Non-participation may bias the results of a psychiatric survey: an analysis from the survey including magnetic resonance imaging within the Northern Finland 1966 Birth Cohort

Assessing the validity of a self-reported clinical diagnosis of schizophrenia

Background

Diagnoses in psychiatric research can be derived from various sources. This study assesses the validity of a self-reported clinical diagnosis of schizophrenia.

Methods

The study included 3,029 clinically ascertained participants with schizophrenia or psychotic disorders diagnosed by self-report and/or research interview and 1,453 UK Biobank participants with self-report and/or medical record diagnosis of schizophrenia or schizoaffective disorder depressed-type (SA-D). We assessed positive predictive values (PPV) of self-reported clinical diagnoses against research interview and medical record diagnoses. We compared polygenic risk scores (PRS) and phenotypes across diagnostic groups, and compared the variance explained by schizophrenia PRS to samples in the Psychiatric Genomics Consortium (PGC).

Results

In the clinically ascertained sample, the PPV of self-reported schizophrenia to a research diagnosis of schizophrenia was 0.70, which increased to 0.81 when benchmarked against schizophrenia or SA-D. In UK Biobank, the PPV of self-reported schizophrenia to a medical record diagnosis was 0.74. Compared to self-report participants, those with a research diagnosis were younger and more likely to have a high school qualification (clinically ascertained sample) and those with a medical record diagnosis were less likely to be employed or have a high school qualification (UK Biobank). Schizophrenia PRS did not differ between participants that had a diagnosis from self-report, research diagnosis or medical record diagnosis. Polygenic liability r2, for all diagnosis definitions, fell within the distribution of PGC schizophrenia cohorts.

Conclusions

Self-report measures of schizophrenia are justified in research to maximise sample size and representativeness, although within sample validation of diagnoses is recommended.

What do we not know (yet) about recovery colleges? A study protocol on their (cost-)effectiveness, mechanisms of action, fidelity and positioning

BACKGROUND

Recovery Colleges (RCs) have spread across the globe as a new way of supporting people with mental vulnerabilities in their recovery journey. RCs focus on 'learning' rather than 'curing' and in that line facilitate a transition from being a passive, dependent patient/client to an active, empowered student learning to live life, despite vulnerabilities. Peer support and co-creation are central in RCs, as peers learn from each other by sharing personal experiences with mental vulnerabilities in an accessible, inspiring and stimulating atmosphere. The implementation of RCs is highly encouraged internationally, and as a result RCs and related self-help initiatives increasingly emerge. However, high-quality research on RCs is scarce and there is a call for thorough investigation of (cost-)effectiveness, mechanisms of action, cross-border fidelity and positioning of RCs. In response, this research project aims to fill these gaps.

METHODS

This research project entails (1) a prospective quasi-experimental effectiveness study and economic evaluation, (2) a multifaceted qualitative study to elaborate on the mechanisms of action of RCs for those involved (3) a study to develop a (Dutch) Fidelity Measure of Recovery Colleges, and (4) an organisational case study to describe the positioning of RCs in relation to other mental health care services and community-based initiatives. Following the ideals of co-creation and empowerment in RCs we conduct this research project in co-creation with RC students from Enik Recovery College in Utrecht, the Netherlands.

DISCUSSION

This research project will lead to one of the first longitudinal controlled quantitative evaluations of both cost-effectiveness and effectiveness of RC attendance in a broad sense (beyond attending courses alone). Moreover, we will gather data on a micro level (i.e., impact on RC students), meso level (i.e., organisational fidelity) and macro level (i.e., positioning in the care and support domain), capturing all important perspectives when scrutinizing the impact of complex systems. Finally, we will demonstrate the validity and value of embracing experiential knowledge in science as a complementary source of information, leading to a more profound understanding of what is researched.

TRIAL REGISTRATION

The prospective quasi-experimental study has been pre-registered at clinicaltrails.gov (#NCT05620212).

Severe and common mental disorders and risk of emergency hospital admissions for ambulatory care sensitive conditions among the UK Biobank cohort

BACKGROUND

People with mental disorders have worse physical health compared with the general population, which could be attributable to receiving poorer quality healthcare.

AIMS

To examine the relationship between severe and common mental disorders and risk of emergency hospital admissions for ambulatory care sensitive conditions (ACSCs), and factors associated with increased risk.

METHOD

Baseline data for England (N = 445 814) were taken from UK Biobank, which recruited participants aged 37-73 years during 2006-2010, and linked to hospital admission records up to 31 December 2019. Participants were grouped into those with a history of either schizophrenia, bipolar disorder, depression or anxiety, or no mental disorder. Survival analysis was used to assess the risk of hospital admission for ACSCs among those with mental disorders compared with those without, adjusting for factors in different domains (sociodemographic, socioeconomic, health and biomarkers, health-related behaviours, social isolation and psychological).

RESULTS

People with schizophrenia had the highest (unadjusted) risk of hospital admission for ACSCs compared with those with no mental disorder (hazard ratio 4.40, 95% CI 4.04-4.80). People with bipolar disorder (hazard ratio 2.48, 95% CI 2.28-2.69) and depression or anxiety (hazard ratio 1.76, 95% CI 1.73-1.80) also had higher risk. Associations were more conservative when including all admissions, as opposed to first admissions only. The observed associations persisted after adjusting for a range of factors.

CONCLUSIONS

People with severe mental disorders have the highest risk of preventable hospital admissions. Ensuring people with mental disorders receive adequate ambulatory care is essential to reduce the large health inequalities they experience.

Schizophrenia and co-morbidity risk: Evidence from a data driven phenomewide association study

Schizophrenia is a chronic debilitating psychiatric disorder with significant morbidity and mortality. In this study, we used information from 337,484 UK Biobank participants and performed PheWAS using schizophrenia genetic risk score on 1135 disease outcomes. Signals that passed the false discovery rate threshold were further analyzed for evidence on the causality of the association. We extended the analysis to 30 serum, four urine, and six neuroimaging biomarkers to identify biomarkers that could be affected by schizophrenia. Schizophrenia GRS was associated with 54 (39 distinct) disease outcomes including schizophrenia in the PheWAS analysis. Of these, a causal association were found with 10 distinct diseases in the MR analysis. Schizophrenia causally linked with higher odds of anxiety (OR = 1.41, 95%CI 1.12 to 1.21), bipolar disorder (OR = 1.52, 95%CI 1.36 to 1.70), major depressive disorder (OR = 1.12, 95%CI 1.08 to 1.16) and suicidal ideation (OR = 1.30, 95%CI 1.19 to 1.42). Lower odds were found for several diseases including type 1 diabetes, coronary atherosclerosis and some musculoskeletal disorders. In analyses using biomarkers, schizophrenia was associated with lower serum 25(OH)D, gamma glutamyltransferase, cystatin C, serum creatinine. However, we did not find association with any of the brain imaging markers. Our analyses confirmed the co-existence of schizophrenia with other mental health disorders but did not otherwise suggest strong effects on disease risk. Biomarker analyses reflected associations which could be explained by unhealthy lifestyles, suggesting patients with schizophrenia may benefit from screening for and managing broader health aspects.

User experiences of an online therapist-guided psychotherapy platform, OPTT: A cross-sectional study

Introduction

In the last few years, online psychotherapy programs have burgeoned since they are a more accessible and scalable treatment option compared to in-person therapies. While these online programs are promising, understanding the user experience and perceptions of care is essential for program optimization.

Methods

This study investigated the experiences of end-users who had previously received online psychotherapy through a web-based platform. A 35-item multiple-choice survey was developed by the research team and distributed to past users to capture their perceptions of the program.

Results

The survey yielded 163 responses, with a 90 % completion rate. Participants were predominantly white and female, with an average age of 42 years. While most participants preferred in-person therapy, they also reported the benefits of the online psychotherapy program. Participants had positive perceptions of the platform, the quality and interaction of their therapist, and the homework assignments and skills covered. Lack of motivation to complete weekly homework assignments was cited as a common struggle.

