Selective Estrogen Receptor Modulators - A Potential Treatment for Psychotic Symptoms of Schizophrenia

Estrogen is hypothesised to be protective for women against early onset of severe symptoms of schizophrenia (Hafner, 1991; Seeman, 1992). This 'estrogen hypothesis' was derived from epidemiological, clinical and animal studies. Following the results of such studies, the investigators conducted a study (Kulkarni et al 1996) in which a group of premenopausal women with schizophrenia were given 0.02mg oral estradiol as an adjunct to antipsychotic drug treatment for eight weeks, and compared their progress with a similar group who received antipsychotic drugs only. The group receiving estrogen made a significantly more rapid recovery from acute psychotic symptoms and also reported improvement in their general health status. Subsequently, the investigators conducted a four week double-blind, placebo-controlled study, using 100mcg estradiol skin patches. The investigators found that the 12 premenopausal women who received the estradiol adjunct had a significantly lower total PANSS and BPRS score than 12 women who received placebo patches plus antipsychotic medication.

The major potential risks in using estrogen as a longer term adjunctive treatment in premenopausal women with schizophrenia appear to be the potential harmful effects of estrogen itself in its action on breast and uterine tissue. Our studies were brief for this reason, in that the investigators used estrogen without progesterone over an eight week or four week period.

With the recent advent of Selective Estrogen Receptor Modulators, in particular Raloxifene Hydrochloride, there is the potential to harness the positive estrogenic effect on CNS neurotransmitter systems without affecting breast or uterine tissue. While the CNS effects of Raloxifene have not been fully studied, its actions are mediated through binding to estrogen receptors and can thereby regulate gene expression that is ligand, tissue or gene specific. By inference then, Raloxifene would be expected to impact on dopamine and serotonin pathways in a similar fashion to conjugated estrogen. A study (Nickleisen et al 1999) on the effect of Raloxifene on cognition in healthy, postmenopausal women found a slight increase in verbal memory performance after one month of high dose treatment, while no other differences were found after 12 months of treatment. There are no studies in women with cognitive impairment where a treatment effect would be more likely to be apparent. Similarly, there are no clinical studies to date investigating the effect of Raloxifene on psychotic symptoms. To this end, the investigators are putting forward an investigator initiated clinical trial proposal to investigate the effect of adjunctive Raloxifene on psychotic symptoms in women with schizophrenia. This is, therefore, a study to follow our Pilot Study in the same area, but with an increase of Raloxifene from 60mg to 120mg daily.

The aim of this project is to study the effect of Raloxifene as an adjunct to antipsychotic medication in women with schizophrenia as a means to developing a novel, safe adjunctive treatment for women with schizophrenia to improve their quality of life.