Effectiveness
of transcranial magnetic stimulation in patients
with drug-resistant major depression
Among
psychiatric disorders major depression is the
mental disease in which repetitive transcranial
magnetic stimulation (rTMS) has been most
extensively applied, mainly as an adjunctive
treatment for drug-resistant patients. Some
studies have suggested that a decreased function
in the prefrontal cortex may be involved in the
pathophysiology of depression. The efficacy of
TMS over the dorsolateral prefrontal cortex has
been studied in drug-resistant depression with
conflicting results. A recent study investigated
the efficacy and safety of high frequency TMS in
drug-resistant depressed patients.
Fifty-four patients, suffering from a severe and
drug-resistant major depressive episode, were
randomly allocated to the sham group or to one
of the two intervention groups according to the
intensity of stimulation, 80% and 100% of motor
threshold (MT). All patients underwent 10
sessions of stimulation, directed to the left
prefrontal cortex, over a 2-week period.
Five out of 18 patients (27.8%) in the 80% MT
group were responders, and 11 out of 18 (61.1%)
in the 100% MT group were responders. In the
sham group only 1 patient out of 16 (6.2%) was a
responder. Using Pearson chi2 test found a
significant difference (p = 0.0008) between the
100% MT and sham groups but not between the 80%
MT and sham groups. A small but significant
difference was observed (p = 0.044) between the
two active groups. Hamilton Rating Scale for
Depression (HAM-D) scores were reduced over time
in the three groups, and a difference among them
emerged at the end of the first week of TMS
treatment, statistically between the 100%
stimulation group and the sham group (p =
0.042). An analysis of variance with repeated
measures for the HAM-D scores showed a
significant decrease over time of depressive
symptoms (p = 0.000002 between the 100% MT group
and the sham group, p = 0.021 between the 100%
group and the 80% group, and p = 0.004 between
the 80% MT group and the sham group). The
treatment was well tolerated.
This study thus confirms that TMS may be a
useful and safe treatment in drug-resistant
depression and highlights that the use of higher
intensities of stimulation can be
beneficial. Rossini
D, Lucca A, Zanardi R, Magri L, Smeraldi E.
Transcranial magnetic stimulation in
treatment-resistant depressed patients: A
double-blind, placebo-controlled trial.
Psychiatry Res 2005, 137:1-10.