35 - Depression

Depression

Drug treatment of psychiatric symptoms in the context of other conditions CHAPTER 10 Multiple sclerosis Individuals with multiple sclerosis (MS) experience a variety of psychiatric and neurological disorders. These include depression, anxiety, pathological laughter and crying (pseudobulbar affect, PBA), mania, euphoria, psychosis, bipolar disorder, fatigue and cognitive impairment. Psychiatric disorders result from a variety of factors – the psychological impact of MS diagnosis and its prognosis, perceived lack of social support or unhelpful coping styles, increased stress, iatrogenic effects of treatments used with MS and MS-­related inflammation and damage to neuronal pathways.1 Depression In people with MS, depression is common with a point prevalence of 14–31%2,3 and lifetime prevalence of up to 50%.4,5 Suicide rates are 2–7.5 times higher than the general population6 and suicidality is seen in more than a fifth of people with MS.7 Depression in MS is often associated with fatigue and pain, although the relationship direction is unclear.8 Overlapping symptoms of depression, PBA and MS can complicate diagnosis and so co-­operation between neurologists and psychiatrists is essential to ensure optimal treatment. Depression in MS may result from structural changes in the brain related to MS pathology and, as such, it may differ fundamentally from non-­MS depression.9,10 Suggested treatments are described in Table 10.12. Table 10.12  Recommendations for treatment for depression in multiple sclerosis (MS). Step Intervention Screen for depression with PHQ-­9 HADS/BDI11/CES-­D.12 Exclude or treat any organic causes. Consider iatrogenic effects of medications as potential cause of depression. Ensure there is no past history of mania or bipolar disorder. People with mild depression should be considered for CBT13 or self-­help.14 Guidelines recommend SSRIs as first-­line treatment12,15,16 but have been criticised for the dearth of MS-­specific data.17 Sertraline was as effective as CBT in one trial18 but paroxetine was equivalent to placebo in another.19 Fluoxetine was effective in MS-­related depression in a small case series.20 For those with comorbid pain, consideration should be given to treating with an SNRI such as duloxetine21 or venlafaxine.22 One RCT of desipramine showed it was more effective than placebo but tricyclics in general are often poorly tolerated.23 In 2011, a Cochrane review was not convinced by many of the studies cited here,24 but there is little reason to suppose that antidepressants are any less effective in depression associated with physical illness.25 In 2023, bupropion was shown to be effective in a small RCT.26 Vortioxetine may also improve both depression and anxiety.27 CBT is the most appropriate psychological intervention with best efficacy in comparison with supportive therapy or usual care, and should be used in conjunction with medication for those who are moderately to severely depressed.18,28,29 Mindfulness training may also help.30 Omega-­3 fatty acids are ineffective.31 Because of reduced tolerability of adverse effects in this patient group, medications should be titrated from an initial half dose. Many MS patients are prescribed low-­dose TCAs for pain/bladder disturbance, so SSRIs should be used with caution and patients should be observed for serotonin syndrome. If SSRIs are not tolerated or there is no response, there are limited data that moclobemide is effective and well tolerated.32,33 There are no published trials on venlafaxine, duloxetine and mirtazapine but these are used widely. Mirtazapine may worsen fatigue, at least initially. Venlafaxine and duloxetine are used for pain management in MS.34 ECT could be considered for people who are actively suicidal or severely depressed and at high risk, but it may trigger an exacerbation of MS symptoms, although some studies suggest that no neurological disturbance occurs.35 CBT, cognitive behaviour therapy; TCAs, tricyclic antidepressants.