[Personal characteristics of paradoxical insomnia: A case-control study]

To compare the personal characteristics between the patients with paradoxical insomnia and the patients with primary insomnia or the normal sleepers.
 Methods: A case-control study with the proportion at 1:1:1 was carried out. The patients with paradoxical insomnia were diagnosed in Sleep Medicine Center of West China Hospital of Sichuan University between March 2013 and December 2013. A case of paradoxical insomnia was matched with two controls: a primary insomnia patient and a normal sleeper. A total of 63 matched cases were collected. A face-to-face survey was conducted by using the following scales: General Data Scale and Eysenck Personality Questionnaire (EPQ).
 Results: The average scores of psychoticism, extraversion, and neuroticism for paradoxical insomnia cases were (52.1±10.2), (49.6±9.8), and (56.0±12.0), respectively. In general, 31.7% of paradoxical insomnia patients had psychoticism or psychoticism tendency in their personality, which were more obvious than those in primary insomnia patients (7.9%) (χ2=11.228, P<0.0125) and normal sleepers (0) (χ2=23.774, P<0.0125). Moreover, 19.0% of paradoxical insomnia patients had extroversion or extroversion tendency in their personality, which were more significant than those in primary insomnia patients (3.2%) (Z=-4.047, P<0.0125) but less obvious than those in normal sleepers (60.3%) (Z=-4.754, P<0.0125). Also, 46.0% of paradoxical insomnia patients had neuroticism or neuroticism tendency in their personality, which were more significant than those in normal sleepers (0) (χ2=37.670, P<0.0125) but similar to those in primary insomnia patients (52.4%) (χ2=0.508, P>0.0125).
 Conclusion: The personal characteristics for paradoxical insomnia patients did not reached obviously abnormal level. However, their psychoticism tendency, extroversion tendency and neuroticism tendency needed to be paid attention.