Interaction between parental psychosis and early motor development and the risk of schizophrenia in a general population birth cohort

Background

Delayed motor development in infancy and family history of psychosis are both associated with increased risk of schizophrenia, but their interaction is largely unstudied.

Aim

To investigate the association of the age of achieving motor milestones and parental psychosis and their interaction in respect to risk of schizophrenia.

Methods

We used data from the general population-based prospective Northern Finland Birth Cohort 1966 (n = 10,283). Developmental information of the cohort members was gathered during regular visits to Finnish child welfare clinics. Several registers were used to determine the diagnosis of schizophrenia among the cohort members and psychosis among the parents. Altogether 152 (1.5%) individuals had schizophrenia by the age of 46 years, with 23 (15.1%) of them having a parent with psychosis. Cox regression analysis was used in analyses.

Results

Parental psychosis was associated (P < 0.05) with later achievement of holding the head up, grabbing an object, and walking without support. In the parental psychosis group, the risk for schizophrenia was increased if holding the head up (hazard ratio [HR]: 2.46; degrees of freedom [df] = 1; 95% confidence interval [95% CI]: 1.07–5.66) and touching the thumb with the index finger (HR: 1.84; df = 1; 95% CI: 1.11–3.06) was later. In the group without parental psychosis, a delay in the following milestones increased the risk of schizophrenia: standing without support and walking without support. Parental psychosis had an interaction with delayed touching thumb with index finger (HR: 1.87; df = 1; 95% CI: 1.08–3.25) when risk of schizophrenia was investigated.

Conclusions

Parental psychosis was associated with achieving motor milestones later in infancy, particularly the milestones that appear early in a child's life. Parental psychosis and touching the thumb with the index finger had a significant interaction on risk of schizophrenia. Genetic risk for psychosis may interact with delayed development to raise future risk of schizophrenia, or delayed development may be a marker of other risk processes that interact with genetic liability to cause later schizophrenia.

Functional mapping of dynamic happy and fearful facial expressions in young adults with familial risk for psychosis - Oulu Brain and Mind Study

BACKGROUND

Social interaction requires mirroring to other people's mental state. Psychotic disorders have been connected to social interaction and emotion recognition impairment. We compared the brain activity between young adults with familial risk for psychosis (FR) and matched controls during visual exposure to emotional facial expression. We also investigated the role of the amygdala, the key region for social interaction and emotion recognition.

METHODS

51 FR and 52 control subjects were drawn from the Northern Finland 1986 Birth Cohort (Oulu Brain and Mind Study). None of the included participants had developed psychosis. The FR group was defined as having a parent with psychotic disorder according to the Finnish Hospital Discharge Register. Participants underwent functional MRI (fMRI) using visual presentation of dynamic happy and fearful facial expressions. FMRI data were processed to produce maps of activation for happy and fearful facial expression, which were then compared between groups. Two spherical regions of interest (ROIs) in the amygdala were set to extract BOLD responses during happy and fearful facial expression. BOLD responses were then compared with subjects' emotion recognition, which was assessed after fMRI. Psychophysiological interaction (PPI) for the left and right amygdala during happy and fearful facial expression was conducted using the amygdala as seed regions.

RESULTS

FR subjects had increased activity in the left premotor cortex and reduced deactivation of medial prefrontal cortex structures during happy facial expression. There were no between-group differences during fearful facial expression. The FR group also showed a statistically significant linear correlation between mean amygdala BOLD response and facial expression recognition. PPI showed that there was a significant negative interaction between the amygdala and the dorsolateral prefrontal cortex (dlPFC) and superior temporal gyrus in FR subjects.

CONCLUSIONS

Increased activations by positive valence in FR were in brain regions crucial to emotion recognition and social interaction. Increased activation of the premotor cortex may serve as a compensatory mechanism as FR subjects may have to exert more effort on processing the stimuli, as has been found earlier in schizophrenia. Failure to deactivate PFC structures may imply error in the default mode network. Abnormal PFC function in FR was also suggested by PPI, as the dlPFC showed decreased functional connectivity with the amygdala in the FR group. This may indicate that in FR subjects the amygdala have to take a greater role in emotion recognition and social functioning. This inference was supported by our discovery of statistically significant correlations between the amygdala BOLD response and emotion recognition in the FR group but not in controls.

