CLINICAL HANDBOOK OF SCHIZOPHRENIA

22 I. CORE SCIENCE AND BACKGROUND INFORMATION• That low rates of fertility and fecundity in women with schizophrenia are offset byhigh rates in men with schizophrenia.• That fertility and fecundity are increased among unaffected family members, whopass on the unexpressed genetic liability.• That unaffected family members benefit from evolutionary physiological advantages,such as resistance to infection or injury.• That an increase over time in environmental causal factors, such as obstetric complications,compensates for a reduction over the same time in genetic risk.However, the supporting evidence for any of these theories is poor, with inconsistent findingsand little resolution of the contradictions that arise. Furthermore, it has been proposedthat in a model of schizophrenia that includes multiple genes and latent carriers,the impact of lowered reproductive fitness leading to loss of susceptibility alleles wouldbe negligible.LONGITUDINAL COURSEThe Kraepelinian notion that schizophrenia (actually dementia precox, a severe earlyonsetsubtype of schizophrenia as we know it today) was a disease with an inevitablypoor outcome has been challenged by more recent longitudinal studies.Problems with research in this area include the following:• Differences in sample selection. For example, including only long-term hospitalizedcases, inevitably biasing toward a poor outcome.• Incomplete ascertainment of cases. It would be expected that patients lost to follow-upwould more likely be those with a good outcome, who no longer requiredactive treatment.• Varying duration of follow-up. Most decline in psychosocial functioning occurs inthe first 5 years of the illness and later flattens out or even shows some degree ofimprovement.• Lack of consistency in defining outcome, with various parameters being considered.For example, symptom alleviation (mostly positive symptoms), social outcome,occupational outcome, “quality of life,” and service utilization.Factors robustly associated with a poorer longitudinal illness course include beingmale, early onset of illness, poor premorbid social and occupational adjustment, lowpremorbid IQ, a predominance of negative symptoms, and a lack of affective symptoms.It has been argued that this reflects a particular subtype of schizophrenia consequent toneurodevelopmental deviance (discussed earlier).A number of other factors serve to perpetuate a poor outcome. These include delayed,suboptimal, or intermittent treatment with antipsychotic medication and ongoingillicit substance use. There is also a strong association between poor outcome and a familyenvironment characterized by so-called high expressed emotion (EE). High EE is aconstruct that encompasses critical comments, hostility, and/or overinvolvement of familymembers with nominally more than 72 hours per week of face-to-face contact with theindividual. Clinical interventions have been shown to be effective in reducing EE in familymembers and enhancing outcomes for patients.