Table 1 The five questions of the Severity Dependence Scale (SDS) adapted for headache medication

1

Do you think your use of headache medication was out of control? (never/almost never = 0, sometimes = 1, often = 2, always/nearly always = 3)

2

Did the prospect of missing a dose make you anxious or worried? (scoring as for question 1)

3

Did you worry about your use of your headache medication? (scoring as for question 1)

4

Did you wish you could stop? (scoring as for question 1)

5

How difficult would you find it to stop or go without your headache medication? (not difficult = 0, quite difficult = 1, very difficult = 2, impossible = 3)