Detecting somatoform disorders in primary care with the PHQ-15.

PURPOSE: Because recognition and management of patients with somatoform disorders are difficult, we wanted to determine the specificity, sensitivity, and the test-retest reliability of the 15-symptom Patient Health Questionnaire (PHQ-15) for detection of somatoform disorders in a high-risk primary care population. METHODS: We studied the performance of the PHQ-15 in comparison with the Structured Clinical Interview for the Diagnostic and Statistical Manual-IV Axis I disorders (SCID-I) as a reference standard. From January through September 2006, we approached patients for participation. This study was conducted in primary care settings in the Netherlands. Patients aged between 18 and 70 years were eligible if they belonged to 1 or more of the following groups: (1) patients with unexplained somatic complaints, (2) frequent attenders, and (3) patients with mental health problems. For the SCID-I interview we invited all patients with a PHQ-15 score of 6 or greater and a random sample of 30% of patients with a PHQ-15 score of less than 6. The primary study outcomes were the sensitivity and specificity for the validity and the kappa coefficient for the test-retest reliability. RESULTS: Of 2,147 eligible patients, 906 (42%) participated (mean age 48 years, 62% female). At a cutoff level of 3 or more severe somatic symptoms during the past 4 weeks, sensitivity was 78% and specificity 71%. The test-retest reliability was 0.60. CONCLUSIONS: The PHQ-15 is a valid and moderately reliable questionnaire for the detection of patients in a primary care setting at risk for somatoform disorders.

Prevalence of psychiatric disorders in patients with chronic solvent induced encephalopathy (CSE).

INTRODUCTION: Long term occupational exposure to organic solvents may induce chronic solvent-induced encephalopathy (CSE), characterized by mild to severe cognitive impairment, generally seen as the key diagnostic feature. Psychiatric disorders are often diagnosed in subjects with CSE, but were never studied in more detail. This study was designed to establish the prevalence rates of DSM IV mood, anxiety, and alcohol and substance related disorders in patients with CSE. MATERIALS AND METHODS: In CSE, n=203 (consecutively recruited between 2002 and 2005), defined according to the criteria of the World Health Organisation (WHO), one month prevalence rates of DSM IV mood, anxiety, and life time alcohol/substance related disorders were assessed using the Structured Clinical Interview for DSM IV disorders (SCID). These prevalences were compared with those from an age and gender matched community sample (n=3212) while controlling for insufficient neuropsychological test effort. RESULTS: In CSE, prevalence rates for major depressive disorder (n=36, relative risk (RR)=7.4), dysthymia (n=15, RR=6.0), panic disorders (n=18, RR=7.1), agoraphobia (n=7, RR=5.5) and generalized anxiety disorder (n=19, RR=15.8) were increased. Reduced prevalence rates were found for alcohol related disorders (n=21, RR=0.3). Insufficient neuropsychological test effort was not associated with increased prevalence rates of DSM IV disorders in subjects suspected of CSE. DISCUSSION AND CONCLUSIONS: In conclusion, in this first large scale study in patients with CSE, prevalence rates of DSM IV mood and anxiety disorders were elevated as compared with those in the general community, while the prevalence rates of alcohol related disorders were reduced. Further study must determine whether CSE, and mood and anxiety disorders, share a same, solvent induced, neurobiological pathway, supporting the use of a more inclusive diagnostic approach. Additionally, randomised controlled trials are needed for the urgent issue of how to treat mood and anxiety disorders in CSE patients effectively.