Published online Jun 22, 2015. doi: 10.5498/wjp.v5.i2.167
Peer-review started: January 20, 2015
First decision: February 7, 2015
Revised: February 23, 2015
Accepted: April 1, 2015
Article in press: April 8, 2015
Published online: June 22, 2015
We studied a population-based sample of 232 first-onset cases of schizophrenia aged 12 to 59 years at first admission retrospectively back to illness onset and prospectively up to 11.2 years later. We compared them with psychiatrically healthy age- and sex-matched population controls and equally matched first-admission patients diagnosed with major depression. At schizophrenia onset women are several years older than men. The social factors tested did not explain the finding. Women’s higher level of social development at onset is associated with a better medium-term functional and social outcome. Prodromal schizophrenia and depression are equal in length and diagnostically distinguishable only after the onset of positive symptoms. The sex difference in age at onset, invariable across cultures and ethnicities, is explained by a protective effect of oestrogen, which down-regulates D2 receptors. A higher genetic load antagonizes this effect. Long-term symptom-related illness course exhibits a plateau after three years, the positive symptom dimension after two years, the depressive and the negative dimensions do so after three to five years. The most prevalent symptom is depressive mood. Male first episodes are more frequent and more severe in the first half of life, female ones in the second half. Aetiological conclusions will be drawn.
Core tip: We studied schizophrenia from onset to 134 mo following first admission: age at onset is higher for women because of oestrogen. Prodromal schizophrenia and depression split diagnostically only after the onset of positive symptoms. Illness course exhibits a plateau after three years, positive symptoms do so after two, depressive and negative symptoms after three to five years. Depressive mood is the most prevalent symptom. Male first episodes are more frequent and more severe in the first half of life, female ones in the second half. Late-onset schizophrenias feature paranoid delusions, early-onset illnesses various severe pathology. Aetiological conclusions will be drawn.