Discussion

The findings support online psychotherapy as a beneficial digital mental health tool and highlight some areas for improvement. Scalability and accessibility are key benefits of the platform. At the same time, improvements in participant engagement, including those from equity-seeking and equity-deserving groups, may enhance the efficacy of the programs offered.

Employment trajectories until midlife in schizophrenia and other psychoses: the Northern Finland Birth Cohort 1966

PURPOSE

Psychoses are associated with poor labour market attachment, but few studies have compared schizophrenia (SZ) and other psychoses (OP). Moreover, studies on long-term employment trajectories over individuals' working life courses are lacking. We compared 30 year employment trajectory patterns in a general population sample among individuals with SZ, OP, and those with no psychosis (NP).

METHODS

Utilising the Northern Finland Birth Cohort 1966, we collected survey data on employment from ages 16 to 45 and detected individuals with register-based history of SZ (n = 62), OP (n = 87), or NP (n = 6464) until age 46. Through gender-specific latent class analyses on annual employment roles, we identified traditional, highly educated, self-employed, delayed and floundering employment trajectories with distinct socioeconomic characteristics. We addressed attrition by conducting weighted analyses.

RESULTS

Floundering trajectories were common among individuals with SZ (79% of men, 73% of women) and OP (52% of men, 51% of women). In NP, a traditional employee trajectory was most common in men (31%), and a highly educated trajectory in women (28%). A history of psychosis was associated with heightened odds ratios (ORs; 95% confidence intervals (CIs)) for floundering trajectories in both men (SZ: 32.9 (13.3-81.4); OP: 7.4 (4.0-13.9)) and women (SZ: 9.9 (4.6-21.5); OP: 3.9 (2.1-7.1)) compared to NP. Weighted analyses produced similar results.

CONCLUSION

Most individuals with SZ or OP have floundering employee trajectories reflecting an elevated risk of unemployment and part-time work until midlife. These results indicate the importance of improving labour market attachment during the early phases of psychoses.

Association between participation in the Northern Finland Birth Cohort 1966 study and use of psychiatric care services

AIMS

In most population-based epidemiological follow-up studies the aim is not to intervene in the life of the participants. Although the idea is not to intervene, being a member of the longitudinal follow-up study and studies conducted during follow-up may affect the target population. A population-based study including mental health enquiries might reduce the unmet need for psychiatric treatment by motivating people to seek treatment for their psychiatric ill-health. We examined the use of psychiatric care services in the population born in the year 1966 in Northern Finland, of whom 96.3% are participants in the prospective Northern Finland Birth Cohort 1966 (NFBC1966).

METHODS

As a study cohort we used people born in 1966 in Northern Finland (n = 11 447). The comparison cohort included all the people born in the years 1965 and 1967 in the same geographical area (n = 23 339). The follow-up period was from age 10 to 50 years. The outcome measure was the use of psychiatric care services, which was analysed using Cox Proportional Hazard regression and Zero-Truncated Negative Binomial Regression.

RESULTS

People born in 1966 in Northern Finland did not differ from those born in 1965 and 1967 in terms of the outcome measure.

CONCLUSIONS

We found no association between participation in an epidemiological follow-up study and the use of psychiatric care services. The NFBC1966 may be regarded as a representative at the population level in terms of psychiatric outcomes despite the personal follow-up of the birth cohort. The associations of participation in epidemiological follow-up studies have previously been under-examined, and the results need to be replicated.

Prevalence of mental disorders among people with opioid use disorder: A systematic review and meta-analysis

BACKGROUND

Opioid use disorder (OUD) and mental disorders are major public health issues and comorbidity is common. Among people with OUD, comorbid mental disorders are associated with poorer health outcomes. To our knowledge, this is the first systematic review and meta-analysis to estimate prevalence of specific mental disorders among people with OUD.

METHODS

We searched Embase, MEDLINE, and PsycInfo from 1990 to 2021 for observational studies of depression, anxiety, post-traumatic stress disorder (PTSD), bipolar, personality, and other pre-specified mental disorders among people with OUD. We pooled current and lifetime estimates of each disorder using random-effects meta-analyses with 95% Confidence Intervals (CIs). Meta-regressions and stratified analyses were used to assess heterogeneity of prevalence estimates by methodological factors and sample characteristics.

FINDINGS

Of the 36,971 publications identified, we included data from 345 studies and 104,135 people with OUD in at least one pooled estimate. Among people with OUD, the prevalence of current depression was 36.1% (95%CI 32.4-39.7%), anxiety was 29.1% (95%CI 24.0-33.3%), attention-deficit/hyperactivity disorder was 20.9% (95%CI 15.7-26.2%), PTSD was 18.1% (95%CI 15.4-20.9%), and bipolar disorder was 8.7% (95%CI 6.7-10.7%). Lifetime prevalence of anti-social personality disorder was 33.6% (95%CI 29.1-38.0%) and borderline personality disorder was 18.2% (95% CI 13.4-23.1%). Sample characteristics and methodological factors, including sex, were associated with variance of multiple prevalence estimates.

INTERPRETATION

Our findings emphasise the need for access to mental disorder treatment among people with OUD. Specific mental disorder estimates may inform clinical guidelines, treatment services, and future research for people with OUD, including subpopulations with distinct treatment needs.

Selection bias in clinical studies of first-episode psychosis: A follow-up study

OBJECTIVES

Selection bias is a concern in studies on psychotic disorders due to high dropout rates and many eligibility criteria for inclusion. We studied how representative the first-episode psychosis study sample in the Turku Early Psychosis Study (TEPS) was.

METHODS

We screened 3772 consecutive admissions to the clinical psychiatric services of Turku Psychiatry, Finland, between October 2011 and June 2016. A total of 193 subjects had first-episode psychosis and were suitable for TEPS. Out of 193 subjects, 101 participated (PA) and 92 did not participate (NPA) in TEPS due to refusal or contact problems. We retrospectively used patient register data to study whether NPA and PA groups differed in terms of clinical outcomes during 1-year follow-up.

RESULTS

In overall sample, the NPA group had a significantly higher rate of discontinuation of clinical treatment than the PA group (48.9 % vs 29.7 %, p = 0.01). In the hospital-treated subsample chi-square tests did not indicate statistically significant differences between the NPA and PA groups in the rate of involuntary care (69.7 % vs 62.7 %, p = 0.34), coercive measures (36.0 % vs 22.7 %, p = 0.06), and readmissions during the follow-up (41.5 % vs 33.8 %, p = 0.31), respectively.

CONCLUSION

The differences in clinical outcomes and treatment characteristics in the non-participating and participating groups were relatively modest. The results do not support a major sample selection bias that would complicate the interpretation of results in this first-episode psychosis study.

Psychopathology in Children and Adolescents in Lebanon Study (PALS): a national household survey

INTRODUCTION

Psychiatric disorders are among the leading causes of disability in children and adolescents globally. In Lebanon, a country that has endured a prolonged history of conflict and economic and political uncertainty, mental health surveys in children and adolescents have been limited to specific disorders or specific settings or cities. PALS (Psychopathology in Children and Adolescents in Lebanon Study) is the first study to screen a nationally representative sample of children and adolescents for psychiatric disorders and estimate the national prevalence of children and adolescents at risk of having a psychiatric disorder.

METHODS

A nationally representative household sample of 1517 children and adolescents (aged 5 years 0 months to 17 years 11 months) was recruited through a multi-stage stratified proportionate sampling technique between February 2018 and November 2018. Parents and adolescents completed a battery of self-reported scales including the Strengths and Feelings Questionnaire (SDQ), Mood and Feelings Questionnaire (MFQ), Screen for Child Anxiety and Emotional Related Disorders (SCARED), the Peer Relations Questionnaire (PRQ), General Health Questionnaire (GHQ), and Conflict Behavior Questionnaire (CBQ), Child Revised Impact of Events Scale (CRIES), and a demographic/clinical information questionnaire. Logistic regression models were used to examine the correlates of screening positive for psychiatric disorders.

