The schizophrenia diagnosis in Denmark. A register-based investigation

Patients, Danish citizens only, admitted for the first time in 1972 to a Danish psychiatric institution were selected from the national psychiatric register. To be included, the probands had to have been diagnosed as schizophrenics at least once in the period from their first admission to 1 September 1983. The study comprised 370 males and 217 females with a total of 5,298 admissions. The probands' diagnostic pattern during the above period was investigated. More males (51.9%) than females (39.2%) (P less than 0.01) were diagnosed as schizophrenics during their first admission. The average period from a patient's first contact with an in-patient institution until schizophrenia was diagnosed for the first time was 2.2 years for females and 1.7 years for males (P less than 0.05). Personality disorders, reactive psychoses, and not classifiable psychoses were the most frequent diagnoses prior to the first schizophrenia diagnosis. The diagnostic stability of schizophrenia as main diagnosis, after its first application, was 73.6% for males among a total of 2,539 admissions and 71.2% for females among 1,141 admissions. There was greater correlation between the latest and former diagnoses than between the first and subsequent diagnoses. This is valid both when distinguishing between schizophrenia and non-schizophrenia and when focusing on schizophrenia subtypes. The results are discussed, particularly the problem concerning the selection of representative cohorts for schizophrenia research projects.     

Sex difference in age at onset of schizophrenia: discrepant findings from India

Consecutive male (n=100) and female (n= 100) DSM-IV schizophrenics newly registered for treatment in a large psychiatric hospital were examined with regard to age at onset of the first psychotic symptom. Age at onset of the first psychotic symptom did not differ between the sexes regardless of whether schizophrenia was diagnosed by DSM-IV or by several alternative systems. Age at onset defined by other criteria, namely age at first contact with a physician, and age at first admission for psychiatric care, also did not show any differences between the sexes. Survival analysis of subjects having a documented date of birth revealed a female preponderance at younger ages. A higher positive symptom score predicted older age at onset of the first psychotic symptom in the total sample. These findings call into question the universality of the traditional view of a younger age at onset of schizophrenia among males. Tentative neurodevelopmental and cultural explanations are presented to explain why there is no sex difference in age at onset of schizophrenia in India.     

Psychiatric morbidity in disintegrative psychosis and infantile autism: A long-term follow-up study.

In order to study the validity of disintegrative psychosis (DP), the authors compared 13 patients given this diagnosis in childhood with a control group of 39 patients with infantile autism (IA) matched for sex, age, IQ and social class on measures of psychiatric morbidity. Almost the same proportion of the two groups had been admitted to a psychiatric hospital during a 22-year follow-up period. However, there was a slight tendency (statistically nonsignificant) for the DP group to utilize the psychiatric health care system more frequently than the IA group. They had more admissions and stayed longer in hospital than patients with IA suggesting that they had more psychiatric symptoms than the IA group. The original IA diagnoses were confirmed fairly consistently during the follow-up period, while the DP group was given more heterogenous diagnoses. No diagnosis of schizophrenia was made in either group.     

Parental age and risk of schizophrenia: a case-control study

BACKGROUND: Advanced paternal age has been suggested as a possible risk factor for schizophrenia. It is not known whether this is explained by known risk factors for schizophrenia, including sibship characteristics, death of a parent before first hospital admission, season and place of birth, and family history of psychiatric illness, or by socioeconomic factors. We investigated the risk of schizophrenia associated with parental age, adjusting for known risk factors for schizophrenia, including family psychiatric history, and controlling for socioeconomic and demographic factors. METHODS: We performed a national population, nested, case-control study based on Danish longitudinal register data. The sample included 7704 patients with an ICD-8 or ICD-10 diagnosis of schizophrenia admitted to a psychiatric facility between 1981 and 1998 in Denmark, and 192 590 individually time-, age-, and sex-matched population controls, their parents, and siblings. The risk of schizophrenia associated with increasing parental age was investigated using conditional logistic regression and controlling for family socioeconomic and demographic factors and family psychiatric history. RESULTS: Advanced paternal and maternal age was associated with increased risk of schizophrenia in univariate analyses. Controlling for socioeconomic factors and family psychiatric history, increased risk of schizophrenia was identified in those with a paternal age of 50 years or older. Sex-specific analyses revealed that the risk of schizophrenia was increased for males with fathers 55 years or older (incidence rate ratio [IRR], 2.10; 95% confidence interval [CI], 1.35-3.28); for females, the risk associated with paternal age was substantial for fathers aged 50 to 54 years (IRR, 2.22; 95% CI, 1.44-3.44) and 55 years or older (IRR, 3.53; 95% CI, 1.82-6.83). CONCLUSION: Increased risk of schizophrenia was associated with advanced paternal age, particularly in females, lending support to the theory that de novo mutations, possibly X-linked, associated with increased parental age might be responsible for some cases of schizophrenia.     

