Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We completed a systematic genome-wide search for evidence of loci linked to schizophrenia using a collection of 70 pedigrees containing multiple affected individuals according to three phenotype classifications: schizophrenia only (48 pedigrees; 70 sib-pairs); schizophrenia plus schizoaffective disorder (70 pedigrees; 101 sib-pairs); and a broad category consisting of schizophrenia, schizoaffective disorder, paranoid or schizotypal personality disorder, psychosis not otherwise specified (NOS), delusional disorder, and brief reactive psychosis (70 pedigrees; 111 sib-pairs). All 70 families contained at least one individual affected with chronic schizophrenia according to DSM-III-R criteria. Three hundred and thirty-eight markers spanning the genome were typed in all pedigrees for an average resolution of 10.5 cM (range, 0-31 cM) and an average heterozygosity of 74.3% per marker. The data were analyzed using multipoint nonparametric allele-sharing and traditional two-point lod score analyses using dominant and recessive, affecteds-only models. Twelve chromosomes (1, 2, 4, 5, 8, 10, 11, 12, 13, 14, 16, and 22) had at least one region with a nominal P value <0.05, and two of these chromosomes had a nominal P value <0.01 (chromosomes 13 and 16), using allele-sharing tests in GENEHUNTER. Five chromosomes (1, 2, 4, 11, and 13) had at least one marker with a lod score >2.0, allowing for heterogeneity. These regions will be saturated with additional markers and investigated in a new, larger set of families to test for replication.
 ...
PMID:A genome-wide search for schizophrenia susceptibility genes. 975 21

The investigation of cognitive deficits in patients with schizotypal personality disorder (SPD) is important both to establish commonalities between SPD and schizophrenia and to clarify the significance of these cognitive deficits for schizophrenic disorders. The purpose of this study was to examine verbal learning and memory with the California Verbal Learning Test (CVLT) in a group of patients with SPD (n=24) and a group of patients with personality disorders other than SPD (OPD; n=25). The results indicated that SPD patients learned significantly fewer words with practice on the CVLT than OPD patients (F=4.32, df=1,47, p < 0.05), and their rate of learning was reduced relative to normative standards. These findings suggest that SPD patients have a deficit in verbal learning that is similar to, although not as severe as, the impairments seen in schizophrenia.
 ...
PMID:Verbal learning and memory in schizotypal personality disorder. 985 95

Although the expressions of both positive and negative symptoms in schizophrenia spectrum illnesses can each occur with varying degrees of severity, researchers have often dichotomized patients as generally positive or negative subtypes. Studies of schizophrenia and schizotypal personality disorder (SPD) have not typically controlled for the severity of the other symptom types when examining the relationship between positive and negative symptom subtypes and cognitive impairment. The present study investigated the relationship between the severity of both symptom types and reaction time crossover task performance in SPD in groups made equivalent on the severity of the other type of symptom. Fifty-eight out of 458 undergraduates were screened into one of four groups (high negative-high positive, low negative-low positive, high negative-low positive or low negative-high positive) by the Schizotypal Personality Questionnaire and assessed with the reaction time crossover task. The results indicated that negative schizotypal symptoms were associated with the early crossover pattern, while positive schizotypal symptoms related to longer overall reaction time. Therefore, different cognitive mechanisms involved in crossover task performance appeared to be associated with different symptom subtypes.
 ...
PMID:Positive and negative schizotypal symptoms relate to different aspects of crossover reaction time task performance. 985 40

Sensorimotor gating of the startle reflex occurs when the presentation of a weak "prepulse" 30-500 msec prior to a startling stimulus inhibits the reflex, and is called prepulse inhibition (PPI). The study of PPI has recently been extended to mice to take advantage of recent advances in molecular genetics, because several neuropsychiatric disorders including schizophrenia, obsessive compulsive disorder, and schizotypal personality disorder are characterized by PPI deficits. Studies in wild-type and 5-HT1B knockout mice suggest that activation of 5-HT1B receptors decreases PPI. The direct 5-HT1A/1B agonist RU24969 decreases PPI in wild-type but not 5-HT1B knockout mice. Likewise, the serotonin releasing compounds MDMA(+), MBDB(+/-), and alpha-ethyltryptamine (AET) have no effect on PPI in wild-type mice, but increase PPI in 5-HT1B knockout mice. As the direct 5-HT1A agonist 8-OH-DPAT increases PPI in mice, the unmasking of these effects may also contribute to the PPI-increasing effects of 5-HT releasers in 5-HT1B knockout mice.
 ...
PMID:5-HT1B receptor modulation of prepulse inhibition: recent findings in wild-type and 5-HT1B knockout mice. 992 42

The aim of this study was to determine whether spiperone binding to lymphocytes could serve as a biological marker of susceptibility to schizophrenia and schizophrenic spectrum disorders or as a measure of response to neuroleptic treatment. Lymphocyte spiperone binding parameters (Bmax, KD) were assessed in 13 patients with schizophrenia and 4 patients with schizotypal personality disorder, all neuroleptic naive, and in 19 age- and sex-matched control subjects. A repeated determination was carried out in 11 of the schizophrenic subjects after several months of neuroleptic treatment. In addition, the binding characteristics of 12 of the schizophrenic/schizotypal patients were compared with those of 13 healthy family members and normal unrelated controls. No significant differences were detected between the schizophrenic subjects and controls before or after neuroleptic treatment or between the patients and their non-affected family members and controls.
 ...
PMID:3H-spiperone binding to lymphocytes in neuroleptic-naive-schizophrenia and the effect of neuroleptic treatment. 1020 8

