Single-parent family background and physical illness in adulthood: a follow-up study of the Northern Finland 1966 birth cohort.

The association between single-parent family background and physical illness in early adulthood was studied in a sample of an unselected, general population: the Northern Finland 1966 Birth Cohort. Between the ages of 16 and 28 years, women of single-parent family background were more commonly treated (61% versus 57%) for any physical condition in hospital wards compared with women of two-parent family background. Spontaneous abortions (odds ratio; OR = 1.4, 95% CI 1.0-2.0), complications of pregnancy (OR = 1.1, 95% CI 1.0-1.3), and intracranial injuries (OR = 2.0, 95% CI 1.0-3.8) were more common among women with single-parent family background. They also had a clearly higher risk for induced abortions (OR = 1.6. 95% CI 1.4-1.9), and a higher incidence of deliveries than did other women. The risk of hospital-treated physical illness did not differ between men of single-parent and two-parent family background. Poisonings and injuries were, however, more common reasons for hospital admission among men with single-parent family background than among other men. In conclusion, our main finding was that, among women, an association between overall hospital-treated physical illness and single-parent family background does exist. However, offspring of single-parent families are mostly in as good physical health as others.

Is grand multiparity associated with offsprings' hospital-treated mental disorders? A 28-year follow-up of the North Finland 1966 birth cohort.

BACKGROUND: A child born to a grand multiparous (GMP) mother (i.e. a mother who has undergone six or more deliveries) is at increased risk of perinatal complications, but it is not known whether or not GMP status is associated with child's adulthood mental disorders. METHODS: The data were obtained from the unselected, general population Northern Finland 1966 Birth Cohort (n = 11,017). The cohort members (children) were followed up prospectively to the age of 28 years. Using the National Hospital Discharge Register, a total of 89 DSM-III-R schizophrenia cases were identified, as well as 55 other psychoses, 87 personality disorders, 36 cases of alcoholism, 53 depressive disorders, and 67 anxiety and other non-psychotic disorders. The association between the mother's grand multiparity and the offspring's adult hospital-treated psychiatric morbidity was analysed using a continuation ratio model, which is a modification of logistic regression. Odds ratios were adjusted for social class, maternal antenatal depression, and wantedness of pregnancy. RESULTS: A total of 1320 mothers (12%) were GMPs. Maternal GMP status was not associated with offspring's schizophrenia, anxiety or other non-psychotic disorders. The risk of other psychoses (OR 2.3; 95% CI 1.2-4.7), alcoholism (OR 2.0; 95% CI 0.8-4.7) and depressive disorder (OR 2.2; 95% CI 1.0-4.5) was elevated among offspring of GMP mothers. CONCLUSIONS: It is possible that the mother's GMP status and the large family size associated with this are causal factors in the development of other psychoses than schizophrenia, alcoholism and depression among adult offspring.

Comorbidity of hospital-treated psychiatric and physical disorders with special reference to schizophrenia: a 28 year follow-up of the 1966 northern Finland general population birth cohort.

We studied the comorbidity of psychiatric and physical disorders in a sample (n = 11,017) from the unselected, general population, Northern Finland 1966 Birth Cohort. During the period 1982-1994, hospital-treated psychiatric patients were more likely than people without psychiatric diagnoses to have been treated for physical disease in hospital wards, 298 out of 387 (77%) vs 6687 out of 10,630 (62.9%) (OR = 2.0, 95% CI = 1.6-2.5). Injuries, poisonings and indefinite symptoms were a more common reason for hospital treatment in people with schizophrenia or other psychiatric disorder as compared with people without a psychiatric disorder. Men with psychiatric disorder had more than a 50-fold risk for poisoning by psychotropic drugs (OR = 52.6, 95% CI = 27.7-99.8), women with psychiatric disorder a 20-fold risk (OR = 19.0, 95% CI = 9.5-38.1) and schizophrenics more than a 30-fold (OR = 37.5, 95% CI = 19.1-73.8). Men with psychiatric disorders were more commonly hospitalised for a variety of gastrointestinal disorders and circulatory diseases (OR = 2.3, 95% CI = 1.2-4.4), as compared with men with no psychiatric disorder. Respiratory diseases (OR = 2.2, 95% CI = 1.2-4.2, vertebral column disorders (OR = 4.2, 95% CI = 1.8-9.9), gynaecological disorders (OR = 2.1, 95% CI = 1.2-3.6) and induced abortions (OR = 1.8, 95% CI = 1.2-2.7) were more prevalent in women with psychiatric disorder than in other women. Epilepsy was strongly associated with schizophrenia (OR = 11.1, 95% CI = 4.0-31.6). Nervous and sensory organ diseases in general (OR = 2.5, 95% CI = 1.1-5.8) and inflammatory diseases of the bowel (OR = 12.8, 95% CI = 3.8-42.7) were also overrepresented in schizophrenia when compared with people without a psychiatric disorder. Our results indicate that physicians must be alert for psychiatric disorder, and mental health professionals must be aware of the considerable morbidity in their patients.