Central executive network in young people with familial risk for psychosis--the Oulu Brain and Mind Study

OBJECTIVE

The central executive network controls and manages high-level cognitive functions. Abnormal activation in the central executive network has been related to psychosis and schizophrenia but it is not established how this applies to people with familial risk for psychosis (FR).

METHODS

We conducted a resting-state functional MRI (R-fMRI) in 72 (29 males) young adults with a history of psychosis in one or both parents (FR) but without psychosis themselves, and 72 (29 males) similarly healthy control subjects without parental psychosis. Both groups in the Oulu Brain and Mind Study were drawn from the Northern Finland Birth Cohort 1986. Participants were 20-25years old. Parental psychosis was established using the Care Register for Health Care. R-fMRI data pre-processing was conducted using independent component analysis with 30 and 70 components. A dual regression technique was used to detect between-group differences in the central executive network with p<0.05 threshold corrected for multiple comparisons.

RESULTS

FR participants demonstrated statistically significantly lower activity compared to control subjects in the right inferior frontal gyrus, a key area of central executive network corresponding to Brodmann areas 44 and 45, known as Broca's area. The volume of the lower activation area with 30 components was 896mm(3) and with 70 components was 1151mm(3).

CONCLUSION

The activity of the central executive network differed in the right inferior frontal gyrus between FR and control groups. This suggests that abnormality of the right inferior frontal gyrus may be a central part of vulnerability for psychosis.

Maternal cigarette smoking during pregnancy predicts drug use via externalizing behavior in two community-based samples of adolescents

BACKGROUND AND AIMS

Prenatal exposure to maternal cigarette smoking (PEMCS) is associated with a higher probability of substance use in adolescence. We explore if externalizing behavior mediates this relationship, while controlling for a number of potential covariates of this mediation process.

METHODS

We used data obtained in two geographically distinct community samples of adolescents. The first (cross-sectional) sample consisted of 996 adolescents (12-18 years of age) recruited from the Saguenay Youth Study (SYS) in Canada (47% with PEMCS). The second (longitudinal) sample consisted of 1141 adolescents (49% with PEMCS) from the Northern Finland Birth Cohort (NFBC1986). In both samples, externalizing behavior and substance use were assessed during adolescence. In the NFBC1986 cohort, externalizing behavior was also assessed in childhood.

RESULTS

In both populations, PEMCS is associated with a higher likelihood of adolescent drug experimentation. In the NFBC1986 cohort, exposed (versus non-exposed) adolescents experiment with an extra 1.27 [B = 0.24, 95% confidence intervals (CI) = 0.15, 0.33 P < 0.001] drugs. In the SYS cohort, a clear protective effect of not being exposed is shown: non-exposed (versus exposed) adolescents are 1.5 times [B = -0.42, 95% CI = -0.75, -0.09, P = 0.013] less likely to take drugs. These associations between PEMCS and drug experimentation remain in the multivariate and mediational analyses.

CONCLUSIONS

Prenatal exposure to maternal cigarette smoking appears to be associated with a higher probability of experimenting with drugs during adolescence, both directly and indirectly via externalizing behavior and the number of peers reported as using drugs.

Longitudinal changes in total brain volume in schizophrenia: relation to symptom severity, cognition and antipsychotic medication

Studies show evidence of longitudinal brain volume decreases in schizophrenia. We studied brain volume changes and their relation to symptom severity, level of function, cognition, and antipsychotic medication in participants with schizophrenia and control participants from a general population based birth cohort sample in a relatively long follow-up period of almost a decade. All members of the Northern Finland Birth Cohort 1966 with any psychotic disorder and a random sample not having psychosis were invited for a MRI brain scan, and clinical and cognitive assessment during 1999-2001 at the age of 33-35 years. A follow-up was conducted 9 years later during 2008-2010. Brain scans at both time points were obtained from 33 participants with schizophrenia and 71 control participants. Regression models were used to examine whether brain volume changes predicted clinical and cognitive changes over time, and whether antipsychotic medication predicted brain volume changes. The mean annual whole brain volume reduction was 0.69% in schizophrenia, and 0.49% in controls (p = 0.003, adjusted for gender, educational level, alcohol use and weight gain). The brain volume reduction in schizophrenia patients was found especially in the temporal lobe and periventricular area. Symptom severity, functioning level, and decline in cognition were not associated with brain volume reduction in schizophrenia. The amount of antipsychotic medication (dose years of equivalent to 100 mg daily chlorpromazine) over the follow-up period predicted brain volume loss (p = 0.003 adjusted for symptom level, alcohol use and weight gain). In this population based sample, brain volume reduction continues in schizophrenia patients after the onset of illness, and antipsychotic medications may contribute to these reductions.

