July 2010
Reviewer: Jeff C. Huffman, MD
Pessimism, worthlessness, anhedonia, and thoughts of death identify DSM-IV major depression in hospitalized, medically-ill patients
McKenzie DP, Clarke DM, Forbes AB, Sim MR
Psychosomatics 2010; 51(4):302-311
Background: Diagnosing major depression in patients with acute medical illness can be challenging. Many symptoms of major depression overlap with physical symptoms that can be attributed to the patient’s physical illness. In addition, many patients experience dysphoria, distress, and adjustment difficulties in the context of the medical admission that, while important, may not reach the level of major depression. There is, therefore, an ongoing need to find symptoms that are strongly associated with a diagnosis of true major depression in medically-ill patients. Such work will assist in depression screening of hospitalized patients and will help us to understand the phenomenology of depression in the medically ill.
Methods: The authors evaluated patients recruited from consecutive admissions to med-surg wards at an Australian general hospital who scored above the “probable psychiatric caseness” cutoff on the General Health Questionnaire. Enrolling subjects then underwent a structured interview with the Monash Instrument for Liaison Psychiatry, which has information necessary to make a diagnosis of major depression and contains additional questions about a broader range of symptoms; this instrument includes symptoms that load on specific Demoralization (8 symptoms) and Anhedonia factors (4 symptoms). The authors then used logistic regression to assess the independent association of the 12 symptoms in question with a diagnosis of major depression. In addition, the authors used “Classification and Regression-Tree” (CART) analysis to assess combinations of variables that could be predictive of major depression; standard performance characteristics (e.g., positive predictive value) were calculated for each of the 12 symptoms using these methods.
Results: 300 subjects met study criteria; 57 (19.0%) met criteria for major depression. Of the studied symptoms (pessimism, discouragement, hopelessness, unable to cope, helplessness, worthlessness, loss of confidence, thoughts of death, and 4 anhedonia questions), pessimism was the symptom that by far was most associated with major depression, independent of demographic confounders, severity of illness, and all other symptoms (odds ratio: 8.3). When combinations of symptoms were used via CART, a combination of pessimism and worthlessness predicted major depression in more than half of the patients (PPV 50.6%, NPV 93.1%, sensitivity 73.7%, specificity 83.1%). Other combinations were less predictive.
Discussion: This was an interesting look at a variety of symptoms medical psychiatrists will discuss with medically-ill patients. It was rather interesting that pessimism, far more than symptoms like hopelessness, helplessness, or anhedonia, was very strongly associated with major depression in hospitalized patients, and that pessimism plus worthlessness turned out to be a reasonable pair of screening items for major depression. The cohort seemed to be a well-represented sample of patients with a variety of illnesses, and the prevalence of major depression is consistent with prior studies, making this a nice sample to explore. Down the road, it may turn out that patients with pessimism, worthlessness, or other symptoms may turn out to have subtypes of depression in the medically ill that require specific treatments.
However, for now, if we are looking for major depression, it seems that we do not need to build a better mousetrap: screens that ask about depressed mood and anhedonia (such as the Patient Health Questionnaire-2) have even better operating characteristics as depression screening tools than any of the symptoms discussed in this paper and indeed are the two cardinal symptoms of major depression.