Symptoms of delusion: the effects of discontinuation of low-dose venlafaxine

OBJECTIVE: We report a patient who experienced delusional symptoms during gradual discontinuation of low-dose venlafaxine and required antipsychotic treatment. METHOD: Case report. RESULTS: A 31-year-old woman with major depression had been treated abroad with venlafaxine before returning to Japan. Since venlafaxine is unavailable here, we supplemented her regular venlafaxine dosage of 37.5 mg/day with clomipramine 20 mg/day. After 5 weeks we reduced venlafaxine to 18.75 mg/day and uptitrated clomipramine to 40 mg/day. Four days later she developed delusions of reference, palpitations and nausea. Clomipramine was increased to 60 mg/day, and her symptoms subsided. Eight weeks later her supply of venlafaxine ran out, and within 4 days her condition deteriorated into more severe symptoms that required 4 months’ antipsychotic treatment. CONCLUSION: We speculate that her symptoms were discontinuation syndrome, including psychotic symptoms and physical symptoms, caused by (i) venlafaxine-clomipramine interaction and/or (ii) the serotonin reuptake inhibitor-like effects of low-dose venlafaxine.