Clinical and Physiological Correlates of Irritability in Depression: Results from the Netherlands Study of Depression and Anxiety

Table 1

Demographic and clinical characteristics of low and high irritable depressed patients: univariate results.

	Low irritable (𝑁=493)	High irritable (𝑁=420)
Demographic features
Age (mean ± SD)	43.4 ± 12.3	40.7 ± 11.7	𝜂^2=.012 *
Sex (% female)	65.9	65.7	OR = 0.99 (CI: 0.75–0.30)
Recruited from:
Specialized mental health care (%)	45.2	58.6	OR = 1.71** (CI: 1.32–2.23)
Community + primary care (%)	54.8	41.4
Clinical features
Age of onset (mean ± SD)^‡	28.6 ± 13.1	26.6 ± 12.2	𝜂^2=.006 *
Smoking (% yes)	43.4	48.1	OR = 1.21 (CI: 0.93–1.57)
Alcohol (% recent abuse and/or dependence)	8.5	8.1	OR = 0.95 (CI: 0.59–1.52)
Comorbid anxiety (CIDI diagnosis%)	73.6	80.2	OR = 1.45* (CI: 1.06–1.99)
GAD (%)	24.9	36.7	OR = 1.74** (CI: 1.31–2.31)
Panic disorder (%)	22.7	37.1	OR = 2.01** (CI: 1.51–2.68)
Social phobia (%)	26.2	39.0	OR = 1.82** (CI: 1.37–2.39)
IDS total score (mean ± SD)^a	27.8 ± 10.1	37.7 ± 9.5	𝜂^2=.204 **
First degree family history with depression (%)	84.4	85.0	OR = 1.05 (CI: 0.73–1.51)
Beck Anxiety Inventory (mean ± SD)	15.8 ± 9.4	23.8 ± 11.4	𝜂^2=.128 **
Suicidality (% ≥1 attempt during lifetime)	17.4	25.2	OR = 1.60* (CI: 1.16–2.20)
	Low irritable (𝑁=202)	High irritable (𝑁=138)
MDQ (% yes)
Elated mood	28.8	32.0	OR = 1.20 (CI: 0.88–1.64)
Increased self-confidence	39.4	39.9	OR = 1.02 (CI: 0.76–1.37)
Less sleep needed	42.0	44.0	OR = 1.09 (CI: 0.81–1.45)
More and/or faster speech	50.7	57.5	OR = 1.34 (CI: 1.01–1.79)*
Racing thoughts	75.6	84.5	OR = 1.84 (CI: 1.27–2.68)*
Concentration problems	74.6	85.3	OR = 2.06 (CI: 1.41–3.00)**
More energy	44.6	45.7	OR = 1.06 (CI: 0.80–1.42)
Increased activity	49.8	48.7	OR = 0.98 (CI: 0.73–1.30)
Heightened sociability	23.9	28.4	OR = 1.27 (CI: 0.92–1.76)
Increased libido	29.1	32.8	OR = 1.20 (CI: 0.88–1.64)
Risk taking	25.8	32.8	OR = 1.41 (CI: 1.03–1.93)
Financial risk taking	13.4	18.2	OR = 1.45 (CI: 0.98–2.14)
^bNEO FFI (mean ± SD)
Neuroticism	40.6 ± 6.6	45.2 ± 6.1	𝜂^2=.009 *
Extraversion	33.9 ± 6.7	31.1 ± 6.6	𝜂^2=.001
Openness	31.1 ± 5.0	30.1 ± 6.0	𝜂^2=.003
Agreeableness	43.5 ± 5.1	41.0 ± 5.6	𝜂^2=.022 **
Conscientiousness	35.3 ± 6.2	34.3 ± 6.3	𝜂^2=.001
	Low irritable (𝑁=427)	High irritable (𝑁=341)
^bLEIDS-R (mean ± SD)
Hopelessness	6.8 ± 4.8	9.2 ± 5.2	𝜂^2<.001
Acceptance	1.9 ± 2.2	2.0 ± 2.6	𝜂^2=.002
Aggression	5.0 ± 4.3	8.6 ± 5.1	𝜂^2=.049 **
Control	6.4 ± 3.8	7.3 ± 4.1	𝜂^2<.001
Risk aversion	10.6 ± 4.5	12.0 ± 4.6	𝜂^2=.001
Rumination	11.4 ± 4.7	13.5 ± 4.2	𝜂^2=.002
Total score	42.2 ± 17.5	52.7 ± 17.3	𝜂^2=.004

*.05 < P >.001.
^∗∗𝑃<.001.
^‡𝑁=751 (low irritable. 𝑁=382, high irritable, 𝑁=369).
^aIDS-SR total score minus the score on the irritability item.
^bControlled for current symptoms (IDS-total minus item 6), gender, and age.