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

Background: The diagnosis of schizophrenia by clinicians is not always accurate in terms of operational diagnostic criteria despite the fact that these diagnoses form the basis of case registers and routine statistics. This poses a challenge to psychiatric research. We studied the reasons for diagnostic discordance between clinicians and researchers. Methods: The Northern Finland 1966 Birth Cohort (n = 11,017) was followed from mid-gestation to the end of the 31st year. Psychiatric outcome was ascertained through linkage to the national hospital discharge register containing clinical diagnoses made by the attending physician. The hospital notes of all subjects admitted to hospital during the period 1982–1997 due to psychiatric disorder were reviewed and 475 research, operational DSM-III-R diagnoses were formulated. Results: Ninety-six cases met operational criteria for schizophrenia. Fifty-five (57 %) had concordant diagnoses: both the clinical and research diagnoses were schizophrenia. Forty-one (43 %) had discordant diagnoses: the clinical diagnosis was other than schizophrenia (mainly schizophreniform or other psychosis). Discordant cases were more likely to be older at onset, experience a shorter treatment duration, fewer treatment episodes, and to have a comorbid diagnosis mental retardation. Conclusions: Clinicians do not make the diagnosis of schizophrenia as often as the application of operational criteria would suggest they should. The discordance between clinical diagnosis and the research, operational diagnosis is especially likely in cases having late onset and few contacts to psychiatric hospital. Accepted: 12 December 2002 Correspondence to Kristiina Moilanen, MD     

Change of diagnosis in schizophrenia and first-rank symptoms: An eight-year follow-up

Fifty-seven patients diagnosed as schizophrenic at the inception hospital admission, because they had Schneider's first-rank symptoms, were investigated 8 years for change of diagnosis. The average duration of their psychiatric contact after the admission was 5 years. During this period 88% still had a diagnosis of schizophrenia, but seven patients had been given other diagnoses. Change of diagnosis was significantly associated with “voices discussing” when it was the only first-rank symptom. The question of whether “voices discussing” should be included in the canon of Schneiderian first-rank symptoms is discussed.     

Older criminals: a descriptive study of psychiatrically examined offenders in Sweden

OBJECTIVE: We retrospectively examined psychiatric diagnoses of older offenders referred by court for psychiatric assessment in Sweden, and compared them with younger offenders. METHOD: In Sweden, structured court-ordered forensic psychiatric evaluations are undertaken by a forensic psychiatric team. Data on age, sex, citizenship, psychiatric diagnoses, offences, and legal insanity declarations were obtained for the years 1988-2000 (n = 7297). RESULTS: There were 210 forensic psychiatric evaluations in those aged 60 and over. 7% had a diagnosis of dementia, 32% psychotic illness, 8% depressive or anxiety disorder, 15% substance abuse or dependence, and 20% personality disorder. Older offenders were significantly less likely to be diagnosed with schizophrenia or a personality disorder, and more likely to have dementia or an affective psychosis compared to younger ones. Logistic regression analyses suggested that of the studied factors, the ones most typical of older offenders were a diagnosis of dementia and being charged with a sexual offence. CONCLUSION: There appear to be important differences in psychiatric morbidity between older offenders and younger ones who come into contact with forensic psychiatric services. This research may assist in the planning of forensic and therapeutic services for the increasing number of older adults passing through the criminal justice system.     

