Kristian Läksy

Obesity and depression: results from the longitudinal Northern Finland 1966 Birth Cohort Study

Objective:To examine the association between body size and depression in a longitudinal setting and to explore the connection between obesity and depression in young adults at the age of 31 years.Design:This study forms part of the longitudinal Northern Finland 1966 Birth Cohort Study (N=12 058). The follow-up studies were performed at 14 and 31 years. Data were collected by postal inquiry at 14 years and by postal inquiry and clinical examination at 31 years.Subjects:A total of 8451 subjects (4029 men and 4422 women) who gave a written informed consent and information on depression by three depression indicators at 31 years.Measurements:Body size at 14 (body mass index (BMI) and 31 (BMI and waist-to-hip ratio (WHR)) years and depression at 31 years by three different ways: depressive symptoms by the HSCL-25-depression questionnaire (HSCL-25), the use of antidepressants and self-reported physician-diagnosed depression.Results:Obesity at 14 years associated with depressive symptoms at 31 years; among male subjects using the cutoff point 2.01 in the HSCL-25 (adjusted odds ratio (OR) 1.97, 95% CI 1.06–3.68), among female subjects using the cutoff point 1.75 (adjusted OR 1.64, 95% CI 1.16–2.32). Female subjects who were obese both at baseline and follow-up had depressive symptoms relatively commonly (adjusted OR 1.40, 95% CI 1.06–1.85 at cutoff point 1.75); a similar association was not found among male subjects. The proportion of those who used antidepressants was 2.17-fold higher among female subjects who had gained weight compared to female subjects who had stayed normal-weighted (adjusted OR 2.17, 95% CI 1.28–3.68). In the cross-sectional analyses male subjects with abdominal obesity (WHR ⩾85th percentile) had a 1.76-fold risk of depressive symptoms using the cutoff 2.01 in the HSCL-25 (adjusted OR 1.76, 95% CI 1.08–2.88). Abdominally obese male subjects had a 2.07-fold risk for physician-diagnosed depression (adjusted OR 2.07, 95% CI 1.23–3.47) and the proportion of those who used antidepressants was 2.63-fold higher among obese male subjects than among male subjects without abdominal obesity (adjusted OR 2.63, 95% CI 1.33–5.21). Abdominal obesity did not associate with depression in female subjects.Conclusion:Obesity in adolescence may be associated with later depression in young adulthood, abdominal obesity among male subjects may be closely related to concomitant depression, and being overweight/obese both in adolescence and adulthood may be a risk for depression among female subjects.

Co-occurrence of Metabolic Syndrome With Depression and Anxiety in Young Adults: The Northern Finland 1966 Birth Cohort Study

Objective: Only a few studies have dealt with the association of metabolic syndrome with depression and anxiety. We studied whether metabolic syndrome and its components are associated with depressive and anxiety symptoms in a young adult population cohort. Methods: This study forms part of the Northern Finland 1966 Birth Cohort Study. The study sample consists of 5,698 members of the cohort who participated in the field study in 1997 to 1998. Metabolic syndrome was defined according to the five criteria of the National Cholesterol Education Program. Depressive and anxiety symptoms were defined by the Hopkins Symptom Checklist-25 questionnaire. Results: Metabolic syndrome was not associated with depression or anxiety. The correlations between the components of the metabolic syndrome and psychological distress as continuous measures were low. High waist circumference (>102 cm in males and >88 cm in females) associated with depression (odds ratio, 1.30; 95% confidence interval, 1.05–1.61), but this association vanished when adjusted for gender, smoking, alcohol consumption, marital status, level of education, and physical activity. Conclusion: No clear association was found between the metabolic syndrome and psychological distress. ATP III = Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Cholesterol in Adults (Adult Treatment Panel III); CI = confidence interval; HSCL-25 = Hopkins Symptom Checklist-25, OR = odds ratio; HDL = high-density lipoprotein.

Psychometric properties of the Finnish 20-item Toronto Alexithymia Scale

The aim of this study was to examine the factor structure and the validity of the Finnish version of the 20-item Toronto Alexithymia Scale (TAS-20). As part of the Northern Finland 1966 Birth Cohort Project, the TAS-20 was presented to a sample of 5034 31-year old persons. A confirmatory factor analysis showed that the three-factor model, earlier established with the original TAS-20, was in agreement with the Finnish version of the scale. Three criteria of goodness-of-fit met the standards for adequacy of fit. For the total scale, internal reliability (Cronbachs alpha) was 0.83 and for the three subscales (factors 1, 2, and 3) it was 0.81, 0.77, and 0.66, respectively. Two- and one-factor models for TAS-20 were also examined, but the other models did not perform as well as the three-factor model. The factor model also worked well with a sample of 516 students with a mean age of 24.8 years. In conclusion, the TAS-20 scale is useful in the Finnish version, too.

