Geographic proximity is associated with transmission of suicidal behaviour among siblings.

OBJECTIVE: The aim of this study was to clarify the role of 'contagion', or social transmission, in risk of suicidal behaviour (SB) among siblings. METHODS: We followed Swedish sibling pairs until one of them (S1; N = 111,848) was registered for a suicide attempt or completion. We tested the effect of geographic proximity between siblings on risk of a first SB registration of S1's sibling (S2). To control for familial confounding, we conducted complementary analyses of sibling trios (N = 701), comparing risk in different siblings as a function of their respective proximity to S1. RESULTS: The best-fitting model across sibling pairs included an effect of distance between siblings (HR = 0.96, 95% CI = 0.93-0.99). Hazard ratios declined quickly up to 25 km and largely stabilized beyond 150 km. Across all pairs, a larger age difference between siblings was associated with reduced SB risk (HR = 0.96 95% CI = 0.93-0.98). Findings were consistent within the sibling trios. CONCLUSIONS: Consistent with the concept of suicide contagion, risk of suicidal behaviour subsequent to a sibling's suicide completion or attempt is higher as a function of sibling closeness. These findings are robust to potentially confounding familial factors.

Gender differences in completed and attempted suicides.

Attempted suicides occur primarily among women, while completed suicides occur primarily among men. Risk factors for both attempted and completed suicides include mental and addictive disorders, disrupted family environments, and precipitating events. This article presents an overview of findings on gender differences from epidemiologic studies of completed and attempted suicides, with a focus on suicide attempts among women, and discusses possible reasons for gender differences in suicidal behaviors.

Identification of suicide risk factors using epidemiologic studies.

Suicide is a complex outcome of multiple, inter-related factors. This article presents the epidemiology of completed and attempted suicide and discusses the known risk factors for suicide within a framework designed to encourage a systematic approach to theory testing and prevention. Mental and addictive disorders, frequently in co-occurrence, are the most powerful risk factors for suicide in all age groups, accounting for over 90 percent of all completed suicides. In combination with proximal risk factors such as access to firearms or other lethal means, recent and severe stressful life events, and intoxication, they can form the necessary and sufficient conditions for suicide.

Epidemiology of suicidal behavior.

This paper presents the epidemiology of suicide and discusses the known risk factors for suicide within a framework designed to encourage a systematic approach to theory testing and prevention. Mental and addictive disorders are the most powerful of the multiple risk factors for suicide in all age groups. Since risk factors for suicide rarely occur in isolation, prevention efforts are more likely to succeed if multiple risk factors are targeted.

Beyond the Tower of Babel: a nomenclature for suicidology.

Suicidology finds itself confused and stagnated for lack of a standard nomenclature. This paper proposes a nomenclature for suicide-related behavior in the hope of improving the clarity and precision of communications, advancing suicidological research and knowledge, and improving the efficacy of clinical interventions.

Epidemiology of suicide.

This article presents the epidemiology of suicide with a special focus on suicides among the elderly, and discusses the known risk factors for suicide within a framework designed to encourage a systematic approach to theory testing and prevention. Throughout the world, suicide rates are highest among the elderly. The risk factors for suicide can be classified as distal or proximal, and, within these broad categories, as sociodemographic, psychiatric, biological, familial, and situational. Mental and addictive disorders are the major risk factors for suicide in all age groups. Other risk factors include male gender, disrupted marital status, prior suicide attempt, reduced brain stem serotonergic activity, family history of psychiatric disorder or suicide, a firearm in the home, and a recent, severely stressful life event. Since risk factors for suicide rarely occur in isolation, prevention efforts are more likely to succeed if multiple risk factors are targeted.

Firearms and youth suicide.

The firearm suicide rate for persons aged 10 to 24 has increased from 2.3 per 100,000 in 1933 to 5.5 per 100,000 in 1982. Over the same period, the suicide rate for this age group by all methods other than firearms has only risen from 2.5 to 3.3. The most dramatic rise in the firearm suicide rate has occurred primarily since 1970, notably among males aged 15 to 24. During the 1960s and 1970s there was a substantial increase in the number of civilian firearms in the United States.

Epidemiologic trends in firearm suicides among adolescents.

Total and firearm suicide rates in the United States from 1933 to 1982 were examined by 5-year age groups for males and females 10-24 years of age. Both total and firearm suicide rates increased in all groups from low points in the 1950s until the 1970s. Rates continued to climb for young people 10-19 years of age, but declined for 20- to 24-year-olds. The proportion of the total suicide rate due to firearms increased from approximately half in the 1930s to nearly two-thirds in the early 1980s. In all three age groups, female suicides used firearms in nearly the same proportion as males. Whether or not the increasing availability of firearms is one of the many causes of the rise in young suicides is unknown.

Core elements of developmental epidemiologically based prevention research.

