Patient Beliefs Predict Response to Paroxetine Among Primary Care Patients with Dysthymia and Minor Depression

Article Figures & Data

TABLE 1

Groups Randomized to Paroxetine or Placebo with at Least Four Treatment Sessions.

* There were no significant differences on any variable between groups randomized to paroxetine and placebo.
PAB = Patient Attitudes and Beliefs Scale, SCL = Hopkins Symptom Checklist-57 scales, SF-36 = Medical Outcomes Study Short-Form 36 Scale.

TABLE 2

Possible Predictors of Response to Paroxetine (n = 152).

Variable	Nonresponse		Response		Wald’s t (P Value)
	No.	%	No.	%
Demographics
Sex (female)	28	44	45	51	0.01
Older cohort ≥59 y	47	75	48	54	5.40 (.02)
Ethnicity (majority)	46	73	80	90	5.59 (.02)
Married	30	48	48	54	0.39
Employed	16	25	42	47	2.37
Income, y <$20,000	37	59	42	47	0.26
Veteran	22	35	19	21	1.49
Dysthymia	29	46	52	58	3.30 (.08)
Education ≤13 y	32	51	40	45	0.36
Site					df = 3; 5.81 (.12)
Lebanon	14	22	37	42
Pittsburgh	7	11	11	12
San Antonio	19	30	16	18
Seattle	23	36	25	28
	Mean	SD	Mean	SD
Patient beliefs (PAB)
Biological belief	3.6	0.9	3.0	1.0	11.74 (.001)
Psychological belief	3.5	1.0	3.6	0.8	0.01
Clinical
Duke Severity of Illness	25.3	14.6	19.6	13.2	1.51
NEO—Neuroticism Scale	3.0	0.7	3.1	0.6	0.01
SCL scales
Depression	1.6	0.6	1.5	0.6	0.01
Somatization	1.3	0.6	0.9	0.7	2.46 (.12)
Anxiety	0.9	0.6	0.8	0.6	7.34 (.007)
Hostility	0.7	0.6	0.8	0.6	0.01, 2.68 (.10)
Interpersonal sensitivity	1.1	0.7	1.0	0.7	4.32 (.04)
SF-36 scales
General health	43.4	21.4	58.5	22.2	12.04 (.001)
Physical function	51.6	28.9	64.0	26.9	4.55 (.03)
Role physical	24.6	33.1	47.8	43.2	9.05 (.003)
Role emotional	30.6	37.2	36.0	37.7	0.57
Pain	48.8	20.3	55.0	26.7	1.41
Vitality	30.2	19.1	33.7	19.5	3.58 (.06)
Mental health	53.2	16.3	52.6	17.6	1.25
Social functioning	53.8	26.2	61.0	25.8	4.23 (.04)

PAB = Patient Attitudes and Beliefs Scale, SCL = Hopkins Symptom Checklist-57 scales, SF-36 = Medical Outcomes Study Short-Form 36 Scale.

TABLE 3

Multivariate Model for Remission on Paroxetine.

Predictors	β	df	Wald’s t	Odds Ratio	95% CI
Younger age cohort (<59 y)	0.99	1	4.10^*	2.68	1.03–6.98
Site
Lebanon (ref)	—	3	5.21	—	—
Pittsburgh	0.19	1	0.07	1.20	0.31–4.63
San Antonio	0.61	1	1.18	0.54	0.18–1.64
Seattle	−0.95	1	3.77^*	0.39	0.15–1.00
Biological belief (low)	1.26	1	9.48^†	3.51	1.58–7.80
Dysthymia	0.99	1	5.82^†	2.69	1.20–6.02
SF-36 general health (high)	1.32	1	11.42^‡	3.73	1.74–8.00

TABLE 4

Possible Predictors of Response for Nonresponders (n = 94, 52%) and Responders (n = 86, 49%) Receiving Placebo (n = 180).

Variable	Nonresponders		Responders		Wald’s t (P Value)
	No.	%	No.	%
Demographics
Sex (female)	45	48	54	63	4.42 (.04)
Age cohort >59 y	64	68	52	61	0.95
Ethnicity (majority)	74	79	70	81	4.94
Married	44	47	55	64	4.72 (.03)
Employed	33	35	32	37	0.08
Income, y <$20,000	42	45	41	48	0.29
Veteran	29	31	18	21	3.24 (.07)
Dysthymia	54	57	38	44	2.04
Education <13 y	49	52	35	41	2.70 (.10)
Sites					4.94
Lebanon	27	29	31	36
Pittsburgh	11	12	17	20
San Antonio	25	26	14	16
Seattle	31	33	24	28
	Mean	SD	Mean	SD
Patient beliefs
Biological beliefs	3.4	1.1	3.0	1.2	4.88 (.03)
Psychological beliefs	3.7	0.9	3.4	1.0	2.74 (.10)
Clinical
Duke Severity of Illness	21.7	13.8	19.4	13.2	0.33
NEO—Neuroticism Scale	3.1	0.7	2.9	0.6	5.04 (.02)
SCL scales
Depression	1.6	0.6	1.3	0.6	8.04 (.005)
Somatization	1.1	0.8	0.9	0.6	3.73 (.05)
Anxiety	1.0	0.7	0.8	0.6	8.04 (.005)
Hostility	0.8	0.8	0.6	0.6	2.52 (.10)
Interpersonal sensitivity	1.1	0.8	0.8	0.7	8.83 (.003)
SF-36
General health	50.4	22.9	58.2	20.6	5.04 (.02)
Physical function	57.0	30.7	66.0	27.0	2.38
Role physical	32.0	35.8	44.3	42.4	3.64 (.06)
Role emotional	30.5	37.3	42.3	39.1	3.72 (.05)
Pain	47.0	24.9	57.0	22.5	7.42 (.006)
Vitality	30.1	19.2	36.6	19.5	5.24 (.02)
Mental health	52.6	16.3	57.0	18.3	4.64 (.03)
Social function	54.7	24.7	64.6	22.7	6.75 (.009)

SCL = Hopkins Symptom Checklist-57 scales, SF-36 = Medical Outcomes Study Short-Form 36 scale.

TABLE 5

Multivariate Model Predicting Remission on Placebo.

Predictors	β	df	Wald’s t	Odds Ratio	95% CI
Younger age cohort (>59 y)	0.51	1	1.45	1.66	0.73–3.80
Site
Lebanon (reference)	—	3	5.15	—	—
Pittsburgh	0.81	1	1.99	2.25	0.73–6.98
San Antonio	−0.22	1	0.18	0.80	0.29–2.23
Seattle	−0.33	1	0.68	0.72	0.32–1.58
Sex, female	0.77	1	5.09^*	2.18	1.11–4.27
Baseline depression severity—low	0.99	1	8.61^†	2.70	1.39–5.24