Reasons for the diagnostic discordance between clinicians and researchers in schizophrenia in the Northern Finland 1966 Birth Cohort

Abstract.Background: The diagnosis of schizophrenia by clinicians is not always accurate in terms of operational diagnostic criteria despite the fact that these diagnoses form the basis of case registers and routine statistics. This poses a challenge to psychiatric research. We studied the reasons for diagnostic discordance between clinicians and researchers. Methods: The Northern Finland 1966 Birth Cohort (n = 11,017) was followed from mid-gestation to the end of the 31st year. Psychiatric outcome was ascertained through linkage to the national hospital discharge register containing clinical diagnoses made by the attending physician. The hospital notes of all subjects admitted to hospital during the period 1982–1997 due to psychiatric disorder were reviewed and 475 research, operational DSM-III-R diagnoses were formulated. Results: Ninety-six cases met operational criteria for schizophrenia. Fifty-five (57 %) had concordant diagnoses: both the clinical and research diagnoses were schizophrenia. Forty-one (43 %) had discordant diagnoses: the clinical diagnosis was other than schizophrenia (mainly schizophreniform or other psychosis). Discordant cases were more likely to be older at onset, experience a shorter treatment duration, fewer treatment episodes, and to have a comorbid diagnosis mental retardation. Conclusions: Clinicians do not make the diagnosis of schizophrenia as often as the application of operational criteria would suggest they should. The discordance between clinical diagnosis and the research, operational diagnosis is especially likely in cases having late onset and few contacts to psychiatric hospital.

Interaction of genetic risk and adoptive parent communication deviance: longitudinal prediction of adoptee psychiatric disorders

BACKGROUND In the Finnish Adoptive Family Study of Schizophrenia, adoptee thinking disorders have been shown to be a joint effect of genetic liability for schizophrenia spectrum disorders and adoptive rearing-parent communication patterns. However, longitudinal predictions of clinical psychiatric disorders of the adoptees have not been reported. METHOD Adoptees (n = 109) who had no DSM-III-R disorder at initial assessment (median age 18 years) were selected from the total sample of the Finnish Adoption Study of Schizophrenia. They were defined as at high versus low genetic risk based upon the lifetime diagnoses of their biological, adopting-away mothers - schizophrenia spectrum disorder versus no spectrum disorder. At initial assessment, adoptive rearing parents were independently evaluated from tape-recorded Rorschach protocols scored as manifesting either high or low Communication Deviance (CD), a composite index of communication patterns that distract and befuddle listeners. Adoptees were independently re-diagnosed after a median interval of 14 years and followed-up from national registers for an additional 7 years. RESULTS The main effects of genetic liability (G) and CD of the adoptive parents (E), each taken separately, predicted significantly for psychiatric disorders of the adoptees as adults. However, when G, E, and their joint interaction effect were entered into the same logistic model, only the interaction effect was significant. The sample included seven adoptees with schizophrenia spectrum disorders, but a separate analysis to predict them was non-significant. CONCLUSION Genetic liability for schizophrenia spectrum disorder and an adoptive family rearing variable interact, predicting longitudinally and significantly to broadly defined adoptee psychiatric disorder.

Birth measures and depression at age 31 years: The Northern Finland 1966 Birth Cohort Study

The aim of the study was to explore whether there is an association between body size at birth measured by birth weight and ponderal index and later depression at the age of 31 years. The analyses were based on 4,007 males and 4,332 females born in 1966 in the two northernmost provinces of Finland with data on current depression measured by the Hopkins Symptom Checklist-25 questionnaire (HSCL-25) and self-reported physician-diagnosed lifetime depression at 31 years and childhood characteristics. The associations between birth measures and later depression were analysed with several confounding factors including maternal depression during pregnancy. Low birth measures did not associate with adult depression in men or women. Women with high birth weight (>or=4,500 g) had a higher risk for current depression compared to women with birth weight 3,000 g-3,499 g. Women with high ponderal index (the highest 90-95 percentiles and >or=95 percentiles) had a 1.53-1.55 higher likelihood for current depression compared with women with normal ponderal index. Based on this study, large body size at birth may be a risk factor for later depression.

