ABSTRACT
BACKGROUND: Executive function deficits in depression implicate involvement of frontal-striatal circuits. However, studies of hypothalamic-pituitary-axis (HPA) function suggest that stress-related brain changes of hippocampus may also implicate prefrontal-hippocampal circuits, which may explain the profile of both executive dysfunction and memory deficits. In this study we examined the performance of patients with major depressive disorder (MDD) on tasks of memory and executive function in relation to melancholic features and to cortisol levels. Our hypothesis was that raised cortisol levels in melancholic patients would correlate with these deficits. METHOD: Forty female MDD patients, 20 having melancholic features (MEL vs. Non-MEL), and 20 sex-age- and education-matched normal controls were investigated using the Cambridge neuropsychological test automated battery (CANTAB), to assess memory (paired associative learning, PAL; short-term recognition memory, SRM) and executive (intradimensional/extradimensional set-shifting, ID/ED; Stockings of Cambridge, SOC) functions. Plasma and salivary cortisol levels were measured. RESULTS: The MDD patients performed worse than controls on PAL and both executive tasks. The MEL group differed from controls on all tests, and differed from the non-MEL only at the ED stage of the ID/ED task. Patient cortisol levels were within the normal range and did not correlate with neuropsychological performance for any group. CONCLUSIONS: MDD patients showed neuropsychological deficits on tasks of executive function and memory, supporting the model of frontal-temporal dysfunction. MEL vs. non-MEL performed worse overall and demonstrated a qualitative difference in set shifting, perhaps implicating more extensive prefrontal involvement. Cortisol levels did not correlate with depression severity or the observed deficits.
Subject(s)
Depression/blood , Depression/physiopathology , Hydrocortisone/metabolism , Neuropsychological Tests , Adult , Analysis of Variance , Antidepressive Agents/therapeutic use , Association Learning/physiology , Chi-Square Distribution , Depression/drug therapy , Female , Humans , Mental Status Schedule , Middle Aged , Problem Solving/physiology , Saliva/drug effects , Saliva/metabolismABSTRACT
We present two patients with demyelinating disease meeting the diagnostic criteria for multiple sclerosis. Both patients had IgG lambda monoclonal gammopathy in serum and cerebrospinal fluid associated with intrathecal antibody synthesis. This association is very unusual and it is not certain whether the co-occurrence of these disorders might be the result of a causal link between multiple sclerosis and monoclonal gammopathy or a fortuitous phenomenon.
