Lamotrigine-induced mania in adolescents.

Stephanie Moor, Sue Luty, and Peter Joyce, Psychotherapy for Bipolar Study, Department of Psychological Medicine, Christchurch School of Medicine, University of Otago, New Zealand: The treatment of bipolar depression is adolescents is not well researched and pharmacological strategies are supported only by case series data [1 5]. Lamotrigine is increasingly recognized as efficacious and is well tolerated as a mood stabilizer in adults with bipolar disorder [6], particularly in the depressive phase [7]. The small number of studies in youth suggest that, as in adults, adolescents with bipolar disorder appear to respond to treatment with lamotrigine, with decreases in depression, mania, and aggression [4]. Lamotrigine has recently been fully funded in New Zealand for use in bipolar disorder although its use in children and adolescents is ‘off label’. We report two cases of lamotrigine-induced mania in the first two (and only) young people we have treated with lamotrigine for bipolar depression. Patient A was a 17-year-old school girl with a 2 year history of bipolar 1 disorder characterized by alternating mixed mood states and depressive episodes with no previous mania. She also had a previous history of comorbid substance abuse with alcohol, marijuana and stimulant drugs (methylphenidate) but for the last 6 months admitted to only abusing alcohol, which was confirmed by urine tests. She was managed on lithium and quetiapine. Following a 4 month period of pervasive low mood with significant impairment in functioning, she was commenced on a trial of lamotrigine. At 25 mg daily she described elevated mood, racing thoughts and agitated behaviour, increased sexual interest and grandiose ideation but no psychosis. On withdrawal of the lamotrigine her symptoms resolved spontaneously within 10 days. Patient B was also a 17-year-old girl with a 3 year history of bipolar 1 disorder that presented with mania. Over the subsequent years her functioning both academically and socially was significantly impaired with long episodes of depression. She had previously had a mixed mood state induced by a selective serotonin re-uptake inhibitor and was on therapeutic doses of lithium and quetiapine. There was no history of substance abuse. Lamotrigine was commenced after a 4 month period of increasing low mood and marked suicidality and was titrated slowly over 8 weeks to 100 mg daily as recommended in this age group [4]. She began to notice an effect on mood at the 50 mg day 1 level and became more motivated and had energy and interest in previously neglected activities. After being on lamotrigine (100 mg daily) for 2 weeks, her energy levels and drive became more marked and by 4 weeks she became manic and required hospitalization. A literature search of journals and adverse report data bases for mania induction by lamotrigine yielded few cases [5,8 10], with only one in childhood [5]. We report these two cases to alert colleagues to this serious effect, which may be a feature of lamotrigine use in younger patients with bipolar disorder.