Effects of noradrenergic stimulation on memory in patients with major depressive disorder

Figures & data

Table I.  Experimental protocol indicating time of cognitive testing.

Day	Time	Procedure^*
Day 1	1500	Saliva sampling, heart rate, blood pressure
		Word list learning and immediate recall^†
	1515	Administration of yohimbine or placebo
	1615	Saliva sampling, heart rate, blood pressure
		AMT^‡
		Working memory test
	1645	Saliva sampling, heart rate, blood pressure
Day 2	1615	Word list (delayed recall)^†

Notes: ^*One week later the study protocol was repeated using the alternate condition (yohimbine/placebo) and parallel versions of the memory tests (word list, AMT)

^† Test of memory consolidation

^‡ Test of memory retrieval.

Table II.  Sociodemographic and clinical characteristics.

	MDD	Controls
Characteristics	(n = 20)	(n = 18)	Statistics
Age	35.1 (9.9)	35.3 (10.0)	tdf36 = − 0.06, p = 0.96
Gender (f/m)	16/4	15/3	χ^2 df1 = 0.07, p = 0.79
BMI	23.8 (4.4)	23.3 (4.0)	tdf36 = 0.39, p = 0.69
Years of school education	10.8 (1.5)	10.7 (1.3)	tdf36 = 0.16, p = 0.87
LPS 3 & 4	54.6 (9.4)	52.6 (8.7)	tdf36 = 0.66, p = 0.51
BDI sum^*	22.1 (9.7)	6.2 (7.5)	tdf35 = 5,48, p < 0.001
CTQ^†
Emotional abuse	11.4 (6.4)	9.2 (4.6)	tdf34 = 1.16, p = 0.25
Physical abuse	7.4 (5.4)	6.0 (1.6)	tdf34 = 1.04, p = 0.31
Sexual abuse	6.1 (4.6)	6.5 (4.3)	tdf34 = − 0.27, p = 0.78
Emotional neglect	14.9 (5.6)	9.7 (4.5)	tdf34 = 3.12, p = 0.004
Physical neglect	8.6 (2.2)	8.0 (3.9)	tdf34 = 0.56, p = 0.75
Total score	48.4 (19.2)	39.4 (15.9)	tdf34 = 1.53, p = 0.17

Notes: MDD, major depressive disorder; BMI, body mass index; LPS, “Leistungsprüfsystem” (intelligence test); BDI, Beck Depression Inventory

^* One control participant did not answer the BDI

^† One MDD patient and one control participant did not answer the CTQ.

Figure 1.  SBP, DBP, and heart rate (mean [SE]) before and after administration of yohimbine and placebo in patients with MDD and healthy controls. Yohimbine leads to an increase in blood pressure but did not affect heart rate.

Figure 2.  Salivary alpha amylase (mean [SE]) before and after administration of yohimbine and placebo in patients with MDD and healthy controls.

Figure 3.  Percentage of words retrieved in the word list paradigm in relation to the last learning list on the previous day (mean [SE]) in patients with MDD and healthy controls after placebo and after administration of 5 mg yohimbine There was a significant effect of drug condition (p = 0.05).

Table III.  Results of the AMT and the working memory test (mean/SD).

	MDD	Controls
	(n = 20)	(n = 18)
AMT—Specificity
Placebo	3.9 (1.7)	3.5 (1.7)
Yohimbine	3.8 (1.6)	3.3 (1.6)
Working memory—neutral
Placebo	8.1 (1.3)	7.8 (2.3)
Yohimbine	8.3 (2.1)	7.9 (2.5)
Working memory—negative
Placebo	8.5 (1.8)	7.6 (2.4)
Yohimbine	8.3 (1.8)	7.7 (2.8)

Notes: MDD, major depressive disorder; AMT, autobiographical memory test.

Table IV.  Multiple regression analyses predicting the effects of yohimbine on memory consolidation in patients with MDDs (N = 19).

Predictor variables	Statistics^*
Step 1	Model
	Fdf5,13 = 4.571
	corr. R ^2 = 0.499
	p = 0.013
CTQ	β	T	p
Emotional abuse	0.233	0.623	0.54
Physical abuse	− 0.454	− 1.444	0.17
Sexual abuse	0.665	3.232	0.007
Emotional neglect	− 0.932	− 3.073	0.009
Physical neglect	0.640	2.948	0.01
Step 2	Model
	Fdf6,13 = 3.837
	corr. R ^2 = 0.489
	p = 0.023
CTQ	β	T	p
Emotional abuse	0.249	0.58	0.52
Physical abuse	− 0.410	1.271	0.29
Sexual abuse	0.561	2.310	0.04
Emotional neglect	− 0.942	− 3.066	0.01
Physical neglect	0.613	2.762	0.02
BDI	0.168	0.836	0.42
Step 3	Model
	Fdf9,9 = 3.340
	corr. R ^2 = 0.540
	p = 0.043
CTQ	β	T	p
Emotional abuse	0.245	0.67	0.52
Physical abuse	− 0.338	− 1.044	0.32
Sexual abuse	0.636	2.709	0.02
Emotional neglect	− 1.061	− 3.370	0.008
Physical neglect	0.646	2.944	0.02
BDI	0.038	0.188	0.85
Age	− 0.271	− 1.438	0.18
Years of education	− 0.240	− 1.155	0.28
LPS 3 & 4	0.151	0.857	0.41

Notes: ^*Dependent variable: memory consolidation after yohimbine minus memory consolidation after placebo.