No change in N-acetyl aspartate in first episode of moderate depression after antidepressant treatment: ¹H magnetic spectroscopy study of left amygdala and left dorsolateral prefrontal cortex

Figures & data

Figure 1 Left dorsolateral prefrontal cortex.

Abbreviations: NAA, N-acetyl aspartate; Cr, creatine.

Figure 2 Left amygdala.

Abbreviations: NAA, N-acetyl aspartate; Cr, creatine.

Table 1 Group characteristics

	Participants (n=29)	Responders (n=17)	Nonresponders (n=12)	P-value
Age, mean (SD)	46.6±7.5	47.0±5.7	46.0±9.7	0.729*
Sex
Male	17	8	9	0.132†
Female	12	9	3
MADRS baseline, mean ± SD		31.4±5.01	32.3±4.09	0.637*
MADRS endpoint, mean ± SD		8.9±3.35	23.7±3.85	0.000*
HAMD baseline, mean ± SD		25.7±4.09	31.1±4.06	0.002*
HAMD endpoint, mean ± SD		8.2±2.94	22.3±2.84	0.000*
BDI baseline, mean ± SD		24.1±8.82	31.1±4.78	0.020*
BDI endpoint, mean ± SD		7.8±3.60	24.9±4.14	0.000*
NAA/Cr DLPFC, mean ± SD, baseline	1.30±0.22	1.31±0.20	1.29±0.24	0.795*
NAA/Cr amygdala, mean ± SD, baseline	1.23±0.22	1.24±0.21	1.21±0.25	0.718*
NAA/Cr DLPFC, mean ± SD, endpoint	1.33±0.20	1.32±0.20	1.34±0.20	0.757*
NAA/Cr amygdala, mean ± SD, endpoint	1.21±0.23	1.18±0.23	1.25±0.21	0.471*

Notes:

* Student’s t-test

† chi-square test.

Abbreviations: MADRS, Montgomery-Asberg Depression Rating Scale; HAMD, Hamilton Rating Scale for Depression; BDI, Beck Depression Inventory; SD, standard deviation; NAA/Cr, N-acetyl aspartate/creatine ratio; DLPFC, dorsolateral prefrontal cortex.

Figure 3 Box plots of NAA/Cr, showing baseline and endpoint in DLPFC and amygdala for all subjects. Shown are medians (squares), interquartile ranges (boxes), and nonoutlier range (whiskers).

Abbreviations: NAA/Cr, N-acetyl aspartate/creatine ratio; DLPFC, dorsolateral prefrontal cortex; F1, baseline in DLPFC; F2, endpoint in DLPFC; A1, baseline in amygdala; A2, endpoint in amygdala.

Figure 4 Box plots of NAA/Cr in responders and nonresponders to antidepressant treatment showing baseline and endpoint in DLPFC and amygdala. Shown are medians (squares), interquartile ranges (boxes), and nonoutlier range (whiskers).

Abbreviations: NAA/Cr, N-acetyl aspartate/creatine ratio; DLPFC, dorsolateral prefrontal cortex; F1, baseline in DLPFC; F2, endpoint in DLPFC; A1, baseline in amygdala; A2, endpoint in amygdala.

Table 2 Changes in scales and NAA/Cr ratios from baseline to endpoint

	n	All subjects	Responders	Nonresponders	P-value
MADRS	29	−16.75 (8.16)	−22.53 (4.62)	−8.58 (3.77)	<0.001
HAMD	29	−13.89 (5.88)	−17.53 (4.15)	−8.75 (3.69)	<0.001
BDI	29	−12.13 (8.30)	−16.35 (7.81)	−6.17 (4.54)	<0.001
NAA/Cr A	29	−0.026 (0.260)	−0.036 (0.25)	−0.003 (0.29)	0.791
NAA/Cr F	29	−0.003 (0.241)	−0.016 (0.23)	0.016 (0.27)	0.767

Note: Values are shown as the mean (standard deviation).

Abbreviations: A, amygdala; F, dorsolateral prefrontal cortex; MADRS, Montgomery-Asberg Depression Rating Scale; HAMD, Hamilton Rating Scale for Depression; BDI, Beck Depression Inventory; NAA/Cr, N-acetyl aspartate/creatine ratio.

Table 3 Correlations of changes in scale scores with changes in NAA/Cr ratios from baseline to endpoint

		Difference endpoint – baseline
		NAA/Cr F	NAA/Cr A
Difference endpoint – baseline	MADRS	0.1442	0.0530
		P=0.556	P=0.829
	HAMD	−0.0737	0.1338
		P=0.764	P=0.585
	BDI	0.3044	0.1521
		P=0.205	P=0.534

Abbreviations: A, amygdala; F, dorsolateral prefrontal cortex; MADRS, Montgomery-Asberg Depression Rating Scale; HAMD, Hamilton Rating Scale for Depression; BDI, Beck Depression Inventory; NAA/Cr, N-acetyl aspartate/creatine ratio.

Table 4 Correlations of changes in scale scores with changes in NAA/Cr ratios from baseline to endpoint in responders and nonresponders

	Responders		Nonresponders
	Diff NAA/Cr F	Diff NAA/Cr A	Diff NAA/Cr F	Diff NAA/Cr A
Diff MADRS	0.3563	0.1609	0.0124	−0.6119
	P=0.232	P=0.600	P=0.981	P=0.197
Diff HAMD	−0.1132	0.3163	−0.0579	0.5784
	P=0.713	P=0.292	P=0.913	P=0.229
Diff BDI	0.4029	0.1246	0.2950	0.0479
	P=0.172	P=0.685	P=0.570	P=0.928

Abbreviations: A, amygdala; F, dorsolateral prefrontal cortex; MADRS, Montgomery-Asberg Depression Rating Scale; HAMD, Hamilton Rating Scale for Depression; BDI, Beck Depression Inventory; NAA/Cr, N-acetyl aspartate/creatine ratio; Diff, difference.