Exaggerated TSH responses to TRH in depressed patients with "normal" baseline TSH

BACKGROUND

Subclinical hypothyroidism (elevated thyroid-stimulating hormone [TSH] with normal thyroid hormone levels) can present with depression. This may be confirmed by an exaggerated TSH response to thyrotropin-releasing hormone (TRH) on the TRH stimulation test (TRH-ST). The objective of this study was to determine the prevalence of exaggerated TRH-ST results in a sample of depressed patients with "high-normal" screening TSH levels.

METHOD

Depressed patients with TSH levels of 3.00-5.50 mIU/L underwent a TRH-ST. After baseline TSH was drawn, TRH 400 micrograms was injected intravenously, and TSH samples were drawn at +20 min, +30 min, and +40 min postinjection. A rise in TSH after TRH (peak value minus baseline) of > 25 mIU/L represented an exaggerated TSH response.

RESULTS

Twenty-three (38%) of 60 patients had an exaggerated TSH response to TRH. The 38% prevalence is significantly (Chi 2 = 59.65, df = 1, p < .001) greater than the 6% prevalence of positive TRH-ST results reported in the euthyroid general population. The prevalence of positive TRH-ST results was not attributable to differential patterns of psychotropic or thyroid hormone treatment. Unexpected observations were a lack of correlation in TSH levels week to week (r = .17, N.S.) and a lack of correlation between screening TSH value and subsequent TRH-ST results (r = .28, N.S.).

CONCLUSION

Subtle thyroid underfunction may be contributing to depression in some patients with TSH in the upper half of the range usually considered normal. If so, then the TRH-ST may be more sensitive in identifying this than measurement of TSH alone.

Relationship of obsessive-compulsive symptomatology to anxiety, depression and schizotypy in a clinical population

The relationship of obsessive-compulsive symptomatology to anxiety disorders, mood disorders and schizophrenia continues to be controversial. In a sample of 117 psychiatric out-patients, we examined the relationship of obsessive-compulsive symptomatology to indices of anxiety, depression and schizotypy. The relationship between obsessive-compulsive symptomatology and schizotypy was found to be significantly higher than that between obsessive-compulsive symptoms and either anxiety or depression. These findings are consistent with recent studies suggesting that there are similar cognitive deficits associated with obsessive-compulsive symptoms and schizotypy and that obsessive-compulsive disorders may be more closely aligned to the schizophrenic constellation of disorders than to anxiety disorders.

AIDS-related obsessive compulsive disorder: deconditioning based on fluoxetine-induced inhibition of anxiety

Abel's (1993) review of treatments for obsessive compulsive disorder (OCD) indicated that both behavioral treatment (exposure with response prevention, and biological treatment (specific serotonin reuptake inhibiting drugs) are effective. It was recognized that having both available for patients is preferable because there would be situations where one treatment is more appropriate than the other. One indication for using drugs would be where situational constraints do not allow for effective exposure treatment. We present a case study of a microbiology technician with AIDS-related OCD who had an excellent response to the administration of fluoxetine without relapse when the drug was discontinued.

Variability in BPRS definitions of positive and negative symptoms

Reviewing Brief Psychiatric Rating Scale (BPRS) research indicates that combining items to form larger 'symptom factors' (e.g., depression, psychosis) has become the standard methodology. Unfortunately, a single symptom factor may be defined by different combinations of different BPRS items in different studies. To examine the potential impact of these differences, a number of different BPRS definitions of positive and negative symptoms in schizophrenia were culled from previous research. To compare these definitions, one hundred schizophrenics were interviewed with regard to current and recent symptomatology and rated on the BPRS, the Schedule for the Assessment of Negative Symptoms (SANS), and the Schedule for the Assessment of Positive Symptoms (SAPS). The four BPRS negative symptom definitions all correlated highly with one another and with the SANS. There were no differences in the amount that these different definitions of negative symptoms correlated with the SANS. Also, the nine definitions of positive symptoms all correlated highly with one another and with the SAPS. However, there were significant differences in how they correlated with the SAPS. Because of these differences, possible standard definitions for negative and positive symptoms of schizophrenia are proposed for future use of the BPRS in research.

