Description of Participant Groups.

<p>Descriptive information for each group, reported as the mean (and SD), including total numbers, breakdown by sex, handedness and research site (Newcastle, Liverpool); age; Cigarettes smoked per day; and Education Level (1..6). Last three columns summarise results from a diagnosis x illness duration two-way ANOVA or from chi-squared analysis, as appropriate.</p><p>*<i>p</i><.05;</p><p>**<i>p</i><.01;</p><p>***<i>p</i><.001; ns Not Significant.