RESULTS

About a third of children and adolescents (32.7%, n = 497) screened positive for at least one psychiatric disorder, of whom only 5% (n = 25) reported ever seeking professional mental health help. Academic performance, having a chronic physical illness, higher parental GHQ scores, and involvement in bullying were associated with a higher odds of screening positive for a psychiatric disorder. Higher family income was negatively associated with screening positive for a psychiatric disorder.

CONCLUSION

This first national study shows a high prevalence of psychiatric symptoms in Lebanese children and adolescents and an alarming treatment gap. School-based primary prevention programs or screening in primary care settings are key for early detection and management of psychiatric symptoms, and prevention of psychiatric disorders.

Participating in Longitudinal Observational Research on Psychiatric Rehabilitation: Quantitative Results From a Patient Perspective Study

BACKGROUND

Longitudinal observational studies play on an important role for evidence-based research on health services and psychiatric rehabilitation. However, information is missing about the reasons, why patients participate in such studies, and how they evaluate their participation experience.

METHODS

Subsequently to their final assessment in a 2-year follow-up study on supported housing for persons with severe mental illness, n = 182 patients answered a short questionnaire on their study participation experience (prior experiences, participation reasons, burden due to study assessments, intention to participate in studies again). Basic respondent characteristics as well as symptom severity (SCL-K9) were also included in the descriptive and analytical statistics.

RESULTS

To help other people and curiosity were cited as the main initial reasons for study participation (>85%). Further motives were significantly associated with demographic and/or clinical variables. For instance, "relieve from boredom" was more frequently reported by men and patients with substance use disorders (compared to mood disorders), and participants 'motive" to talk about illness" was associated with higher symptom severity at study entry. Furthermore, only a small proportion of respondents indicated significant burdens by study participation and about 87% would also participate in future studies.

CONCLUSIONS

The respondents gave an overall positive evaluation regarding their participation experience in an observational study on psychiatric rehabilitation. The results additionally suggest that health and social care professionals should be responsive to the expectations and needs of patients with mental illness regarding participation in research.

Socio-economic resources and adult mental health in Canada: controlling for time-invariant confounders and investigating causal directionality

OBJECTIVE

The aim of this study was to investigate whether family income and education have a causal effect on psychological distress among Canadian adults.

METHODS

We executed fixed-effects regression analyses using data from the Longitudinal and International Study of Adults (LISA). We investigated whether changes in family income and education from wave 2 (2014) to wave 3 (2016) corresponded with changes in psychological distress during this same time period. We also investigated whether changes in these socio-economic resources from wave 1 (2012) to wave 2 (2014) corresponded with lagged changes in psychological distress from wave 2 (2014) to wave 3 (2016). These models controlled for all time-invariant confounders with time-invariant effects, as well as the time-varying factors age, marital status, household size, and employment status.

RESULTS

Obtaining a postsecondary degree corresponded with lagged decreases in psychological distress among women ages 18 to 32 (b = -1.97; 95% CI = -3.53, -0.42) and men over the age of 32 (b = -1.86; 95% CI = -3.57, -0.15). The effect of postsecondary education was stronger when considering adults who stayed married throughout the three waves (b = -2.29; 95% CI = -4.37, -0.21).

CONCLUSION

Completing postsecondary education may have a lagged causal effect on psychological distress, and the life course timing for when postsecondary completion reduces distress is different for women and men.

Biases in health expectancies due to educational differences in survey participation of older Europeans: It's worth weighting for

Health expectancies are widely used by policymakers and scholars to analyse the number of years a person can expect to live in good health. Their calculation requires life tables in combination with prevalence rates of good or bad health from survey data. The structure of typical survey data, however, rarely resembles the education distribution in the general population. Specifically, low-educated individuals are frequently underrepresented in surveys, which is crucial given the strong positive correlation between educational attainment and good health. This is the first study to evaluate if and how health expectancies for 13 European countries are biased by educational differences in survey participation. To this end, calibrated weights that consider the education structure in the 2011 censuses are applied to measures of activity limitation in the Survey of Health, Ageing and Retirement in Europe. The results show that health expectancies at age 50 are substantially biased by an average of 0.3 years when the education distribution in the general population is ignored. For most countries, health expectancies are overestimated; yet remarkably, the measure underestimates health for many Central and Eastern European countries by up to 0.9 years. These findings highlight the need to adjust for distortion in health expectancies, especially when the measure serves as a base for health-related policy targets or policy changes.

Brain morphometry of individuals with schizophrenia with and without antipsychotic medication – The Northern Finland Birth Cohort 1966 Study

Background

In schizophrenia, brain morphometric changes may be associated with antipsychotic medication. Only limited data is available concerning individuals with schizophrenia without antipsychotic medication. We aimed to study the associations of: use versus no use of antipsychotic medication; length of continuous time without antipsychotic medication; cumulative dose of lifetime antipsychotic medication; and type of antipsychotic medication; with brain morphometry in schizophrenia after an average of 10 years of illness.

Methods

Data of 63 individuals with schizophrenia (mean duration of illness 10.4 years) from the Northern Finland Birth Cohort 1966 were gathered by interview and from hospital and outpatient records. Structural MRI data at age 34 years were acquired and grey matter volume maps with voxel-based morphometry were analyzed using FSL tools.

Results

Of the individuals studied, 15 (24%) had taken no antipsychotic medication during the previous year. Individuals with antipsychotic medication had lower total grey matter (TGM) volume compared with non-medicated subjects, although this association was not statistically significant (Cohen's d = –0.51, P = 0.078). Time without antipsychotic medication associated with increased TGM (P = 0.028). Longer time without antipsychotic medication associated with increased regional volume in right precentral gyrus and right middle frontal gyrus. There were no associations between cumulative dose of lifetime antipsychotic medication or type of antipsychotic medication and brain morphometry.

Conclusions

Unlike some previous investigators, we found no association between cumulative dose of lifetime antipsychotic medication and brain morphological changes in this population-based sample. However, longer continuous time without antipsychotic medication preceding the MRI scan associated with increased gray matter volume.

Sex differences in youth with mental health problems in inpatient, outpatient and youth justice settings

BACKGROUND

Approximately 40-70% of justice-involved youth have untreated mental health problems. There is no current research that directly compares the mental health profiles of youth involved in the justice system to that of inpatients and outpatients. The research reported is significant because it directly compares the needs of these population by use of the same suite of standardized assessment tools.

METHODS

The sample consisted of 755 youth aged 16-19 years recruited from youth justice and mental health facilities in Ontario, Canada. Participants completed semi-structured assessment interviews using the interRAI child and youth suite of instruments to assess for internalizing and externalizing concerns as well as exposure to traumatic life events.

RESULTS

Findings indicated that justice-involved youth experienced higher levels of certain types of trauma. Analyses examining sex differences indicated that, controlling for age, males in the youth justice group reported higher cumulative trauma compared to male outpatients but not inpatients. Females in the youth justice group reported experiencing higher cumulative trauma compared to female outpatients and inpatients. In addition, controlling for sex and age, the youth justice group reported lower internalizing symptoms scores than inpatients and outpatients. Finally, males in the youth justice group scored lower than inpatients in externalizing symptoms, whereas females within the youth justice group scored higher in externalizing symptoms compared to inpatients and outpatients.

CONCLUSIONS

Results indicated that youth who are involved with the justice system exhibit significant psychosocial issues that represent complex service needs which require unique interventions in order to be addressed appropriately.

Vitamin D status and correlates of low vitamin D in schizophrenia, other psychoses and non-psychotic depression - The Northern Finland Birth Cohort 1966 study

There is limited knowledge available on the association of vitamin D with psychiatric disorders in young adults. We aimed to investigate vitamin D levels and associating factors in schizophrenia, other psychoses and non-psychotic depression. We studied 4,987 participants from the Northern Finland Birth Cohort 1966 (31 years) with available serum 25-hydroxyvitamin D [25(OH)D] measurements. The final sample was divided into four groups: schizophrenia (n = 40), other psychoses (n = 24), non-psychotic depression (n = 264) and control (n = 4659). To account for the influence of environmental and technical covariates, we generated a vitamin D score variable with correction for season, sex, batch effect and latitude. We further examined how vitamin D levels correlate with anthropometric, lifestyle, socioeconomic and psychiatric measures. Neither serum 25(OH)D concentration nor vitamin D score differed between schizophrenia, other psychoses, non-psychotic depression and control group. The prevalence of vitamin D deficiency was 3.2%, insufficiency 25.5%, and sufficiency 71.3%. Low vitamin D score correlated with regular smoking in the group with schizophrenia. No difference was observed in other psychiatric conditions. We did not find any difference in vitamin D status between schizophrenia, psychoses, non-psychotic depression and control groups, but future studies are warranted to elucidate the role of vitamin D in psychiatric conditions.

