A composition for use in treating or improving at least one disorder or parameter of sleep in a human subject, the composition comprising the compound of formula or a pharmaceutically acceptable salt, hydrate, or solvate thereof, wherein each symbol in the formula means as follows: a bond represented by a solid line and a dotted line shows a double bond or a single bond; X is a hydrogen atom, a hydroxy group, a C 1 -C 8 alkoxy group, an acyloxy group or an oxo group; R 1 is a group of the following formula wherein R 5 is optionally substituted aryl group or optionally substituted aromatic heterocyclic group, Z is void or --CH 2 --, and R 6 is hydrogen atom, hydroxy group, acetamido group, carboxyl group, alkoxycarbonyl group, cyano group or C 1 -C 8 alkoxy group; R 3 is a hydrogen atom, a C 1 -C 18 alkyl group or a halogen atom; V is --O--; W is void; R 7 is a C 1 -C 4 hydroxyalkyl group, an acyl group, an optionally substituted saturated or unsaturated heterocyclic group, an optionally substituted fused heterocyclic group, a C 1 - C 4 alkylsulfonyl group or the formula --Q--R 9 wherein Q is --C(=O)--, --C(=S)--, --CH 2 -- or --S(=O) 2 --, and R 9 is a group of the following formula or --NH--NH--R 15 wherein R 10 and R 11 are each independently hydrogen atom, C 1 -C 18 alkyl group, optionally substituted aryl group, optionally substituted aralkyl group or alkoxy group, R 12 is hydrogen atom, optionally substituted aryl group, C 1 -C 18 alkyl group, C 1 -C 8 alkoxy group or acyl group, and R 15 is hydrogen atom, phenyl group, C 1 -C 4 alkyl group, C 1 -C 2 halogenated alkyl group, halogen atom, C 2 -C 4 alkenyl group, C 1 -C 4 hydroxyalkyl group, alkoxyalkyl group, alkyloxycarbonyl group, optionally substituted amino group, acetamido group, carboxyl group, acyl group, optionally substituted alkyloxy group, alkylthio group or cyano group; Ra, Rb and Rc are each independently a hydrogen atom, a C 1 -C 18 alkyl group, a hydroxy group, a C 1 -C 8 alkoxy group, a halogen atom, an acyl group, a nitro group or an amino group; an optically active compound thereof, a pharmaceutically acceptable salt thereof or a hydrate thereof; wherein the compound of formula is present in the composition between 0.01 mg/kg and 0.2 mg/kg of the subject's weight, and the subject suffers from depression. wherein each symbol in the formula means as follows: a bond represented by a solid line and a dotted line shows a double bond or a single bond; X is a hydrogen atom, a hydroxy group, a C 1 -C 8 alkoxy group, an acyloxy group or an oxo group; R 1 is a group of the following formula wherein R 5 is optionally substituted aryl group or optionally substituted aromatic heterocyclic group, Z is void or --CH 2 --, and R 6 is hydrogen atom, hydroxy group, acetamido group, carboxyl group, alkoxycarbonyl group, cyano group or C 1 -C 8 alkoxy group; R 3 is a hydrogen atom, a C 1 -C 18 alkyl group or a halogen atom; V is --O--; W is void; R 7 is a C 1 -C 4 hydroxyalkyl group, an acyl group, an optionally substituted saturated or unsaturated heterocyclic group, an optionally substituted fused heterocyclic group, a C 1 - C 4 alkylsulfonyl group or the formula --Q--R 9 wherein Q is --C(=O)--, --C(=S)--, --CH 2 -- or --S(=O) 2 --, and R 9 is a group of the following formula or --NH--NH--R 15 wherein R 10 and R 11 are each independently hydrogen atom, C 1 -C 18 alkyl group, optionally substituted aryl group, optionally substituted aralkyl group or alkoxy group, R 12 is hydrogen atom, optionally substituted aryl group, C 1 -C 18 alkyl group, C 1 -C 8 alkoxy group or acyl group, and R 15 is hydrogen atom, phenyl group, C 1 -C 4 alkyl group, C 1 -C 2 halogenated alkyl group, halogen atom, C 2 -C 4 alkenyl group, C 1 -C 4 hydroxyalkyl group, alkoxyalkyl group, alkyloxycarbonyl group, optionally substituted amino group, acetamido group, carboxyl group, acyl group, optionally substituted alkyloxy group, alkylthio group or cyano group; Ra, Rb and Rc are each independently a hydrogen atom, a C 1 -C 18 alkyl group, a hydroxy group, a C 1 -C 8 alkoxy group, a halogen atom, an acyl group, a nitro group or an amino group; an optically active compound thereof, a pharmaceutically acceptable salt thereof or a hydrate thereof; wherein the compound of formula is present in the composition between 0.01 mg/kg and 0.2 mg/kg of the subject's weight, and the subject suffers from depression.