PROBLEM TO BE SOLVED: To provide a pharmaceutical composition used in prevention of and/or therapeutic agents against various diseases involving phosphodiesterase 10(PDE10), e.g. mental disorders and neurodegeneration disorders.SOLUTION: Compounds having a 4-heteroarylpyrazole-5-carboxylic acid amide structure of formula (I) and their pharmaceutically acceptable salts and solvates are provided. A pharmaceutical composition which contains one or more of the compounds and their pharmaceutically acceptable salts and solvates as an effective ingredient and has a PDE10 inhibitory effect and a medicinal application consisting of administration of one or more of the compounds and their pharmaceutically acceptable salts and solvates to patients are also provided.【課題】ホスホジエステラーゼ１０（ＰＤＥ１０）が関与する各種疾患（例えば、精神障害、神経変性障害等）の予防及び／又は治療剤に用いられる医薬組成物の提供。【解決手段】式（Ｉ）で表される４－ヘテロアリールピラゾール－５－カルボン酸アミド構造を持つ化合物、或いはそれらの製薬学的に許容される塩、又はそれらの溶媒和物、及び、当該化合物、或いはそれらの製薬学的に許容される塩又はそれらの溶媒和物を有効成分として含有するＰＤＥ１０阻害作用を有する医薬組成物。亦、該化合物、それらの製薬学的に許容される塩、又はそれらの溶媒和物の医薬用途として患者への投与。【選択図】なし
