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Biomedical subjects

S M Lawrie

Publications and source records attributed to S M Lawrie.

At least 37 records · Page 2Linked to original sources
PubMed2001

A factor model of the functional psychoses and the relationship of factors to clinical variables and brain morphology.

BACKGROUND: Despite more than 100 years of study, there remains no definitive diagnostic validation of the functional psychoses. Factor analysis suggests the presence of three or more psychopathological syndromes in functional psychoses as a whole. The relationship between these factors and cerebral anatomy has been investigated in schizophrenia only. This study aimed to address the relationship of symptom factors to clinically important variables and cerebral anatomy in a sample of psychotic patients with a spread of diagnoses. METHODS: In a sample of patients with functional psychoses, symptom data was obtained on four consecutive admissions using the OPCRIT symptom checklist. OPCRIT data was used to generate operational diagnoses in accordance with pre-set criteria and a principle components analysis was performed on symptom data. Factor loadings were compared between each admission to examine factor stability over time. Factor scores at first admission were also correlated with clinical variables obtained from patients' case notes. From the sample of 204 patients, 64 subjects were recruited and underwent an MRI scan of the brain. Regional anatomical volumes were compared with diagnosis and factor loadings at first admission. RESULTS: A principal components analysis gave a four-factor solution of 'manic', 'depressive', 'disorganization' and 'reality distortion' factors at each admission. Factors showed a high degree of stability over the four admissions studied. The factors were significantly associated with several clinical variables. Three of the four factors were associated with a specific pattern of cerebral anatomy. CONCLUSIONS: This study suggests that factors may correspond to relatively specific disease processes underlying functional psychotic illness. We propose that the use of symptom factors may facilitate the investigation of the underlying mechanisms of psychotic illness.

Activities of Daily Living↗
PubMed2001

Neurodevelopmental indices and the development of psychotic symptoms in subjects at high risk of schizophrenia.

BACKGROUND: Neurological 'soft signs' and minor physical anomalies (MPAs) are reported to be more frequent in patients with schizophrenia than in controls. AIMS: To determine whether these disturbances are genetically mediated, and whether they are central to the genesis of symptoms or epiphenomena. METHOD: We obtained ratings in 152 individuals who were antipsychotic drug-free and at high risk, some of whom had experienced psychotic symptoms, as well as 30 first-episode patients and 35 healthy subjects. RESULTS: MPAs and Neurological Evaluation Scale (NES) 'sensory integration abnormalities' were more frequent in high-risk subjects than in healthy controls, but there were no reliable differences between high-risk subjects with and without psychotic symptoms. MPAs were most frequent in high-risk subjects with least genetic liability and NES scores showed no genetic associations. CONCLUSIONS: The lack of associations with psychotic symptoms and genetic liability to schizophrenia suggests that soft signs and physical anomalies are nonspecific markers of developmental deviance that are not mediated by the gene(s) for schizophrenia.

Abnormalities, Multiple↗
PubMed2000

Edinburgh high risk study--findings after four years: demographic, attainment and psychopathological issues.

This study reports findings of the Edinburgh High Risk Study four years after it began. This study is designed to explore the pathogenesis of schizophrenia by examining a large sample of young adults aged 16-25 years who are at enhanced risk of developing schizophrenia by having two close relatives with the disorder, and comparing them with matched controls. This paper presents comparisons of the high risk subjects, well controls and subjects with first-episode schizophrenia in terms of demographic, childhood, psychopathological, educational and employment, forensic and social work variables. High risk subjects have more psychological difficulties, poorer educational and employment attainment, and more social work contact than controls. The enhanced social work involvement related to the presence of a schizophrenic parent (especially a mother) but the other difficulties could not be attributed to that situation. Neurotic, partially held psychotic and fully held psychotic symptoms all occurred in both subjects and controls, but all were significantly more common in high risk subjects. Clinical schizophrenia has so far developed in 10 high risk subjects and in no controls. Possible confounding effects of drug or alcohol misuse were considered but were found unlikely to be important.

Adolescent↗
PubMed2000

Depression after stroke and lesion location: a systematic review.

