Natural remedies for anxiety disorders: potential use and clinical applications.

BACKGROUND: Natural remedies have been widely used and generally accepted as established treatments of depressive disorders, leading to the investigation of their potential role and efficacy in the treatment of the various anxiety disorders. METHODS: Numerous case reports, open-label, and placebo-controlled trials investigating the use of natural remedies in the treatment of anxiety disorders have yielded some encouraging results. RESULTS: Overall, these studies have indicated a potential role for natural remedies in the treatment of anxiety and suggest that such agents may possess a safer side effects profile when compared to conventional agents. However, these early findings, albeit promising, are yet to be supported by further investigation in large-scale, placebo-controlled studies. CONCLUSIONS: This article reviews past and present research being performed in this area of clinical interest, while also revealing a remarkable paucity of data.

Olfactory deficits, cognition and negative symptoms in early onset psychosis.

BACKGROUND: Smell identification deficits (SID) are common in adult schizophrenia, where they are associated with negative symptoms and lower intelligence. However, smell identification has not been examined in adolescents with early onset psychosis, wherein diagnosis is often obscure, and there are few prognostic predictors. METHOD: We examined smell identification, diagnosis, neuropsychological performance and symptoms in 26 well characterized adolescents with early onset psychosis, age 11-17 years. RESULTS: SID existed in the sample and were more common in patients with schizophrenia and psychotic depression than in patients with psychosis NOS and bipolar disorder. As in adults, SID were significantly associated with greater negative symptoms and lower verbal IQ. However, the associations of verbal IQ (and other verbal tasks) to smell identification in this pediatric sample were explained by the relation of both of these types of variables to negative symptoms. CONCLUSIONS: SID existed across this sample of youths with psychotic disorder, and were specifically related to typical characteristics of schizophrenia, such as negative symptoms and lower intelligence, but not to features of bipolar disorder, such as grandiosity. SID is a characteristic of early onset psychosis that may be useful for prognostic purposes.

The reliability and clinical correlates of figure-ground perception in schizophrenia.

Schizophrenia subjects are impaired in a number of visual attention paradigms. However, their performance on tests of figure-ground visual perception (FGP), which requires subjects to visually discriminate figures embedded in a rival background, is relatively unstudied. We examined FGP in 63 schizophrenia patients and 27 control subjects and found that the patients performed the FGP test reliably and had significantly lower FGP scores than the control subjects. Figure-ground visual perception was significantly correlated with other neuropsychological test scores and was inversely related to negative symptoms. It was unrelated to antipsychotic medication treatment. Figure-ground visual perception depends on "top down" processing of visual stimuli, and thus this data suggests that dysfunction in the higher-level pathways that modulate visual perceptual processes may also be related to a core defect in schizophrenia.

Olfactory identification and WAIS-R performance in deficit and nondeficit schizophrenia.

INTRODUCTION: An expanding database supports the notion that the deficit syndrome (DS) is a discrete condition within schizophrenia and recent data argues that Smell Identification Deficits (SID) may have a primary relationship with its pathophysiology. If so, then the relationship of University of Pennsylvania Smell Identification Test (UPSIT) scores with other neurocognitive measures in DS patients may point to the neural substrate of the deficit syndrome. METHOD: We examined the relationship of UPSIT scores and Wechsler Adult Intelligence Scale-Revised (WAIS-R) performance in 46 DSM-IV schizophrenia patients. The Schedule for the Deficit Syndrome (SDS) interview was used to subgroup the sample into 13 DS and 33 nondeficit syndrome (NDS) patients. RESULTS: DS and NDS groups had similar mean ages, age of onset, and GAF scores, but DS patients had fewer years of education. DS and NDS patients also did not differ in full scale, verbal or performance IQ or in any WAIS-R subtest. However, UPSIT scores were significantly worse in the DS patients, most of whom met criteria for a clinically meaningful olfactory impairment. In DS patients, UPSIT scores were significantly correlated with Performance IQ, Block Design, and Object Assembly, all of which are associated with complex visual-motor organizational function thought to be mediated by parietal circuitry. UPSIT scores in NDS patients were significantly related with Vocabulary, Similarities, and Digit Symbol subtests, which are indicative of verbal functioning. CONCLUSION: These preliminary data support previous findings suggesting that in addition to frontal neuropsychological abnormalities, DS patients may have greater performance impairments on tasks associated with parietal functioning. Our findings furthermore suggest that the parietal circuitry may be a conspicuous substrate for impaired odor identification ability in these patients. The lesser abnormalities in UPSIT ability in NDS patients may be attributed to verbal ability. These data are preliminary and further investigations with larger samples are needed to support our findings.

A brief smell identification test discriminates between deficit and non-deficit schizophrenia.

