An observational study from Sardinia has found that rapid discontinuation of antidepressants places patients at increased risk of early relapse.

There were 398 patients, 261 women and 137 men, included in the study: 224 had a DSM-IV diagnosis of recurrent major depressive disorder, 75 panic disorder and 99 bipolar disorder. Patients were followed up with regular semistructured interviews and rating scale assessments. All were considered to have responded well to antidepressant treatment. Mean duration of treatment was 8.5 months.

A total of 188 patients stopped their treatment rapidly (within seven days) and 210 patients stopped their treatment gradually (over 14 days or more). Twelve months later, 146/188 (78%) of the rapid discontinuation group had relapsed compared with 124/210 (59%) of the gradual discontinuation group. Moreover, the median time to relapse in the rapid discontinuation group was only 40% of the median time in the gradual discontinuation group (3.62 and 8.42 months respectively).

The association between the speed of discontinuation and time to relapse remained highly significant after adjustment for factors known to be associated with increased risk of relapse, including the number of previous episodes, depression severity and shorter duration of antidepressant treatment.¹ However, not all potential confounders were accounted for. It is possible, for example, that those patients who choose to stop their treatment abruptly are more likely to have personality traits or mood cycling disorders which place them at increased risk of relapse.²

One in five patients who stop their antidepressant medication suddenly will experience acute discontinuation symptoms, including sleep disturbance, affective symptoms, flu-like symptoms, nausea, imbalance and sensory symptoms. It is good practice to warn patients of this when initiating treatment and to taper over a period of 6-8 weeks when stopping treatment.³

Almost all the patients from the rapid discontinuation group took the decision to stop treatment themselves. Many patients are reluctant to take antidepressants and may be tempted to stop taking them as soon as they begin to feel better. We should explain that this is inadvisable:

• Treatment should be continued for at least six months after full remission to reduce the risk of relapse.¹
• If treatment is stopped suddenly:

- There is a 20% risk of discontinuation syndrome

- There may be an increased risk of early relapse

One clinical situation in which we may choose to stop antidepressants abruptly is the first trimester of pregnancy, where exposure to SSRIs has been linked to a small increase in the risk of septal heart defects.⁴ However, this needs to be set against the much greater risk that stopping treatment will lead to a relapse of depression during the pregnancy; the present study tips the balance further in favour of continuing treatment.

Dr Phillip Bland