Cocaine use and psychopathology: associations among young adults

Cocaine use has been associated with psychopathology in clinic and treatment samples and among chronic, excessive users. These relationships have been tested rarely in general epidemiological samples. This study examines the association between cocaine involvement and numerous measures of psychopathology in general community sample of 739 young adults. There were no sex differences in level of cocaine involvement, nor on associations between cocaine use and psychopathology. There were several small relationships between cocaine use and several indicators of psychopathology (i.e., increased sleep disturbance, decreased panic and phobia symptoms, a lack of purpose in life, increased psychotic proneness). It appears that the severe psychopathology associated with cocaine use often cited in the literature is the result of using clinic or treatment samples or chronic abusers, and that such strong associations are not apparent in the general population of young adults with relatively brief cocaine use careers.     

Evaluation of an adaptive directional system in a DSP hearing aid

The effectiveness of an adaptive directional microphone design, as implemented in the Phonak Claro behind-the-ear hearing aid, is evaluated. Participants were fit bilaterally and tested in 2 environments, an anechoic chamber and a moderately reverberant classroom, with the microphones in the fixed (cardioid) setting and the adaptive setting. Five speakers were placed between 110 degrees and 250 degrees azimuth around the listener. Speech-weighted noise was presented from those speakers at an overall level (OAL) of 65 dB (A). Noise was increased by 8 dB from 1 speaker at a time, using 2-s modulation and random assignment, while the output from the other speakers was reduced to maintain the constant OAL. Results of 2 speech perception tasks used as outcome measures indicated that the adaptive system was not able to follow the dominant noise source in the presence of lower level noise sources. Self-report measures obtained after blinded home trials were consistent with laboratory findings that the participants did not perceive this adaptive microphone design to be more effective than the default fixed-microphone option.     

Pooled analysis of antidepressant levels in lactating mothers, breast milk, and nursing infants

OBJECTIVE: The available data on antidepressant levels in nursing infants were analyzed in order to calculate average infant drug levels and determine what factors influence plasma drug levels in breast-feeding infants of mothers treated with antidepressants. METHOD: Electronic searches of MEDLINE, PreMEDLINE, Current Contents, Biological Abstracts, and PsycINFO from 1966 through July 2002 followed by bibliographic searches identified 67 relevant studies (two unpublished). By consensus the authors identified 57 studies of maternal plasma, breast milk, and/or infant plasma antidepressant levels from nursing mother-infant pairs, measured by liquid chromatography. RESULTS: Infants with recent prenatal exposure and symptomatic infants included in case reports were analyzed separately. Infant plasma levels were standardized against the average maternal level for each drug. The average infant-maternal plasma ratio was calculated for each drug, and correlations of infant plasma level to maternal dose, maternal plasma level, and breast milk level were calculated. Nortriptyline, paroxetine, and sertraline usually produce undetectable infant levels. Of drugs currently used, fluoxetine produces the highest proportion (22%) of infant levels that are elevated above 10% of the average maternal level. Based on smaller numbers, the data on citalopram indicate that it produces elevated levels in 17% of infants. The milk-to-plasma ratios for 11 antidepressants had a statistically significant negative association with the percentage of the drug bound to protein. CONCLUSIONS: Nortriptyline, paroxetine, and sertraline may be preferred choices in breast-feeding women. Minimizing the maternal dose may be helpful with citalopram. Current data do not support monitoring breast milk levels in individual patients. Future researchers should report maternal, breast milk, and infant antidepressant levels along with other appropriate variables.     

Assessing observational studies of medical treatments

Background  

Previous studies have assessed the validity of the observational study design by comparing results of studies using this design to results from randomized controlled trials. The present study examined design features of observational studies that could have influenced these comparisons.     

Childhood play activities of male and female homosexuals and heterosexuals

This study examined the differences in childhood play behavior reported by adult male homosexuals (N =198) and heterosexuals (N =198) and those reported by female homosexuals (N =198) and heterosexuals (N =198). Two checklists with a total of 58 sports, games, and play activities were assembled: one for ages 5–8 and the other for ages 9–13. These were administered to the four samples. Monotonicity analysis (a type of factor analysis) revealed four scales within each checklist that were statistically reliable in each of the four samples. Scale and item mean comparisons revealed large significant differences between heterosexual males and females, male homosexuals and heterosexuals, and female homosexuals and heterosexuals. A majority of homosexuals reported significant degrees of cross-sex behavior in childhood play. Favorite play activities, age trends, play-related attitudes, and parent-child interactions were also examined. This research was partially supported by USPHS Grant DA01070.     