Early developmental differences between DSM-III-R schizophrenics treated with clozapine and typical neuroleptics.

Developmental deviance is known to be associated with schizophrenia. We tested the hypothesis that the most severe schizophrenia requiring treatment with clozapine would particularly show these effects. Therefore, associative factors from pregnancy, delivery, neonatal and socio-demographic characteristics were compared between the clozapine-treated schizophrenic cases (n = 17) and the remaining cases of schizophrenia treated with typical neuroleptics (n = 59) from an unselected, general population North Finland 1966 Birth Cohort, (n = 11,017). By the end of 1994, seventeen (22%) of a total 76 DSM-III-R schizophrenia patients, had received clozapine treatment. The mean length at birth was 52 cm in the clozapine group (in the non-clozapine group 50 cm) and correspondingly the mean one year weight 10.4 kg (9.8 kg), with the differences between the groups being statistically significant (P < 0.05). Other pregnancy, delivery, and socio-demographic characteristics were, however, similar in the clozapine-treated and the remaining cases with schizophrenia. There was no evidence that severe schizophrenia requiring treatment with clozapine was associated with impaired intrauterine or post-natal development. Indeed, during the first years of life the former group was larger in terms of weight and length than those treated with typical neuroleptics. These early developmental characteristics did not predict clinical severity of schizophrenia in adulthood.

Hospital-treated psychiatric disorders in adults with a single-parent and two-parent family background: a 28-year follow-up of the 1966 Northern Finland Birth Cohort.

This study investigates the relationship between the family type (two-parent and 4 different single-parent types, mainly divorced) during childhood up to 14 years of age and adult hospital-treated psychiatric disorders in a sample from the unselected, general population Northern Finland 1966 Birth Cohort (N = 11,017). Up to the end of 1994, a total of 387 individuals (3.5%) had a hospital-treated psychiatric disorder, with 3.1% in two-parent families and 5.4% in single-parent families (p < .001). The single-parent family was not associated with the child's schizophrenia or other psychotic disorders. The adjusted odds ratios (OR) for personality disorders were highest among individuals without a father before the age of 14 years (OR 4.8), or at birth only (OR 4.0), or with a history of parental divorce (OR 2.8). Parental divorce was also associated with alcoholism (OR 3.7) and parental death with depressive disorders (OR 3.4). In conclusion, we found an elevated risk of hospital-treated nonpsychotic disorder among individuals from a single-parent family background. It is likely that a combination of the single-parent family and psychosocial and/or genetic risk may influence the development of these disorders.

Accuracy of register-based schizophrenia diagnoses in a genetic study.

In order to assess the accuracy of schizophrenia diagnoses for genetic studies, we identified all schizophrenia patients (n = 492) in an isolated community with a diagnosis of schizophrenia in the Finnish Hospital Discharge Register (HDR) between 1969-1991. For the accuracy study we identified a sample of 73 patients from registers with Diagnostic and Statistical Manual (DSM)-III-R for schizophrenia (codes 295.10, 295.30, 295.60, 295.90) (n = 62) or "schizophrenia spectrum" diagnoses (295.40, 295.70, 297.10, 301.20, 301.22) (n = 11). When the operational criteria (DSM-III-R) were applied by two senior researchers using information from the original mental hospital records, 93% (68/73) of the cases fulfilled criteria for schizophrenia or schizophrenia spectrum. The results demonstrate that the schizophrenia diagnoses of the registers are accurate when a broad concept of schizophrenia is applied. When using operational DSM-III-R schizophrenia criteria, eight false positive cases were found among the 62 mental hospital schizophrenia diagnoses. Consequently, there may be a need to reassess schizophrenia diagnoses depending on the purpose of the study. We also found good agreement between DSM-III-R (kappa 0.93) and operational criteria (OPCRIT) diagnostic system (kappa 0.89) diagnoses, made by one researcher, compared with operational diagnoses. This indicates the possibility for the reliable use of one of these methods alone for diagnostic reassessment. The information in the HDR on primary diagnoses and on the dates of admission and discharge was accurately transferred from the hospital records.

