Prevalence of psychiatric disorders among patients investigated for occupational asthma: an overlooked differential diagnosis?

RATIONALE: Up to one-third of patients assessed for occupational asthma (OA) do not receive a diagnosis of OA or any other medical disorder. Although several differential diagnoses are considered (e.g., rhinitis, chronic obstructive pulmonary disease), psychiatric disorders (many with somatic complaints that mimic asthma) are rarely considered or assessed. OBJECTIVES: To assess the prevalence of psychiatric disorders (mood and anxiety disorders and hypochondriasis) in patients suspected of having OA, and whether psychiatric morbidity increases the risk of not receiving any medical diagnosis. METHODS: A total of 219 consecutive patients (57% male; mean age, 41.8 ± 11.1 yr) underwent sociodemographic and medical history interviews on the control or specific inhalation testing day of their OA evaluation. The Primary Care Evaluation of Mental Disorders was used to assess mood and anxiety disorders, and the Whiteley Hypochondriasis Index was used to assess hypochondriasis. MEASUREMENTS AND MAIN RESULTS: A total of 26% (n = 50) of patients had OA; 25% (n = 48) had asthma or work-exacerbated asthma; 14% (n = 28) had another inflammatory disorder; 13% (n = 26) had a noninflammatory disorder; and 22% (n = 44) did not receive any medical diagnosis. A total of 34% (n = 67) of patients had a psychiatric disorder: mood and anxiety disorders affected 29% (n = 57) and 24% (n = 46) of the sample, respectively, and 7% (n = 12) had scores on the Whiteley Hypochondriasis Index indicating hypochondriasis. Hypochondriasis, but not mood or anxiety disorders, was associated with an increased risk of not receiving any medical diagnosis (adjusted odds ratio, 3.92; 95% confidence interval, 1.18-13.05; P = 0.026). CONCLUSIONS: Psychiatric morbidity is common in this population, and hypochondriasis may account for a significant proportion of the "undiagnosable" cases of patients who present for evaluation of OA.

Association Between Depression, Lung Function, and Inflammatory Markers in Patients with Asthma and Occupational Asthma.

OBJECTIVE: Depression is associated with autonomic and immune dysregulation, yet this remains poorly explored in asthma. We assessed associations between depressive disorder, lung function, and inflammatory markers in patients under investigation for occupational asthma (OA). METHODS: One hundred twelve patients under investigation for OA (60% men) underwent a psychiatric interview to assess depressive disorder, and spirometry, a methacholine test, sputum induction, and specific inhalation challenge (SIC) to assess OA. Blood and sputum inflammatory markers were assessed. RESULTS: There was a statistically significant association between depressive disorder (P = 0.0195) and forced expiratory volume in 1 second (FEV1) responses, with the drop in FEV1 post-SIC smaller in patients with OA and depression, versus OA with no depression (P < 0.001). CONCLUSION: The presence of depressive disorder may influence FEV1 in patients with OA, which may be via autonomic pathways. However, further studies are warranted in order to determine the mechanisms that underlie these effects.

Association of asthma self-efficacy to asthma control and quality of life.

BACKGROUND: Achieving optimal asthma control relies upon several behavioral factors (self-monitoring, treatment adherence) that may be influenced by asthma self-efficacy (ASE). PURPOSE: To assess the extent to which levels of ASE are associated with asthma control and asthma-related quality of life in patients with asthma. METHODS: A total of 557 adult patients with documented asthma completed a battery of questionnaires (Asthma Self-Efficacy Scale, ASES; Asthma Control Questionnaire, ACQ; Asthma Quality of Life Questionnaire, AQLQ) and standard spirometry. Patients also underwent a sociodemographic, medical history, and psychiatric interview. Partial correlations adjusting for covariates were conducted to assess associations between ASES scores and ACQ and AQLQ scores. RESULTS: Results indicated that ASES scores were negatively correlated with ACQ total score and individual items scores, indicating that higher levels of ASE were associated with improved asthma control, and positively correlated with AQLQ total and subscale scores, indicating that higher levels of ASE were associated with better asthma-related quality of life. All findings were independent of covariates. CONCLUSIONS: Findings suggest that being confident in one's ability to control asthma symptoms is associated with better asthma control and quality of life. Future studies should assess the direction of the association between self-efficacy and asthma morbidity in order to determine optimal treatment targets.

