A15 15..15

Gunnell et al (pp. 298–305) investigate whether the established association between impaired intellectual performance and schizophrenia is due to the confounding influence of adverse prenatal and early childhood exposures on both intellectual development and the risk of schizophrenia. By studying a large cohort of Swedish male conscripts, results show that the association is not explained by cerebral damage caused by early insults. The adverse effects of prodromal disease on cognition, however, may in part contribute to the association between cognition and psychosis. Fearon & Murray (pp. 276–277), in an accompanying editorial, consider the methodological issues raised in the study and point out that it may be distance from the cognitive norm – in either direction – that increases the risk of schizophrenia. Continuation of thought disorder after the resolution of an acute psychotic episode is a strong predictor of poor outcome. However, formal thought disorders, especially the less florid forms characteristic of chronic illness, are difficult to assess. Liddle et al (pp. 326–330) examine the interrater reliability, sensitivity and factor structure of a new assessment instrument, the Thought and Language Index (TLI). It is found to provide a sensitive and reliable measurement of thought and language disorders in schizophrenia and comparisons of scores with healthy controls suggest that there is a continuum of severity of disorganised thought and language in the human population. People with schizophrenia are significantly more likely to misuse substances compared with general population controls (McCreadie et al, pp. 321–325), with 7% and 17% misusing drugs and alcohol, respectively, in the past year. However, the most striking difference between patients and controls was in tobacco consumption – 65% of patients in the study were current smokers compared with 40% of controls. The authors underline the importance of helping those with schizophrenia give up smoking, especially in view of their high mortality from smoking-related diseases.