Antidepressants withdrawal effects and duration of use: a survey of patients enrolled in primary care psychotherapy services.

Background: Previous studies of antidepressant withdrawal have been limited by short duration of drug exposure or self-selected samples. Our study aimed to estimate withdrawal effects in routine clinical practice.

Methods: Participants from NHS primary care psychological treatment services who had ever tried to stop an antidepressant were surveyed. Regression models were constructed to examine the association between personal and medication characteristics, and withdrawal.

Results: Respondents(n = 310) were mostly female(78 %), white(75 %), with an average age of 38.79(SD 12.4). The response rate was 18 % of eligible patients. 62 % reported antidepressants had been helpful. Withdrawal symptoms of some degree were reported by 79 %. 45 % reported severe or moderately severe symptoms. 43 % met the most stringent definition of a withdrawal syndrome, reporting 4 or more 'non-emotional' withdrawal symptoms. 38 % of participants reported being unable to stop their antidepressant when they tried to do so. 20 % reported withdrawal symptoms lasting more than three months and 10 % for more than a year. In fully adjusted models those using antidepressants for over 24-months prior to stopping were more likely to experience a withdrawal syndrome (OR(95 %CI)=10.41(2.88;37.67)), report severe withdrawal effects (OR(95 %CI) = 5.16(2.75;9.70)), report longer lasting symptoms (Beta(95 %CI)=18.11(3.85;32.38), and be less likely to be able to stop (OR(95 %CI)=27.55(10.29;73.81), than those using for less than six-months.

Conclusion: Antidepressant withdrawal symptoms were common, and severe and prolonged for a substantial proportion of users. Longer duration of use was associated with greater likelihood of severe and protracted symptoms and being less likely to be able to stop. A limitation of this study is the low rate of response.