Identifying predictive clinical characteristics of the treatment efficacy of mirtazapine monotherapy for major depressive disorder

Figures & data

Figure 1 Study flowchart.

Notes: There were 72 patients with MDD who were treated with mirtazapine monotherapy, and four patients dropped out before the definition of remission. Among 68 depressive subjects, 25 were classified into the remission group, and the treatment efficacy rate of mirtazapine monotherapy was 36.8% (25/68). Oversedation and jitteriness/anxiety syndrome occurred only in the nonremission group, and their incidence was 13.2% (9/68) and 11.8% (8/68), respectively.
Abbreviations: CGI-I, Clinical Global Impression Improvement; MDD, major depressive disorder.

Table 1 Demographic and clinical characteristics of subjects

Characteristics	Remission group (n=25)	Nonremission group (n=43)	P-values
Demographic variables
Age (years)	50.4 (±18.9)	48.3 (±17.5)	0.645
Sex (male/female)	11/14	19/24	0.347
Clinical variables
Onset age	48.2 (±18.8)	45.9 (±17.1)	0.628
Number of recurrent major depressive episodes >2	4 (16.0%)	10 (23.2%)	0.549
Family history of MDD	1 (4.0%)	2 (4.7%)	1.000
Severity (mild/moderate/severe)	6/15/4	8/32/3	0.377
Pharmacologic variables
Duration of mirtazapine monotherapy (week)	10.2±6.3	4.8±6.6	0.002*
Dose of mirtazapine (mg)	27.6±13.5	26.0±141	0.642
Depressive symptoms
Somatic symptoms	12 (48.0%)	19 (44.2%)	0.760
Appetite loss	22 (88.0%)	32 (74.4%)	0.226
Insomnia	23 (92.0%)	39 (90.7%)	1.000
Feelings of guilt	3 (12.0%)	16 (37.2%)	0.029*
Suicidal ideation	4 (16.0%)	8 (18.6%)	1.000
Psychotic symptoms	0 (0%)	4 (9.3%)	0.289
Anxiety	12 (48.0%)	28 (65.1%)	0.167
Psychomotor retardation	20 (80.0%)	24 (55.8%)	0.065
Agitation	3 (12.0%)	9 (20.9%)	0.513

Notes: Data presented as mean ± standard deviation unless otherwise indicated.

* P<0.05.

Abbreviation: MDD, major depressive disorder.

Table 2 Predictors of the treatment efficacy of mirtazapine monotherapy

Predictor	ORa	95% CI	P-value
Severity	0.45	0.16–1.10	0.08
Feelings of guilt	0.15	1.66–37.24	0.006*
Psychomotor retardation	4.26	1.30–16.60	0.016*

Notes:

* P<0.05.

a Calculated by multiple logistic regression analysis using independent variables selected by the stepwise method based on Akaike’s information criterion.¹²

Abbreviations: CI, confidence interval; OR, odds ratio.

Table 3 Confounding factors of the discontinuation rates in mirtazapine monotherapy due to oversedation and jitteriness/anxiety syndrome

Characteristics	Oversedation (+) (N=9)	Oversedation (−) (N=59)	P-value
Age (years)	37.4±19.3	50.8±17.2	0.078
Sex (male/female)	2/7	28/31	0.280
Dose of mirtazapine (mg)	14.2±7.0	28.5±13.6	0.0005*
Combined use of benzodiazepine	3 (0.33%)	36 (0.61%)	0.156
	Jitteriness/anxiety syndrome (+) (N=8)	Jitteriness/anxiety syndrome (−) (N=60)	P-value
Age (years)	51.8±13.6	48.7±18.5	0.579
Sex (male/female)	3/5	27/33	1.000
Dose of mirtazapine (mg)	19.7±12.0	27.5±13.9	0.121
Combined use of benzodiazepine	5 (0.63%)	34 (0.57%)	1.000

Notes: Data presented as mean ± standard deviation unless otherwise indicated. (+) Present; (−) absent.

* P<0.05.

YamaokaKNakagawaTUnoTApplication of Akaike’s information criterion (AIC) in the evaluation of linear pharmacokinetic equationsJ Pharmacokinet Biopharm197862165175671222

 PubMedGoogle Scholar