Autism prevalence in China is comparable to Western prevalence

Background

Autism prevalence in the West is approximately 1% of school age children. Autism prevalence in China has been reported to be lower than in the West. This is likely due to at least two reasons: (1) most studies in China only included the special school population, overlooking the mainstream school population; and (2) most studies in China have not used contemporary screening and diagnostic methods. To address this, we tested total autism prevalence (mainstream and special schools) in Jilin City, and mainstream school autism prevalence in Jiamusi and Shenzhen cities.

Methods

The study included a three-step process: (1) screening; (2) clinical assessment of 'screen positives' plus controls; and (3) research diagnostic assessment of those meeting clinical threshold for concerns at step 2. Prevalence estimates per 10,000 children aged 6-10 years old were weighted for study design using diagnostic criteria applied at the research assessment stage.

Results

In Jilin City, 77 cases of autism were identified from a total population of 7258, equating to a prevalence of 108 per 10,000 (95% confidence interval (CI) 89, 130). In Shenzhen City: 21,420 children were screened and 35 cases of autism were identified, resulting in a mainstream prevalence of 42 per 10,000 (95% CI 20-89). In Jiamusi City, 16,358 children were screened, with 10 autism cases being identified, with a mainstream prevalence of 19 per 10,000 (95% CI 10-38).

Conclusions

Results from Jilin City, where both mainstream and special school data were available, revealed a similar prevalence of autism in China to the West, at around 1%. Results from Shenzhen and Jiamusi cities, where only mainstream data were available, prevalence is also in line with Western estimates. In all three cities, new cases of autism were identified by the study in mainstream schools, reflecting current under-diagnosis. Non-significant variation across different cities is seen indicating the need to explore potential variation of autism across diverse Chinese regions with large sample sizes to achieve a fully robust national picture.

Cloninger's Temperament Dimensions and Longitudinal Alcohol Use in Early Midlife: A Northern Finland Birth Cohort 1966 Study

BACKGROUND

Temperament is theorized to be an important factor contributing to the development of alcohol use disorder, but longitudinal studies on how temperament is related to alcohol use among general population in midlife are scarce. Our aims were to investigate potentially reciprocal associations between temperament and changes in alcohol use from age 31 to 46 using prospective birth cohort data.

METHOD

Within the Northern Finland Birth Cohort 1966, alcohol use and temperament were studied at ages 31 and 46. Participants (N = 5,274) were classified into moderate users, abstainers and heavy users based on their mean alcohol use (g/d). Additionally, participants were categorized as steady users, reducers, or increasers. Multinomial regression analyses were conducted with Cloninger's Temperament and Character Inventory (TCI) scores as factors influencing alcohol use using moderate and stable users as reference groups. Reciprocity of relations was assessed with cross-lagged structural equation modeling.

RESULTS

Temperament and alcohol use are rather stable in midlife. Novelty seeking (NS) predicted heavy use (OR = 1.4; CI: 1.3 to 1.6 for men, OR = 1.3; CI: 1.1 to 1.5 for women) and increasing use (OR = 1.2; CI: 1.1 to 1.4 for men, OR = 1.1; CI: 1.0 to 1.3 for women), whereas low NS predicted abstaining among women (OR = 0.7; CI: 0.6 to 0.8). High harm avoidance (HA) predicted abstaining (OR = 1.3; CI: 1.1 to 1.5) for men. Low persistence (P) among men predicted both abstaining (OR = 0.9; CI: 0.7 to 0.98) and heavy use (OR = 0.9; CI: 0.8 to 0.98). Among women, low reward dependence (RD) predicted heavy use (OR = 0.8; CI: 0.7 to 0.9). Among TCI scores, only NS predicted increasing use in the cross-lagged models.

CONCLUSIONS

Temperament has an impact on alcohol use in midlife. Of the TCI dimensions, only NS seems to predispose to increased alcohol use and problem use throughout life. Additionally, RD among women and P among men are significant factors from a life-course perspective. Our results did not support Cloninger's theory on type I alcoholism, as HA showed no relation to problematic alcohol use in midlife.

The Representativeness of Participants With Severe Mental Illness in a Psychosocial Clinical Trial

Introduction: Cardiovascular morbidity and mortality are increased in severe mental illnesses (SMI). Trials of psychosocial health interventions to improve physical health in SMI, including in treatment-resistant schizophrenia, have shown some benefit. However, the representativeness of participants in such trials has not been determined. Method: We utilized an anonymised case register to determine if participants in a randomized controlled trial (RCT) of a novel psychosocial health intervention aiming to improve physical health in SMI had similar severity of illness to eligible non-participants. A retrospective database analysis was performed, using Health of the Nation Outcome Scale (HoNOS) data from the sample of patients participating in the IMPaCT (Improving Physical health and reducing substance use in Psychosis) RCT (n = 293) compared to all eligible participants with a psychotic illness (n = 774). Results: The mean total HoNOS score in the eligible comparator population (Mean = 9.09, SD = 5.8, range = 0-30) was significantly greater than that of the IMPaCT RCT participants (Mean = 7.16, SD = 4.7, range = 0-26), (t = 3.810, p = 0.006), as was the degree of overall illness severity and functional impairment, as measured by HoNOS. Conclusion: This study shows for the first time that the patient population participating in an RCT of a lifestyle intervention for those with SMI had a better mental health status at entry to the trial, than the total eligible population, although there was no difference in physical health needs. This has relevance to the applicability of RCTs of lifestyle interventions in service planning and suggests that when people are more unwell, greater effort may be needed to include them in psychosocial interventions. A more careful and focused recruitment approach should be followed to improve the participation of the more severely ill patients in psychosocial interventions in order to enhance the external validity of such studies.

Predictors of Long-Term Change in Adult Cognitive Performance: Systematic Review and Data from the Northern Finland Birth Cohort 1966

OBJECTIVE

Several social life events and challenges have an impact on cognitive development. Our goal was to analyze the predictors of change in cognitive performance in early midlife in a general population sample. Additionally, systematic literature review was performed.

METHOD

The study sample was drawn from the Northern Finland Birth Cohort 1966 at the ages of 34 and 43 years. Primary school performance, sociodemographic factors and body mass index (BMI) were used to predict change in cognitive performance measured by the California Verbal Learning Test, Visual Object Learning Test, and Abstraction Inhibition and Working Memory task. Analyses were weighted by gender and education, and p-values were corrected for multiple comparisons using Benjamini-Hochberg procedure (B-H).

RESULTS

Male gender predicted decrease in episodic memory. Poor school marks of practical subjects, having no children, and increase in BMI were associated with decrease in episodic memory, though non-significantly after B-H. Better school marks, and higher occupational class were associated with preserved performance in visual object learning. Higher vocational education predicted preserved performance in visual object learning test, though non-significantly after B-H. Likewise, having children predicted decreased performance in executive functioning but non-significantly after B-H.

CONCLUSIONS

Adolescent cognitive ability, change in BMI and several sociodemographic factors appear to predict cognitive changes in early midlife. The key advantage of present study is the exploration of possible predictors of change in cognitive performance among general population in the early midlife, a developmental period that has been earlier overlooked.

Longitudinal regional brain volume loss in schizophrenia: Relationship to antipsychotic medication and change in social function

BACKGROUND

Progressive brain volume loss in schizophrenia has been reported in previous studies but its cause and regional distribution remains unclear. We investigated progressive regional brain reductions in schizophrenia and correlations with potential mediators.

