SHORT REPORT |
Department of Psychiatry, NIHR Biomedical Research Centre, South London and Maudsley NHS Foundation Trust, and Institute of Psychiatry, King's College London, UK
Correspondence: Eugenia Kravariti, PhD, Box 58, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK. Email: e.kravariti{at}iop.kcl.ac.uk
None. Funding detailed in Acknowledgements.
We analysed Stroop (neuropsychological screening test) measures of response inhibition in 18 twin pairs discordant for bipolar I disorder compared with 17 healthy control pairs, as well as 40 singletons with bipolar disorder with psychotic features and a family history of psychosis, 46 of their first-degree relatives without bipolar disorder or psychosis and 48 controls. In both studies, individuals with bipolar disorder showed Stroop deficits and their first-degree relatives showed intact performance. In the twin patients, an interference score was associated with depressive symptoms. Having a first-degree relative with bipolar disorder, even a familial, psychotic form, did not confer risk for enhanced susceptibility to interference in our studies.