Prospective Impact of Psychiatric Disorders on Employment Status and Health Care Use in Patients Investigated for Occupational Asthma.

OBJECTIVE: We previously reported high rates (34%) of psychiatric disorders (PSY) in patients evaluated for occupational asthma (OA). We determined the impact of PSY on employment status and health care use 12 to 18 months later. METHODS: One hundred ninety-six patients underwent clinical and psychiatric interviews on the day of their OA evaluation. Patients were re-contacted 12to 18 months later to assess employment status and health care use. RESULTS: Results indicated that patients with a PSY at baseline were less likely to be employed (adjusted odds ratio = 2.88; 95% confidence interval = 1.29 to 6.44) irrespective of final medical diagnosis (including OA), and had higher rates of emergency visits (35% vs 19%, P = 0.04). CONCLUSION: Psychiatric morbidity is common in this population and associated with lower employment rates and greater use of emergency services. Greater efforts should be made to assess and treat PSY in this population.

Association between asthma medications and suicidal ideation in adult asthmatics.

BACKGROUND: Asthma has been associated with suicidal ideation (SI), though the mechanisms remain poorly understood. Some asthma medications (e.g., theophylline and beta-2 adrenergic agonists) have been shown to provoke feelings of anxiety, fear, and irritability, but their link to SI among asthmatics has not been examined, which was the purpose of the present study. METHODS: 664 adult asthma outpatient (39% male, M age = 49 ± 14.3) underwent a sociodemographic, psychiatric, and medical history interview. Patients reported asthma medication use, which was verified by chart review. All patients underwent spirometry and completed questionnaires including the beck depression inventory-II (BDI-II) which includes an item that assesses SI in the past two weeks. RESULTS: 11.5% of patients reported having SI in the past two weeks. After adjusting for age, sex, smoking, asthma severity, and depressive disorders, analyses indicated that theophylline use was associated with an increased likelihood of SI (OR = 2.67, 95% CI = 1.07-6.65). Sensitivity analyses including asthma control levels and benzodiazepine use as additional covariates did not alter this association (respectively: OR = 2.54, 95% CI = 1.04-6.37; OR = 2.71, 95% CI = 1.09-6.78), though adding cohabitation rendered it no longer statistically significant (OR = 2.34, 95% CI = 0.90-6.09). There were no associations between SI and LABA use. CONCLUSIONS: Findings suggest that theophylline but not LABA use may be associated with an increased risk of SI among adult asthmatics independent of depressive disorders, asthma control levels, and asthma severity, but not cohabitation, suggesting that cohabitation may be important for SI in this population. Physicians should be cautious when prescribing theophylline or similar agents to asthmatics, and ensure adequate follow-up.

Psychological distress and occupational asthma.

PURPOSE OF REVIEW: To summarize recent findings on the psychological impact of occupational asthma, on the basis of a review of medical and psychological literature published between 1998 and 2008. For the purposes of this review, 'psychological impacts' are defined as the experience of psychological stress or distress, which refers to the experience of negative emotions (e.g., anxiety and sadness/depression). When severe and chronic, psychological distress may reach clinical levels and is referred to as a 'psychiatric disorder', which is a clinical diagnosis based on established diagnostic criteria. RECENT FINDINGS: Only one original article assessing psychological impacts has been published in the past 10 years (in 2007). Levels of psychological distress (i.e., depression, anxiety, and cognitive dysfunction) were all in the clinical range, and rates of anxiety disorders and dysthymia (a chronic form of depression) affected approximately 35 and 23% of patients, respectively. SUMMARY: The paucity of available literature indicates that the study of psychological factors associated with occupational asthma is still in its infancy. Though preliminary and in need of replication, the only published study to date suggests that patients with occupational asthma may be highly anxious and many are chronically depressed, a finding that is consistent with previous studies with nonoccupational asthmatics. The established link between psychological factors (e.g., depression and anxiety) and nonoccupational asthma suggests that future studies are desperately needed to more comprehensively assess the scope and severity of the psychological burden of this disease.