The Mental Health Commission has urged the Government to act to change the law to ensure Electro Convulsive Therapy is not used as a treatment for unwilling patients.
Figures released by the commission show a reduction in the number of patients treated with ECT in 2012.
In over 83% of cases where it was used, the patient had a depressive disorder.
The fifth report of the MHC shows a reduction in both the use of ECT and seclusion, where a patient is left alone in a locked room, in Ireland's mental health facilities in 2012.
There were 244 patients treated with ECT that year, down from 332 in 2011.
The report said 27 of those patients were administered ECT without their consent and four were considered to be unwilling to consent.
MHC chairman John Saunders said his position is that it should not be used as a treatment against the will of the patient.
He said imposing ECT on an unwilling patient is a breach of human rights.
The chairman said both the previous and current governments committed to changing the law to ensure this could not happen, but so far there has been no progress.
The report also showed a drop in the use of seclusion, while the figures for use of restraints remained relatively static.
Mental Health Reform has also called on the Government to urgently prohibit the use of Electro Convulsive Therapy against an individual's will.