Longitudinal associations between childhood and adulthood externalizing and internalizing psychopathology and adolescent substance use

BACKGROUND

Emotional and behavioral problems are commonly associated with substance use in adolescence but it is unclear whether substance use precedes or follows mental health problems. The aim was to investigate longitudinal associations between externalizing and internalizing psychopathology and substance use in a prospective population study design.

METHOD

The sample was the Northern Finland Birth Cohort 1986 Study (NFBC 1986; n = 6349; 3103 males). Externalizing and internalizing mental health problems were assessed at age 8 years (Rutter scales), substance use and externalizing and internalizing problems [Youth Self-Report (YSR)] at age 15-16 years, and hospital diagnoses for internalizing disorders (age 25) and criminal offences (age 20) from nationwide registers in adulthood.

RESULTS

Externalizing problems at age 8 were associated with later substance use. After adjustment for sociodemographic factors, parental alcohol use and psychiatric disorders, and earlier externalizing and internalizing problems, substance use predicted criminality, especially among males, with the highest odds ratio (OR) for cannabis use [adjusted OR 6.2, 95% confidence interval (CI) 3.1-12.7]. Early internalizing problems were not a risk for later substance use. Female adolescent cannabis (OR 3.2, 95% CI 1.4-7.3) and alcohol (OR 2.1, 95% CI 1.1-4.2) use predicted internalizing disorders in adulthood.

CONCLUSIONS

Externalizing problems precede adolescent substance use in both genders, whereas, among boys, substance use also precedes criminal offences. Internalizing problems may follow substance use in females. These associations were robust even when taking into account previous mental health problems.

Response initiation in young adults at risk for psychosis in the Northern Finland 1986 Birth Cohort

INTRODUCTION

This is one of the very few studies to investigate the specific executive function/processing speed component of response initiation in subjects at familial risk (FR) for psychosis, and the first such study in subjects at clinical risk (CR) for psychosis.

METHODS

Participants (N = 177) were members of the general population-based Northern Finland 1986 Birth Cohort in the following four groups: FR for psychosis (n = 62), CR for psychosis (n = 21), psychosis (n = 25) and control subjects (n = 69). The response initiation of these groups was compared in three different tests: Semantic fluency, Stockings of Cambridge and Spatial working memory.

RESULTS

The two risk groups did not differ significantly from control group, but differed from, and outperformed the psychosis group in semantic fluency response initiation.

CONCLUSIONS

Response initiation deficits were not evident in a non-help seeking psychosis high-risk sample.

Brain structure in different psychosis risk groups in the Northern Finland 1986 birth cohort

We tested the hypothesis that family risk for psychosis (FR) and clinical risk for psychosis (CR) are associated with structural brain abnormalities, with increased deficits in those at both family risk and clinical risk for psychosis (FRCR). The study setting was the Oulu Brain and Mind Study, with subjects drawn from the Northern Finland 1986 Birth Cohort (n=9479) using register and questionnaire based screening, and interviews using the Structured Interview for Prodromal Symptoms. After this procedure, 172 subjects were included in the study, classified as controls (n=73) and three risk groups: FR excluding CR (FR, n=60), CR without FR (CR, n=26), and individuals at both FR and CR (FRCR, n=13). T1-weighted brain scans were acquired and processed in a voxel-based analysis using permutation-based statistics. In the comparison between FRCR versus controls, we found lower grey matter volume (GMV) in a cluster (1689 voxels at -4.00, -72.00, -18.00mm) covering both cerebellar hemispheres and the vermis. This cluster was subsequently used as a mask to extract mean GMV in all four groups: FR had a volume intermediate between controls and FRCR. Within FRCR there was an association between cerebellar cluster brain volume and motor function. These findings are consistent with an evolving pattern of cerebellar deficits in psychosis risk with the most pronounced deficits in those at highest risk of psychosis.

