The Effect of Selective Serotonin Releasing Agents in the Chronic Mild Stress Model of Depression in Rats

Chronic exposure to mild unpredictable stress has been found to depress the consumption of, and preference for, highly palatable sucrose solution in rats. Stress-induced behavioral deficits may be maintained for a long time, however chronic administration of clinically effective antidepressants can restore normal behavior. This is the first report showing that Sprague-Dawley rats can be used in this model. A preference deficit in this strain of rats took at least 7 weeks to develop; about twice the time required when hooded Lister or Wistar rats are used in this model. Water consumption was not effected by chronic exposure to the mild stress regime and/or by chronic administration of the selective serotonin (5-HT) releasing agent MMAI (5-methoxy-6-methyl-2-aminoindan). The stress-induced deficit in sucrose intake was completely reversed by chronic treatment with MMAI (5 mg/kg, 2 x day) over 3 weeks in the two-bottle tests. In single-bottle tests, chronic treatment with the selective 5-HT releasers, MMAI (5 mg/kg, 2 x day) or MTA (p-methylthioamphetamine; 5 mg/kg, 2 x day), reversed the deficit in rewarded behavior (anhedonia) measured as a decrease in the consumption of 1% sucrose solution in the chronic mild stress model of depression in rats. With the experimental procedure employed, and at a dose of 10 mg/kg/day of 5-HT releasers, the magnitude and onset of this effect were greater than observed following similar administration of the selective 5-HT reuptake inhibitor (SSRI) sertraline (10 mg/kg/day), used as a standard anti-depressant drug.     

DEVELOPMENT OF MULTIPLE JOB PERFORMANCE MEASURES IN A REPRESENTATIVE SAMPLE OF JOBS

The goal of criterion development in Project A was to construct multiple measures of the major components of job performance such that the total performance domain for a representative sample of the population of entry-level enlisted positions in the U.S. Army was covered. These measures were to be used as criteria against which to validate both experimental and existing predictors of job performance. The initial model specified that performance is multidimensional within two major categories of dimensions designated as organization-wide and job specific. The development strategy involved describing the total domain of job content via extensive task analyses and critical incident analyses, generating the critical performance dimensions that constitute it, constructing measures for each dimension, and evaluating each measure using expert judgment and field test data. The specific measures developed consisted of rating scales, tests of job knowledge, hands-on job samples, and archival records. The major steps in the job analyses, content sampling, instrument construction, and instrument evaluation are described, and the final array of criterion measures is presented.     

Perceived Parental Attitudes and Family Concepts of Disturbed Adolescents,Normal Siblings and Normal Controls

This study tested the hypotheses that disturbed adolescents perceive lower parental attitudes (positive regard, empathic understanding, genuineness and unconditional regard) than are perceived by their normal siblings and normal controls; that normal siblings do not differ from normal controls on these variables; that levels of perceived attitudes are positively related to family concept measures of adjustment and satisfaction; and that attitudes perceived in one parent are positively associated with those perceived in the other. The hypotheses were substantially confirmed. In contrast to both normal groups, the disturbed adolescents failed to show positive relationships between maternal attitudes and the family concept measures and between perceived paternal and maternal attitudes.