METHOD

Participants were drawn from the Northern Finland Birth Cohort 1966. A total of 33 schizophrenia individuals and 71 controls were MRI scanned at baseline (mean age=34.7, SD=0.77) and at follow-up (mean age=43.4, SD=0.44). Regional brain change differences and associations with clinical mediators were examined using FSL voxelwise SIENA.

RESULTS

Schizophrenia cases exhibited greater progressive brain reductions than controls, mainly in the frontal and temporal lobes. The degree of periventricular brain volume reductions were predicted by antipsychotic medication exposure at the fourth ventricular edge and by the number of days in hospital between the scans (a proxy measure of relapse duration) at the thalamic ventricular border. Decline in social and occupational functioning was associated with right supramarginal gyrus reduction.

CONCLUSION

Our findings are consistent with the possibility that antipsychotic medication exposure and time spent in relapse partially explain progressive brain reductions in schizophrenia. However, residual confounding could also account for the findings and caution must be applied before drawing causal inferences from associations demonstrated in observational studies of modest size. Less progressive brain volume loss in schizophrenia may indicate better preserved social and occupational functions.

Neurocognition as a predictor of outcome in schizophrenia in the Northern Finland Birth Cohort 1966

The purpose of this study was to study neurocognitive performance as a predictor of outcomes in midlife schizophrenia. There is a lack of studies with unselected samples and a long follow-up. The study is based on the prospective, unselected population-based Northern Finland Birth Cohort 1966. The study includes 43 individuals with schizophrenia and 73 controls, whose neurocognitive performance was assessed twice, at 34 and 43 years. At both time points we used identical neurocognitive tests to assess verbal and visual memory and executive functions. Our main aim was to analyse neurocognitive performance at 34 years as a predictor of clinical, vocational and global outcomes at 43 years. Additionally, the analysis addressed cross-sectional associations between cognitive performance and clinical, vocational and global measures at 43 years. The assessment of outcomes was performed in the schizophrenia group only. In the longitudinal analysis poorer visual memory predicted poorer vocational outcome and poorer long-term verbal memory predicted poorer global outcome. In the cross-sectional analysis poorer visual memory and lower composite score of neurocognition were associated with poorer global outcome. No individual neurocognitive test or the composite score of these predicted remission. These data indicate that neurocognition, especially memory function, is an important determinant of long-term functional outcome in midlife schizophrenia.

Poor premorbid school performance, but not severity of illness, predicts cognitive decline in schizophrenia in midlife

Neurocognitive dysfunction is common in schizophrenia but its course and determinants remain uncertain. Our aim was to analyse if premorbid school performance and the severity of illness and functioning predict change in cognition in schizophrenia in a general population sample. The sample included cases with schizophrenia spectrum disorder from the Northern Finland Birth Cohort 1966. Data on school marks at the age of 16 years, educational level at the age of 34 years, severity of symptoms and occupational functioning around first episode and after years of illness were gained from national registers, hospital notes and interviews. Change of verbal and visual learning and memory and executive functioning were examined between ages 34 and 43 years. The number of cases varied in analyses from 29 to 41, depending on missing data in particular cognitive tests. Lower school marks at age 16 years and lower education at age 34 years predicted more decline of cognition. Measures of severity of illness or functioning were not associated statistically significantly with change of cognition. Premorbid school performance, but not later course of schizophrenia, related to change of cognition in midlife. Poor premorbid scholastic performance and post-onset cognitive decline may represent related processes as part of an endophenotype of schizophrenia.

Changes in verbal learning and memory in schizophrenia and non-psychotic controls in midlife: A nine-year follow-up in the Northern Finland Birth Cohort study 1966

Findings on longitudinal change of cognitive performance in schizophrenia are extremely variable in the case of verbal learning and memory, and it is still unclear which dimensions of verbal learning and memory exhibit possible deterioration over the long-term. Our aim was to compare the change in verbal learning and memory in individuals with schizophrenia 10-20 years after the illness onset and healthy controls during a nine-year follow-up in a general population sample. Our sample included 41 schizophrenia spectrum subjects and 73 controls from the Northern Finland Birth Cohort study 1966. The California Verbal Learning Test (CVLT) was used to estimate the degree of change in verbal learning and memory during a nine-year follow-up from age 34-years to 43- years. Both cases and controls deteriorated. There was statistically significant decline in two out of 20 CVLT items among cases and in 13 out of 20 CVLT items among controls. With the exception of two variables, the decline in verbal learning and memory over nine years was not significantly larger in cases. We conclude that during midlife verbal learning and memory in schizophrenia mostly declines in a normative fashion with aging at the same rate as the general population.

Twenty Years of Schizophrenia Research in the Northern Finland Birth Cohort 1966: A Systematic Review

Birth cohort designs are useful in studying adult disease trajectories and outcomes, such as schizophrenia. We review the schizophrenia research performed in the Northern Finland Birth Cohort 1966 (NFBC 1966), which includes 10,934 individuals living in Finland at 16 years of age who have been monitored since each mother's mid-pregnancy. By the age of 44, 150 (1.4%) had developed schizophrenia. There are 77 original papers on schizophrenia published from the NFBC 1966. The early studies have found various risk factors for schizophrenia, especially related to pregnancy and perinatal phase. Psychiatric and somatic outcomes were heterogeneous, but relatively poor. Mortality in schizophrenia is high, especially due to suicides. Several early predictors of outcomes have also been found. Individuals with schizophrenia have alterations in brain morphometry and neurocognition, and our latest studies have found that the use of high lifetime doses of antipsychotics associated with these changes. The schizophrenia research in the NFBC 1966 has been especially active for 20 years, the prospective study design and long follow-up enabling several clinically and epidemiologically important findings. When compared to other birth cohorts, the research in the NFBC 1966 has offered also unique findings on course and outcome of schizophrenia.

Lifetime use of antipsychotic medication and its relation to change of verbal learning and memory in midlife schizophrenia - An observational 9-year follow-up study

BACKGROUND

The association between the course of cognition and long-term antipsychotic medication in schizophrenia remains unclear. We analysed the association between cumulative lifetime antipsychotic medication dose and change of verbal learning and memory during a 9-year follow-up.

METHOD

Forty schizophrenia subjects and 73 controls from the Northern Finland Birth Cohort 1966 were assessed by California Verbal Learning Test (CVLT) at the ages of 34 and 43 years. Data on the lifetime antipsychotic doses in chlorpromazine equivalents were collected. The association between antipsychotic dose-years and baseline performance and change in CVLT was analysed, controlling for baseline performance, gender, age of onset and severity of illness.

RESULTS

Higher antipsychotic dose-years by baseline were significantly associated with poorer baseline performance in several dimensions of verbal learning and memory, and with a larger decrease in short-delay free recall during the follow-up (p=0.031). Higher antipsychotic dose-years during the follow-up were associated with a larger decrease of immediate free recall of trials 1-5 during the follow-up (p=0.039). Compared to controls, decline was greater in some CVLT variables among those using high-doses, but not among those using low-doses.

CONCLUSION

This is the first report of an association between cumulative lifetime antipsychotic use and change in cognition in a long-term naturalistic follow-up. The use of high doses of antipsychotics may be associated with a decrease in verbal learning and memory in schizophrenia years after illness onset. The results do not support the view that antipsychotics in general prevent cognitive decline or promote cognitive recovery in schizophrenia.

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.

Associations between brain morphology and outcome in schizophrenia in a general population sample

OBJECTIVE

To analyse associations between brain morphology and longitudinal and cross-sectional measures of outcomes in schizophrenia in a general population sample.

METHODS

The sample was the Northern Finland 1966 Birth Cohort. In 1999-2001, structural brain MRI and measures of clinical and functional outcomes were analysed for 54 individuals with schizophrenia around the age of 34. Sex, total grey matter, duration of illness and the use of antipsychotic medication were used as covariates.

RESULTS

After controlling for multiple covariates, increased density of the left limbic area was associated with less hospitalisations and increased total white matter volume with being in remission. Higher density of left frontal grey matter was associated with not being on a disability pension and higher density of the left frontal lobe and left limbic area were related to better functioning. Higher density of the left limbic area was associated with better longitudinal course of illness.

