Body mass index and subjective well-being in young adults: a twin population study.

BACKGROUND: Body mass index (BMI) is associated with subjective well-being. Higher BMI is believed to be related with lower well-being. However, the association may not be linear. Therefore, we investigated whether a nonlinear (U-shaped) trend would better describe this relationship, and whether eating disorders might account for the association in young adults. METHODS: FinnTwin16 study evaluated multiple measures of subjective well-being, including life satisfaction, General Health Questionnaire (GHQ-20), satisfaction with leisure time, work, and family relationships, and satisfaction with sex life in young adulthood in the 1975-79 birth cohorts of Finnish twins (n=5240). We studied the relationship between indicators of subjective well-being and BMI both in full birth cohorts and in subgroups stratified by lifetime DSM-IV eating disorders. RESULTS: We found an inverse U-shaped relationship between all indicators of subjective well-being and BMI in men. There was no overall association between BMI and subjective well-being in women. However, there was an inverse U-shaped relationship between BMI and indicators of subjective well-being in women with a lifetime eating disorder and their healthy female co-twins. Subjective well-being was optimal in the overweight category. CONCLUSIONS: Both underweight and obesity are associated with impaired subjective well-being in young men. The BMI reflecting optimal subjective well-being of young men may be higher than currently recognized. Categorization of body weight in terms of BMI may need to be reassessed in young men. BMI and subjective well-being are related in women with a lifetime eating disorder, but not in the general population of young women.

Depression and drive for thinness are associated with persistent bulimia nervosa in the community.

OBJECTIVE: To examine psychiatric comorbidity and factors that influence the outcome of bulimia nervosa (BN) in the general population. METHOD: Women from the nationwide birth cohorts of Finnish twins were screened for lifetime BN (N = 59) by using questionnaires and the Structured Clinical Interview for DSM-IV. We assessed psychiatric comorbidity and other prognostic factors. RESULTS: Among women with lifetime BN, the following were more common than among unaffected women: current major depressive disorder (p = 0.004), lifetime major depressive disorder (p = 0.00001) and heavy drinking (p = 0.01). Decreased likelihood of recovery was associated with a history of lifetime major depressive disorder (hazard ratio (HR) 0.44, 95% confidence interval (CI) 0.23-0.84) and high drive for thinness at time of assessment (HR 0.96, 95% CI 0.93-0.99). DISCUSSION: Heavy drinking and depression present challenges for many women with BN. Major depressive disorder emerged as the only statistically significant prognostic factor of BN in this nationwide cohort; high drive for thinness was characteristic of the persistently ill.

Depressive symptoms and alcohol use are genetically and environmentally correlated across adolescence.

Depressive symptoms and alcohol use are frequently positively associated during adolescence. This study aimed to assess the heritability of each phenotype across adolescence; to assess potential shared liabilities; to examine changes in the nature of shared liabilities across adolescence; and to investigate potential causal relationships between depressive symptoms and alcohol use. We studied a longitudinally assessed sample of adolescent Finnish twins (N = 1,282) to test hypotheses about genetic and environmental influences on these phenotypes within and across ages, using data from assessments at ages 12, 14, and 17.5 years. The heritability of depressive symptoms is consistent across adolescence (~40-50%), with contributions from common and unique environmental factors. The heritability of alcohol use varies across time (a(2) = .25-.44), and age 14 alcohol use is heavily influenced by shared environmental factors. Genetic attenuation and innovation were observed across waves. Modest to moderate genetic (r(A) = .26-.59) and environmental (r(C) = .30-.63) correlations between phenotypes exist at all ages, but decrease over time. Tests for causal relationships between traits differed across ages and sexes. Intrapair MZ difference tests provided evidence for reciprocal causation in girls at ages 14 and 17.5. Formal causal models suggested significant causal relationships between the variables in both boys and girls. The association between depressive symptoms and alcohol use during adolescence is likely due to a combination of shared genetic and environmental influences and causal influences. These influences are also temporally dynamic, complicating efforts to understand factors contributing to the relationship between these outcomes.

