Depressive symptomatology is influenced by chronotypes
Received 3 October 2008; received in revised form 25 February 2009; accepted 26 February 2009.
Abstract
Background
Rhythm disturbances are a frequent clinical manifestation of depression. In recent years a possible relationship between depression and chronotypes has emerged. Specifically eveningness has been proposed as vulnerability factor. The aim of this study was to describe sleep features of depressed patients according to chronotypes and to explore possible associations with the clinical features of depressive episodes.
Methods
100 patients diagnosed with Major Depressive Disorder according to the Mini International Neuropsychiatric Interview (MINI) were included (age: 34±11.74, range: 18–60 years; female/male:79/21). At admission the Hamilton Rating Scale for Depression (HRSD) was administered. Patients were also administered the Morningness–Eveningness Questionnaire (MEQ), the Epworth Sleepiness Scale, the Athens Insomnia Scale and the Pittsburgh Sleep Quality Index.
Results
According to MEQ scores patients were classified in three groups: a) eveningness (n=18), b) neither (n=61) and c) morningness type (n=21). The age was different among chronotypes, being morningness-type patients older. The eveningness-type group showed higher scores in suicidal thoughts, more impaired work and activities, higher paranoid symptoms, higher scores on the anxiety cluster (HRSD), while the morningness-type group showed lower proportion of melancholic symptoms (MINI). We did not find association between sleep parameters and specific chronotypes.
Limitations
The relatively small sample size and the concurrent assessment of chronotypes and depression may have biased our findings.
Conclusions
Our data suggest the idea that chronotypes have an impact on depressive episodes features, with higher severity for the eveningness-type.
bInstitute of Psychiatry, University of Bologna, Viale Carlo Pepoli 5, 40123 Bologna, Italy
cDepartment of Psychology, University of Bologna, Bologna, Italy
Corresponding author. Institute of Psychiatry, University of Bologna, Viale Carlo Pepoli 5, 40123 Bologna, Italy. Tel.: +39 051 6584233; fax: +39 051 521030.
ABSTRACT