CONCLUSIONS

This study, based on unselected general population data, long follow-up and an extensive database, confirms findings of previous studies, that morphological abnormalities in several brain structures are associated with outcome. The difference in brain morphology in patients with good and poor outcomes may reflect separable aetiologies and developmental trajectories in schizophrenia.

Association between the duration of untreated psychosis and short- and long-term outcome in schizophrenia within the Northern Finland 1966 Birth Cohort

BACKGROUND

Long duration of untreated psychosis (DUP) may relate to poor outcome in schizophrenia. However, the associations between DUP and outcomes, particularly in later course of illness, remain unclear. Our aim was to explore the associations between DUP and short- and long-term outcomes in schizophrenia.

METHODS

Data was collected for subjects with schizophrenia (n=89) in the population-based Northern Finland 1966 Birth Cohort. DUP was obtained from medical records, and its associations with short- (under 2years) and long-term clinical and social outcomes were assessed extending to 20years after the onset of the illness.

RESULTS

Longer DUP predicted longer length of first hospitalisation and increased the risk of rehospitalisation during the first two years. Longer DUP associated with decreased probability of disability pension, smaller amount of time spent in hospital, and higher proportion of time at work during the first 10years of the follow-up.

CONCLUSIONS

Regarding early outcome, long DUP may be a modest marker and proxy measure of a more severe clinical phenotype. The divergent results of earlier studies and the association between long DUP and better long-term outcome in our study, indicate that the length of DUP does not necessarily predict poor outcome in long-term follow-up. This may also be due to methodical difficulties, e.g. insufficient power and residual confounding linked to long follow-up studies.

External validity of studies on aggressive behavior in patients with schizophrenia: systematic review

STUDIES ON VIOLENCE IN SCHIZOPHRENIA USE TWO DIFFERENT APPROACHES: use of epidemiological data, and clinical studies recording direct patient data after gaining informed consent. With regard to informed consent requiring agreement and cooperation, the question arises as to what extent participants represent patients with schizophrenia and violent behaviour (external validity). We conducted a systematic literature research. In most of the studies, aggression or violence, respectively, were poorly defined. Only 5 (15.2%) studies used a cut-off score on an aggression scale. Only 6 studies (18.2%) reported the number of patients who refused to participate, and 16 (48.5%) reported the number of drop-outs. Only 3 studies (9.1%) reported a systematic comparison of participants and non-participants. We found that data which allow for the assessment of representativeness of the investigated samples are poorly reported. For most studies, doubts regarding external validity seem justified and generalisability is questionable due to possible selection bias.

Does health differ between participants and non-participants in the MRI-HUNT study, a population based neuroimaging study? The Nord-Trøndelag health studies 1984-2009

BACKGROUND

Bias with regard to participation in epidemiological studies can have a large impact on the generalizability of results. Our aim was to investigate the direction and magnitude of potential bias by comparing health-related factors among participants and non-participants in a MRI-study based on HUNT, a large Norwegian health survey.

METHODS

Of 14,033 individuals aged 50-65, who had participated in all three large public health surveys within the Norwegian county of Nord-Trøndelag (HUNT 1, 2 and 3), 1,560 who lived within 45 minutes of travel from the city of Levanger were invited to a MRI study (MRI-HUNT). The sample of participants in MRI-HUNT (n = 1,006) were compared with those who were invited but did not participate (n = 554) and with those who were eligible but not invited (n = 12,473), using univariate analyses and logistic regression analyses adjusting for age and education level.

RESULTS

Self-reported health did not differ between the three groups, but participants had a higher education level and were somewhat younger than the two other groups. In the adjusted multivariate analyses, obesity was consistently less prevalent among participants. Significant differences in blood pressure and cholesterol were also found.

CONCLUSION

This is the first large population-based study comparing participants and non-participants in an MRI study with regard to general health. The groups were not widely different, but participants had a higher level of education, and were less likely to be obese and have hypertension, and were slightly younger than non-participants. The observed differences between participants and non-invited individuals are probably partly explained by the inclusion criterion that participants had to live within 45 minutes of transport to where the MRI examination took place. One will expect that the participants have somewhat less brain morphological changes related to cardiovascular risk factors than the general population. Such consequences underline the crucial importance of evaluation of non-participants in MRI studies.

Verbal learning and memory and their associations with brain morphology and illness course in schizophrenia spectrum psychoses

The California Verbal Learning Test and structural brain imaging were administered to 57 subjects with schizophrenia spectrum disorders and 94 controls in a general population sample. Cases had lower semantic cluster scores. Poorer verbal memory strategies were associated with longer duration of illness and heavier use of antipsychotic medication. After controlling for duration of illness, sex, and total gray matter, poorer verbal memory was associated with lower gray matter volume in the cingulate cortex, juxtapositional lobule, right superior temporal gyrus, and precuneus. After controlling for use of antipsychotic medication, there was an association between higher serial clustering and smaller anterior cingulate gyrus and larger intracalcarine cortex.

Alcohol use and mental distress as predictors of non-response in a general population health survey: the HUNT study

PURPOSE

To investigate to what degree alcohol use and mental distress are associated with non-response in a population-based health study.

METHODS

From 1995 to 1997, 91,488 persons were invited to take part in a health study at Nord-Trøndelag, Norway, and the response rate was 69.2%. Demographics were available for everyone. Survey answers from a previous survey were available for most of the participants and a majority of non-participants. In addition, the survey responses from spouses and children of the invitees were used to predict participation in the aforementioned study. Crude and adjusted ORs for a number of predictors, among these alcohol consumption and mental distress, are reported.

RESULTS

Both heavy drinkers (OR = 1.27) and abstainers (OR = 1.64) had a higher probability of dropping out in comparison to people who usually do not drink. High levels of mental distress (OR = 1.84) also predicted attrition.

CONCLUSION

Alcohol use and mental distress are moderately associated with non-response, though probably not a major cause, as controlling for other variables weakened the associations. Nevertheless, the moderate but clear underrepresentation at the crude level of people with high alcohol consumption, abstainers and people with poor mental health should be taken into consideration when interpreting results from health surveys.

Use of inverse probability weighting to adjust for non-participation in estimating brain volumes in schizophrenia patients

Low participation is a potential source of bias in population-based studies. This article presents use of inverse probability weighting (IPW) in adjusting for non-participation in estimation of brain volumes among subjects with schizophrenia. Altogether 101 schizophrenia subjects and 187 non-psychotic comparison subjects belonging to the Northern Finland 1966 Birth Cohort were invited to participate in a field study during 1999-2001. Volumes of grey matter (GM), white matter (WM) and cerebrospinal fluid (CSF) were compared between the 54 participating schizophrenia subjects and 100 comparison subjects. IPW by illness-related auxiliary variables did not affect the estimated GM and WM mean volumes, but increased the estimated CSF mean volume in schizophrenia subjects. When adjusted for intracranial volume and family history of psychosis, IPW led to smaller estimated GM and WM mean volumes. Especially IPW by a disability pension and a higher amount of hospitalisation due to psychosis had effect on estimated mean brain volumes. The IPW method can be used to improve estimates affected by non-participation by reflecting the true differences in the target population.

Pain complaints as risk factor for mental distress: a three-year follow-up study

The main aim of this study was to investigate the effect of pain complaints at baseline and mental distress at follow-up. We included adolescents from two longitudinal studies of 18/19 years of age with two corresponding cross-sectional baseline studies at age 15/16. A total of 5750 were invited for the baseline study, and we have 3-year follow-up data for 3316 (57.8% follow-up rate). All information is based on self-report. The questions of pain are asking for severe pain the past year. Mental distress is measured by Hopkins Symptoms Check List (HSCL-10). Number of pain sites increased among girls and decreased among boys from baseline to follow-up. There was a cross-sectional dose-response association between number of pain sites and mental distress at both time points. Also, in the follow-up study, there was dose-response relationship between numbers of pain sites at baseline and mental distress at follow-up even after controlling for possible confounding factors. We found no effect of mental distress at baseline on pain reports at follow-up. There is a strong association between pain at 15/16 years and mental distress at 18/19 years of age. Clinicians should therefore take pain complaints among adolescents seriously and be aware of comorbid and later development of mental health problems.