BACKGROUND: There is conflicting evidence on the hypothesis that the risk of depression after stroke is influenced by the location of the brain lesion. We undertook a systematic review to examine the hypotheses that depression is more commonly associated with left-hemisphere strokes than with right-hemisphere strokes and with lesions of the left anterior brain than with other regions. METHODS: We did a computer-aided search of MEDLINE, BIDS ISI, and PsychLit databases supplemented by hand searches of key journals. We included all reports on the association of depression after stroke with the location of the brain lesion. Studies were systematically and independently examined by two investigators. Fixed-effects and random-effects meta-analyses were done. FINDINGS: 143 reports were identified by the search strategy. 48 were eligible for inclusion. Not all reports included original data. Only two reports of original data supported the hypotheses and seven clearly did not. The pooled (random-effects) relative risk of depression after a left-hemisphere stroke, compared with a right-hemisphere stroke, was 0.95 (95% CI 0.83-1.10). For depression after a left anterior lesion compared with all other brain areas the pooled (random-effects) relative risk was 1-17 (0.87-1.62). Restriction of the analyses to reports from high-quality studies or major depressive disorder did not substantially affect the findings. Nor were they affected by stratification of the time between stroke and the assessment of depression. Multiple publications from the same samples of patients were apparent. INTERPRETATION: This systematic review offered no support for the hypothesis that the risk of depression after stroke is affected by the location of the brain lesion.

Aphasia↗
PubMed2000

The difference in patterns of motor and cognitive function in chronic fatigue syndrome and severe depressive illness.

BACKGROUND: Chronic fatigue syndrome (CFS) and major depressive disorder (MDD) share many symptoms and aetiological factors but may have different neurobiological underpinnings. We wished to determine the profile of the biological variables disturbed in CFS and MDD, and identify any critical factors that differentiate the disorders. METHODS: Thirty patients with CFS, 20 with MDD and 15 healthy controls matched group-wise for age and sex were recruited. Subjects were given a detailed battery of motor and cognitive tests, including measures of psychomotor speed, memory and maximal voluntary muscle contraction in both the morning and evening that were balanced to avoid order effects. RESULTS: CFS patients generally performed worse on cognitive tests than healthy controls, but better than patients with MDD. Both patient groups had markedly impaired motor function compared with healthy controls. MDD subjects showed a significantly greater diurnal improvement in maximal voluntary contraction than healthy controls. CONCLUSIONS: Patients with CFS and MDD show similarly substantial motor impairment, but cognitive deficits are generally more marked in MDD. Diurnal changes in some functions in MDD may differentiate the disorder from CFS.

Adult↗
PubMed2000

Neuropsychological change in young people at high risk for schizophrenia: results from the first two neuropsychological assessments of the Edinburgh High Risk Study.

BACKGROUND: Studies of groups of individuals who have a genetically high risk of developing schizophrenia, have found neuropsychological impairments that highlight likely trait markers of the schizophrenic genotype. This paper describes the change in neuropsychological function and associations with psychiatric state of high risk participants during the first two assessments of the Edinburgh High Risk Study. METHODS: Seventy-eight high risk participants and 22 normal controls, age and sex matched completed two neuropsychological assessments 18 months to 2 years apart. The areas of function assessed include intellectual function, executive function, learning and memory, and verbal ability and language. RESULTS: The high risk participants performed significantly worse on particular tests of verbal memory and executive function over the two assessments than matched controls. Those high risk participants who experienced psychotic symptoms were found to exhibit a decline in IQ and perform worse on tests of verbal memory and executive function than those without symptoms. An increase in psychotic symptoms between the two assessments in the high risk group was found to be associated with an apparent decline in IQ and memory. CONCLUSIONS: The results suggest that the development of psychotic symptoms is preceded by a decline in IQ and memory. This may reflect a general and a more specific disease process respectively.

Adolescent↗
PubMed2000

Evidence-based psychiatry--do psychiatrists want it and can they do it?