Prospective associations of early-onset Axis I disorders with developing eating disorders.

OBJECTIVE: The purpose of this study is to analyze the developmental relationships of adolescent-onset Axis I mental disorders and eating disorders (EDs). METHOD: One thousand three hundred eighteen adolescent twins born from 1983 to 1987 completed a professionally administered semistructured psychiatric interview at the age of 14 years and a questionnaire follow-up at the age of 17.5 years. RESULTS: Eating disorders at the age of 17.5 years were significantly predicted by major depressive disorder (odds ratio, 5.9; 95% confidence interval, 2.6-15.3) and generalized anxiety disorder (GAD) (odds ratio, 4.7; 95% confidence interval, 1.8-15.6) at the age of 14 years, when baseline EDs were excluded. Early-onset major depressive disorder in combination with GAD increased the likelihood of developing EDs compared with either mood or anxiety disorders alone. Similar risks and trends were evident in within-family analyses of twin pairs discordant for baseline predictors and ED outcome. CONCLUSIONS: Depressive disorder and GAD that manifest at that age of 14 years predict future EDs. Analysis of discordant twins suggested that early-onset depressive disorder and GAD prospectively relate to EDs in adolescence, even after familial factors are taken into account.

Physiological responses to affiliation during conversation: Comparing neurotypical males and males with Asperger syndrome.

We examined the emotional and psychophysiological underpinnings of social interaction in the context of autism spectrum disorder, more specifically, involving participants diagnosed with Asperger syndrome (AS). We recorded participants' autonomic nervous system (ANS) activation (electrodermal activity, heart rate, and heart rate variability) and facial muscle activation during conversations in two different types of male dyads: (1) ten dyads where one participant has been diagnosed with AS (AS/NT dyads) and (2) nine dyads where both participants are neurotypical (NT/NT dyads). Afterwards, three independent raters assessed continuously each participant's affiliative and dominant behaviors during the first and last 10 minutes of the conversations. The relationship between the assessed data and ANS responses was examined. We found that, in the NT/NT dyads, a high level of affiliation displayed by the conversational partner calms down the participant when they are actively dominating the interaction. In contrast, when the participants themselves expressed affiliation, their psychophysiological responses indicated increase in arousal, which suggests that the giving of affiliation is physiologically "hard work." The affiliation-related ANS responses were similar in those NT participants whose conversational partner had AS, while some differences in facial muscle activation did occur in comparison to NT/NT dyads. In the AS participants, in contrast, a high level of affiliation provided by the conversational partner was associated with increase in arousal, suggesting heightened alertness and stress. As for their own affiliative behavior, the AS participants exhibited similar indicators of alertness and stress as the NT participants, but only when their own level of dominance was low. Our results increase understanding of how individuals with AS experience social interaction at the physiological level, and how this experience differs from that in NT individuals. Moreover, our results confirm and further specify our earlier results, where we proposed that affiliation involves the type of "sharing of the burden" that also reverberates in the participants' bodies.

Lifetime anorexia nervosa in young men in the community: five cases and their co-twins.

OBJECTIVE: To describe patterns, comorbidity, and outcomes from a case series of anorexia nervosa (AN) among young men from the general population and their co-twins. METHOD: Men (N = 2,122) born between 1975 and 1979 from Finnish twin cohorts were screened for lifetime eating disorders by questionnaire. The administration of the short version of the Structured Clinical Interview for DSM-IV for screen positives led to a lifetime AN diagnosis in five participants, described here with their co-twins. RESULTS: In males, overweight commonly predated AN, and symptoms of body dysmorphic disorder, particularly of muscle dysmorphia, were common among the anorexia-discordant co-twins. Affective and anxiety disorders were present in both the probands and their co-twins. CONCLUSION: We found a strong familial clustering of AN, affective and anxiety disorders, and symptoms of muscle dysmorphia among men in the general population. In men, muscle dysmorphia may represent an alternative phenotype of AN.

