Medication used to treat schizophrenia and manic episodes can now include a digital tracker that alerts doctors if patients fail to keep up with their prescription.

US regulatory board the FDA (Food and Drug Administration) approved the use of the digitally enhanced pills, called Abilify MyCite, as it is an objective way to monitor a patients schedule. It can also be used for patients suffering from bipolar disorder and depression.

A sensor in the pill will send a message to a wearable patch once it has been ingested. The patch then relays the signal to a mobile application. FDA Center for Drug Evaluation and research employee Mitchell Mathis said technology could benefit patients. "The FDA supports the development and use of new technology in prescription drugs and is committed to working with companies to understand how technology might benefit patients and prescribers."

"Being able to track ingestion of medications prescribed for mental illness may be useful for some patients," Mathis said.

Experts, such as Harvard Medical School instructor Ameet Sarpatwari, said the pill "has the potential to improve public health" but "if used improperly, it could foster more mistrust instead of trust", according to the New York Times.

The digital part of the pill is about the size of a grain of salt and becomes active when in contact with stomach juices. A completed circuit then generates a small electrical charge, which is detected by the patch. The detection process takes between 30 minutes and two hours. The information can only be sent from the smartphone to the patient's doctor if the person agrees.

The patch will also be able to record activity levels, heart rate, steps and sleeping patterns. It will need to be replaced every seven days.