Please note that depression rarely occurs in isolation and is usually accompanied by fatigue, anxiety and cognitive problems (difficulty concentrating, poor memory and inability to think clearly and efficiently). Depression may be associated with 'sickness behaviour', which in MS may be due to ongoing inflammation in the brain. Therefore if you are depressed your MS should be assessed to see if it is active. The latter would involve being seen by a neurologist and examined for new clinical signs and almost invariably include a new MRI scan to see if you have new or enlarging MS lesions. In some centres, such as Barts-MS, you may be offered a lumbar puncture to have your neurofilament levels measured in your spinal fluid. If the neurofilament levels are raised it indicates that your MS is active. If you are not on a disease-modifying therapy (DMT) and your MS is active you should be offered a DMT. The latter is not universal and will be determined by local and regional treatment guidelines and whether or not your neurologist accepts depression as a clinical marker of possible disease activity. If you are on a DMT already and have evidence of disease activity this may prompt a switch in your treatment.
In conclusion, depression like other hidden symptoms of MS should not be ignored. Depression, or the black-dog, is a red-flag and indicates that something is going on inside your brain.
van Geest et al. Fronto-limbic disconnection in patients with multiple sclerosis and depression. Mult Scler. 2018 Mar 1:1352458518767051.
BACKGROUND: The biological mechanism of depression in multiple sclerosis (MS) is not well understood. Based on work in major depressive disorder, fronto-limbic disconnection might be important.
OBJECTIVE: To investigate structural and functional fronto-limbic changes in depressed MS (DMS) and non-depressed MS (nDMS) patients.
METHODS: In this retrospective study, 22 moderate-to-severe DMS patients (disease duration 8.2 ± 7.7 years), 21 nDMS patients (disease duration 15.3 ± 8.3 years), and 12 healthy controls underwent neuropsychological testing and magnetic resonance imaging (MRI; 1.5 T). Brain volumes (white matter (WM), gray matter, amygdala, hippocampus, thalamus), lesion load, fractional anisotropy (FA) of fronto-limbic tracts, and resting-state functional connectivity (FC) between limbic and frontal areas were measured and compared between groups. Regression analysis was performed to relate MRI measures to the severity of depression.
RESULTS: Compared to nDMS patients, DMS patients (shorter disease duration) had lower WM volume ( p < 0.01), decreased FA of the uncinate fasciculus ( p < 0.05), and lower FC between the amygdala and frontal regions ( p < 0.05). Disease duration, FA of the uncinate fasciculus, and FC of the amygdala could explain 48% of variance in the severity of depression. No differences in cognition were found.
CONCLUSION: DMS patients showed more pronounced (MS) damage, that is, structural and functional changes in temporo-frontal regions, compared to nDMS patients, suggestive of fronto-limbic disconnection.