In the early 1990's, important progress was documented in prevention research on mental and behavioral disorders, with recommendations for a prevention research agenda. One of the earliest implementation efforts was the workshop, "A Scientific Structure for the Emerging Field of Prevention Research," sponsored by the National Institute of Mental Health and The Johns Hopkins University Prevention Research Center, and held in Baltimore, Maryland, in December of 1994. The purpose of the workshop was to merge three perspectives from the traditionally disparate areas of epidemiology, life course development, and intervention trials technology into an integrated, interdisciplinary effort that would define a scientific structure enabling rapid advancement in prevention science. As a consequence of that workshop, the papers were written that are contained in this and the next special issue on prevention of the American Journal of Community Psychology. This first paper is a description of the salient features of developmental epidemiologically-based prevention research. Beyond the above three perspectives, we discuss the role of developmental and intervention theories; measurement of implementation, mediators, and moderators, including multi-stage sampling and measurement; the central role of multilevel growth modeling; concepts of attributable risk and prevented fraction; proximal/distal modeling and effect sizes; and partnerships between researchers and communities.

Depression among Puerto Ricans in New York City: the Hispanic Health and Nutrition Examination Survey.

This study was conducted to analyze determinants of depression among Puerto Ricans by replicating and expanding earlier studies of depression among Cuban Americans and Mexican Americans. Data from the Hispanic Health and Nutrition Examination Survey, 1982-1984, were employed to examine depression and associated characteristics among Puerto Ricans. We utilized descriptive and multivariate statistics to examine the Center for Epidemiologic Studies Depression Scale (CES-D)-assessed depressive symptomatology and the DSM-III/DIS specification of major depression. The findings indicated that CES-D-assessed depressive symptomatology among Puerto Ricans was associated with female gender, disrupted marital status, poor health, and lower socioeconomic status as indicated by low education, low household income, age, and unemployment. For both 6-month and 1-month DIS major depression, age, disrupted marital status, and income of less than $5,000 were significant risk factors. For 6-month DIS major depression, never married persons had a higher risk for depression. For 1-month diagnoses, writing Spanish better than English was associated with lower risk. In general, our findings for Puerto Ricans were similar to studies of depression among other Hispanic groups. We remained unable to explain the relatively extreme levels of depression among Puerto Ricans in New York, though several probable explanations are elaborated. We emphasized the general need to expand the range of research designs and current risk models in epidemiology in an effort to capture the complexity of psychosocial and cultural processes relevant to psychological distress.

An epidemiologic investigation of potential risk factors for suicide attempts.

This is a report of new research on suicide attempts, based on an analysis of data from the Epidemiologic Catchment Area surveys in the United States. Risk of making a suicide attempt during a 1-2 year observation interval in the early 1980s was estimated in relation to selected personal and behavioral attributes of 13,673 study participants who completed baseline and follow-up interviews for these surveys. Being an active case of Major Depression was associated with increased risk of suicide attempt (estimated relative odds, RO = 41; 95% CL = 6.46-262), as was active alcoholism (RO = 18; 95% CL = 2.75-118) and being separated or divorced (RO = 11; 95% CL = 1.64-77). Being a user of cocaine was associated with increased risk of making a suicide attempt (RO = 62; 95% CL = 2.51-1528), but illicit use of marijuana, sedative-hypnotics, or sympathomimetic stimulants was not (P greater than 0.30). Educational achievement was inversely associated with risk of suicide attempt at a marginal level of statistical significance (P = 0.068). These multivariable conditional logistic regression results were obtained by applying a conventional epidemiologic strategy with post-stratification of subjects into homogeneous risk sets. Limitations of the study data and the analytic strategy are discussed in relation to directions for future epidemiologic field surveys.

Hearing loss in the elderly: an epidemiologic study of the Framingham Heart Study Cohort.

This study used epidemiologic methods to examine hearing loss in the elderly. The Framingham Heart Study Cohort was the reference population. The participants were 935 men and 1358 women, aged 57 to 89 years. Using a conservative definition of hearing loss as threshold levels greater than 20 dB above audiometric zero for at least one frequency from 0.5 to 4 kHz, the prevalence was estimated to be 83%. The majority of cases displayed a sensorineural hearing loss. There were no statistically significant differences by sex at 1 kHz and below. Women had significantly better hearing than men at 2 kHz and above. A multivariate model was constructed to determine which variables had a significant impact upon hearing loss. Under the model, age, sex, illness, family history of hearing loss, Meniere's disease, and noise exposure were significant population risk factors. Age was by far the most critical risk factor.

Depressive symptoms among Mexican Americans: the Hispanic Health and Nutrition Examination Survey.

