Risk factors for an anxiety disorder comorbidity among Thai patients with bipolar disorder: results from the Thai Bipolar Disorder Registry

Figures & data

Table 1 Bipolar disorder illness course and current clinical characteristics in association with comorbid anxiety disorder

		Comorbid anxiety disorder
		Yes (N=53)	No (N=371)	P-value
Family history
Presence of psychiatric disorder	N=423
Yes	132	14 (10.6%)	118 (89.4%)	0.26
No	291	39 (13.4%)	252 (86.6%)
Presence of substance use disorder	N=132
Yes	4	1 (25%)	3 (75%)	0.37
No	128	13 (10.2%)	115 (89.8%)
Illness course of BD
Age (year) mean ± SD	N=424
1. Age onset of mood disturbance	32.0±11.9	28.5±10.8	32.5±12.0	0.02
2. Age onset of BD	36.1±12.2	32.9±11.2	36.6±12.3	0.04
3. Age at the first treatment for BD	36.2±12.2	33.1±11.3	36.6±12.3	0.05
4. Duration of BD	10.7±9.0	9.8±8.5	10.8±9.1	0.42
Polarity of the first lifetime mood episode	N by subtype
1. Mixed	28	10 (35.7%)	18 (64.3%)	<0.01
2. Depressed	109	17 (15.6%)	92 (84.6%)
3. Manic/hypomanic	274	26 (9.5%)	248 (90.5%)
4. Unknown	13	0 (0.0%)	13 (100.0%)
Current clinical status (baseline)	N=424
The current age (years) mean ± SD	42.7±12.3	38.6±10.9	43.29±12.4	0.008
Pole of the current mood episode	N by subtype
1. Recovered	255	20 (8.5%)	235 (91.5%)	<0.01
2. Recovering	48	7 (17.1%)	41 (82.9%)
3. Roughening	3	0 (0.0%)	3 (100.0%)
4. Continued symptomatic	26	1 (4.0%)	25 (96.0%)
5. Depressed	30	13 (76.5%)	17 (23.5%)
6. Mixed	20	6 (42.9%)	14 (57.1%)
7. Manic	29	4 (16.0%)	25 (84.0%)
8. Hypomanic	13	2 (18.2%)	11 (91.8%)
Psychometric scales mean ± SD	N=424
1. Thai YMRS	3.8±5.6	5.3±5.5	3.6±5.6	0.05
2. Thai MADRS	4.8±6.6	10.4±7.8	4.0±6.0	<0.01
3. CGI-BP-S-mania	1.7±1.2	2.0±1.4	1.6±1.1	0.04
4. CGI-BP-S-depression	1.5±1.1	2.4±1.5	1.4±0.9	<0.01
5. CGI-BP-S-overall BP illness	1.9±1.3	2.5±1.4	1.7±1.2	<0.01
Suicidal risk	N=424
1. No	314	30 (9.6%)	284 (90.4%)	<0.01
2. Low	90	16 (17.8%)	74 (82.2%)
3. Moderate	11	4 (36.4%)	7 (63.6%)
4. High	9	3 (33.3%)	6 (66.7%)
Current substance use disorder	N=424
1. Positive	38	6 (15.8%)	32 (84.2%)	0.45
2. Negative	386	47 (12.2%)	339 (87.8%)
Quality of life SF-36 Thai version mean ± SD	N=424
1. Physical functioning	81.8±20.0	76.3±21.0	82.6±19.7	0.03
2. Role physical	70.2±40.2	38.7±39.4	74.8±38.3	<0.01
3. Bodily pain	76.4±23.3	60.2±26.7	78.8±22.3	<0.01
4. General health	58.1±22.8	60.9±21.6	38.2±21.1	<0.01
5. Vitality	60.4±16.3	46.1±17.9	62.3±15.0	<0.01
6. Social functioning	77.3±24.1	55.7±27.8	80.4±21.9	<0.01
7. Role emotional	63.9±42.1	33.3±38.1	68.3±40.9	<0.01
8. Mental health	70.0±18.3	72.2±17.2	53.7±17.3	<0.01

Abbreviations: BD, bipolar disorder; CGI-BP-S, Clinical Global Impression Severity of Illness Scale for Bipolar Disorder; MADRS, Montgomery–Åsberg Depression Rating Scale; SD, standard deviation; YMRS, Young Mania Rating Scale.

Table 2 Multivariate analysis of factors associated with comorbidity

Factor	Wald	df	Odds ratio	95% CI	P-value
Substance use disorder in the family	5.14	1	2.18	1.11–4.27	0.02
MADRS score	25.24	1	1.10	1.06–1.15	<0.01
Age of onset of BD	27.07	1	0.95	0.93–0.97	<0.01

Notes: R² is 0.228; −2 log likelihood is 73.24; Hosmer–Lemeshow test’s P=0.656.

Abbreviations: MADRS, Montgomery–Åsberg Depression Rating Scale; BD, bipolar disorder; Wald, Wald statistic; df, degrees of freedom; CI, confidence interval.