A comparison of clinical and research DSM-III-R diagnoses of schizophrenia in a Finnish national birth cohort. Clinical and research diagnoses of schizophrenia.

As a prerequisite to the use of the Finnish National Hospital Discharge Register in psychiatric epidemiological research, we studied the diagnostic reliability of the register in terms of the psychiatric morbidity experienced by a national birth cohort. We investigated all entries to the register for a sample based upon the Northern Finland 1966 birth cohort at the age of 16 years (n = 11017). Until the end of 1993 (age 27 years), a total of 563 subjects had a register diagnosis indicating a psychiatric illness, 37 of them being schizophrenia. When operational criteria (DSM-III-R) were applied to clinical information in the available original hospital records for cases of psychosis, personality disorder and substance abuse (n = 249), 71 fulfilled criteria for schizophrenia, including all of the 37 cases in the register and an additional 34 (48% false-negatives), most frequently diagnosed in the register as schizophreniform or other psychosis. Despite the official use of DSM-III-R nomenclature, it appears that the clinical concept of schizophrenia in Finland, manifest within the register, remains very restrictive. The application of operational criteria is a necessary prerequisite for scientific research on schizophrenia.

Schizophrenia in the genetic isolate of Finland.

We compared the features of schizophrenia in the homogeneous population of Finland (population about 5,000,000) and in an internal isolate in northeastern Finland inhabited in the 1680s by a small group of founders (current population about 18,000) in a register-based epidemiological study. We identified all cases with a diagnosis of schizophrenia in Finland born between 1940-1969 using three national computerized registers and found a total of 267 schizophrenia patients in the internal isolate and 29,124 in Finland. The lifetime prevalence was 2.21% in the internal isolate and 1.21% in Finland, respectively. The age-corrected lifetime risk was 3.2% in the internal isolate and 1.1% in the whole country. The risk of schizophrenia to siblings in the internal isolate was 6.4% (95% confidence interval 0.052, 0.078), 9.1% (95% CI 0.062, 0.130), and 6.8% (95% CI 0.028, 0.135) given 1, 2, or 3 affected siblings, and for all Finland 4.2% (95% CI 0.036, 0.043), 6.4% (95% CI 0.058, 0.071), and 8.7% (95% CI 0.068, 0.107) given 1, 2, or 3, affected siblings, respectively. The mean number of children in schizophrenia families and thus the number of families having at least two affected individuals were clearly higher in the isolate (24.9% vs 9.2%). We did not find any other epidemiological features differing between these two regions. It seems that the family material collected from the internal isolate is a representative subsample from the entire country and hopefully it enables easier identification of at least some predisposing genes for schizophrenia due to its unique population structure.

Is a child's risk of early onset schizophrenia increased in the highest social class?

In a sample from the unselected, general population Northern Finland 1966 Birth Cohort, 11017 individuals alive at the age of 16 years were studied until the age of 27. The cumulative incidence of early onset schizophrenia until 23 years was higher (1.14%; 9/792) among young persons from the highest social class or class I (determined according to father's occupation) than among children from lower social classes (0.47%; 48/10225), the difference being statistically significant (p < 0.05). The incidence of schizophrenia in the highest social class was higher than expected among girls, firstborns, children of young mothers under 30 and urban residents (p < 0.05) compared with lower social classes. When cases from the highest and other social classes were compared, there was no clear difference in background factors or clinical course. Four alcoholics, one of them also schizophrenic, were found among nine social class I fathers. The results suggest that in some families in Northern Finland, a father's professional advancement, often linked to mental disorder, may be one determinant of an increased risk of schizophrenia in the child.