Schizophrenia Daily News Blog

Brains of People who Have Schizophrenia Show Sex Pattern Reversal, Compared With General Population

Research has shown that there are a few minor differences between the brains of men and women. New research by neuroscientist Adrianna Mendrek indicates a reversal of these differences in the brains of schizophrenics.

"In comparison to the general population, women's brains seem masculine and men's brains seem feminine," says Mendrek, a researcher from the Centre de recherche Fernand-Seguin that is affiliated with the Université de Montréal's Department of Psychiatry.

The main difference between a man’s brain and a woman's brain has to do with how certain structures and circuits treat emotion. These structures and circuits are usually more elaborate in a woman’s brain. Mendrek wanted to know how a schizophrenic’s brain would react to certain emotional stimuli.

Image: Differences in activation of brains, in white, of men (top row) and women (bottom row) schizophrenics. (Credit: Image courtesy of University of Montreal)

The researcher showed two film excerpts to her test subjects: the first was sad, and the second showed anger. Meanwhile, her subjects underwent an fMRI as they watched the films. The sad film activated certain parts of the male brain that remained unaffected in women. The angry excerpts activated more elaborate and more intense reactions in men.

“These results are surprising seeing as women are usually more emotionally expressive than men,” says Mendrek. “The differences aren’t the result of drugs or of subjective past experience seeing as the emotions were felt identically in all subjects.” But according to the researcher, the profiles of activation in women would indicate that they have more difficulty integrating cognition and emotion associated to stimuli related to empathy.

Dr. Mendrek notes on her web site:

"I have used fMRI to explore sex differences in the cerebral function associated with the emotion processing in schizophrenia. The existence of sex differences in various aspects of epidemiology and phenomenology of schizophrenia was already noted by Kraepelin at the beginning of the 20th century.

Today it is widely acknowledged that men have poorer premorbid functioning, earlier age at onset, worse response to treatment, and more severe course of the illness, than women. Men with the diagnosis of schizophrenia exhibit more pronounced negative symptoms such as social withdrawal, blunted affect and poverty of speech, whereas women display more affective symptoms such as dysphoria, impulsivity, inappropriate affect, as well as more atypical psychotic symptoms.

Recent neuroanatomical studies imply a reversal of normal sexual dimorphism in schizophrenia. Prompted by these reports we have analyzed data of fifteen men and ten women with the diagnosis of schizophrenia who underwent functional magnetic resonance imaging (fMRI) during exposure to two emotion processing tasks: sad vs. neutral film clips, and aversive vs. neutral pictures.

Overall both tests evoked much more extensive and intense cerebral activations in men than in women with schizophrenia. The pattern of obtained results differs significantly from what has been observed in the general population, thus giving support for the recent suggestion of “masculinization” of females and “feminization” of males with schizophrenia (at least at the neuroanatomical level)."

Source: University of Montreal (2008, April 1). Schizophrenic Brains Show Sex Pattern Reversal, Compared With General Population.