Prevalence and Impact of Depression and Anxiety in Cystic Fibrosis
Condition: Cystic Fibrosis
MeSH terms: Cystic Fibrosis; Fibrosis; Depression
Study type: Observational

Summary: 
      The Impact of cystic fibrosis (CF) on psychological and emotional functioning has been the
      focus of several studies over the past 20 years. The results from a current meta-analysis
      indicated that depressed patients were three times more likely to be noncompliant with
      treatment recommendations than nondepressed patients with chronic illness.

      To date, most studies of the prevalence of psychiatric symptoms have been limited by small
      sample size; reliance on samples of convenience that are potentially biased in term of rates
      of symptomatology, and measures that contain legitimate symptoms that are part of the
      respondent's chronic disease. Estimating the prevalence of depression and anxiety has become
      important as new evidence indicates that these symptoms may have a significant impact on
      health outcomes, including adherence to medical treatments, utilization of health care
      services, and rates of morbidity and mortality. More depressive the symptoms are associated
      with poorer lung function, and that in the absence of depression, poor lung function is
      minimally associated with lower patient ratings of quality of life.

      The purpose of the current study is to estimate the regional, and if possible the national
      prevalence of depressive and anxious symptoms in children and adults with CF and parents
      caregivers. Patients with CF ages 14 to 17, and parents of children ages 14 to 17, will
      complete and depression/anxiety screening measure at a routine clinic visit. These will then
      be linked with demographic and medical variables reported to the CF registry and analyzed
      cross sectionally. Adults with CF ages 18 and older will also complete the depression /
      anxiety screening measure at a routine clinic visit. Efforts will be made to recruit a
      representative sample of patients from each clinic.
    

Detailed description: 
      Numerous studies have demonstrated that patients with chronic illnesses are at increased risk
      for depression and anxiety. In large, well-controlled epidemiological studies, rates of
      depression in medical populations have ranged from 17% to 50% compared to 5% to 17.5% in
      healthy populations. Reporting on a community-based sample, Wells and colleagues concluded
      that individuals with a chronic medical condition have a 41% increase in the risk of having a
      psychiatric disorder as well.

      In patients with chronic illnesses, depression and anxiety have been shown to have direct and
      indirect consequences for health outcomes, and this has been addressed in a recent ATS/ERS
      consensus statement on pulmonary rehabilitation. Depressed patients are less compliant with
      medical regimens, less likely to follow dietary regimes, more likely to cancel or miss clinic
      appointments, report worse functioning on several quality of life domains, have increased
      health care utilization and higher health care costs, and are also more likely to engage in
      risky behaviors, such as smoking, drinking and drug use.

      To date, studies of the impact of depression and anxiety in patients with CF have been
      limited by small samples sizes, samples of convenience that may provide biased estimates of
      symptom rates, and have used measures that confound symptoms of depression with those of a
      chronic illness. Given the importance of identifying and treating these symptoms, and their
      implications for long-term health outcomes, the current study proposes to conduct the first
      national prevalence study of depression and anxiety in CF patients and parent caregivers.
      Furthermore, we plan to examine the impact of these psychological symptoms on health
      outcomes, such as pulmonary exacerbations and nutritional status.

        1. Anxiety and Depression are common in Cystic Fibrosis, but their exact prevalence is
           unknown.

           Specific Aim 1: To estimate the prevalence of depression and anxiety in patients with CF
           ages 14 to 17 and parent caregivers of those adolescents

           Of the few studies of school-age children and adolescents with CF, one reported a rate
           of depression ranging from 11% to 14.5% in contrast to a rate of 2-6% in the general
           pediatric population. Published rates of anxiety have ranged from 5% to 9% which may
           approximate that of the general childhood population. Furthermore, the rate of
           depression in parent caregivers is also high compared to parents of healthy children. In
           a multi-site adherence intervention trial of 88 parents of young children with CF, ages
           1 to 11, 29% of parents scored in the clinical range on a depression screening tool.
           This is similar to a study of role strain in parents of young children with CF, in which
           36.4% of the mothers' depressive symptoms fell within the clinical range. Furthermore,
           even higher rates of depression were reported in a study of parents soon after the
           diagnosis, with 64% of mothers and 43% of fathers scoring in the clinical range.

           Previous estimates of the prevalence of depression and anxiety in patients with CF have
           been hampered by serious methodological limitations, such as small sample size,
           convenience sampling that is potentially biased, and the use of diagnostic screening
           instruments that attribute somatic symptoms to a depressive disorder which may be due to
           having a chronic illness like CF (e.g., fatigue). Furthermore, studies of depression and
           anxiety in pediatric CF populations have not considered developmental and gender
           differences in depression that emerge in the general population during adolescence.

        2. Identifying patients and parents at risk for depression and anxiety disorders is
           important, but risk factors in the CF population are not known.

           Specific Aim 2: To identify risk factors associated with symptoms of depression and
           anxiety.

           This study was cross-sectional, making it impossible for the authors to distinguish
           whether psychological symptoms preceded or followed patients' employment status, or how
           either of these might have been related to changes in health outcomes.

        3. Anxiety and depression probably lead to worse clinical outcomes in CF, but this has not
           been evaluated.

      Specific Aim 3: To evaluate how depression and anxiety influence health outcomes
      (particularly number of exacerbations and hospitalizations, FEV1 and nutritional measures)
      over the ensuing year.

      There is wide variability in the progression of disease in patients with CF, as reflected in
      the distribution of age at diagnosis, age-related pulmonary function, and age at death
      (Cystic Fibrosis Foundation Patient Registry, 2004). This variability is partially explained
      by CFTR mutation and gene modifiers, but environmental and sociodemographic factors, and
      variations in the use of various healthcare interventions are of equal or greater importance
      in explaining this variability in health outcomes.
    

Intervention name(s): Questionnaires
Intervention type(s): Other
Intervention description(s): Evaluation of the prevalence of anxiety, depression and quality of life
Observational model: Other
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        1. Patients with CF aged 14 to 17. Patients awaiting organ transplantation will be
             included in the study, but those who have received an organ transplant shall be
             excluded. No other exclusionary criteria will be used.

          2. Parents of the patients included.
      
Keywords: Cystic fibrosis; Anxiety; Depression; Adolescence