Daily and spaced treatment with transcranial magnetic stimulation in major depression: a pilot study

Transcranial magnetic stimulation is an emerging treatment of treatment-resistant depression. Current protocols rely on daily treatments. This study was designed to determine whether the time period over which treatment is delivered is an important factor in efficacy.

Sixteen adult patients with treatment-resistant major depression were randomly assigned to one of the two treatment groups, both of which received 2 weeks of treatment. One group received daily treatment (10 treatments, on business days). The other group received three treatments in week one, and two treatments in week two (five treatments, on spaced business days). Mood was rated using the Hamilton Depression Rating Scale (HDRS) and a self-rated visual analogue scale. Response was defined as a 50% reduction in HDRS rating, and remission was defined as achieving an HDRS score of 8 or less. The groups were compared throughout the 2-week study period.

At entry, there were no demographic differences between the groups. Multivariate tests showed a significant main effect for time (Pillai trace=0.76, F(4,56)=8.56, p<0.001, power=0.99) reflecting the improvement in both measures of depression during treatment. There was no significant difference between the groups overall (Pillai trace=0.25, F(2,13)=2.12, p=0.16, power=0.36). Additionally, there was no significant interaction between time and treatment group (Pillai trace=0.18, F(4,56)=1.35, p=0.26, power=0.39) indicating that the significant improvement in depression over time was similar for both treatment groups. There were no significant differences in response and remission rates between the groups.

The time period of treatment appeared to be an important outcome factor. This suggests that less than daily transcranial magnetic stimulation treatment may be a useful clinical alternative.