Ability to speak at the age of 1 year and alexithymia 30 years later

OBJECTIVE We studied the association between speech development in the first year of life and alexithymia in young adulthood. METHODS The study forms a part of the Northern Finland 1966 Birth Cohort. The original material consisted of all liveborn children in the provinces of Lapland and Oulu in Finland with an expected delivery date during 1966. The comprehensive data collection began during the antenatal phase. In 1997, a 31-year follow-up study was made on a part of the initial sample. The 20-item version of the Toronto Alexithymia Scale (TAS-20) was given to 5983 subjects. Of them, 84% returned the questionnaire properly filled in. The ability to talk was classified according to whether the child spoke no words, one or two words, or three or more words at the age of 1 year. Statistical analyses on the association between the ability to speak at the age of 1 year and alexithymia at the age of 31 years were performed, adjusted for birth weight, mothers parity, place of residence and wantedness of pregnancy. RESULTS The mean of the total TAS score was lowest among early speakers and for both genders separately. The differences were statistically significant. A parallel significant difference was found among males on TAS Factors 2 and 3 and in case of females on TAS Factors 1 and 3. CONCLUSIONS We found evidence for an association between speaking development in early childhood and later alexithymia. Our results support the theory that alexithymia may be a developmental process starting in early childhood and reinforcing itself in a social context.

Early presence of thought disorder as a prospective sign of mental disorder

The purpose of this study was to assess whether premorbid signs, such as thought disorder, could predict the subsequent manifestation of psychiatric disorders. A group of 75 adoptees at high genetic risk for schizophrenia and 96 low-risk adoptees without any psychiatric disorder at the initial assessment were assessed blindly with the Thought Disorder Index (TDI). Their psychiatric status was re-assessed according to DSM-III-R criteria in a re-interview 11 years later and based on available registers 16 years later. High scores on several TDI variables at the initial assessment predicted a psychiatric disorder of all adoptees at follow-up. Prediction was statistically unsuccessful among the high-risk adoptees because of the small number of cases, but high scores at the 0.50 severity level did predict mental disorders among the low-risk adoptees.

Long-term stability of communication deviance

Communication deviance (CD), forms of communication that are not bizarrely thought disordered but are hard to follow and that make difficult the consensual sharing of attention and meaning, has been hypothesized as a nonspecific contributor of rearing parents to psychopathology of offspring, including schizophrenia. This hypothesis, or an alternative of genetic transmission, would gain plausibility if CD has long-term stability. CD was evaluated, using tape-recorded and reliably scored Rorschachs in 158 Finnish adoptees, and retested after a median interval of 11 years. Adolescent CD was not stably correlated with follow-up CD. However, initial CD at a mean age of 32 and follow-up CD were significantly correlated. Gender, genetic risk for schizophrenia, and DSM-III-R (American Psychiatric Association, 1987) psychiatric diagnoses had no effect on adult CD stability. CD appears to be a stable, traitlike feature of adult but not adolescent functioning.

Childhood family structure and personality disorders in adulthood

BACKGROUND The association between childhood family structure and sociodemographic characteristics and personality disorders (PDs) in a general population sample was studied. METHODS This study is a substudy of the prospective Northern Finland 1966 Birth Cohort Project with 1588 young adult subjects. The case-finding methods according to the DSM-III-R criteria for PDs were: (1) Structured Clinical Interview for DSM-III-R (SCID) for 321 cases who participated in a 2-phase field study, (2) Finnish Hospital Discharge Register data, and (3) analysis of the patient records in public outpatient care in 1982-1997. Statistical analyses were performed on the association between PDs and family background factors. RESULTS Altogether 110 (7.0%) of the subjects had at least one probable or definite PD. After adjusting for confounders (gender, parental social class and parental psychiatric disorder) the results indicated that single-parent family type in childhood was associated with cluster B PDs in adulthood. Being an only child in childhood was associated with cluster A PDs. No special childhood risk factors were found for cluster C PDs. CONCLUSIONS Results suggest that single-parent family type at birth and being an only child in the 1960s are associated with PD in adulthood. Further studies are needed to explore the psychosocial aspects of family environment which may nowadays promote vulnerability to PDs in adulthood.