David Baxter PhD
Late Founder
Men at greater risk of schizophrenia than women
12 March 2007
Psychol Med 2007; 37: 479?484
Being male is a major risk factor for the development of schizophrenia, Danish researchers have confirmed in a large population-based study.
Several studies have reported gender differences for various aspects of schizophrenia, particularly in terms of the age at onset.
However, Anne Thorup, from Bispeberg Hospital in Copenhagen, and colleagues point out that few investigations have looked at the age- and gender-specific incidence of schizophrenia in people aged up to 71 years, while none have examined the cumulative incidence.
To investigate further, the team used the Danish Civil Registration System, which holds information on birth, gender, date of death, and date of emigration for everyone alive or born after 1968, and the Danish Psychiatric Central Register, which includes every psychiatric in-patient admission from 1970 and every out-patient attendance from 1995.
They created a "young" cohort of all people born between 1955 and 1990 and an "old" cohort of everyone born between 1934 and 1954 in order to include all incident cases of schizophrenia from 15 to 71 years of age. The team then calculated the gender- and age-specific, as well as cumulative, incidence of schizophrenia up to 71 years.
In all, 16,762 people developed schizophrenia during a total of 58.0 million person-years. The incidence of schizophrenia, defined as the number of new cases per 100,000 person-years at risk, showed that, between 17 and 40 years of age, the incidence was significantly higher among men than among women. Between ages 50 and 68 years, the incidence rate was significantly higher among women than men.
Adjusting for diagnostic changes over the study period and including in- and outpatients, the team find that the cumulative incidence of schizophrenia by the 72nd birthday was 1.59% for all males and 1.17% for all females, the team writes in the journal Psychological Medicine.
The average of onset of schizophrenia was 29.31 years among men, compared with 32.78 years among women. The median age of onset was 26.77 years for men, versus 29.08 years in women. In both men and women, the incidence of schizophrenia peaked at 22?23 years.
The team concludes: "Our data strongly indicate that the lifetime risk of developing schizophrenia is dependent on gender [and] our results confirm that the incidence rates vary a good deal over the lifetime risk period."
Abstract
12 March 2007
Psychol Med 2007; 37: 479?484
Being male is a major risk factor for the development of schizophrenia, Danish researchers have confirmed in a large population-based study.
Several studies have reported gender differences for various aspects of schizophrenia, particularly in terms of the age at onset.
However, Anne Thorup, from Bispeberg Hospital in Copenhagen, and colleagues point out that few investigations have looked at the age- and gender-specific incidence of schizophrenia in people aged up to 71 years, while none have examined the cumulative incidence.
To investigate further, the team used the Danish Civil Registration System, which holds information on birth, gender, date of death, and date of emigration for everyone alive or born after 1968, and the Danish Psychiatric Central Register, which includes every psychiatric in-patient admission from 1970 and every out-patient attendance from 1995.
They created a "young" cohort of all people born between 1955 and 1990 and an "old" cohort of everyone born between 1934 and 1954 in order to include all incident cases of schizophrenia from 15 to 71 years of age. The team then calculated the gender- and age-specific, as well as cumulative, incidence of schizophrenia up to 71 years.
In all, 16,762 people developed schizophrenia during a total of 58.0 million person-years. The incidence of schizophrenia, defined as the number of new cases per 100,000 person-years at risk, showed that, between 17 and 40 years of age, the incidence was significantly higher among men than among women. Between ages 50 and 68 years, the incidence rate was significantly higher among women than men.
Adjusting for diagnostic changes over the study period and including in- and outpatients, the team find that the cumulative incidence of schizophrenia by the 72nd birthday was 1.59% for all males and 1.17% for all females, the team writes in the journal Psychological Medicine.
The average of onset of schizophrenia was 29.31 years among men, compared with 32.78 years among women. The median age of onset was 26.77 years for men, versus 29.08 years in women. In both men and women, the incidence of schizophrenia peaked at 22?23 years.
The team concludes: "Our data strongly indicate that the lifetime risk of developing schizophrenia is dependent on gender [and] our results confirm that the incidence rates vary a good deal over the lifetime risk period."
Abstract