Changes in the manifestation of vulnerability to schizophrenia across the lifespan may hold important clues about aetiology. They may also illustrate some general principles about the nature of neurodevelopmental processes. Within the framework of a neural diathesis-stress model, we review findings on the precursors of schizophrenia and schizotypal personality disorder. The findings suggest that there are critical developmental periods for the manifestation of dysfunction and that, within certain domains of behaviour, there is a temporal disjunction between the onset of the neuropathology and its expression. It also appears that the diathesis for schizophrenia involves polymorphic behavioural expression, such that it can be manifested in multiple domains - motoric, cognitive and socio-emotional. Taken together, the data on the longitudinal course of schizophrenia indicate that the expression of the diathesis is moderated by central nervous system maturational processes. One putative moderating system, the hypothalamic-pituitary-adrenal (HPA) axis, is discussed, and implications for preventive intervention are explored.
 ...
PMID:Developmental neuropathology and the precursors of schizophrenia. 1022 28

Past research has revealed that schizophrenia is associated with voluntary movement abnormalities, as well as higher rates of involuntary movements. On instrumental motor tasks, patients manifest reduced motor stability, excessive force and more contralateral motor overflow (movement in the non-responding hand). In the present study, an instrumental motor task (manual response forced-choice task) was administered to a group of adults with schizotypal personality disorder (SPD) in order to determine whether they show motor deficits similar to those observed in schizophrenia. As predicted, the schizotypal subjects were excessive and more variable in motor force, compared to healthy controls and other personality-disordered subjects. Additionally, the force and variability of the motor responses were positively correlated with ratings of both positive and negative SPD symptoms. Finally, motor overflow and negative symptoms were associated with higher salivary cortisol levels. The pattern of findings is consistent with previous reports linking motor abnormalities and heightened cortisol with schizotypal personality disorder.
 ...
PMID:Motor dysfunction in schizotypal personality disorder. 1046 61

Motor dysfunction is associated with schizophrenia, and recent longitudinal studies indicate that it precedes the onset of clinical symptoms. Of particular interest is the heightened occurrence of involuntary movements, which are apparent as early as infancy and suggest the presence of subcortical brain abnormalities. In this article, we present the results of a study of spontaneous movements in adolescents with schizotypal personality disorder (SPD). SPD is a syndrome that has been shown to be genetically linked with schizophrenia and is often observed prior to the early adult onset of schizophrenia. Systematic coding of videotapes of diagnostic interviews revealed that the SPD group showed significantly more involuntary movements of the head, trunk, and upper limbs than did normals and adolescents with other personality disorders. There were no diagnostic group differences in the rate of voluntary movements. Salivary cortisol, measured before the interview, was positively correlated with involuntary movements. Taken together, the findings provide further support for the hypothesized etiologic relation between SPD and schizophrenia. Based on a neural diathesis-stress model, potential underlying mechanisms are discussed.
 ...
PMID:Motor dysfunction and risk for schizophrenia. 1053 22

Seeking to unite psychological and biological approaches, this paper links cognitive and cellular hypotheses and data about thought and language abnormalities in schizophrenia. The common thread, it is proposed, is a dysregulated suppression of associations (at the behavioral and functional neural systems level), paralleled by abnormalities of inhibition at the cellular and molecular level, and by an abnormal anatomical substrate (reduced MRI gray matter volume) in areas subserving language. At the level of behavioral experiments and connectionist modeling, data suggest an abnormal semantic network connectivity (strength of associations) in schizophrenia, but not an abnormality of network size (number of associates). This connectivity abnormality is likely to be a preferential processing of the dominant (strongest) association, with the neglect of preceding contextual information. At the level of functional neural systems, the N400 event-related potential amplitude is used to index the extent of "search" for a semantic match to a word. In a short stimulus-onset-asynchrony condition, both schizophrenic and schizotypal personality disorder subjects showed, compared with controls, a reduced N400 amplitude to the target words that were related to cues, e.g. cat-dog, a result compatible with behavioral data. Other N400 data strongly and directly suggest that schizophrenics do not efficiently utilize context.
 ...
PMID:Cognitive dysfunction in schizophrenia: unifying basic research and clinical aspects. 1065 12

The present article comments on a classic study by Garfield (1947) then reviews research on the Rorschach and psychiatric diagnoses. Despite a few positive findings, the Rorschach has demonstrated little validity as a diagnostic tool. Deviant verbalizations and bad form on the Rorschach, and indices based on these variables, are related to Schizophrenia and perhaps to Bipolar Disorder and Schizotypal Personality Disorder. Patients with Borderline Personality Disorder also seem to give an above-average number of deviant verbalizations. Otherwise the Rorschach has not shown a well-demonstrated relationship to these disorders or to Major Depressive Disorder, Posttraumatic Stress Disorder (PTSD), anxiety disorders other than PTSD, Dissociative Identity Disorder, Dependent, Narcissistic, or Antisocial Personality Disorders, Conduct Disorder, or psychopathy.
 ...
PMID:The Rorschach test in clinical diagnosis: a critical review, with a backward look at Garfield (1947). 1079 11


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>