Why schizophrenia affects men and women differently

Schizophrenia is a complex psychiatric disorder in which sex differences have long been observed.¹ Men typically experience earlier illness onset with more severe negative symptoms, while women tend to develop symptoms later and are more likely to exhibit affective symptoms.^2,3 Growing evidence suggests that fluctuations and long-term changes in sex hormones – particularly oestrogen and testosterone, and to a lesser extent progesterone – may contribute substantially to these gender differences.⁴ Understanding the influence of sex hormones is essential for advancing gender-informed approaches to clinical care.

Clear gender differences exist between men and women in schizophrenia onset, symptoms and disease trajectory

Gender differences in schizophrenia emerge early in the illness. Generally, schizophrenia is slightly more prevalent in men than in women with a ratio of nearly 1.4:1.^1,2 Men typically develop the disorder in late adolescence or early adulthood – around 3–5 years earlier than women – and often show more severe negative symptoms, poorer premorbid functioning and a more deteriorating disease course.^2,3,5 Women, by contrast, frequently demonstrate later onset in early and mid-adulthood, better premorbid adjustment and comparatively preserved social functioning.^2,3 

While men have a single peak of onset between 21–25 years, women display a bimodal illness pattern, with a first onset peak in the late twenties and a second around menopause.^3,6 Symptom worsening during midlife often coincides with falling oestrogen levels, reinforcing the hypothesis that hormonal fluctuations influence vulnerability, symptom burden and long-term outcomes.^4,6,7 

Oestrogen appears to offer neuroprotective effects that modulate symptom severity and illness course in women

The “oestrogen protection hypothesis”, which is supported by multiple studies, proposes that oestrogen acts as a protective factor in women, reducing the risk of psychosis and symptom severity during reproductive years.^7,8 Oestrogen modulates clinical symptoms via its influence on dopaminergic pathways, its role in maintaining mitochondrial function, and its modulation of the stress-response system.⁹ Clinical evidence shows that women with schizophrenia frequently experience symptom exacerbations during low-oestrogen phases such as the late luteal period, postpartum, and perimenopause.^3,4,7 Conversely, high-oestrogen states, including pregnancy, may correspond with symptom improvement.^6,7  

Progesterone and testosterone affect schizophrenia risk through distinct but less clearly defined mechanisms

Although oestrogen is the most extensively studied hormone in schizophrenia research, progesterone and testosterone also appear to exert important influences. Progesterone fluctuates in parallel with oestrogen across the menstrual cycle.¹⁰ Recent findings indicate that individuals with first-episode, antipsychotic-naïve schizophrenia show significantly elevated baseline progesterone levels relative to healthy controls. It was proposed that lower baseline progesterone may serve as a predictor of improved therapeutic response to antipsychotic therapy.⁴ However, findings remain inconsistent and more rigorous studies are needed.^4,10 

Testosterone has been implicated in the earlier onset and higher incidence of schizophrenia reported in males.⁴ The marked rise in testosterone during adolescence corresponds with the developmental window in which men most frequently experience first-episode illness.¹¹ Evidence also suggests that testosterone can modulate dopaminergic, glutamatergic and GABAergic neurotransmission systems, all of which are thought to contribute to the underlying pathophysiology of schizophrenia.¹¹ However, findings on circulating testosterone levels in patients remain inconsistent, with studies reporting lower, higher, or no significant differences compared with healthy controls. These discrepancies underscore the need for further research to clarify the precise role of testosterone in schizophrenia.¹¹ 

Hormone-informed approaches can improve assessment and care in women

As evidence for hormonal influences grows, clinicians increasingly recognise the importance of integrating reproductive stage and endocrine factors into psychiatric assessment and planning. In women, symptom fluctuations may correspond with menstrual cycle phase, postpartum changes, or perimenopausal hormonal decline.^4,8 Women with schizophrenia therefore have distinct clinical needs across the lifespan of the illness, requiring tailored pharmacological strategies, attentive reproductive and perinatal care, and proactive support around safety, social functioning, and parenting. As oestrogen levels decline with age, treatment often requires adjustment, and emerging hormone-informed approaches show promise for improving outcomes in this population.⁸ Prolactin-sparing antipsychotics are preferable, particularly in premenopausal women.⁹ Since oestrogen increases the bioavailability of certain antipsychotic medications, this should be taken into account when selecting starting doses in women.⁹ Premenopausal women typically require lower doses than men and postmenopausal women, may need temporary dose increases during low-oestrogen phases, and where clinically appropriate, may benefit more from oestrogen-containing contraceptives rather than from progestogen-only options.⁹