Brain activation patterns in major depressive disorder and work stress-related long-term sick leave among Swedish females.
Deficits in executive functioning and working memory associated with frontal lobe dysfunction are prominent in depression and work-related long-term sick leave (LTSL). This study used functional magnetic resonance imaging (fMRI) to investigate potential differences in brain activation patterns in these conditions. In addition, the function of the hypothalamic-pituitary-adrenal (HPA) axis was examined and compared between groups. Since there is a clear overrepresentation of women in these diagnostic groups, and to ensure a more homogenous sample population, only women were included. To examine the neural correlates of relevant cognitive processes in patients on sick leave >90 days due to work-related LTSL, recently diagnosed patients with major depression Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV criteria, untreated), and healthy controls (n = 10, each group), a 2-back working memory task and a visual long-term memory task were administered during fMRI scanning. HPA axis functioning was investigated using a diurnal curve of saliva cortisol and a dexamethasone suppression test. Task performance was comparable among the three groups. Multivariate image analysis revealed that both memory tasks engaged a similar brain network in all three groups, including the prefrontal and parietal cortex. During the 2-back task, LTSL patients had significant frontal hypoactivation compared to controls and patients with depression. Saliva cortisol measurements showed a flattening of the diurnal rythmicity in LTSL patients compared to patients with depression and healthy contols. Taken together, these findings indicate that work stress-related LTSL and major depression are dissociable in terms of frontal activation and diurnal cortisol rhythmicity.
Remonthagen Stroke och hjärnskadecenter, Östersund, Sweden. agneta.sandstrom@jll.se
Agneta
A
Sandström
Roland
R
Säll
Jonas
J
Peterson
Alireza
A
Salami
Anne
A
Larsson
Tommy
T
Olsson
Lars
L
Nyberg
D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000523:psychology; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D057567:Memory, Long-Term / Q000502:physiology; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D018582:Sick Leave; D013315:Stress, Psychological / Q000523:psychology*; D013548:Sweden; D013647:Task Performance and Analysis
D006854:Hydrocortisone