ECT has been the most effective treatment of depression for decades. Despite of this, neither
the mechanism of action or side-effects are fully elucidated. The reason why some patients
relapse shortly after remission is still not completely understood. Thus, there is a need to
find predictors of the favourable clinical effect, relapse and side-effects. ECT is
considered by professionals to be a safe procedure. Additionally, many patients do not
consent to this treatment because they fear a permanent loss of memory or that they will
contract a brain damage after the completed ECT series. Therefore, it is very important to
examine whether ECT might have negative effects on the structure or function of the brain,
using state of the art Magnetic Resonance Imaging (MRI) techniques.
DANSECT is a prospective, observational follow-up study with the aim of examining why
cognitive side-effects of ECT occur and potentially find predictors for whom they may affect
by investigating the ECT-associated cognitive disturbances, structural brain changes and
clinical outcomes. Second, DANSECT examines the mechanisms of effect of ECT.
DANSECT comprises an ECT-group (30 patients) and a clinical control group (30 patients). The
former consists of patients with depression receiving ECT, and the latter consists of matched
patients with depression treated pharmacologically. The examinations will take place at three
time-points; before, immediately after ECT or just before discharge, and 6 months after.
DANSECT is a naturalistic clinical project. This means that the number of ECT sessions given
to the patients in the ECT-group is up to the referring physician.
The aim of DANSECT is to investigate the cognitive side-effects of ECT. Specifically, the
research project aims to examine:
Prevalence, extent and persistence of adverse cognitive effects following ECT.
Associations between neuroimaging findings and cognitive changes following ECT.
Predictors of adverse cognitive effects of ECT.
Hypotheses:
Consistency in autobiographical memories will be reduced over time in both study groups.
However, the reduction will be significantly larger for the ECT patients after ECT
compared to the control group. The group difference is expected to be present at both
short-term and long-term.
Autobiographical memory deterioration is expected to correlate with volumetric changes
of the hippocampi.
Processing speed, anterograde memory and executive functions will be temporarily
deteriorated after ECT. The cognitive changes will correlate with volumetric brain
changes and changes in structural connectivity.
Baseline atrophy, age, years of education and cognitive reserve will predict the
cognitive side-effects following ECT.
Machine learning will reveal patterns and inference enabling the development of a
predictive model of clinical and cognitive outcome after treatment with ECT, by
combining neuropsychological tests, structural and functional neuroimaging (MRI) and
other neurobiological measures.
In addition, the aim of DANSECT is to investigate the mechanisms of effect of ECT. The
secondary aims of the project are thus to examine:
Clinical, biochemical and neurobiological predictors of response to ECT
Clinical, biochemical and neurobiological predictors of relapse of depression after ECT
Biochemical and neurobiological mechanisms of response to ECT
Hypotheses:
Smaller baseline hippocampal volume is associated with a larger post-pre reduction of
depressive symptoms
Thinner cortical thickness predicts better clinical improvement
The cortisol trajectory before ECT is associated with clinical outcome
Elevated peripheral baseline VEGF is associated with a larger post-pre reduction of
depressive symptoms
Baseline microRNA levels are associated with clinical outcome
A higher baseline structural connectivity predicts better clinical improvement
A larger post-ECT increase in hippocampal volume, cortical thickness, BDNF and VEGF
predicts a lower risk of relapse within six months after an ECT series