Under the Mental Health Act 1993 s 12, a detained person must be examined by a psychiatrist as soon as practicable (within 24 hours of admission if possible). The psychiatrist can confirm or revoke the initial detention order. If the initial detention order is confirmed a psychiatrist may make a further detention order for a period of up to 21 days commencing on the expiry of the initial detention order.

During this 21 day period two psychiatrists who have separately examined the person may extend the period of detention for one (and only one) further period of 21 days. Only one of the psychiatrists can be the same doctor who made the previous order, that is, one must be independent.

During the three day, 21 day or further 21 day periods of detention, a total of up to 45 days, the doctors at the Approved Treatment Centre may compulsorily prescribe medical treatment for the person.[s.18].

In summary, the Mental Health Act 1993 allows doctors a discretion to detain and treat a person in an Approved Treatment Centre where the doctors believe the person has a mental illness and where the other requirements of the Act, (as discussed above), are met. The Director of the Treatment Centre can approve leave of absence for the patient, can arrange to transfer the patient to a more suitable Treatment centre or can revoke the detention order if it is no longer judged necessary.