List equivalency and test-retest reliability of the Speech in Noise test

The Speech in Noise (SIN) test consists of a series of Institute of Electrical and Electronic Engineers sentences presented in a background of four-talker babble at two presentation levels (83 and 53 dB SPL) and four signal-to-noise ratios (SNR) (15, 10, 5, and 0 dB). In this study, the nine lists were tested for equivalency and the test-retest reliability was determined. Twenty listeners with normal hearing and 20 listeners with sloping sensorineural hearing losses served as subjects. Five sentences were presented at each SNR at each level, and five key words in each sentence were scored (100 key words per presentation level). Each key word was scored as correct or incorrect, with errors of plurality scored as half-correct words. For percent-correct scores, Lists 1, 2, and 9 and Lists 3, 4, and 5 were found to be equivalent for listeners with normal hearing. For both groups of listeners, the test-retest correlations were high, and the critical differences appropriate for sentence material were 10 to 16% at a .95 level of confidence. Because of floor and ceiling effects across the different lists, many subjects with normal hearing did not score as low as the 50% level, and many subjects with hearing loss did not score as high as 50%. Suggestions are offered for alternate scoring in order to obtain a SNR for 50% performance. Future versions of this test should be designed with improved list equivalency and 50% performance capability.     

Randomized controlled trial of Siberian ginseng for chronic fatigue

BACKGROUND: Chronic fatigue greatly affects quality of life and is a common reason for consulting a physician. Since conventional therapy is often of limited help, fatigued patients may use herbal treatments. This randomized controlled trial evaluated the effectiveness of Siberian ginseng. METHOD: Subjects were recruited from advertisements in Iowa (82%) and members of chronic fatigue syndrome support groups (18%). Potential subjects were required to have substantial fatigue > or = 6 months with no identifiable cause. The mean change in a fatigue measure was compared for placebo and Siberian ginseng at 1 and 2 months. Comparisons were for all subjects and for subjects with characteristics previously identified in the literature as important for categorizing chronic fatigue. RESULTS: Ninety-six subjects were randomized to treatment groups, and 76 provided information at 2 months of follow-up. Fatigue among subjects assigned to either placebo or Siberian ginseng was substantially reduced during the study, but differences between treatment groups were not statistically significant in the full sample. Fatigue severity and duration had a statistically significant interaction with response to Siberian ginseng at the P < 0.05 level. Treatment was effective at 2 months for 45 subjects with less severe fatigue (P = 0.04 unadjusted for multiple comparisons) and for 41 subjects with fatigue for > or = 5 years (P = 0.09 unadjusted for multiple comparisons). CONCLUSION: Overall efficacy was not demonstrated. However, the findings of possible efficacy for patients with moderate fatigue suggests that further research may be of value.     

Impact of frequency compression on music perception

Objective: To determine the effects of frequency compression on music perception, and the impact of previous music training and hearing status. It was hypothesized that lesser amounts of compression would be preferred, and that this pattern of preference would be more evident in the musically trained groups. Design: A paired-comparison paradigm was used. Subjects listened to pairs of musical passages as processed by a hearing aid with different frequency-compression settings. Subjects indicated their preferred passage and the strength of their preference. Study sample: Fifty-seven subjects divided in four groups, according to hearing status (normal hearing, mild-to-moderate hearing loss), and previous music experience (trained, not trained). Results: Subjects generally preferred the conditions with the lesser amount of compression. Listeners in the group with previous music training showed stronger preference for less compression than those without training, as did listeners with normal hearing when compared to subjects with hearing loss. Conclusions: Although less frequency compression was in general preferred, there was more variability in the comparisons involving the default settings for a 50-dB hearing loss (i.e. start frequency 4000 Hz, compression ratio 2.5:1) and no compression, suggesting that mild amounts of compression may not be detrimental to perceived sound quality.