Characteristics of subjects with schizophrenia spectrum disorder with and without antipsychotic medication - a 10-year follow-up of the Northern Finland 1966 Birth Cohort study

OBJECTIVE

To estimate the prevalence of non-medicated subjects having schizophrenia spectrum disorder and to study how they differ from medicated subjects in terms of sociodemographic and illness-related variables. We also aim to find the predictors for successful antipsychotic withdrawal.

METHODS

Data of 70 subjects with schizophrenic psychoses (mean duration of illness 10.4 years) from the Northern Finland 1966 Birth Cohort were gathered by interview at the age of 34 and from hospital records. The stability of remission was assessed by comparing hospitalization rates between non-medicated and medicated subjects over an 8.7-year additional follow-up period.

RESULTS

Twenty-four (34%) subjects were currently not receiving medication. They were more often males, less often on a disability pension, more often in remission, and had better clinical outcomes. Relapses during the follow-up were equally frequent between non-medicated and medicated subjects (47% vs. 56%). Not having been hospitalised during previous 5 years before the interview predicted long-term successful antipsychotic withdrawal without relapse.

CONCLUSIONS

Despite a lack of precise predictors, there might be subgroup of schizophrenia spectrum subjects who do not need permanent antipsychotic medication, and a fewer previous psychiatric treatments may indicate such a subgroup.

Participation bias among suicidal adults in a randomized controlled trial

Although individuals who attempt suicide have poor compliance rates with treatment recommendations, the nature and degree of participation bias in clinical treatment research among these individuals is virtually unknown. The purpose of this study was to examine participation bias by comparing the demographic and diagnostic characteristics of adult suicide attempters who participated in a randomized controlled trial to a sample of nonparticipants. Results indicated that males and individuals with a diagnosis of substance abuse or dependence were more likely to be participants in the randomized controlled trial. The implications of these findings for suicide intervention research are discussed.

Association between duration of untreated psychosis and brain morphology in schizophrenia within the Northern Finland 1966 Birth Cohort

BACKGROUND

Duration of untreated psychosis (DUP) has been linked with poor prognosis and changes in the brain structure in schizophrenia at least at the beginning of the disease, but it is still unknown whether DUP relates to brain morphometry in the longer term. Our aim was to analyze the relation between DUP and the brain structure in schizophrenia in the general population, after several years of illness.

METHODS

Brains of subjects with psychosis from the Northern Finland 1966 Birth Cohort (NFBC 1966) were scanned with MRI during 1999-2001 after an 11-year follow-up. DUP was assessed from medical records and regressed against global and local tissue density measurements. The brain morphometric and the DUP information were available for 46 subjects with DSM-III-R schizophrenia.

RESULTS

The DUP did not correlate with volumes of the total gray or white matter or the cerebrospinal fluid. The length of DUP associated positively with reduced densities of the right limbic area and the right hippocampus.

CONCLUSIONS

Long DUP was slightly associated with reductions of gray matter densities in the limbic area and especially the hippocampus after several years follow-up, supporting the hypothesis that, compared to short DUP, long DUP might be a marker of different disease trajectories including subtle morphometric changes.

Morphometric brain abnormalities in schizophrenia in a population-based sample: relationship to duration of illness

Biased recruitment and sample selection may cause variability in neuroimaging studies. Epidemiologically principled population-based magnetic resonance imaging (MRI) studies of schizophrenia are very rare. We gathered structural MRI data on 154 subjects from the Northern Finland 1966 Birth Cohort, aged 33-35 (100 controls, 54 schizophrenia patients). Regional differences in density of gray matter, white matter, and cerebrospinal fluid (CSF) were identified between groups using nonparametric statistical analysis, and the relationship of the regional differences to duration of illness was explored. Gray matter reductions were found bilaterally in the cerebellum, thalamus, basal ganglia, middle frontal gyrus, inferior frontal gyrus, precentral gyrus, insula, superior temporal gyrus, fusiform gyrus, parahippocampal gyrus, cuneus, and lingual gyrus; in the left posterior cingulate, superior frontal gyrus, transverse temporal gyrus, and precuneus; and in the right postcentral gyrus. Gray matter excesses were observed bilaterally in the basal ganglia, anterior cingulate, and medial orbitofrontal cortices. There were white matter deficits in an extensive network including inter- and intrahemispheric tracts bilaterally in the frontal, temporal, parietal, and occipital lobes, subcortical structures, cerebellum, and brain stem. CSF excesses were found bilaterally in the lateral ventricles, third ventricle, interhemispheric, and left Sylvian fissure. We replicated the previous findings of structural brain abnormalities in schizophrenia on a general population level. Gray and white matter deficits were associated with duration of illness suggesting either that developmental brain deficits relate to an earlier age of onset or that brain abnormalities in schizophrenia are progressive in nature.

Negative symptoms and their predictors in schizophrenia within the Northern Finland 1966 Birth Cohort

Negative symptoms are a major scientific and therapeutic challenge in schizophrenia. We report the occurrence and predicting factors of negative symptoms at two time points in a population-based birth cohort. The negative symptoms of subjects with Diagnostic and Statistical Manual of Mental Disorders, third edition, revised (DSM-III-R) schizophrenia (n=46) were scrutinized at the first hospitalization due to psychosis from hospital records (first-episode psychosis) and with an interview approximately 10 years later (follow-up phase). Developmental and sociodemographic predictors of negative symptoms in first-episode psychosis, follow-up phase and at both measurements were analysed. Forty-one percent of the subjects had negative symptoms at the first episode, 39% in the follow-up phase, and in 24% the symptoms persisted at both measurements. Smoking at the age of 14, definite psychosocial stressor and not being married predicted more negative symptoms whereas good school performance and using less alcohol at age 14 predicted fewer persistent negative symptoms. These findings are new. However, we were not able to identify any major premorbid phenotype or endophenotype predicting negative symptoms which support the view that negative symptoms might mainly be a specific part of the illness.

Agreement between self-reported and pharmacy data on medication use in the Northern Finland 1966 Birth Cohort

OBJECTIVE

To compare self-reported (SR) medication use and pharmacy data for major psychoactive medications and three classes of medications used for different indications, and to determine the socio-economic factors associated with the congruence.

METHODS

Postal questionnaire data collected in 1997 were compared with the register of the Social Insurance Institution of Finland on the reimbursed prescriptions purchased during 1997. Altogether 7625 subjects were included in this study. Drugs were categorized according to the Anatomical Therapeutic Chemical (ATC) system.

RESULTS

Kappa values were 0.77, 0.68, 0.84, 0.92 and 0.55 for antipsychotics, antidepressants, antiepileptics, antidiabetics and beta-blocking agents, respectively. Prevalence-adjusted and bias-adjusted kappa values were almost perfect (0.98-1.00). Reliability of antipsychotics use was better for married subjects than for those who were not married; and of antidepressants use for highly educated and married subjects than for those who were less educated and were not married. Altogether 414 (5.4%) responders and 285 (7.1%) non-responders had used at least one of the selected medications.

CONCLUSION

Agreement between the SR and pharmacy data was moderate for psychoactive medication use. Even though data collected by postal questionnaire may underestimate the prevalence of medication use due to non-participation it can be assumed accurate enough for study purposes.

Do mental health and behavioural problems of early menarche persist into late adolescence? A three year follow-up study among adolescent girls in Oslo, Norway

Early menarche has been linked to mental health and behavioural problems in several studies. Most of these studies are cross-sectional, the data gathered during puberty. Thus, there is a lack of research on the long-term effect of early menarche on mental health. The main aim of this study was to explore whether the differences in mental health problems between girls with early and late menarche persist into late adolescence. The data consisted of responses from a large school-based survey of all 10th grade girls (15 years of age) in Oslo, Norway. Of the 1860 participating girls in the 2001 survey, 1377 were included in the three year follow-up study in 2004, giving a response rate of 74%. Mental distress was measured with the Hopkins Symptom Check list 10-version. Additional items assessed were number of sexual partners, weight and body satisfaction. All information was self-reported, including age of menarche. We found a clear gradient in the cross sectional analyses at baseline of higher odds for mental distress at lower age of menarche even after adjustment for socio demographic and other factors. In the analysis of the follow-up data there was no statistically significant difference in mental distress across age of menarche, even though the differences in body and weight satisfaction and average body mass index remained at the same level between baseline and follow-up. We therefore conclude that the effects of age of menarche on mental health problems are a transitory problem during puberty.

