic strength. The chemical potential was estimated by using the Poisson-Boltzmann equation.