Young people at risk for psychosis: case finding and sample characteristics of the Oulu Brain and Mind Study

AIM

Set within the general population-based Northern Finland Birth Cohort 1986, the Oulu Brain and Mind Study aims to explore the causes and pathogenesis of psychotic illness by following young people at risk for psychosis due to having a first-degree relative with psychotic illness or due to having experienced psychotic-like symptoms themselves. We report the study methods and explore the relationship between these definitions of high risk for psychosis and operational criteria for a prodromal psychosis syndrome based on interview.

METHODS

Prospectively collected data from earlier follow-ups of this cohort were combined with health register data to categorize subjects as those with familial risk (n = 272), symptomatic risk (n = 117), psychosis (n = 78), attention deficit hyperactivity disorder (ADHD) (n = 103) and a sample of controls (n = 193) drawn randomly from the remaining cohort. The Structured Interview for Prodromal Syndromes (SIPS) was applied to all, 295 participants together with questionnaires measuring psychosis vulnerability and schizotypal traits.

RESULTS

There were 29 (10%) current prodromal cases. Criteria for the current prodromal syndrome were fulfilled by 12% of the familial risk group and 19% of the symptomatic risk group, compared with 5% of the ADHD group and 4% of controls.

CONCLUSION

We successfully detected young people with a prodromal psychosis syndrome although relatively few subjects deemed to be at high risk met the full operational criteria according to the SIPS interview. Combining methods from familial, clinical and psychometric high-risk approaches provides a tractable method for studying risk of psychosis in the general population.

Association of depressiveness with chronic facial pain: a longitudinal study

OBJECTIVE

Depression and pain are often co-morbid. Temporomandibular disorders (TMD) include facial pain as one main symptom. Reports are lacking on the association between chronic facial pain and earlier depressiveness. The aim of the study was to investigate whether depressiveness increases the risk for chronic facial pain in a longitudinal population-based study.

MATERIALS AND METHODS

Subjects included in the Northern Finland Birth Cohort 1966 (n = 5696) answered a questionnaire on facial pain and depressiveness using the Symptom Checklist-25 depression sub-scale at the age of 31 years. In addition, reported depression diagnosed by a doctor was enquired about. Three years later a sub-sample of the cohort, including 63 cases with chronic facial pain and 85 pain-free controls, was formed based on the question concerning facial pain.

RESULTS

Of the chronic facial pain cases 17.5% and of the pain-free controls 7.1% were depressive 3 years earlier at baseline (p = 0.050, χ(2) test, crude OR = 2.8, 95% CI = 1.0-8.0). Of the chronic facial pain cases 6.3% and of the pain-free controls 1.2% reported having had diagnosed depression (p = 0.085, crude OR = 5.7, 95% CI = 0.6-52.2). After adjusting the gender, the association between depressiveness reported at the baseline and chronic facial pain was significant (OR = 4.2, 95% CI = 1.1-16.2). When widespread pain was included in the analysis, the association was not significant.

CONCLUSIONS

Depressiveness increases the risk for chronic facial pain in a 3-year follow-up. This association seems to be mediated through widespread pain.

Ante- and perinatal circumstances and risk of attempted suicides and suicides in offspring: the Northern Finland birth cohort 1966 study

PURPOSE

To investigate those ante- and perinatal circumstances preceding suicide attempts and suicides, which have so far not been studied intensively.

METHODS

Examination of the Northern Finland Birth Cohort 1966 (n = 10,742), originally based on antenatal questionnaire data and now followed up from mid-pregnancy to age 39, to ascertain psychiatric disorders in the parents and offspring and suicides or attempted suicides in the offspring using nationwide registers.

RESULTS

A total of 121 suicide attempts (57 males) and 69 suicides (56 males) had occurred. Previously unstudied antenatal factors (maternal depressed mood and smoking, unwanted pregnancy) were not related to these after adjustment. Psychiatric disorders in the parents and offspring were the risk factors in both genders. When adjusted for these, the statistically significant risk factors among males were a single-parent family for suicide attempts (OR 3.71, 95% CI 1.62-8.50) and grand multiparity for suicides (OR 2.67, 95% CI 1.15-6.18). When a psychiatric disorder in females was included among possible risk factors for suicide attempts, it alone remained significant (OR 15.55, 8.78-27.53).

CONCLUSIONS

A single-parent family was a risk factor for attempted suicides and grand multiparity for suicides in male offspring even after adjusting for other ante- and perinatal circumstances and mental disorders in the parents and offspring. Mothers' antenatal depressed mood and smoking and unwanted pregnancy did not increase the risk of suicide, which is a novel finding.