Early-onset tobacco use and suicide-related behavior - A prospective study from adolescence to young adulthood.

BACKGROUND: Developmental relationships between tobacco use and suicide-related behaviors (SRB) remain unclear. Our objective was to investigate the longitudinal associations of tobacco use in adolescence and SRB in adulthood. METHODS: Using a prospective design, we examined whether tobacco use in adolescence is associated with SRB (intentional self-injury, suicide ideation) in young adulthood in a population-based sample of 1330 twins (626 males, 704 females). The baseline and follow-up data were collected by professionally administered semi-structured poly-diagnostic interviews at ages 14 and 22, respectively. RESULTS: After adjusting for multiple potential confounders, those who reported early-onset of regular tobacco use had a significantly increased risk for intentional self-injury, such as cutting or burning, at age 22 (adjusted odds ratio [AOR] 4.57, 95% CI 1.93-10.8) in comparison to those who had not at all initiated tobacco use. Also, daily cigarette smoking at baseline was associated with future intentional self-injury (AOR 4.45, 95% CI 2.04-9.70). Early-onset tobacco use was associated with suicidal ideation in females (AOR 3.69, 95% CI 1.56-8.72) but not in males. Considering any SRB, baseline daily smokers (AOR 2.13, 95% CI 1.12-4.07) and females with early onset of regular tobacco use (AOR 3.97, 95% CI 1.73-9.13) had an increased likelihood. Within-family analyses among twin pairs discordant for exposure and outcome controlling for familial confounds showed similar, albeit statistically non-significant, associations. CONCLUSION: Early-onset tobacco use in adolescence is longitudinally associated with SRB (intentional self-injury and/or suicide ideation) in young adulthood, particularly among females. Further investigation may reveal whether this association has implications for prevention of SRB in adolescence and young adulthood.

Epidemiology and course of anorexia nervosa in the community.

OBJECTIVE: Most previous studies of the prevalence, incidence, and outcome of anorexia nervosa have been limited to cases detected through the health care system, which may bias our understanding of the disorder's incidence and natural course. The authors sought to describe the onset and outcomes of anorexia nervosa in the general population. METHOD: Lifetime prevalences, incidence rates, and 5-year recovery rates of anorexia nervosa were calculated on the basis of data from 2,881 women from the 1975-1979 birth cohorts of Finnish twins. Women who screened positive for eating disorder symptoms (N=292), their screen-negative female co-twins (N=134), and 210 randomly selected screen-negative women were assessed for lifetime eating disorders by telephone by experienced clinicians. To assess outcomes after clinical recovery and to detect residua of illness, women who had recovered were compared with their unaffected co-twins and healthy unrelated women on multiple outcome measures. RESULTS: The lifetime prevalence of DSM-IV anorexia nervosa was 2.2%, and half of the cases had not been detected in the health care system. The incidence of anorexia nervosa in women between 15 and 19 years of age was 270 per 100,000 person-years. The 5-year clinical recovery rate was 66.8%. Outcomes did not differ between detected and undetected cases. After clinical recovery, the residua of illness steadily receded. By 5 years after clinical recovery, most probands had reached complete or nearly complete psychological recovery and closely resembled their unaffected co-twins and healthy women in weight and most psychological and social measures. CONCLUSIONS: The authors found a substantially higher lifetime prevalence and incidence of anorexia nervosa than reported in previous studies, most of which were based on treated cases. Most women recovered clinically within 5 years, and thereafter usually progressed toward full recovery.

Minor depression in adolescence: phenomenology and clinical correlates.