This paper presents findings on depressive symptomatology among 3,118 Mexican-American adults who participated in the Hispanic Health and Nutrition Examination Survey (HHANES). In 1982-1984, the National Institute of Mental Health Center for Epidemiologic Studies Depression Scale was administered to Mexican Americans aged 20-74 years as part of the HHANES examination component. Respondents reported in either English or Spanish on both the presence and persistence of depressive symptoms during the week prior to the interview. The caseness rate (high levels of depressive symptoms) was 13.3%. Factors associated with increased risk of high levels of depressive symptoms were female sex, low educational achievement, low income, and US birth combined with Anglo-oriented acculturation. There were no significant differences by language. The relatively low prevalence rate and the increased risk associated with US birth/Anglo-oriented acculturation indicate the need for more multifactor studies and the investigation of possible additional factors that may contribute to the mental health of Mexican Americans.

Concordance between two measures of depression in the Hispanic Health and Nutrition Examination Survey.

A concordance analysis between the Center for Epidemiologic Studies Depression Scale (CES-D) and the National Institute of Mental Health (NIMH) Diagnostic Interview Schedule (DIS) for current major depression was conducted using data from Cuban Americans and Puerto Rican respondents to the Hispanic Health and Nutrition Examination Survey (HHANES). Overall agreement between the two depression measures was relatively high, which suggested that the CES-D might be appropriate as a first-stage screening instrument for community-based surveys of clinical depression. Female gender and indicators of social class (education, income, poverty index, and employment) were related to low specificity and low agreement. The estimated cutoff points of the CES-D that best predicted DIS current major depression were different between the two ethnic groups; 17 for Cuban Americans, and 20 for Puerto Ricans. A receiver operating characteristics (ROC) curve analysis revealed that the traditional method of defining CES-D cases by summing the scores for each item was superior to counting only the persistent symptoms, that is, those present nearly everyday.

Suicide attempts in the Epidemiologic Catchment Area Study.

This study examines risk factors for attempted suicide in the general community. Data from the five-site NIMH Epidemiologic Catchment Area (ECA) Study were used to estimate lifetime prevalence and identify risk factors for suicide attempts. Occurrence of suicide attempts and lifetime diagnosis of psychiatric disorder were ascertained, using the NIMH Diagnostic Interview Schedule (DIS). Of 18,571 adult respondents aged 18 and over, 2.9 percent reported that they had attempted suicide at some time in their lives. A weighted logistic regression model was constructed to ascertain significant (p less than .0028 with Bonferroni correction) risk factors for attempted suicide. Persons who had a lifetime diagnosis of a psychiatric disorder had the highest risk of attempted suicide (odds ratio [OR] = 8.4). Females (OR = 3.3), separated or divorced persons (OR = 2.5), Whites (OR = 1.7), persons in the two lowest socioeconomic quartiles (ORs = 2.2, 2.3), and respondents from the Los Angeles ECA (OR = 1.8) were also more likely to have attempted suicide. These findings contribute to an understanding of suicide and suicidal behavior in general populations, outside the clinical setting.

Physical activity and depressive symptoms: the NHANES I Epidemiologic Follow-up Study.

The relation between self-reported physical activity and depressive symptoms was analyzed for 1,900 healthy subjects aged 25-77 years in the Epidemiologic Follow-up Study (1982-1984) to the first National Health and Nutrition Examination Survey (NHANES I). Depressive symptomatology as measured by the Center for Epidemiologic Studies Depression Scale (CES-D) was examined by sex and race in relation to recreational physical activity and physical activity apart from recreation, controlling for age, education, income, employment status, and chronic conditions. Little or no recreational physical activity and little or no physical activity apart from recreation were cross-sectionally associated with depressive symptoms in whites and in blacks. After exclusion of those with depressive symptoms at baseline, recreational physical activity was an independent predictor of depressive symptoms an average of eight years later in white women. The adjusted odds of depressive symptoms at follow-up were approximately 2 for women with little or no recreational physical activity compared with women with much or moderate recreational physical activity (95% confidence interval 1.1-3.2). These findings are the first indication from a prospective study of a large community sample that physical inactivity may be a risk factor for depressive symptoms.

Depression among Cuban Americans. The Hispanic Health and Nutrition Examination Survey.

This paper presents the findings on depressive symptomatology and major depressive disorder in Cuban American respondents to the Hispanic Health and Nutrition Examination Survey (HHANES). The HHANES represents the first population-based assessment of the mental health status of Cuban Americans. High levels of depression, as measured by a CES-D score of 16 or more, were found in ten percent of the sample. Female gender was independently associated with CES-D caseness. The lifetime, six-month, and one-month prevalence rates of major depressive disorder, as measured by the National Institute of Mental Health Diagnostic Interview Schedule (DIS), were 3.15%, 2.12%, and 1.50%, respectively. An income level of less than ten thousand dollars was independently associated with a lifetime diagnosis of major depression.