People who undergo electric shock treatment for depression involuntarily have similar outcomes to those who undergo it voluntarily, new Irish research has found.

People who suffer with severe depression can lose the capacity to make decisions and in some cases, they require treatment under mental health law in order to recover.

Electroconvulsive therapy (ECT), also known as electric shock treatment, is the most effective acute treatment for severe depression and is sometimes administered involuntarily.

Every year in Ireland, around 50 people undergo involuntary ECT.

Researchers in the Department of Psychiatry at Trinity College Dublin (TCD) decided to look into this further. This is one of the very few studies to report on people who have undergone involuntary ECT treatment and is the largest study of its kind internationally.

The research team studied the records of five years of involuntary ECT treatment at St Patrick's Mental Health Services in Dublin. They compared 48 involuntary cases with 96 voluntary cases.

The team said the results shed light on a group of patients about which little is known.

"People who require involuntary ECT are among the most severely unwell in our mental health services. Yet, because they generally lack decision-making capacity and cannot take part in research, we do not know for sure if we can apply research advances to persons having involuntary ECT.

"Our knowledge of how best to use ECT to help someone recover from severe depression is based on research samples comprised entirely of people choosing to have voluntary ECT," explained lead researcher, Prof Declan McLoughlin, of TCD.

He said that these results are ‘reassuring for people who have had involuntary ECT and their families'.

"It's also a relief to mental health professionals to know that the research results on which we base treatment decisions for voluntary treatment can now be used with greater confidence to also guide treatment for people having involuntary ECT," Prof McLoughlin noted.

The study found that those who had involuntary ECT were more severely unwell before treatment compared to those having voluntary ECT. They were more likely to have psychotic symptoms such as hallucinations and delusions, and they also had more physical deterioration as a result of severe self-neglect.

However, in both groups, outcomes at the end of ECT, whether voluntary or involuntary, were similar. Overall, the large majority of people said they were ‘very much improved' or ‘much improved' after the treatment.

Prof McLoughlin emphasised however that while ECT is a safe and effective evidence-based treatment, ‘ongoing research is essential to understand who will benefit most from the treatment, and how to help people with depression stay well after recovery'.

Details of these findings are published in the journal, Brain Stimulation.