Table 1.

Factor Structure of 20-item General Health Questionnaire (GHQ) using Principal Axis Analysis with Varimax Rotation Method

General Health Questionnaire Items‡	Factor Loadings*
	Factor 1	Factor 2	Factor 3
Able to concentrate		0.341
Feeling reasonably happy	0.414
Full of energy		0.542
Managing to keep yourself busy and occupied		0.629
Getting out of the house as much as usual		0.496
Felt on the whole that you were doing things well		0.671
Felt that you are playing a useful part in things		0.654
Felt capable of making decisions about things		0.491
Felt constantly under strain	0.680
Felt you couldn't overcome your difficulties	0.539
Able to enjoy your normal day-to-day activities as much as usual		0.509
Been taking things hard	0.623
Able to face up to your problems		0.261
Found everything getting too much for you	0.607
Feeling unhappy and depressed	0.654
Been losing confidence in yourself			0.622
Been thinking of yourself as a worthless person			0.616
Felt that life was entirely hopeless			0.723
Losing sleep because of worry	0.469
Feeling nervous and strung-up all the time	0.600
Eigenvalue (% of variance)	6.285 (31.42)	2.407 (12.04)	1.196 (5.98)

^‡adapted from the 60-item General Health Questionnaire by Goldberg (1978)

^*Factor analysis on the 28-item GHQ from ECA Wave 3 data found that all six apathy items loaded onto a single factor as found with Wave 1 data based on 20 items from the GHQ. The items and their factor loadings are: full of energy: 0.557; managing to keep yourself busy and occupied: 0.597; getting out of the house as much as usual: 0.426; felt on the whole that you were doing well: 0.407; felt that you are playing a useful part in things: 0.618; able to enjoy your normal day-to day activities as much as usual: 0.546. When a confirmatory factor analysis using MPlus software was conducted, the same factors were identified with good model fit (CFI= 0.88; TLI= 0.94; RMSEA=0.114).