Ratio scales of the reward values and punisher aversions of depressed undergraduates

Taste identification used as a potential discriminative test among depression and Alzheimer׳s disease in elderly: A pilot study

Major Depression and Alzheimer׳s disease (AD) are two diseases in the elderly characterized by an overlap of early symptoms including memory and emotional disorders. The identification of specific markers would facilitate their diagnosis. The aim of this study was to identify such markers by investigating gustatory function in depressed and AD patients. We included 20 patients with unipolar major depressive episodes (MDE), 20 patients with mild to moderate AD and 24 healthy individuals. We investigated the cognitive profile (depression, global cognitive efficiency and social/physical anhedonia) and gustatory function (ability to identify four basic tastes and to judge their intensity and hedonic value) in all participants. We found that AD patients performed worse than healthy participants in the taste identification test (for the analysis of all tastants together); however, this was not the case for depressed patients. We found no significant differences among the three groups in their ability to evaluate the intensity and hedonic value of the four tastes. Overall, our findings suggest that a taste identification test may be useful to distinguish AD and healthy controls but further investigation is required to conclude whether such a test can differentiate AD and depressed patients.

Sweet liking in patients with Parkinson's disease

Pleasant tastes and odors are considered phylogenetically old natural rewards and their hedonic evaluation is regarded as a good indicator of the reward system function. The primary aim of the present study was to compare pleasantness ratings of sucrose solutions (1-30%, w/w) and sweet liking/disliking status in 20 patients with Parkinson's disease (PD) and in 20 age-matched healthy controls. In addition, basic sensory aspects of gustatory (intensity ratings, electrogustometric thresholds) and olfactory function (identification abilities in the Sniffin' Stick test) were assessed in both groups. The number of odors rated as pleasant, unpleasant, and neutral was also compared. As expected, the PD patients showed a significant impairment in olfactory identification abilities. There were no differences between the PD patients and controls in electrogustometric thresholds. Rated intensity of higher sucrose concentrations did not differ between the groups. The PD patients tended to rate water taste as more intense in comparison with the controls. Pleasantness ratings of sucrose solutions, the proportion of subjects rating 30% sucrose as the most pleasant (sweet likers), and the number of odors rated as pleasant did not differ between the study groups. The present results suggest that PD does not lead to any obvious alterations in pleasantness ratings of chemosensory stimuli. The study requires replication in larger samples.

Gustatory and olfactory function in patients with unipolar and bipolar depression

Although the crucial distinction between unipolar depressive disorder and bipolar disorder is the presence of mania (or hypomania) in the course of the latter, significant differences between unipolar and bipolar depression have also been found in clinical studies. The primary aim of the present investigation was to assess pleasantness/unpleasantness ratings of chemosensory stimuli in depressed patients, including subjects with unipolar and bipolar depression. Sensory aspects (thresholds and identification abilities) of gustatory and olfactory function were also assessed. There were no major differences between a depression group, as a whole, and healthy controls in terms of gustatory and olfactory thresholds and identification abilities. Similarly, pleasantness ratings of various gustatory and olfactory stimuli did not differ between the control and depression group. Gustatory and olfactory thresholds and identification abilities did not differ between individuals with unipolar and bipolar depression. Bipolar patients tended to rate less gustatory stimuli as unpleasant and more olfactory stimuli as pleasant compared to unipolar patients. The present results suggest that: i) depression is not associated with any major deficit in sensory aspects of gustatory and olfactory function or altered hedonic ratings of chemosensory stimuli; ii) hedonic responses to chemosensory stimuli tend to be increased in bipolar as compared to unipolar depressed patients.

The relation between depression and anxiety: an evaluation of the tripartite, approach-withdrawal and valence-arousal models

Epidemiological studies have consistently reported that depressive and anxiety disorders co-occur frequently. This paper reviews the evidence for three models that have been proposed to explain the relation between these two conditions-the tripartite, the approach-withdrawal, and valence-arousal models. Specifically, we focus on predictions that the three models generate for cross-sectional studies, prospective and family/twin studies of personality, and EEG studies. In sum, no model was strongly supported across all types of studies, though specific aspects of each model were. Because of the heterogeneity of depression and anxiety disorders, a model with 2-4 factors or dimensions may not be sufficient to explain the relation between the two conditions.

Need for achievement and performance on measures of behavioral fluency

This investigation was designed to assess the relationship between a validated personality characteristic, need for achievement (nAch), and performance on measures of behavioral fluency. To infer this relationship, 50 neurologically intact college undergraduates were administered a questionnaire assessing nAch and a battery of tests including a short form of the WAIS and measures of behavioral fluency (i.e., verbal fluency). Statistical analysis indicated that subjects high on nAch obtained higher scores than subjects low on nAch on the measures of figural fluency and the WAIS Verbal Scale. No significant difference on verbal fluency was seen between the two groups. Secondly, the group high on nAch also had a higher mean Verbal IQ but not a higher mean Performance IQ as measured by a short form of the WAIS than did subjects scoring low on nAch.

Motivational deficit in depressed cancer patients

A motivational theory of depression states that depression consists of low expectations and low values for rewards. This theory accurately describes one class of depression, the affective disorders. The present study tested its accuracy for another class of depression, adjustment disorder with depressed mood. This class of depression is precipitated by environmental stresses, such as chronic illness. The focus was therefore on people (N = 48) who were experiencing terminal cancer and nonterminal cancer. Results supported each prediction generated by the motivational theory. The cancer patients exhibited low expectations and low values; hence, they were unmotivated and depressed. Implications are that some of the symptoms exhibited by cancer patients may be manifestations of negative beliefs rather than physical impairments.

Motivational deficit in childhood depression and hyperactivity

A recent theory states that the immediate cause of adult depression is low motivation, where motivation is the multiplicative product of a person's expectation for a reward times his value for that reward. The present experiment supported the extension of this theory to childhood depression. The expectations, values, and motivations of three groups of children (Ns = 18; mean ages = 10) were measured: A depressed group and a hyperactive control group were selected from a population of clinically disturbed children, while normal controls were selected from regular classrooms. As predicted, the depressed children exhibited reduced motivation, primarily because their expectations were pessimistic. Unexpected findings were that the depressives' expectations were not abnormally irrational; and that hyperactives exhibited optimistic expectations, inflated values, and, hence, inflated motivation--especially for tangible rewards. Cognitive therapy techniques that focus upon expectations were recommended for the treatment of both depressed and hyperactive children.