OBJECTIVE: To examine (a) psychiatrists' attitudes to evidence-based psychiatry, (b) whether psychiatrists have identifiable clinical information needs, (c) if such information is practically obtainable, and (d) how psychiatrists respond to the information obtained. DESIGN: We surveyed senior psychiatrists to enquire about their attitudes and to request up to three clinical questions they would like answered. We attempted to find evidence to answer the five most frequently asked questions using recommended strategies and timed how long it took us. We fed our answers back to those who had asked one of these questions and asked if they found the answers useful. SETTING: Specialist registrars, senior registrars and consultants in south-east Scotland. RESULTS: Ninety three (76%) of those surveyed returned usable questionnaires. Respondents thought that only 40% of their practice is evidence-based. They reported that 'insufficient time' was the biggest barrier to implementing evidence-based psychiatry. The most frequently asked questions concerned the treatment of major psychiatric disorders. It took us--three experienced researchers, trained in critical appraisal, with excellent local facilities--between 15-60 minutes to answer each question. Most of those who had asked the questions (15/22) thought they would not have been able to answer them and stated that such a 'question answering service' as piloted here would be valuable. CONCLUSIONS: An evidence-based psychiatry appears to be desirable and possible, but impractical for the individual clinician. There is a need for short accessible evidence-based summaries of optimal treatment in psychiatry.

Attitude of Health Personnel↗
PubMed1999

Methodological issues in volumetric magnetic resonance imaging of the brain in the Edinburgh High Risk Project.

The Edinburgh High Risk Project is a longitudinal study of brain structure (and function) in subjects at high risk of developing schizophrenia in the next 5-10 years for genetic reasons. In this article we describe the methods of volumetric analysis of structural magnetic resonance images used in the study. We also consider potential sources of error in these methods: the validity of our image analysis techniques; inter- and intra-rater reliability; possible positional variation; and thresholding criteria used in separating brain from cerebro-spinal fluid (CSF). Investigation with a phantom test object (of similar imaging characteristics to the brain) provided evidence for the validity of our image acquisition and analysis techniques. Both inter- and intra-rater reliability were found to be good in whole brain measures but less so for smaller regions. There were no statistically significant differences in positioning across the three study groups (patients with schizophrenia, high risk subjects and normal volunteers). A new technique for thresholding MRI scans longitudinally is described (the 'rescale' method) and compared with our established method (thresholding by eye). Few differences between the two techniques were seen at 3- and 6-month follow-up. These findings demonstrate the validity and reliability of the structural MRI analysis techniques used in the Edinburgh High Risk Project, and highlight methodological issues of general concern in cross-sectional and longitudinal studies of brain structure in healthy control subjects and neuropsychiatric populations.

Adolescent↗
PubMed1999

Magnetic resonance imaging of brain in people at high risk of developing schizophrenia.

BACKGROUND: Schizophrenia is a multifactorial disorder that is associated with disturbed cerebral development. Structural brain-imaging studies have consistently shown that the volumes of some parts of the brain, particularly the mesial temporal lobes, are smaller in patients with schizophrenia than in healthy people. Whether these abnormalities of brain structure predate the onset of symptoms is not known. METHODS: 100 people at high risk of developing schizophrenia (two or more first-degree or second-degree relatives affected), 20 patients in their first episode of schizophrenia, and 30 healthy controls underwent magnetic resonance imaging of the brain. The volumes of regions of interest were measured by standard techniques. FINDINGS: Mean whole-brain volume was 1356 cm3 (SD 178) in the first-episode group, 1347 cm3 (122) in the high-risk group, and 1334 cm3 (149) in the controls (p=0.8). The mean volume of the left amygdala-hippocampal complex (AHC) was lower in the first-episode group (4.3 cm3 [0.6]) than in the high-risk group (4.6 cm3 [0.6]), and in turn than in the controls (4.8 cm3 [0.7]); these differences were significant (p<0.05) both for absolute volumes and values adjusted for brain volume and other confounders. The right AHC showed a similar pattern (absolute volumes 4.5 cm3 [0.7], 4.8 cm3 [0.6], 4.9 cm3 [0.9], respectively). Both thalamic nuclei were significantly smaller in the high-risk group than in the control group. INTERPRETATION: People at high risk of developing schizophrenia for genetic reasons have several structural brain abnormalities that are similar to those in patients with the disorder. If at-risk individuals with particularly small AHC or thalami are most likely to develop schizophrenia, this feature might assist in early detection and treatment.

Adolescent↗
PubMed1999

Personality dimensions in chronic fatigue syndrome and depression.