Adult schizophrenia following prenatal exposure to an influenza epidemic

In the context of a Finnish birth cohort, we tested the hypothesis that viral infection during the latter two thirds of fetal development would increase the risk of adult schizophrenic outcome. Psychiatric hospital diagnoses were recorded for all individuals in greater Helsinki who were fetuses during the 1957 type A2 influenza epidemic. Those exposed to the viral epidemic during their second trimester of fetal development were at elevated risk of being admitted to a psychiatric hospital with a diagnosis of schizophrenia. This was true for both males and females and independently in several psychiatric hospitals. The second-trimester effect was seen in the elevated proportion of schizophrenics among those admitted to a psychiatric hospital and also in higher rates of schizophrenia per 1000 live births in the city of Helsinki. The study has several limitations: (1) We have no direct evidence that the subjects actually suffered a viral infection. (2) The psychiatric data were obtained only for subjects up to the age of 26 years, 56 days. (3) The findings are based on hospital diagnoses. (4) The determination of stage of gestation at time of exposure to the epidemic is based on date of birth. The viral infection might have occurred outside the official epidemic window; the infant may have had a preterm or postterm delivery. These sources of error, however, should not serve to enhance the findings. The observed viral effect is interpreted as being one of many potential perturbations of gestation. We suggest that it is less the type than the timing of the disturbance during fetal neural development that is critical in determining risk for schizophrenia.     

The temporal relationship between schizophrenia and crime

Background Little is known about the temporal relationship between illness onset and the possible beginning of a criminal career among people with schizophrenia, even though criminality, especially violent criminality, has been shown to be more common among people with schizophrenia than among people in general. Aim: The aim of this study was to analyse the temporal relationship between registered crime and contact to the psychiatric hospital system. Method: This is a register-based study merging data on the psychiatric career with criminal records. Results: Among the males with schizophrenia, 37% started a criminal career and 13% had committed first violent crime before first contact with the psychiatric hospital system. Conclusion: The criminality committed before first contact to the psychiatric hospital system is substantial, especially among males with schizophrenia. Accepted: 22 February 2003 Correspondence to Runa Munkner, MD     

Discharge curve among psychiatric patients after admission and risk factors associated with long stay based on "patient survey"]

The "Reform Vision of Mental Health Services" (2004) announced the basic policy for the transition from hospital based to community based care, and set up numerical objectives, such as the average proportion remaining hospitalized in the first year after admission and the incidence rate of discharge among psychiatric patients hospitalized for more than one year. Using data from the "Patient Survey" performed in 2002 by the Ministry of Health, Labour and Welfare, we estimated discharge curves for each mental disorder during the first year after admission and assessed the effects of variables, i.e., diagnosis, sex, age, hospital type, and residential area, on remaining hospitalized after one year from admission and the incidence rate of discharge among psychiatric patients hospitalized for more than one year. The estimated number of discharged psychiatric patients was 27,974 in September, 2002, and 86% of them were discharged less than one year after admission. The incidence rate of discharge (per 100 person-year) in the first year was 314.8, but the rate after the second year sharply decreased to 19.9. Patients with dementia, mental retardation, and schizophrenia tended to stay for a long period in hospital, and proportions remaining hospitalized after one year from admission were 27.0%, 16.4%, and 14.6% respectively. Based on multivariate analysis using the weighted Poisson regression model, risk factors associated with an increased chance of remaining hospitalized after the first year included a long length of continuous hospitalization, diagnoses of dementia, mental retardation, and schizophrenia, male, older age, and being in a mental hospital. On the other hand, as to the incidence rate of discharge after one year, a long length of continuous hospitalization and being in a mental hospital were related with a long stay, but other variables were slightly different. Being female, patients aged 45-54 years old, and diagnoses of epilepsy and schizophrenia were associated with a long stay. These results clarify the present situation of discharge among psychiatric inpatients and indicate the important variables associated with discharge to prevent new long hospital-stay cases in Japan.     

Neurobehavioral deficits at adolescence in children at risk for schizophrenia: The Jerusalem Infant Development Study.

