Development, cross-validation, and assessment of reliability of the Christensen Dietary Distress Inventory.

Abstract

A series of two studies was conducted to develop and cross-validate a psychometric instrument capable of identifying individuals experiencing a dietary induced mood disturbance. The first study focused on the development of the Christensen Dietary Distress Inventory (CDDI) by identifying the items which would differentiate dietary responders from nonresponders. Dietary responders were identified as those individuals whose mood disturbance improved following a dietary intervention and deteriorated following either a return to their typical diet or following a challenge of refined sucrose or caffeine as opposed to placebo or aspartame. The results revealed that 34 CDDI items differentiated dietary responders from the nonresponders. The test-retest reliability of this scale was .87. The second study cross-validated the CDDI. Using an A-B single-subject design and double-blind challenges, seven of 23 research participants were identified as definite dietary responders, nine as definite dietary nonresponders, and seven as probable dietary responders. The dietary responders' and nonresponders' CDDI scores were significantly different and a point-biseral of .48 existed between the subjects' CDDI score and their group categorization. Such data indicate that the CDDI is a valid psychometric instrument. Inspection of the sensitivity and specificity indices indicates that a cutoff score of 13 results in the selection of the most true positives with the least number of false positives.

Effects of eating behavior on mood: A review of the literature

“…Christensen, Krietsch, White, and Stagner (1985) demonstrated that a caffeine and refined sucrose free diet resulted in a reduction of emotional distress and reintroduction of these substances in a double-blind format resulted in a return of the distress. Several additional studies (Christensen, Krietsch, & White, 1989;Krietsch, Christensen, & White, 1988) have replicated these findings providing confirmation of the efficacy of this dietary intervention for ameliorating emotional distress. In a subsequent study Christensen and Burrows (1990) demonstrated that elimination of caffeine and refined sucrose from the diet was particularly effective in the amelioration of depression in a subsample of depressed individuals.…”

Issues in the design of studies investigating the behavioral concomitants of foods.

“…(Beck, Ward, Mendelson, Mock, & Erbaugh, 1961) change scores for dietary responders and nonresponders separately and as a mixed group. (A reanarysis of data from Christensen, Krietsch, & White, 1989. ) This document is copyrighted by the American Psychological Association or one of its allied publishers.…”

“…It would be erroneously concluded that an effect did not exist, when the null results existed only because the sensitive population was not sampled. Christensen et al (1989) have developed a psychometric instrument, the Christensen Dietary Distress Inventory (CDDI; Christensen, 1990), for the purpose of identifying distressed individuals responsive to caffeine and refined sucrose. The CDDI is a 34-item self-report inventory including statements responded to in terms of frequency of occurrence, reaction to, or perceived cause of a physical or psychological condition.…”

Functional food science and behaviour and psychological functions

“…One argument is that affected individuals self-medicate, using food or drink to combat aversive mood states characterized by frustration, anxiety, or depression. Alternatively, some individuals may refrain from eating certain foods in order to avoid their putative behavioural toxicity, according to the view that certain dietary constituents are aetiological agents for various forms of dysfunctional behaviour and negative affect (Christensen et al 1989). For example, simple sugars have been variously blamed for disturbances in mood, sleep, and cognitive performance (Kruesi & Rapoport, 1986).…”