Chronic fatigue syndrome (CFS) is a poorly understood condition. Possible etiological factors include infectious agents, psychiatric disorders, and personality characteristics. We examined personality dimensions in 30 nondepressed patients with CFS, 20 patients with major depressive disorder (MDD), and 15 healthy controls. On the NEO-FFI, patients with CFS scored significantly lower than healthy controls on the extroversion subscale. On the neuroticism dimension of the Eysenck Personality Questionnaire (EPQ), patients with MDD scored higher than those with CFS, who in turn scored significantly higher than the healthy controls. CFS patients rated themselves as higher on neuroticism and less extroverted when ill than when they were well. Our results suggest that high scores on neuroticism and low scores on extroversion in CFS could be a reaction to chronic illness.

Adult↗
PubMed1999

Errorless learning and the cognitive rehabilitation of memory-impaired schizophrenic patients.

BACKGROUND: In recent years, evidence has accumulated that a significant proportion of schizophrenic patients have severe memory impairment, which cannot be attributed to the effects of medication, chronicity or institutionalization. Our group has demonstrated that memory impairment is associated with poor psychosocial outcome and treatment resistance. Work on the classical amnesic syndrome has suggested that memory training is facilitated by adopting an 'errorless learning' approach, where subjects do not experience failure during learning. This is based on the theory that the preserved implicit memory of amnesic patients results in implicitly remembered incorrect responses interfering with target items, in the absence of a functioning explicit memory system to allow differentiation. METHOD: We compared three groups of subjects, memory-impaired schizophrenic patients, memory unimpaired schizophrenic patients and healthy controls. RESULTS: An errorless learning approach conferred a significant advantage on the memory-impaired schizophrenic group, bringing their performance up to the level of both control groups. In contrast, adopting a traditional trial and error, or errorful approach resulted in markedly impaired performance in the memory-impaired schizophrenic group only. CONCLUSIONS: We conclude that errorless learning approaches may be worthy of further evaluation in the cognitive rehabilitation of memory-impaired schizophrenic patients.

Adult↗
PubMed1999

Schizophrenia and complications of pregnancy and labor: an individual patient data meta-analysis.

Several epidemiological studies have reported an association between complications of pregnancy and delivery and schizophrenia, but none have had sufficient power to examine specific complications that, individually, are of low prevalence. We, therefore, performed an individual patient meta-analysis using the raw data from case control studies that used the Lewis-Murray scale. Data were obtained from 12 studies on 700 schizophrenia subjects and 835 controls. There were significant associations between schizophrenia and premature rupture of membranes, gestational age shorter than 37 weeks, and use of resuscitation or incubator. There were associations of borderline significance between schizophrenia and birthweight lower than 2,500 g and forceps delivery. There was no significant interaction between these complications and sex. We conclude that some abnormalities of pregnancy and delivery may be associated with development of schizophrenia. The pathophysiology may involve hypoxia and so future studies should focus on the accurate measurement of this exposure.

Case-Control Studies↗
PubMed1999

Volumetric magnetic resonance imaging study of the brain in subjects with sex chromosome aneuploidies.

OBJECTIVES: Cognitive impairment has been reported in people with sex chromosome aneuploides (SCAs) and it has been proposed that the presence of an extra sex chromosome may have an adverse effect on neurodevelopment. This study examines the hypothesis with structural MRI of the brain. METHODS: Thirty two subjects with SCA (XXX (n=12), XYY (n=10), and XXY (n=10)) from a birth cohort study were matched groupwise for age, parental social class, and height with normal controls (13 female, 26 male). Brain MRI, measurements of IQ, and a structured psychiatric interview were performed. RESULTS: The XXX females and XXY males had significantly smaller whole brain volumes than controls of the same phenotypic sex (p=0.003 and p</=0.05 respectively). The XXY group also had bilaterally enlarged lateral ventricles (p</=0.05). No significant differences were found between the XYY group and controls. IQ scores in all SCA groups were lower than in the control groups. CONCLUSIONS: The main result of reduced brain volumes in XXX and XXY subjects, but not in XYY subjects, indicates that the presence of a supernumerary X chromosome has a demonstrable effect on brain development.

Adolescent↗