Trial Platform - Reducing adverse ECT effects on memory by magnetic stimulation,

Depression is of overwhelming public interest simply due to its fequency and the fact that many working hours and lives are lost through it. There is a public interest in making the treatments used as effective, evidence based and user friendly as possible. We, therefore, plan to make the study details and results publicly available, possibly under the umbrella of the Scottish ECT Audit (SEAN).

Electroconvulsive Therapy (ECT) is the most controversial treatment regularly used in British psychiatry. Systematic reviews confirm it as one of the most effective treatments for depression, particularly for the more severe, psychotic form (Kho et al., 2003; UK ECT Review Group, 2003; NICE Guidance: http://www.nice.org.uk/cat.asp?c=68305). Its effect on memory limits its usefulness: ECT interferes with the laying down of new memories and creates islands of memory loss sometimes as far back as 2 years before the treatment started (Donahue, 2000; Lisanby et al., 2000; Prudic et al., 2000; Tang et al., 2002). An urgent effort has, therefore, to be made to find a mode of convulsive treatment that minimises side effects on memory (NICE Guidance: http://www.nice.org.uk/cat.asp?c=68305).

While ECT relies on relatively large electric currents being applied across the head, which partially flow through brain tissue, but also over scalp and superficial muscles, MST (magnetIc seizure therapy) uses strong currents through an electrically insulated coil to create a focussed magnetic field that in turn can generate electric discharges in brain tissue directly under the stimulation coil. If the magnetic stimulus is applied at high frequency (50-100 Hz), the local nerve cell activity can generalise into a grand mal seizure (Kosel et al., 2003; Lisanby et al., 2003a; Lisanby et al., 2003b; Dwork et al., 2004; Morales et al. 2004).

It is thought that ECT side effects on memory are proportional to the amount of electric energy applied to brain tissue. The efficacy of ECT is thought to depend on the precipitation of a seizure. Thus causing a seizure with a minimum of electric current flow should result in the most advantageous balance of costs and benefits. Elaborate techniques have been developed to minimise the energy applied: by building up the current over the first few treatments which results in suboptimal first treatments, or limiting stimulation to the right brain hemisphere. These manoeuvres tend to result in reduced efficacy (Sackeim et al., 2000).

We propose a randomised controlled pilot trial (Trial Platform) of ECT as usual versus MST, predicting that MST causes less cognitive disturbance in patients than ECT, while retaining its efficacy within the power available.