[Young person's first-episode psychosis]

Young person's first-episode psychosis may signify the onset of schizophrenia, psychotic depression or bipolar disorder. It can also be a brief condition resulting in full recovery. The psychosis may be caused by drugs. First-episode psychosis is usually preceded by a long period of nonspecific symptoms. Provision of close and active follow-up is important in the prodromal phase. Treatment of first-episode psychosis is individual. Usually it involves medication, individual discussions, psychotherapy or music therapy as well as family meetings. The therapy helps the young person become independent.

Symptoms associated with psychosis risk in an adolescent birth cohort: improving questionnaire utility with a multidimensional approach

AIM

Specialized self-report questionnaires have been developed for detection of symptoms indicative of psychosis risk. The identification of at-risk individuals is typically based on sum scores, which assume equal severity and discriminability of all symptoms, and a single dimension of illness. Our aim was to test whether separable dimensions of risk could be identified in the general population.

METHODS

We explored the latent structure of one such questionnaire using full-information item factor analysis, deriving exploratory models from the PROD-Screen questionnaire responses of the adolescent general population based on the Northern Finland 1986 Birth Cohort (n=6611).

RESULTS

A three-dimensional factor structure of positive, negative and general symptoms emerged. The factor structure, the appropriateness of the statistical model and the application of the results to the detection of heightened psychosis risk are discussed.

CONCLUSIONS

In explicitly taking into account the multidimensionality and varying symptom severity of the included items, the current model provides an improvement in questionnaire-based assessment of psychosis risk.

Teachers' assessments of children aged eight predict life satisfaction in adolescence

The objective was to investigate how teachers' assessments of children predict life satisfaction in adolescence. This is a prospective cohort study on the population-based Northern Finland Birth Cohort 1986 (n = 8,959). Information was gathered from parents, teachers and adolescents using questionnaires at the age of 7, 8 and 15. Response rates were 80-90%. Emotional and behavioural problems were assessed with Rutter Children's Behavioural Questionnaires for teachers (RB2) and parents (RA2) during the first grade at age 8. At adolescence, self-reported life satisfaction was measured with a question including five response alternatives. According to teachers' assessments, 13.9% of the children had high emotional or behavioural problems (RB2 ≥9). These assessments predicted life dissatisfaction in adolescence (OR(crude) = 1.77; 95% CI 1.43-2.20) in several models including also health behaviour and use of psychotropic medicine. However, introducing all the significant variables in the same model, RB2 lost its significance (OR = 1.28; 0.96-1.70), but good school achievement assessed by teachers was still a significant predictor. Life satisfaction in adolescence was associated with a variety of favourable concurrent factors. In conclusion teachers' assessments of children during the first school year predicted life satisfaction in adolescence. In mental health promotion, teachers' early assessments should be utilized for the benefit of children.

Interaction of early environment, gender and genes of monoamine neurotransmission in the aetiology of depression in a large population-based Finnish birth cohort

Objectives Depression is a worldwide leading cause of morbidity and disability. Genetic studies have recently begun to elucidate its molecular aetiology. The authors investigated candidate genes of monoamine neurotransmission and early environmental risk factors for depressiveness in the genetically isolated population-based Northern Finland Birth Cohort 1966 (12 058 live births). Design The authors ascertained and subdivided the study sample (n=5225) based on measures of early development and of social environment, and examined candidate genes of monoamine neurotransmission, many of which have shown prior evidence of a gene-environment interaction for affective disorders, namely SLC6A4, TPH2, COMT, MAOA and the dopamine receptor genes DRD1-DRD5. Results and conclusion The authors observed no major genetic effects of the analysed variants on depressiveness. However, when measures of early development and of social environment were considered, some evidence of interaction was observed. Allelic variants of COMT interacted with high early developmental risk (p=0.005 for rs2239393 and p=0.02 for rs4680) so that the association with depression was detected only in individuals at high developmental risk group (p=0.0046 and β=0.056 for rs5993883-rs2239393-rs4680 risk haplotype CGG including Val158), particularly in males (p=0.0053 and β=0.083 for the haplotype CGG). Rs4274224 from DRD2 interacted with gender (p=0.017) showing a significant association with depressiveness in males (p=0.0006 and β=0.0023; p=0.00005 and β=0.069 for rs4648318-rs4274224 haplotype GG). The results support the role of genes of monoamine neurotransmission in the aetiology of depression conditional on environmental risk and sex, but not direct major effects of monoaminergic genes in this unselected population.