Is there an "unhealthy volunteer effect" in mental health outpatient research?

The ability to generalize clinical research findings depends on whether patients who agree to participate in studies have more or less severe illness than applicable clinical populations. We analyzed data from standardized clinical interviews given to patients seeking outpatient mental health treatment to determine whether there were differences between those who were willing to consider research participation and those who were not. Univariate and multivariable logistic regression analyses were conducted using measures of demographics, symptom and illness severity, and social environment. Factors associated with increased likelihood of willingness to consider research participation in the multivariable analysis were: moderate to severe depressive symptoms (OR=1.26; 95%CI: 1.07,1.48), hazardous drinking (OR=1.44, 95%CI: 1.19,1.75), having 1-15 days of partial disability due to mental illness (OR=1.19, 95%CI: 1.00,1.42), having any mental health outpatient visits in the last 2 years (OR=1.24; 95%CI: 1.09,1.42), and having a family member with mental illness (OR=1.57, 95%CI: 1.37,1.79). These results suggest an "unhealthy volunteer effect"-that patients interested in volunteering for outpatient mental health research have more severe illness, longer treatment history, and possibly greater genetic loading for mental illness than those not included in research trials. The possibility of such an effect should be considered when conducting and interpreting clinical trials.

The prevalence of autism spectrum disorders: impact of diagnostic instrument and non-response bias

BACKGROUND

A large part of the variability in rates of autism spectrum disorders (ASD) across studies is non-aetiologic, and can be explained by differences in diagnostic criteria, case-finding method, and other issues of study design.

AIM

To investigate the effects on ASD prevalence of two methodological issues; non-response bias and case ascertainment. We compared the findings of using a semi-structured parent interview versus in-depth clinical assessment, including an ASD specific interview. We further explored whether including information on non-responders affected the ASD prevalence estimate.

METHOD

A total population of 7- to 9-year olds (N = 9,430) was screened for ASD with the autism spectrum screening questionnaire (ASSQ) in the Bergen Child Study (BCS). Children scoring above the 98th percentile on parent and/or teacher ASSQ were invited to participate in the second and subsequently in the third phase of the BCS where they were assessed for ASD using the Development and Well-Being Assessment (DAWBA), and the Diagnostic Interview for Social and Communication disorders (DISCO), respectively.

RESULTS

Clinical assessment using DISCO confirmed all DAWBA ASD cases, but also diagnosed additional cases. DISCO-generated minimum prevalence for ASD was 0.21%, whereas estimated prevalence was 0.72%, increasing to 0.87% when adjusting for non-responders. The DAWBA estimate for the same population was 0.44%.

CONCLUSION

Large variances in prevalence rates across studies can be explained by methodological differences. Both information about assessment method and non-response are crucial when interpreting prevalence rates of ASD.

Is the relationship between smoking and mental health influenced by other unhealthy lifestyle factors? Results from a 3-year follow-up study among adolescents in Oslo, Norway

PURPOSE

Several studies have confirmed that smoking is a risk factor for depression in adolescence. These studies have not controlled for other lifestyle factors. The aim of this longitudinal study was to assess the relationship between smoking and depressive symptoms, controlling for other lifestyle factors.

METHODS

This school-based longitudinal self-report survey was conducted among 15- and 18-year-old students in Oslo, Norway. From a baseline cohort of 3811 students, 2489 (65%) participants were followed up after 3 years and completed questionnaires at baseline and follow-up. Mental distress was assessed with Hopkins Symptom Checklist, version 10.

RESULTS

There was a statistically significant association between daily smoking at age 15 and mental distress at age 18 for girls, but not for boys (odds ratio [OR]=2.0 [1.5-2.8] and 1.3 [0.7-2.4], respectively). In girls, the association remained statistically significant even after adjustment for sociodemographic variables and several lifestyle factors. In an analysis of 15-years-old "never smokers," a statistically significant association was found between smoking and mental distress for both genders at age 18. Mentally distressed adolescents at age 15 did not show a higher proportion of smoking at age 18 compared with those not distressed.

CONCLUSIONS

In addition to supporting earlier findings that smoking seems to be causally related to depressive symptoms among adolescent girls, the contribution of this study is that this association only to some extent is confounded by other unhealthy lifestyle habits.

Volumes of brain, grey and white matter and cerebrospinal fluid in schizophrenia in the Northern Finland 1966 Birth Cohort: an epidemiological approach to analysis

Magnetic resonance imaging (MRI) studies in schizophrenia have seldom involved a general population birth cohort or other epidemiological samples. We studied the Northern Finland 1966 Birth Cohort and identified all people with psychotic disorders. Along with an unaffected age-matched control sample (n = 100) from the cohort, 54 subjects with schizophrenia underwent MRI brain scan at age 33-35 years from which we defined volumes of whole brain, grey and white matter and intracranial cerebrospinal fluid (CSF). Whole brain, grey and white matter volumes were 2-3% smaller in the schizophrenia subjects, who showed a 7% increase in CSF volume. These volume changes were independent of the effects of gender, family history of psychosis, perinatal risks or age at onset of illness. Moreover, there was no evidence that the effects were due to particular subgroups of cases having very low or high values. Rather, there were linear trends in the associations between whole brain and grey matter volume measures and schizophrenia. Our study replicates the previous findings of brain volume differences in schizophrenia on a general population level.

The influence of temperament on symptoms and functional outcome in people with psychosis in the Northern Finland 1966 Birth Cohort

OBJECTIVE

To describe symptom expression and functional outcome in psychotic disorders in relation with temperament traits assessed with the Temperament and Character Inventory (TCI) in a population-based sample.

METHOD

As part of the 31-year follow-up survey of the Northern Finland 1966 Birth Cohort, TCI temperament items were filled in by 4349 members of the cohort. In individuals with psychotic disorders, also positive and negative symptoms and outcome variables were assessed in a 35-year follow-up. Information of TCI and outcomes were available for altogether 41 individuals with psychosis.

RESULT

Reward dependence (RD) (rho=-0.45) and Persistence (P) (rho=-0.52) were significantly correlated with Positive and Negative Syndrome Scale (PANSS) negative symptoms. Higher P scores predicted higher social and occupational functioning (as measured by Social and Occupational Functioning Assessment Scale [SOFAS]), and higher Harm avoidance (HA) predicted a higher likelihood of being on a disability pension.

CONCLUSION

Results indicate that understanding of personality dimensions support better understanding of outcome and symptom expressions in psychotic disorders.

Are there developmentally limited forms of bipolar disorder?

Bipolar spectrum disorders have traditionally been thought to be chronic in course. However, recent epidemiologic research suggests that there may be developmentally limited forms of bipolar disorder. Two large, nationally representative studies reveal a strikingly high prevalence of bipolar disorders in emerging adulthood (5.5%-6.2% among 18-24-year-olds) that appear to resolve substantially during the latter half of the 3rd decade of life (3.1%-3.4% among 25-29-year-olds). Although ascertainment bias due to early mortality, institutionalization, incarceration, and homelessness may account for some of this reduction, the prevalence distribution suggests a high incidence in late adolescence and emerging adulthood that appears to resolve spontaneously in most cases. There were very few differences across age groups in symptom endorsement and comorbid diagnoses, suggesting that 18-24-year-olds that meet criteria for bipolar diagnoses experience clinically significant impairment and associated consequences of the disorder. More fine-grained longitudinal research is needed to determine whether developmentally limited forms of bipolar disorder exist and, if so, what markers might distinguish these forms of the disorder from more chronic courses.