[Problem] To provide a compound which has a positive allosteric modulating effect (PAM effect) for an a7 nicotinic acetylcholine receptor (a7 nACh receptor). [Solution] The inventors have achieved the present invention by making studies on PAM effects for an a7 nACh receptor and confirming that a tetrahydrooxepinopyridine compound has a PAM effect for an a7 nACh receptor. A tetrahydrooxepinopyridine compound according to the present invention has a PAM effect for an a7 nACh receptor, and is promising as a prophylactic or therapeutic agent for dementia, cognitive impairment, schizophrenia, Alzheimer's disease, CIAS, negative symptoms of schizophrenia, inflammatory diseases or pain.