Laryngeal airway resistance of older men and women as a function of vocal sound pressure level

This study examined laryngeal airway resistance (RLAW) in 10 healthy male and 10 female subjects within three age groups (55:0-64:11; 65:0-74:11; and 75:0+ years). A noninvasive procedure (Smitheran & Hixon, 1981) was employed to investigate RLAW at four vocal sound pressure levels (SPL) (25th, 50th, 75th percentiles of the SPL range, and comfortable voice level [CV]), RLAW values for the oldest group of females were found to be higher at each SPL percentile than those of the two younger age groups. The oldest group of males differed from the youngest group of males in RLAW values only at the 75th percentile level of SPL. Laryngeal airway resistance values were higher for females than males. As a group, the females generally had transglottal airflow that increased or remained relatively steady, whereas males maintained more linear changes in transglottal airflow and transglottal pressure as relative SPL increased. The present results suggest that separate norms need to be employed for males and females when determining RLAW values. Further, consideration should be given to examining the underlying airflow and pressure values when evaluating or monitoring changes in aerodynamic activity during voice production.

Aerodynamic, acoustic, and perceptual changes following adenoidectomy

Fourteen children were seen prior to adenoidectomy and at 1 month, 3 months, and 6 months following surgery. On each visit, nasal airway resistance values, nasal cross-sectional area estimates, nasalance scores, and perceptual ratings of nasality were collected. These data were analyzed to identify changes that were related to the time of the test, and to the primary indication for surgery (nasal airway obstruction or recurrent infection). Results revealed significant reduction in nasal airway resistance and significant changes in nasalance following surgery. Perceptual changes were not significant. Clinical implications of these findings are discussed.

Classification of the schizophrenias according to symptomatology: a two-factor model

Various methods of subtyping schizophrenia are briefly reviewed. It is concluded that the paranoid-nonparanoid dichotomy has been the most consistently supported both clinically and in experimental research. In an attempt to deal with its limitations, a tentative reconceptualization is proposed for schizophrenia. This new model is based on two independent factors: severity of disorder and severity of symptom. The present dimensional approach is shown to be consistent with a number of empirical findings regarding differences and associations between paranoid and nonparanoid symptomatology. The relative advantages of dimensional and categorical descriptions, as well as their combination, are presented.

Classification of the schizophrenias according to symptomatology: a two-factor model

Various methods of subtyping schizophrenia are briefly reviewed. It is concluded that the paranoid-nonparanoid dichotomy has been the most consistently supported both clinically and in experimental research. In an attempt to deal with its limitations, a tentative reconceptualization is proposed for schizophrenia. This new model is based on two independent factors: severity of disorder and severity of symptom. The present dimensional approach is shown to be consistent with a number of empirical findings regarding differences and associations between paranoid and nonparanoid symptomatology. The relative advantages of dimensional and categorical descriptions, as well as their combination, are presented.

Are heritability estimates generalizable? Lack of evidence from cross-sample correlations

The majority of research indicates that estimates of heritability are not generalizable beyond the specific sample on which they have been calculated. This research has been limited, however, in its scope. The present set of investigations center upon an examination of previously reported heritability estimates for the scales of the Minnesota Multiphasic Personality Inventory (MMPI). The first investigation correlates the estimates for eight samples derived from a variety of published studies. The second investigated correlates the DZ twin pair and MZ twin pair intraclass correlations from four of the first investigation's samples. The third investigation correlates the estimates from one study in which the same sample was tested twice over a period of less than five years. It is concluded that no evidence is available for the generalizability of these estimates of MMPI scale heritability either across samples or even across time with the same sample.