Sex matters

More men get schizophrenia - is this the full picture?

Prof Riecher-Rössler (University of Basel Psychiatric Clinics, Switzerland) challenged the long-held idea that schizophrenia incidence is much higher in men. This is true below the age of 40 - but above 50, the incidence is higher in women. The life-time risk is actually similar when the upper age limit is 60 or older. There are no differences in prevalence.

Women tend to develop schizophrenia later. The average (mean) age at first episode is above 30.

Are symptoms different?

The symptoms experienced by men and women are slightly different. Prof Riecher-Rössler explained that women experience less negative but more affective symptoms. These differences are small in young women. Women have better social functioning and less substance abuse.

Coping with stress

Prof Myin-Germeys (KU Leuven, Belgium) uses experience sampling to study sex differences in stress and emotions in psychosis.

A mobile app beeps 10 times a day for 6 days. At each beep, the person answers questions on the device to describe their mood, symptoms and their context (e.g., what are they doing? are they alone?). No recall is needed - it’s an in-the-moment snapshot.

More than 700 subjects in control, at risk and psychotic groups have been included.

Experience sampling showed that men and women had similar symptoms. Behaviour in context had greater sex differences. Men were alone more than women in the ‘at risk’ group, and woman were involved in more goal-directed activities.

Women are more reactive to the environment

Prof Myin-Germeys showed that stress negatively affects women more than men. Interestingly, positive events produce a stronger affect in women. So women are a bit more reactive to stress than men, but also more sensitive to reward.

Why do women do better than men?

The course of schizophrenia is generally better in women - especially women with first episode psychosis. Because the disease starts later in life, women have had more time to complete their education, get married or develop a stable relationship, and establish a network of friends. They are socially integrated. And they gain more from positive experiences, such as relationships, than men do.

Women also tend to be more adherent than men. They do what the doctor tells them. They may receive more intensive therapy and they respond better to treatment.

A further factor is that oestrogen has a protective effect on the central nervous system.

Oestrogen and psychosis

Oestrogen’s neuroprotection is due gene transcription, signalling pathways and antioxidant effects on the brain. It is involved in a number of neurotransmitter systems and has antipsychotic properties. This may explain why onset of schizophrenia is later in women than in men. Interestingly, many women with schizophrenic psychoses have low oestrogen levels.

At low-oestrogen phases of the menstrual cycle, risk of schizophrenia onset and relapse is greater, and cognitive function is worse.

Prof Judith Usall (Cibersam, Spain) spoke about the effects of menopause on schizophrenia. When women stop producing oestrogen, there is a peak of late-onset schizophrenia, with more severe symptoms. In chronic psychosis, the course deteriorates after menopause.

Sex differences in cognition

There are sex differences in cognition. Men tend to have better working memory and women have better verbal learning.

Prof Javier Labad (Corporació Sanitària Parc Taulí, Spain) showed that there are sex differences in the relationship between some hypothalamic-pituitary-adrenal axis measures and cognition - specifically processing speed and memory - in patients with early psychosis.