Different vulnerability indicators for psychosis and their neuropsychological characteristics in the Northern Finland 1986 Birth Cohort

This study is one of very few that has investigated the neuropsychological functioning of both familial and clinical high risk subjects for psychosis. Participants (N = 164) were members of the Northern Finland 1986 Birth Cohort in the following four groups: familial risk for psychosis (n = 62), clinical risk for psychosis (n = 20), psychosis (n = 13), and control subjects (n = 69). The neurocognitive performance of these groups was compared across 19 cognitive variables. The two risk groups did not differ significantly from controls, but differed from the psychosis group in fine motor function. Neuropsychological impairments were not evident in a non-help-seeking high-risk sample.

Impact of temperament on depression and anxiety symptoms and depressive disorder in a population-based birth cohort

BACKGROUND

The aim of this study was to characterize at the population level how innate features of temperament relate to experience of depressive mood and anxiety, and whether these symptoms have separable temperamental backgrounds.

METHODS

The study subjects were 4773 members of the population-based Northern Finland Birth Cohort 1966, a culturally and genetically homogeneous study sample. Temperament was measured at age 31 using the temperament items of the Temperament and Character Inventory and a separate Pessimism score. Depressive mood was assessed based on a previous diagnosis of depressive disorder or symptoms of depression according to the Hopkins Symptom Check List - 25. Anxiety was assessed analogously.

RESULTS

High levels of Harm avoidance and Pessimism were related to both depressive mood (effect sizes; d=0.84 and d=1.25, respectively) and depressive disorder (d=0.68 and d=0.68, respectively). Of the dimensions of Harm avoidance, Anticipatory worry and Fatigability had the strongest effects. Symptoms of depression and anxiety showed very similar underlying temperament patterns.

LIMITATIONS

Although Harm avoidance and Pessimism appear to be important endophenotype candidates for depression and anxiety, their potential usefulness as endophenotypes, and whether they meet all the suggested criteria for endophenotypes will remain to be confirmed in future studies.

CONCLUSIONS

Personality characteristics of Pessimism and Harm avoidance, in particular its dimensions Anticipatory worry and Fatigability, are strongly related to symptoms of depression and anxiety as well as to depressive disorder in this population. These temperamental features may be used as dimensional susceptibility factors in etiological studies of depression, which may aid in the development of improved clinical practice.

Physical activity and fitness in adolescents at risk for psychosis within the Northern Finland 1986 Birth Cohort

BACKGROUND

Literature regarding physical activity and fitness among subjects at risk for psychosis especially in adolescents is scarce. This study evaluated the level of physical activity and cardio-respiratory fitness among subjects at risk for psychosis in a relatively large birth cohort sample.

METHODS

The study population consisted of the Northern Finland Birth Cohort 1986 including 6987 adolescents who self-reported their physical activity by responding to a postal inquiry in 2001-2002 at the age of 15-16 years. Their cardiorespiratory fitness was measured in a clinical examination by a submaximal cycle ergometer test. Vulnerability to psychosis was defined in three ways: having a parent with a history of psychosis, having prodromal symptoms of psychosis measured by PROD-screen questionnaire at the age of 15-16 years or having actually developed psychosis after the field study (in 2002-2005). The Finnish Hospital Discharge Register was used to find out about parental and the individual's own psychosis.

RESULTS

Those individuals who developed psychosis were more likely to be physically inactive (OR 3.3; CI 95% (1.4-7.9) adjusted for gender, parental socio-economic status, family structure and parents' physical activity) and to have poor cardiorespiratory fitness (OR 2.2; 95% CI 0.6-7.8 adjusted for parental socio-economic status, family structure and parents' physical activity) compared to those who did not develop psychosis.

CONCLUSIONS

Adolescents who would actually develop psychosis had a relatively low level of physical activity compared to their age mates. General recommendations for physical activity would be important for subjects at risk for developing psychosis in order to avoid detrimental effect of physical inactivity on overall health.

Schizophrenia in the offspring of antenatally depressed mothers in the northern Finland 1966 birth cohort: relationship to family history of psychosis

OBJECTIVE

Maternal depression is relatively common during pregnancy. The authors examined whether maternal antenatal depressed mood increased the risk of schizophrenia and other psychoses among offspring with and without a familial history of psychosis.

