Page 20 - The clinical aspects and management of chronic migraine Judith Anne Pijpers

Chapter 1
for potential confounders. Secondly, frequent medication use seems to enhance the process of central sensitisation, both in human and animal studies. Patients with medication overuse were hypersensitive for mechanical pain compared to healthy controls, which reverted after withdrawal. In animal studies, recurrent administration of triptans resulted in cutaneous allodynia.32,33
Box 2. Medication overuse criteria. Synopsis of criteria on medication overuse according to the International Classification of Headache Disorders (ICHD-3β criteria)3 .
Medication overuse
Regular overuse for >3 months of one or more drugs that can be taken for acute treatment of headache. Regular overuse is use of:
1. triptans, ergots, opioids, combination-analgesics on ≥ 10 days per
month
2. simple-analgesics (such as paracetamol, NSAID), on ≥ 15 days per
month
3. combinations of multiple drug classes on ≥ 10 days per month
18
Psychiatric and psychological factors
Depression, a psychiatric disorder characterized by symptoms of anhedonia, low or sad mood, difficulties with eating, sleeping and concentrations, is highly prevalent disorder.34 As is the case for others neurological disorders, such as dementia,35 Parkinson disease36 and multiple sclerosis,37 and chronic pain conditions,38 depression is even more prevalent in migraine patients, than would be expected based on prevalence in the general population.39 This might lead to the reasoning that depression is caused by the somatic disorders, sometimes referred to in terms like ‘chronic-pain induced depression’. However, migraine and depression don’t have a purely unidirectional, causal relationship, but seem to have a bidirectional relationship: patients with migraine have higher risk on first-onset depression (OR = 5.8), and patients with depression have a higher risk on first onset migraine (OR = 3.4).39
This appearance of a bidirectional relationship leads to the hypothesis that migraine and depression have shared risk factors with a partial common pathway, which might be genetic factors.40,41 A recent study measuring