BACKGROUND: The Jerusalem Infant Development Study is a prospective investigation comparing offspring of schizophrenic parents with offspring of parents who have no mental disorder or have nonschizophrenic mental disorders. During infancy and school age, a subgroup of offspring of schizophrenic parents showed global neurobehavioral deficits that were hypothesized to be indicators of vulnerability to schizophrenia. The purposes of the present investigation were to determine if neurobehavioral deficits were present in the offspring of schizophrenics at adolescence, to examine their stability over time, and to explore their relation to concurrent mental adjustment. METHODS: Sixty-five Israeli adolescents were assessed on a battery of neurologic and neuropsychological assessments. They were also administered psychiatric interviews from which best-estimate DSM-III-R diagnoses and scores of global adjustment were derived. RESULTS: Adolescents with poor neurobehavioral functioning were identified from composites of motor and cognitive-attentional variables. A disproportionate number of offspring of schizophrenic parents (42%; 10/24), and especially male offspring of schizophrenic parents (73%; 8/11), showed poor neurobehavioral functioning relative to offspring of nonschizophrenic parents (22%; 9/41). Adolescent offspring of schizophrenics with poor neurobehavioral functioning had been poorly functioning at earlier ages and had poor psychiatric adjustment at adolescence. All 4 offspring of schizophrenics receiving schizophrenia spectrum diagnoses by adolescence showed a pattern of poor neurobehavioral functioning across developmental periods. CONCLUSIONS: Results are consistent with the hypothesis that individuals at genetic risk for schizophrenia may display lifelong neurobehavioral signs that are indicators of vulnerability to schizophrenia and that are associated with psychiatric adjustment generally and schizophrenic spectrum disorder specifically.     

Does racial bias influence psychiatric diagnoses assigned at first hospitalization?

BACKGROUND: Research on racial bias in psychiatric diagnosis has largely been limited to studies of admission diagnoses assigned to chronically ill patients. This study tests whether racial bias influences diagnoses assigned to patients at discharge from their first psychiatric hospitalization. METHODS: In a county-wide sample of patients with psychosis, hospital diagnoses were compared with research diagnoses formulated using structured interviews and strict adherence to DSM-III-R. Symptom patterns were also examined. RESULTS: Racial differences were observed in the distribution of both hospital and research diagnoses. Using research diagnoses as the gold standard, the sensitivities and specificities of hospital diagnoses were similar by race (for blacks the sensitivity and specificity of schizophrenia was 0.33 and 0.91, and for whites, 0.43 and 0.89). The only suggestion of possible bias was that more blacks were discharged without a definitive diagnosis (38.7% of blacks vs. 26.3% of whites, chi(2) = 5.80, df = 1, p = 0.02). CONCLUSIONS: We did not observe the expected racial bias in the assignment of diagnoses of schizophrenia and affective disorders. While there was evidence that hospital clinicians had more difficulty diagnosing black patients, the low concordance between hospital and research diagnoses for both black and white patients demonstrates the need to better understand the clinical diagnostic process for all patients with psychotic disorders at their first hospitalization.     

Incipient offending among schizophrenia patients after first contact to the psychiatric hospital system.

The study examines how age, sex and substance use disorder are associated with the risk of committing a criminal offence. The study explicitly examines the risk after the first contact to the psychiatric hospital system and after the diagnosis of schizophrenia for those with no previous criminal record; the association between previous non-violent criminality and later violent criminality is also analysed. The study sample comprised 4619 individuals ever diagnosed with schizophrenia. All solved offences were accessible. Data were analysed using Cox's regression. Schizophrenic men had twice the risk of schizophrenic women of committing both violent and non-violent offences. A registered substance use disorder increased the risk 1.9- to 3.7-fold, depending on the starting point for the analyses, while increasing age on first contact or when diagnosed with schizophrenia diminished the risk. Previous non-violent criminality increased the risk for later violent criminality 2.5- to 2.7-fold, depending on the starting point for the analyses. The results suggest that the psychiatric treatment system can play an active role in preventing criminality among individuals with schizophrenia. The preventive measures should be based on a thorough assessment including criminal history at intake and alertness toward young psychotic men with substance use disorders and especially if they also have a criminal history.     

