Selective serotonin reuptake inhibitor discontinuation syndrome: a randomized clinical trial

Recent reports describe discontinuation-emergent adverse events upon cessation of selective serotonin reuptake inhibitors including dizziness, insomnia, nervousness, nausea, and agitation. We hypothesized that interruption of fluoxetine treatment would be associated with fewer discontinuation-emergent adverse events than interruption of sertraline or paroxetine treatment, based on fluoxetine's longer half-life.

In this 4-week study, 242 patients with remitted depression receiving maintenance therapy with open-label fluoxetine, sertraline, or paroxetine for 4-24 months had their maintenance therapy interrupted with double-blind placebo substitution for 5-8 days. The Symptom Questionnaire (SQ), the Discontinuation-Emergent Signs and Symptoms checklist, the 28-item Hamilton Depression Rating Scale, and the Montgomery-Asberg Depression Rating Scale were used to assess somatic distress and stability of antidepressant response.

Two hundred twenty patients (91%) completed the study. Following interruption of therapy, fluoxetine-treated patients experienced fewer discontinuation-emergent events than either sertraline-treated or paroxetine-treated patients (p < .001). The mean SQ somatic symptom scale score in fluoxetine-treated patients was significantly lower than that in sertraline-treated and paroxetine-treated patients (p < .001). Fluoxetine-treated patients also experienced less reemergence of depressive symptoms than sertraline-treated or paroxetine-treated patients (p < .001).

Abrupt interruption of antidepressant therapy for 5-8 days was associated with the emergence of new somatic and psychological symptoms in patients treated with paroxetine and to a lesser degree sertraline, with few symptoms seen with fluoxetine.