Ms S had been suffering from acne vulgaris since the start of puberty. In December 2010 treatment was initiated with the oral vitamin A derivative isotretinoin, 20 mg/day. She took the medication for 3 weeks, during which time the psychotic condition developed insidiously. A clear temporal link between starting the vitamin A derivative

and developing the disorder was reported by both relatives and also by the Ribociclib solubility dmso patient Inhibitors,research,lifescience,medical herself. Once the vitamin A derivative was discontinued, the psychotic symptoms quickly improved and fully remitted within 10 days. Despite the patient’s complete remission, for security reasons a neuroleptic treatment with quetiapine was initiated a few days later and titrated up to 400 mg as Inhibitors,research,lifescience,medical a prophylactic measure. The reason for this decision was the fact that our patient was entering a particularly

demanding phase at university and her positive family history for bipolar disorder. The acne vulgaris was treated systemically for 14 days with 50 mg oral doxycycline and topical acne gel (clindamycin 10mg, benzoyl peroxide 50 mg) and ketoconazole 2% (20mg) solution. After 6 weeks of dermatological treatment the acne vulgaris was almost completely remitted. The Inhibitors,research,lifescience,medical patient tolerated quetiapine well and showed no recurrence of psychopathological symptoms, which were also absent at the regular follow-up investigations (the most recent of which was in October 2011). Treatment with Inhibitors,research,lifescience,medical quetiapine is being continued for now. Discussion Excess dietary vitamin A has been reported to induce psychosis [O’Reilly et al. 2008]. However, case reports suggest that isotretinoin is associated predominantly with depression and suicidal behaviour [Citrome, 1998; Hazen et al. 1983; Wysowski and Swartz, 2005]. Our case reveals the importance of regular psychiatric examination of any patient being treated with vitamin A derivates. Moreover, any psychiatric

side effects during treatment with vitamin A should be recorded in special drug registers to allow better assessment of the incidence of psychotic symptoms with this treatment. Footnotes Funding: Inhibitors,research,lifescience,medical This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. Conflict of STK38 interest statement: The authors declare no conflicts of interest in preparing this letter. Contributor Information Felix Maximilian Segmiller, Ludwig Maximilian University, Nussbaumstrasse 7, 80336 Munich, Germany. Tobias Rüther, Department of Psychiatry and Psychotherapy, Ludwig Maximilian University, Munich, Germany. Andrea Linhardt, Department of Psychiatry and Psychotherapy, Ludwig Maximilian University, Munich, Germany. Sandra Dehning, Department of Psychiatry and Psychotherapy, Ludwig Maximilian University, Munich, Germany. Hans-Jürgen Möller, Department of Psychiatry and Psychotherapy, Ludwig Maximilian University, Munich, Germany.