Odour identification impairment is a trait but not a disease-specific marker for bipolar disorders: Comparisons of bipolar disorder with different episodes, major depressive disorder and schizophrenia.

OBJECTIVE: Olfactory deficits have been reported in bipolar disorder, but this finding is controversial. This study investigated whether olfactory deficit can serve as a specific marker for bipolar disorder by comparing olfactory function in different mood episodes of bipolar disorder. We also compared olfactory function in bipolar disorder and other mental disorders - namely, major depressive disorder and schizophrenia. METHODS: The study consisted of two experiments. Experiment 1 enrolled 175 bipolar disorder patients (70 depressed subgroup, 70 manic subgroup and 35 euthymic subgroup) and 47 controls. Experiment 2 enrolled the participants from Experiment 1, along with 85 major depressive disorder and 90 schizophrenia patients. The Sniffin' Sticks test was used to evaluate odour identification ability and odour threshold (as a measure of odour sensitivity). The Hamilton Depression Rating Scale and Young Mania Rating Scale were used to assess depressive symptoms in all subjects and manic symptoms in bipolar disorder patients, respectively. We also used the Positive and Negative Syndrome Scale to assess clinical symptoms in schizophrenia patients. RESULTS: All three bipolar disorder patient subgroups (depressed, manic and euthymic subgroup) showed reduced odour identification ability compared to controls; however, only patients in the acute phase of a mood episode (depressed, and manic subgroup) showed impaired odour sensitivity. Clinical symptoms were negatively correlated with odour sensitivity but not odour identification ability. Bipolar disorder and major depressive disorder patients showed less odour identification and sensitivity impairment than schizophrenia patients. CONCLUSION: Odour sensitivity is a potential dopaminergic marker for distinguishing between bipolar disorder patients in acute phase vs remission, while odour identification is a trait but a nonspecific marker of bipolar disorder.

Olfactory identification impairment in early-and late-onset obsessive-compulsive disorder.

BACKGROUND: Early-onset obsessive-compulsive disorder (EOCD) is a comparatively severe subtype of obsessive-compulsive disorder (OCD). Olfactory dysfunction is a common symptom of OCD, but all previous studies have focused on late-onset OCD (LOCD). METHODS: The current study compared olfactory identification ability in EOCD patients and age-matched and sex-matched LOCD patients and healthy controls. Thirty patients with EOCD, 30 patients with LOCD and 30 healthy controls were included in the study. Olfactory function was measured using the University of Pennsylvania Smell Identification Test. The Logical Memory and Visual Reproduction components of the Revised Wechsler Memory Scale were used to evaluate verbal and visual memory. RESULTS: There were significant differences in olfactory identification ability between the three groups. EOCD patients were comparable to LOCD patients, while both patients' group showing worse olfactory identification ability than controls. Olfactory identification ability was not significantly correlated with verbal and visual memory or clinical symptoms in the EOCD group or the LOCD group. CONCLUSIONS: The results of the present study suggest that olfactory identification ability may be a relatively stable indicator of OCD, independent of age, duration of illness, verbal and visual memory, and severity of clinical symptoms.

Early-Onset Schizophrenia Showed Similar but More Severe Olfactory Identification Impairment Than Adult-Onset Schizophrenia.

BACKGROUND: "Early-onset schizophrenia" (EOS) is defined as disease with onset before the age of 18 years. This subset of schizophrenia exhibits worse cognitive function and carries a worse prognosis than adult-onset schizophrenia (AOS). Olfactory impairment has been found in patients with schizophrenia-spectrum disorders. However, most research has focused on olfactory impairment in patients with AOS: olfactory function in EOS is not known. The aim of this study was to investigate the olfactory identification ability in EOS, and its relationship with negative symptoms. METHODS: We compared olfactory function between two independent samples: 40 patients with EOS and 40 age- and sex-matched healthy controls (HCs); as well as 40 patients with AOS and 40 age- and sex-matched HCs. The University of Pennsylvania Smell Identification Test was administered. RESULTS: The EOS group and AOS group exhibited worse olfactory identification ability than HCs; impairment correlated significantly with negative symptoms. Olfactory identification was worse in patients suffering EOS compared with those suffering AOS. CONCLUSION: Olfactory identification impairment may be a trait marker of schizophrenia.

Chemosensory Anhedonia in Patients With Schizophrenia and Individuals With Schizotypy: A Questionnaire Study.

Anhedonia, the loss or decline of the ability to enjoy pleasure, is an important clinical characteristic of schizophrenia. Schizotypal traits refer to the appearance of subclinical symptoms of schizophrenia across normal people. Still, few studies have investigated chemosensory anhedonia in schizophrenia patients and schizotypy individuals. Seventy-one schizophrenia patients (SCZ), 162 schizotypy individuals (SCT) as selected by the Schizotypal Personality Questionnaire (SPQ), and 182 healthy controls (HC) participated in our study. We used the Positive and Negative Syndrome Scale (PANSS) to measure the clinical symptoms of schizophrenia patients. All participants completed the Chemosensory Pleasure Scale (CPS), which was used to assess participants' smell and taste hedonic capacities. We found that the three groups differed in chemosensory anhedonia. The SCZ group presented more severe chemosensory anhedonia than the SCT group, and the SCT group presented more severe chemosensory anhedonia than the HC group. We also found that chemosensory hedonic capacity was negatively correlated with negative schizotypal traits in the SCT group. Our results suggested that chemosensory anhedonia is an important characteristic of schizophrenia spectrum disorders.

[Hedgehog signaling pathway and osteoporosis].

Hedgehog signaling pathway is a conserved and important signaling pathway involved in proliferation and differentiation of many types of cells. Latest studies have found that Hedgehog signaling pathway may induce MSCs osteoblast differentiation by increasing the expression of the Runx2 and Osx and inhibit MSCs differentiate to adipocyte. Hedgehog signaling pathway may also promote osteoblast proliferation by regulating cyclin. This review summarizes the mechanism that Hedgehog signaling pathway regulates osteoblast differentiation and proliferation,and concludes that Hedgehog signaling pathway can regulate bone metabolism. It might provide new ideas for the treatment of osteoporosis.