TY - JOUR

T1 - Identifying patients with therapy-resistant depression by using factor analysis

AU - Andreasson, K

AU - Liest, V

AU - Lunde, M

AU - Martiny, K

AU - Unden, M

AU - Dissing, S

AU - Bech, P

N1 - © Georg Thieme Verlag KG Stuttgart · New York.

PY - 2010/11/1

Y1 - 2010/11/1

N2 - INTRODUCTION: 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 17-30% 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.

AB - INTRODUCTION: 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 17-30% 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.

KW - Antidepressive Agents

KW - Clinical Trials as Topic

KW - Depressive Disorder, Major

KW - Drug Resistance

KW - Factor Analysis, Statistical

KW - Female

KW - Humans

KW - Male

KW - Placebos

KW - Principal Component Analysis

KW - Psychiatric Status Rating Scales

KW - Transcranial Magnetic Stimulation

KW - Treatment Failure

KW - Treatment Outcome

U2 - 10.1055/s-0030-1263166

DO - 10.1055/s-0030-1263166

M3 - Journal article

C2 - 20821367

VL - 43

SP - 252

EP - 256

JO - Pharmacopsychiatry

JF - Pharmacopsychiatry

SN - 0176-3679

IS - 7

ER -