Rapid cyclerの臨床背景と治療戦略—同等の平均罹病期間を有するnon-rapid cycler症例との比較を中心に

Clinical Background and Treatment strategy for Rapid Cycling Bipolar Affective Disorder: Comparison with non-rapid cycling patients

【抄録】　Rapid cycler（RC）13例を対象に，平均罹病期間のほぼ等しいnon-rapid cycler（NRC）13例と比較しながら，その臨床背景，治療戦略，転帰について調査した，RC群の平均初発年齢はNRC群に比較して有意に若年であった。甲状腺機能低下所見はRC群で有意に多く認められたが，リチウム（Li）服用時のみに甲状腺機能低下を認めた症例数には差がなかった。Li単剤が有効な症例はRC群には皆無であったが，他剤との併用で有効に使用されている症例は少なくなかった。RC群の効果的治療ではレボサイロキシン（T4）の使用頻度が高いほか，双極I型では抗うつ薬の中止とバルプロ酸の併用が，双極II型ではLiの増量，抗うつ薬の再開が有効と考えられた。

　The clinical backgrounds, course, and the most effective treatment in 13 patients with rapid cycling (RC) bipolar affective disorder were compared with those of 13 non-rapid cycling (NRC) patients whose mean affected periods were almost same as the RC subjects. The mean age at onset of affective symptoms for the RCsubjects was 25.3±4.4 (Mean±SD) years, which was significantly lower than the age of those in the NRC group (34.4±5.8 years). Subclinical hypothyroidism was more frequently observed in the RC group (92%) than in the NRC group (31%). Although all of the patients in both groups had received lithium administration once at least before, four RC and three NRC patients exhibited hypothyroid function only during lithium treatment. Five NRC patients and only one RC patient showed no change in their thyroid status despite long-term lithium treatment. Lithium monotherapy was effective in five NRC patients, but not effective in all of the RC patients. Lithium administration had been stopped once in the course oftreatment of all the RC patients, but eight RC patients experienced relief after lithium was resumed subsequently. While discontinuation of antidepressant medication and addition of valproate were effective for bipolar type I RC patients, raising dosage of lithium and resumption of antidepressant drugs seemed to be preferable strategies for the bipolar type II RC patients. Levothyroxine added to the baseline medication regimen resulted in a stablizing effect in 12 RC patients.