BACKGROUND: Depressions that fail to meet the diagnostic criteria for major depressive disorder (MDD) may be underdiagnosed and undertreated in adolescent population. Traditionally, they are not considered as serious conditions and the phenomenological nature and clinical correlates of these disorders are largely unknown. In the present study, we used a large, representative and age-standardized sample of adolescents to examine the phenomenology and clinical correlates of minor depression, a poorly understood condition included in the category of Depressive Disorder Not Otherwise Specified in Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revised (DSM-IV-TR). METHODS: 909 girls and 945 boys, with mean age of 14, were interviewed by professionals using the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA). RESULTS: Although clearly milder condition than MDD, minor depression was associated with marked suicidal thoughts, plans and attempts, recurrences and a high degree of comorbidity. At this early age, despite that 14% of adolescents under 15 had suffered from depressive conditions with severe clinical implications, most of them failing to meet the diagnostic threshold for MDD, only 1.7% had received any psychiatric treatment. 40% of depressive adolescents who had attempted suicide had no contact with mental health services. LIMITATIONS: Analyzed in a cross-sectional setting, no conclusions about long-term implications could be made. CONCLUSIONS: The results highlight the clinical and public health significance of non-MDD depressions, e.g. minor depression, which need to be more carefully identified and treated at early age.

Serotonin transporter binding of [123I]ADAM in bulimic women, their healthy twin sisters, and healthy women: a SPET study.

BACKGROUND: Bulimia Nervosa (BN) is believed to be caused by an interaction of genetic and environmental factors. Previous studies support the existence of a bulimia-related endophenotype as well as disturbances in serotonin (5-HT) transmission. We studied serotonin transporter (SERT) binding in BN, and to investigate the possibility of a SERT-related endophenotype for BN, did this in a sample of female twins. We hypothesized clearly reduced SERT binding in BN women as opposed to healthy women, and intermediate SERT binding in unaffected co-twins. METHODS: We studied 13 female twins with BN (9 with purging and 4 with non-purging BN) and 25 healthy women, including 6 healthy twin sisters of BN patients and 19 women from 10 healthy twin pairs. [123I]ADAM, a selective SERT radioligand for single photon emission tomography (SPET) imaging, was used to assess SERT availability in the midbrain and the thalamus. RESULTS: No differences in SERT binding were evident when comparing the BN women, their unaffected co-twins and the healthy controls (p = 0.14). The healthy sisters of the BN patients and the healthy control women had similar SERT binding in both brain regions. In a post hoc subgroup analysis, the purging bulimics had higher SERT binding than the healthy women in the midbrain (p = 0.03), but not in the thalamus. CONCLUSION: Our finding of increased SERT binding in the midbrain in the purging BN women raises the possibility that this subgroup of bulimics might differ in serotonergic function from the non-purging ones. The similarity of the unaffected co-twins and the healthy controls doesn't support our initial assumption of a SERT-related endophenotype for BN. Due to the small sample size, our results need to be interpreted with caution and verified in a larger sample.

Serotonin transporter in attention-deficit hyperactivity disorder--preliminary results from a positron emission tomography study.

The serotonin transporter (SERT) in attention-deficit hyperactivity disorder (ADHD) patients has not been explored by earlier positron emission tomography (PET) studies. We measured SERT availability in female ADHD patients (n=8) and healthy controls (n=14) with PET and [11C]MADAM as a tracer. No significant group differences in [11C]MADAM binding potential were noted.

Brain serotonin transporter binding of [123I]ADAM: within-subject variation between summer and winter data.

The neurotransmitter serotonin (5-HT) controls several physiological functions, and a disturbance of the 5-HT system is implicated in many psychiatric conditions. Seasonal variation has been suggested in the 5-HT system. We investigated within-subject seasonal variation in brain serotonin transporter (SERT) binding with the SERT-ligand [(123)I]ADAM and single photon emission computed tomography (SPECT) in 12 healthy individuals. No systematic variation was found in the midbrain or thalamus areas between scans done in summer and winter. Our results suggest that factors other than season are more important in causing within-subject variation of brain SERT binding between summer and winter.

Anorexia and bulimia nervosa in same-sex and opposite-sex twins: lack of association with twin type in a nationwide study of Finnish twins.