METHOD

In the Northern Finland 1966 birth cohort, mothers of 12,058 children were asked at mid-gestation at the antenatal clinic if they felt depressed. The offspring were followed for over 30 years, and subsequent schizophrenia and other psychoses were detected using the Finnish Hospital Discharge Register, which was also used for identifying psychosis in the parents. Familial risk for psychosis was considered as a genetic risk factor and mothers' depressed mood as an environmental or genetic risk factor.

RESULTS

The risk for schizophrenia was higher in the offspring with both maternal depressed mood during pregnancy and parental psychosis (OR=9.4, 95% CI=4.2-20.9 adjusted for sex and perinatal complications) than in those with a depressed mother but without parental psychosis (OR=1.0, 95% CI=0.6-1.8) or those without maternal depression and with a psychotic parent (OR=2.6, 95% CI=1.2-5.4). The reference group was birth cohort members without maternal antenatal depression and without parental psychosis.

CONCLUSIONS

Maternal depressed mood during pregnancy per se is unlikely to increase the risk for schizophrenia in the offspring but may affect subjects with a family history for psychosis. This finding could be an example of a gene-environment or possibly a gene-gene interaction in the development of schizophrenia. Mothers' antenatal depression may act as additive factor for subjects vulnerable to schizophrenia.

No difference in insulin resistance and lipid levels between controls and adolescent subjects who later develop psychosis

Type 2 diabetes and dyslipidemias co-occur frequently with psychoses, but it is not known how common they are in adolescents who later develop psychosis. We investigated waist circumference, blood glucose, lipid and insulin levels and insulin resistance in the Northern Finland 1986 Birth Cohort at the age of 15/16 (N=5410). The Social Insurance Institute register and the Finnish Hospital Discharge Register were used to find the participants who developed psychosis (N=21), and they were compared with other participants. There were no differences in the cardiometabolic variables, suggesting that psychotic episode is not preceded by glucose and lipid metabolism disturbances.

Association of cannabis use with prodromal symptoms of psychosis in adolescence

Recent interest has focused on the association between cannabis use and risk of psychosis. In the largest unselected, population-based study on this topic to date, we examined cannabis use and prodromal symptoms of psychosis at age 15-16 years among 6330 adolescents. Those who had tried cannabis (n=352; 5.6% of the total sample) were more likely to present three or more prodromal symptoms even after controlling for confounders including previous behavioural symptoms (OR=2.23; 95% CI 1.70-2.94). A dose-response effect was seen. We conclude that cannabis use is associated with prodromal symptoms of psychosis in adolescence.

Insulin resistance and lipid levels in adolescents with familial risk for psychosis

OBJECTIVE

Type 2 diabetes and dyslipidemias co-occur frequently with schizophrenia. It is not known how common they are in adolescents with a familial risk for psychosis.

METHOD

The Northern Finland 1986 Birth Cohort consists of 9432 children born alive in the two Northernmost provinces in Finland. At the age of 15/16 they participated in clinical examination including measurements of glucose, lipids and IR, and a questionnaire including items about their diet and physical activity. The Finnish Hospital Discharge Register was used to find out non-organic psychoses in parents during 1972-2000. This familial risk was found out in 54 boys and 68 girls. Their results were compared with other cohort members.

RESULTS

No differences were observed in the cardiometabolic risk factors between the study groups.

CONCLUSION

Our results suggest that familial risk for psychosis is not directly associated with disturbances of glucose and lipid metabolism among adolescents.

Risk factors for schizophrenia. Follow-up data from the Northern Finland 1966 Birth Cohort Study

This paper updates single risk factors identified by the Northern Finland 1966 Birth Cohort Study up to the end of year 2001 or age 34. Impaired performance (e.g., delayed motor or intellectual development) or adverse exposures (e.g., pregnancy and birth complications, central nervous system diseases) are associated with an increased risk for schizophrenia. However, upper social class girls and clever schoolboys also have an increased risk to develop schizophrenia, contrasted to their peers. Individuals who subsequently develop schizophrenia follow a developmental trajectory that partly and subtly differs from that of the general population; this trajectory lacks flexibility and responsiveness compared to control subjects, at least in the early stages. We propose a descriptive, lifespan, multilevel systems model on the development and course of schizophrenia.