The association between comorbid psychiatric diagnoses and hospitalization-related factors among individuals with schizophrenia

BackgroundThough schizophrenia is associated with substantial psychiatric comorbidity, data pertaining to multiple comorbid psychiatric disorders among individuals with schizophrenia is missing. Furthermore, despite abundant research indicating that the course of schizophrenia is characterized by relapses, often leading to psychiatric emergency room visits and consequent hospitalizations, data regarding the association between different comorbid psychiatric diagnoses among schizophrenia patients, and these hospitalization-related factors is lacking. The aim of this study was to describe the number and types of comorbid psychiatric diagnoses of inpatients diagnosed with schizophrenia, and to explore whether these are associated with hospitalization-related factors.MethodsRegistry data from the years 1997–2017 was analyzed from a large psychiatric hospital database. We compared the annual mean number of psychiatric emergency room visits and hospitalizations, as well as mean length of hospitalizations, among individuals with schizophrenia and no additional psychiatric diagnosis, to those with one or more comorbid psychiatric diagnoses. Furthermore, we compared these hospitalization-related based on the different types of the comorbid diagnoses.ResultsAmong inpatient individuals with schizophrenia, the greater the number of comorbid psychiatric diagnoses, the higher the increase in number of emergency room visits and hospitalizations, as well as in the mean length of hospitalizations. Furthermore, all comorbid psychiatric disorders explored were found to be associated with an increase in the mentioned hospital-related factors. Such diagnoses include substance use disorders, bipolar, personality and depressive disorders, which were the most common disorders associated with schizophrenia.ConclusionsComorbid psychiatric disorders among inpatients with schizophrenia are associated with greater utilization of hospital-related services. These comorbid disorders should be addressed in the assessment and treatment of patients suffering from schizophrenia.     

Why has the incidence of schizophrenia in Danish psychiatric institutions decreased since 1970?

From The Danish Psychiatric Register five cohorts of all first-admitted patients to Danish psychiatric institutions from the years 1970, 1973, 1976, 1979, and 1980 have been followed, and trends in age-standardized rates of schizophrenia investigated. The first-admission rates have decreased in both sexes, significantly in males. In addition, the cumulated schizophrenia rates for the cohorts, including those of patients diagnosed as schizophrenics only at a later admission within periods of 2 and 5 years, decreased. This decrease is significant at 2 years of observation in both sexes and at 5 years in females. The decreasing first-admission rates might be explained partly by changes in diagnostic habits. The differential diagnoses of schizophrenia (paranoid states (ICD-8:297), paranoid reactive psychoses (298.3), unspecified psychoses (298.9 and 299), and borderline states (ICD-8 Danish version: 301.83] are increasingly used as first-admission diagnosis for patients later to be diagnosed as schizophrenic, possibly owing to a tendency to avoid the diagnosis of schizophrenia, when treatment of a patient is possible. A method of calculating the hospital incidence of schizophrenia approaching the real incidence better than the incidence of first-admission diagnoses is suggested.     

Differences between schizophrenics born in winter and summer.

A total of 1814 patients were studied from the Mississippi State Hospital with a DSM-III diagnosis of schizophrenia and aged 15-39 years at the time of admission. The 634 schizophrenics with a birth date between 1 December and 31 March were compared with the 1180 born between 1 April and 30 November for age of admission, race, sex, marital status, duration of initial admission and clinical subtype. The only significant difference between the variables was the duration of the first admission: winter-born patients had a shorter psychiatric hospitalization than summer-born schizophrenics. These findings are discussed in accord with similar studies.     

Brain-derived neurotrophic factor Val66Met and psychiatric disorders: meta-analysis of case-control studies confirm association to substance-related disorders, eating disorders, and schizophrenia.

BACKGROUND: There is an increasing recognition that the pathophysiology of mental disorders could be the result of deregulation of synaptic plasticity with alterations of neurotrophins. The valine (Val)66-to-methionine (Met) variant, located in the pro brain-derived neurotrophic factor (BDNF) sequence, has been extensively studied through linkage and association approaches in several psychiatric disorders. METHODS: We performed a meta-analysis restricted to individual case-control studies in different categories of mental disorders and BDNF Val66Met polymorphism. We included data from 39 case-control studies encompassing psychiatric phenotypes: eating disorders, substance-related disorders, mood disorders, and schizophrenia, among others. RESULTS: The association of Val66Met was confined to three diagnoses: substance-related disorders, eating disorders, and schizophrenia. The Val/Met and the Met/Met genotypes increase the risk for eating disorders up to 33%, while these same genotypes confer a 21% protective effect in substance-related disorders. The homozygous carriers Met/Met showed a 19% increased risk of schizophrenia with respect to the heterozygous state. CONCLUSIONS: The study confirms the association of Val66Met to substance-related disorders, eating disorders, and schizophrenia. It remains to be determined if other variants in tight linkage disequilibrium with Val66Met could configure an extended functional haplotype that would explain observed discrepancies in risk estimations across studies.     