OBJECTIVE: The authors tested the hypothesis that either prenatal feminization or masculinization hormone influences in utero or later socialization affects the risk for anorexia and bulimia nervosa and disordered eating in members of opposite-sex twin pairs. METHOD: Finnish twins (N=2,426 women, N=1,962 men with known zygosity) from birth cohorts born 1974-1979 were assessed at age 22 to 28 years with a questionnaire for eating disorder symptoms. Based on the questionnaire screen, women (N=292), men (N=53), and their cotwins were interviewed to assess diagnoses of anorexia nervosa and bulimia nervosa (per DSM-IV and broad criteria). RESULTS: In women from opposite-sex twin pairs, the prevalence of DSM-IV or broad anorexia nervosa was not significantly different than that of women from monozygotic pairs or same-sex dizygotic pairs. Of the five male anorexia nervosa probands, only one was from an opposite-sex twin pair. Bulimia nervosa in men was too rare to be assessed by zygosity; the prevalence of DSM-IV or broad bulimia nervosa did not differ in women from opposite- versus same-sex twin pairs. In both sexes, the overall profile of indicators on eating disorders was rather similar between individuals from opposite- and same-sex pairs. CONCLUSIONS: The authors found little evidence that the risk for anorexia nervosa, bulimia nervosa, or disordered eating was associated with zygosity or sex composition of twin pairs, thus making it unlikely that in utero femininization or masculinization or socialization effects of growing up with an opposite-sex twin have a major influence on the later development of eating disorders.

Early-onset depressive disorders predict the use of addictive substances in adolescence: a prospective study of adolescent Finnish twins.

AIMS: To explore the developmental relationships between early-onset depressive disorders and later use of addictive substances. DESIGN, SETTING AND PARTICIPANTS: A sample of 1545 adolescent twins was drawn from a prospective, longitudinal study of Finnish adolescent twins with baseline assessments at age 14 years and follow-up at age 17.5 years. MEASUREMENTS: At baseline, DSM-IV diagnoses were assessed with a professionally administered adolescent version of Semi-Structured Assessment for Genetics of Alcoholism (C-SSAGA-A). At follow-up, substance use outcomes were assessed via self-reported questionnaire. FINDINGS: Early-onset depressive disorders predicted daily smoking [odds ratio (OR) 2.29, 95% confidence interval (CI) 1.49-3.50, P < 0.001], smokeless tobacco use (OR = 2.00, 95% CI 1.32-3.04, P = 0.001), frequent illicit drug use (OR = 4.71, 95% CI 1.95-11.37, P = 0.001), frequent alcohol use (OR = 2.02, 95% CI 1.04-3.92, P = 0.037) and recurrent intoxication (OR = 1.83, 95% CI 1.18-2.85, P = 0.007) 3 years later. ORs remained significant after adjustment for comorbidity and exclusion of baseline users. In within-family analysis of depression-discordant co-twins (analyses that control for shared genetic and familial background factors), early-onset depressive disorders at age 14 predicted significantly frequent use of smokeless tobacco and alcohol at age 17.5. CONCLUSIONS: Our results suggest important predictive associations between early-onset depressive disorders and addictive substance use, and these associations appear to be independent of shared familial influences.

Reliability of self-reported eating disorders: Optimizing population screening.

OBJECTIVE: The objective of this study was to assess whether short self-report eating disorder screening questions are useful population screening methods. METHOD: We screened the female participants (N = 2881) from the 1975-1079 birth cohorts of Finnish twins for eating disorders, using several short screening questions and three Eating Disorder Inventory (EDI) subscales. Comparing these measures with clinician-conducted semi-structured diagnostic interviews (N = 549) of Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) anorexia and bulimia, we calculated their sensitivities and specificities and drew receiver operating characteristic curves to further compare these items. RESULTS: For current and lifetime bulimia, best tradeoffs between sensitivity and specificity were reached by addressing purging behaviors. For current and lifetime anorexia, the questions "Have you ever had anorexia" and "Has anybody ever suspected that you might have an eating disorder?" optimized tradeoffs between sensitivity and specificity. These questions generally outperformed EDI subscales. CONCLUSION: Simple screening questions, although less than ideal, are at least as good as other available instruments for community screenings.