Evidence is accumulating that smell identification deficits (SID) and social dysfunction in schizophrenia may share a common pathophysiology. While most schizophrenia studies utilize the lengthy 40-item University of Pennsylvania Smell Identification Test (UPSIT) to assess smell identification ability, a brief 12-item smell identification test (B-SIT) has recently been constructed as a culturally neutral substitute for the UPSIT. By selecting the 12 items of the UPSIT from which the B-SIT was originally derived, we constructed a proxy for the B-SIT and compared the performance of 83 patients with schizophrenia to 69 normal subjects. We examined select properties of the B-SIT proxy in relation to the UPSIT to determine its efficacy for use in psychiatric populations. We considered the sensitivity of the B-SIT proxy and evaluated a cutoff score for identifying deficit syndrome schizophrenia (DS). The UPSIT and B-SIT proxy were significantly related in the patients (n=83, r=0.85, P=0.01) and in comparison subjects (n=69, r=0.83, P=0.01), and both measures similarly distinguished DS from non-deficit syndrome (non-DS) patients. The results of this study support the utility of the B-SIT for schizophrenia research and highlight the robustness of the relationship between SID and social dysfunction in schizophrenia.

Olfaction and social drive in schizophrenia.

BACKGROUND: The neurobiology of social dysfunction in schizophrenia is unknown, but smell identification deficits (SIDs) exist in schizophrenia, and olfaction is related to social affiliation in other mammals. The SIDs have been linked with negative symptoms and the deficit syndrome, but any specificity of SIDs for social dysfunction is unstudied. Low intelligence might explain this relationship, if it is associated with both negative symptoms and SIDs. We examined whether SIDs in schizophrenia were related broadly to negative symptoms, as are a number of other neuropsychological measures, or whether they might show a more specific relationship with social drive. METHODS: Smell Identification Test scores, Wechsler Adult Intelligence Scale-Revised IQ, symptomatology assessed with the Positive and Negative Syndrome Scale, and the deficit syndrome were determined in 70 patients with DSM-IV schizophrenia. RESULTS: The SIDs were related to negative symptoms and the deficit syndrome, but the association of SIDs with diminished social drive explained both relationships. Smell identification was also related to Wechsler Adult Intelligence Scale-Revised IQ, but intelligence was independent of the relationship of SID and social drive. The worse Smell Identification Test scores in male patients were attributable to a greater preponderance of men with the deficit syndrome. CONCLUSIONS: These analyses demonstrated independent relationships of Smell Identification Test scores to social drive and intelligence that together accounted for almost 50% of the variance in Smell Identification Test scores. There may be common neural substrates for the low social drive and SIDs in schizophrenia.

Odor identification, eye tracking and deficit syndrome schizophrenia.

BACKGROUND: Deficit syndrome (DS) schizophrenia patients have smooth pursuit eye movement (SPEM) dysfunction. We examined if they also had smell identification deficits, since social affiliation is related to olfaction in other mammals. METHODS: Sixty-seven patients had DS assessments: 31 patients had SPEM and 50 had Smell Identification Test (SIT) assessments, and 14 patients had both measurements. RESULTS: DS patients had worse SPEM and SIT performance than the non-DS patients. Areas under the receiver-operator characteristic (ROC) curves for SIT and SPEM were both fairly accurate in identifying the DS. The odds ratio (OR) for the DS for impaired versus normal SPEM was 6.21 (95% confidence interval [CI]: 1.21, 32.25) and for microsmia versus normosmia was 10.4 (95% CI: 1.23, 88.18). Further analyses showed that the association of SIT with both SPEM and the DS could account for the SPEM-DS association. CONCLUSIONS: We found a strong association between the DS and SIT scores suggesting that the neural substrates of olfaction may be related to social affiliation in humans, as they are in other mammals. These data further support the notion that the DS defines a homogeneous subgroup of schizophrenia patients and further suggest that dysfunction in the neural circuitry of olfaction may contribute to its pathophysiology.

Odor identification impairments in schizophrenia: relationship with demographic measures, clinical variables, and diagnostic subtypes.

Smell identification deficits are consistently found in schizophrenia (SZ), but little is known about the nature and characterization of this deficit or its relationship to the phenomenology of the illness. This study aims to further delineate smell identification errors in SZ by examining the relationship of patient demographic differences with smell-identification performance. Our results showed that a patient's gender and education were related to odor-identification scores, with better performance seen in female patients and in those with greater educational attainment. However, there was no effect related to age, ethnicity, or socioeconomic status on odor identification. A smell identification deficit was also unrelated to clinical characteristics of the patients, including age at first hospitalization, number of psychiatric hospitalizations, and duration of illness. Odor identification also did not differ by SZ subtype, nor between SZ and schizoaffective disorder patients. These findings emphasize that odor identification deficits in SZ are unrelated to clinical illness features, cannot be explained by other confounds related to olfaction in the general population, and may be core features related to the SZ disease process.