Stability of diagnosis: a 20-year retrospective cohort study of Israeli psychiatric adolescent inpatients.

Outcome according to diagnosis and stability of diagnosis were investigated in a follow-back study of 351 adolescents with various psychiatric disorders hospitalized in a closed psychiatric ward. The duration of follow-back was 15-19 years. All diagnoses were based on the ICD-9. Data were collected from the Health Ministry registry and, in the patients who could be located, by structured telephone interview. Special attention was directed at the diagnosis of transient adolescent psychosis (TAP) vs. schizophrenia and prognostic indicators of suicide. The results showed that the most stable diagnosis was anxiety disorder. The stability of the different diagnoses over time was greater between the second and last admission than between the first and last (for patients with three or more admissions). Number of hospitalizations correlated negatively with prognosis. TAP at second admission was an unstable diagnosis; 66% of these patients had a final diagnosis of schizophrenia. However, patients with a diagnosis of TAP at first admission had a higher predictive index score and a higher outcome score than schizophrenic patients. TAP appeared to be a valid diagnostic entity, distinguishable from schizophrenia in course, frequency of suicidal behaviour and social-occupational outcome. Suicide victims had a higher cumulative length of stay than age- and sex-matched non-suicidal patients. Fifty per cent of the suicide victims had a final diagnosis of schizophrenia, compared to 30 per cent for the whole sample. In conclusion, these findings indicate that TAP is associated with a relatively good prognosis and should probably be differentiated from schizophrenia. Further retrospective and prospective studies of adolescent psychiatric inpatients may help delineate the nature and course of psychosis and other psychopathology in this age group.     

Gender and duration of untreated psychosis: a systematic review and meta-analysis

Aim: Duration of untreated psychosis (DUP) can influence the prognosis of schizophrenia. Previous studies have suggested that gender may influence the length of DUP. This study reports the result of the first systematic literature review and meta‐analysis on the role of gender in influencing DUP in first‐episode psychosis. Method: Systematic literature search in PubMed/Medline and Ovid/PsychINFO. Twenty‐seven studies presenting data on 4721 patients diagnosed with psychosis at their first episode (2834 males and 1887 females) were included in the analysis. Results: Samples had a higher proportion of males: odds ratio = 2.5 (95% confidence interval: 1.8–3.3). Mean age at first contact was 25.4 for males and 27.5 for females. Patients from non‐Western countries were older at first contact than patients from Western countries. Average DUP in schizophrenia was 64 weeks and did not differ between genders but was shorter in Western compared with non‐Western countries. Conclusion: Earlier age at first contact and larger incidence in males support the existence of specific gender differences in first‐episode psychosis; however, these are not associated with DUP length.     

Total population-based study of the impact of substance use disorders on the overall survival of psychiatric inpatients

Background: Patients with severe mental illness have a shortened lifespan, and substance use disorder (SUD) is an especially important diagnosis in this respect. There have been no studies comparing directly SUD to other diagnoses in a nationwide cohort. Aims: To directly compare differences in mortality rates of psychiatric inpatients with a discharge diagnosis of SUD versus other psychiatric diagnoses. Methods: A register-based study was made of all patients admitted to psychiatric hospitals in Iceland between 1983 and 2007. Patients were grouped according to discharge diagnoses. Survival with respect to SUD was compared using Cox-proportional hazard ratio, excluding those with an organic mental disorder. Furthermore, the survival of patients with SUD and co-morbid diagnoses was evaluated. Results: A total of 14,281 patients (over the age of 18 years) were admitted to a psychiatric hospital in Iceland during the study period, with a total of 156,356 years of follow-up. For both men and women, a diagnosis of SUD conferred similar mortality as a diagnosis of schizophrenia without SUD, while individuals with a diagnosis of a mood disorder or “other disorders” had significantly lower mortality than SUD. For men with SUD, a co-occurring mental disorder was associated with an increased risk of dying, however, this was not found for women. Conclusions: SUD was the psychiatric diagnosis that had the highest mortality rate among psychiatric inpatients, in both men and women. An additional psychiatric diagnosis on a pre-existing SUD diagnosis did increase the risk for men but not women.