Table 1.

Table 1-a Recent studies of psychosocial stress and asthma morbidity
Reference	Study design	Main findings	Study limitations
Longe et al. [11▪▪]	Longitudinal study of 339 twin pairs in Puerto Rico, followed from birth to age 3 years	Indicators of maternal and paternal psychosocial stress were associated with increased asthma morbidity in early childhood	Potential misclassification of asthma in early childhood; Inability to adequately exclude ‘reverse causation’ (asthma morbidity in the children leading to increased parental stress); uncertain generalizability to nontwins
Shankardass et al. [13]	Prospective multilevel cohort study of 2456 children in 274 Census Tracks within the CHS cohort	Children attending schools receiving Title 1 funds and living in areas with higher rates of larceny crime had an increased risk of asthma	Limited assessment of the school social environment
Ressler et al. [15▪▪]	Cohort study of more than 1200 highly traumatized adults with and without PTSD	Alterations in the PACAP-PAC1 receptor pathway underlie abnormal stress responses in PTSD	Lack of association between PACAP blood level and PTSD or fear responses in men may be due to limited statistical power due to insufficient sample size
Spitzer et al. [16]	Cross sectional study of 1772 German adults in the SHIP	PTSD was associated with asthma symptoms but not with FEV1 or FEV1/FVC. In contrast, traumatic stress was associated with modest reductions in FEV1 and FEV1/FVC	Inability to exclude reverse causation; potential selection bias
Wright et al. [17]	Longitudinal study of war stressors and asthma in Kuwaiti adults	A high level of war-related stress exposure was associated with an approximately two-fold increased risk of asthma	Potential misclassification of asthma; residual confounding by access to healthcare
Wisnivesky et al. [18]	Prospective study of 326 adults with moderate to severe asthma in New York City and New Jersey	Higher perceived stress associated with decreased asthma control, medication adherence and quality of life	Inability to exclude reverse causation; residual confounding by smoking; lack of objective measures of asthma control or severity (e.g. lung function)
Chen et al. [19▪]	Prospective study of 121 children aged 9–18 years with a physician’s diagnosis of asthhma	Children who came from low SES but engaged in shift-and-persist strategies had less asthma inflammation at baseline and less asthma impairment after 6 months of follow-up than those from low SES who did not engage in shift-and-persist strategies	Infrequent follow-up; lack of data on medication adherence
Kang and Weaver [20]	Murine study of the effects of acute and chronic stress on cytokine levels in BAL Fluid following antigen challenge of mice with and without AAI	Compared with antigen-challenged mice with AAI but no stress exposure, antigen challenged mice exposed to acute or chronic stress had significantly higher levels of IL-4 but significantly lower levels of IFN-γ in BAL fluid. Antigen-challenged mice with AAI that were exposed to acute stress had higher IL-4 and IL-4/IFN-γ levels in BAL fluid than those exposed to chronic stress	Lack of assessment of cells involved in immune responses; uncertainty regarding what constitutes chronic stress in murine models, as well as generalizability of findings in murine models to humans
Clougherty et al. [21▪]	Study of the effects of stress and exposure to Fine CAPs on biomarkers of inflammation in 24 rats	Rats exposed to both CAPs and stress had higher levels of inflammatory markers, white blood cell counts and worse respiratory and lung function than those exposed only to stress or air pollutions	Small sample size; uncertain generalizability of results to humans

Table 1-b Recent studies of psychosocial stress and asthma morbidity
Islam et al. [22▪]	Cross-sectional study or 1399 children of school age in Southern California	Parental stress was associated with increased susceptibility to detrimental effects of traffic particulate exposures on FEV1	Potential misclassification of traffic-related particulate exposures; utilization of parental/household stress measure as proxy for child stress
Wright et al. [23▪▪]	Birth cohort study of 557 mother–child pairs from the Urban Environment and Childhood Asthma Study	Prenatal composite cumulative stress was associated with altered innate and adoptive immune responses, as assessed by CBMC cytokines	Longitudinal follow-up of children needed to assess true impact of stress on development of allergy and asthma
Nagano at al. [30]	Prospective study of 223 children with asthma (ages 2–12 years) and their mothers	After 1 year of follow-up, maternal irritation/anger or emotional suppression was associated with greater asthma severity in children younger than 7 years. In children 7 years and older, maternal self-centered behavior was associated with greater asthma severity	Lack of objective markers of asthma severity or control; no formal testing of an interaction between maternal stress and children’s age; potential residual confounding by baseline asthma severity
Suglia et al. [31]	Birth cohort study of 3116 families with an over-representation of nonmarital births	Chronic IPV was associated with two-fold increased odds of physician-diagnosed asthma at age 3 years. In an analysis stratified by MCAs, children whose mothers were exposed to chronic IPV and a low level of MCAs had higher odds of asthma at age 3 years than those exposed to chronic IPV but with a high level of MCAs	Potential misclassification of asthma in young children; lack of formal testing for interaction between IPV and MCAs; noncorrection of results for multiple testing; self report of care-giving behaviors and IPV experience
Suglia et al. [32]	Birth cohort study of 3116 families with on over-representation of nonmarital births	Modification of the effect of chronic IPV by living in deteriorated or disarrayed housing, as well as, by housing hardship	Cross-sectional analysis; potential misclassification of asthma in young children; lack of formal testing for interaction between IPV and disarrayed housing/housing hardship; noncorrection of results for multiple testing
Sternthal et al. [34▪]	Longitudinal multilevel study of 2071 children aged 0–9 years in Chicago	Community violence was associated with asthma risk after controlling for potential individual-level and neighborhood-level confounders. However, community violence and other individual-level factors failed to fully account for the excess asthma burden in African Americans	Limited data on other contextual stressors (e.g. other stressful life events, racism, housing); potential misclassification of asthma; lack of objective measures of lung function or allergy
Apter et al. [37▪]	Prospective longitudinal study of 397 inner-city adults with moderate to severe asthma seen at the emergency department	Participants exposed to community violence had increased odds of visits to the emergency department and hospitalizations for asthma	Self-reported measure of exposure to community violence; generalizability of findings to other adults with asthma is uncertain
Quinn et al. [40▪]	Cross-sectional study of 682 children diagnosed and undiagnosed with asthma in Chicago	Housing stressors were significantly associated with reduced exercise tolerance, unplanned medical visits and nocturnal awakenings due to asthma	Potential misclassification of asthma, nonvalidated measure of household stress; lack of objective measures of asthma severity or control

Table 1-c Recent studies of psychosocial stress and asthma morbidity
Long et al. [42▪]	Interventional study in 18 children (ages 7–12 years) with asthma	A problem-solving emotional management intervention led to significant improvement in lung function, perceived stress and depressed mood	Small sample size; limited duration of intervention and follow-up

AAI, allergic airway inflammation; BAL, bronchoalveolor lavage; CAP, concentrated ambient particles; CBMC, cord blood mononuclear cell; CHS, Children’s Health Study; IFN, Interferon; IPV intimate partner violence; MCA, mother-child activities; PACAP, Pituitary Adenylate Cyclase-Activating Polypeptide; PTSD, Posttraumatic Stress Disorder; SES, Socioeconomic status; SHIP, Study of Health in Pomerania.