A medicament dispensing system for dispensing sleep medication, comprising: an electronic dispensing device comprising one or more medicament holding areas being electronically releasable to dispense a controlled dose of medicament; a processing arrangement, operatively coupled to the dispensing device, and adapted to: receive sleep pattern information related to a user from a local or remote source wherein the user sleep pattern information is indicative of patterns in one or more properties of the user's sleep over time and wherein the received sleep pattern information comprises information representative of historical patterns in the one or more properties of the user's sleep and/or projected future sleep pattern information for the user; generate a predicted value or measure for one or more properties of the user's sleep for a future sleep session based on the received user sleep pattern information; and control release of a medicament dose dependent upon an outcome of a release assessment, the release assessment being based at least in part on the predicted value or measure; and characterized in that the user sleep pattern information comprises information indicative of a historical cyclical pattern in one or more sleep properties over a time scale, and the release assessment is based on estimating a current point or phase within the temporal cycle of the cyclical pattern wherein the release assessment comprises determining whether a second order derivative in the cyclical pattern is negative at said estimated current point or phase in the temporal cycle. an electronic dispensing device comprising one or more medicament holding areas being electronically releasable to dispense a controlled dose of medicament; a processing arrangement, operatively coupled to the dispensing device, and adapted to: receive sleep pattern information related to a user from a local or remote source wherein the user sleep pattern information is indicative of patterns in one or more properties of the user's sleep over time and wherein the received sleep pattern information comprises information representative of historical patterns in the one or more properties of the user's sleep and/or projected future sleep pattern information for the user; generate a predicted value or measure for one or more properties of the user's sleep for a future sleep session based on the received user sleep pattern information; and control release of a medicament dose dependent upon an outcome of a release assessment, the release assessment being based at least in part on the predicted value or measure; and receive sleep pattern information related to a user from a local or remote source wherein the user sleep pattern information is indicative of patterns in one or more properties of the user's sleep over time and wherein the received sleep pattern information comprises information representative of historical patterns in the one or more properties of the user's sleep and/or projected future sleep pattern information for the user; generate a predicted value or measure for one or more properties of the user's sleep for a future sleep session based on the received user sleep pattern information; and control release of a medicament dose dependent upon an outcome of a release assessment, the release assessment being based at least in part on the predicted value or measure; and characterized in that the user sleep pattern information comprises information indicative of a historical cyclical pattern in one or more sleep properties over a time scale, and the release assessment is based on estimating a current point or phase within the temporal cycle of the cyclical pattern wherein the release assessment comprises determining whether a second order derivative in the cyclical pattern is negative at said estimated current point or phase in the temporal cycle.