Abstract
Attempts to identify the factor structure in patients with treatment-resistant depression have been very limited. Methods: Principal component analysis was performed using the baseline datasets from 3 add-on studies [2 with repetitive transcranial magnetic stimulation and one with transcranial pulsed electromagnetic fields (T-PEMF)], in which the relative effect as percentage of improvement during the treatment period was analysed. Results: We identified 2 major factors, the first of which was a general factor. The second was a dual factor consisting of a depression subscale comprising the negatively loaded items (covering the pure depression items) and a treatment resistant subscale comprising the positively loaded items (covering lassitude, concentration difficulties and sleep problems). These 2 dual subscales were used as outcome measures. Improvement on the treatment resistant subscale was 40% in the active treatment group compared to 1730% improvement in the sham treatments. Discussion: It is possible to describe patients with therapy-resistant depression by a factor structure. Both rTMS and T-PEMF had a clinical effect on the factor-derived scales when compared to sham treatment.
| Original language | English |
|---|---|
| Journal | Pharmacopsychiatry |
| Volume | 43 |
| Issue number | 7 |
| Pages (from-to) | 252-6 |
| Number of pages | 5 |
| ISSN | 0176-3679 |
| DOIs | |
| Publication status | Published - 1 Nov 2010 |
Keywords
- Antidepressive Agents
- Clinical Trials as Topic
- Depressive Disorder, Major
- Drug Resistance
- Factor Analysis, Statistical
- Female
- Humans
- Male
- Placebos
- Principal Component Analysis
- Psychiatric Status Rating Scales
- Transcranial Magnetic Stimulation
- Treatment Failure
- Treatment Outcome