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Biomedical subjects

Shon Lewis

Publications and source records attributed to Shon Lewis.

8 recordsLinked to original sources

Hallucination proneness, schizotypy and meta-cognition.

Disordered or maladaptive meta-cognitive processing appears to be a prominent feature for some individuals with a diagnosis of schizophrenia. We sought to establish whether healthy individuals distinguished either in terms hallucination proneness (HP) or level of schizotypy could also be differentiated on the sub-scales of the Meta-cognitions Questionnaire (MCQ), or a modified version of it in which items about worry were replaced with items specifically related to thinking. A total of 106 healthy volunteers completed the Oxford and Liverpool Inventory of Feelings and Experiences and Launay-Slade hallucination scale, the Schizotypal Personality Questionnaire and two versions of the MCQ: the original which assesses five domains of meta-cognition and an adapted version in which items relating to worry had been replaced by items relating to thinking or reflecting on thinking (MCQ-th). ANOVA indicated highly significant differences between three groups of individuals differentiated in terms of high, medium and low proneness to hallucinations on four of the five MCQ sub-scales, and three of the four MCQ-th factors. Regression analyses indicated that the MCQ factors encompassing (1) a sense of uncontrollability of thinking (and the perceived attendant dangers of this) and (2) negative beliefs about thinking related to suspicion and punishment were the strongest predictors of high schizotypy. Individuals who score higher on a measure of HP are more likely to display patterns of meta-cognitive processing that resemble, in certain respects, those reported in individuals with a diagnosis of schizophrenia. High schizotypy predicts a negative appraisal about both the controllability and consequences of thinking.

Adolescent↗

Suicide behaviour over 18 months in recent onset schizophrenic patients: the effects of CBT.

The results of a trial of cognitive behaviour therapy, supportive counselling and treatment as usual in recent onset schizophrenia on suicide behaviour are reported. Treatment was delivered over a five week period during hospitalisation for an acute episode. Participants were assessed at baseline, 6 weeks, 3 and 18 months. Over the 18 months there were 3 definite suicides and 2 deaths by accidental causes. The rates of moderate to severe suicidal behaviour were 13% at admission, 4% at six weeks, 1.5% at three months and 6% at 18 months. There were no beneficial or adverse effects of psychological treatment on suicide behaviour that reduced significantly with clinical recovery. There is a general picture of those who suffer persistently higher levels of psychotic symptoms, poorer functioning, depression and low self-esteem have higher severity of suicide behaviour, although the numbers with clinically significant suicide behaviour are low. CBT may need to be modified to directly target suicide behaviour and its antecedents to significantly reduce risk; recommendations on this are made.

Acute Disease↗

Cannabis use prior to first onset psychosis predicts spared neurocognition at 10-year follow-up.

A priori cannabis use was recorded at index admission for 112 participants in the Manchester first-episode psychosis cohort. 69 of the 100 surviving (mainly schizophrenia) patients were followed up 10-12 years later and assessed on a battery of clinical, behavioural and neurocognitive measures. Individuals who had not used cannabis before the first episode of illness were generally indistinguishable from cannabis users at follow-up, except that the latter group evidenced a marked 'sparing' of neurocognitive functions. These findings are briefly discussed in relation to other casual factors in psychosis.

Case-Control Studies↗

Association between duration of untreated psychosis and outcome in cohorts of first-episode patients: a systematic review.

CONTEXT: Duration of untreated psychosis (DUP) is the time from manifestation of the first psychotic symptom to initiation of adequate treatment. It has been postulated that a longer DUP leads to a poorer prognosis. If so, outcome might be improved through earlier detection and treatment. OBJECTIVES: To establish whether DUP is associated with prognosis and to determine whether any association is explained by confounding with premorbid adjustment. DATA SOURCES: The CINAHL (Cumulative Index to Nursing and Allied Health), EMBASE, MEDLINE, and PsychLIT databases were searched from their inception dates to May 2004. STUDY SELECTION: Eligible studies reported the relationship between DUP and outcome in prospective cohorts recruited during their first episode of psychosis. Twenty-six eligible studies involving 4490 participants were identified from 11 458 abstracts, each screened by 2 reviewers. DATA EXTRACTION: Data were extracted independently and were checked by double entry. Sensitivity analyses were conducted excluding studies that had follow-up rates of less than 80%, included affective psychoses, or did not use a standardized assessment of DUP. DATA SYNTHESIS: Independent meta-analyses were conducted of correlational data and of data derived from comparisons of long and short DUP groups. Most data were correlational, and these showed a significant association between DUP and several outcomes at 6 and 12 months (including total symptoms, depression/anxiety, negative symptoms, overall functioning, positive symptoms, and social functioning). Long vs short DUP data showed an association between longer DUP and worse outcome at 6 months in terms of total symptoms, overall functioning, positive symptoms, and quality of life. Patients with a long DUP were significantly less likely to achieve remission. The observed association between DUP and outcome was not explained by premorbid adjustment. CONCLUSIONS: There is convincing evidence of a modest association between DUP and outcome, which supports the case for clinical trials that examine the effect of reducing DUP.

Adaptation, Psychological↗

Neurocognitive function and outcome in first-episode schizophrenia: a 10-year follow-up of an epidemiological cohort.

The natural history of neurocognitive impairments in schizophrenia is unclear. We aimed to characterise this in an epidemiological first-episode cohort and relate it to long-term outcome. All but 1 of 112 first-episode psychosis cases ascertained from a geographical catchment area were traced at 10-12 years. Neurocognitive and multi-dimensional outcome assessments were made at interview in 49 cases with schizophrenia and related disorders. Twenty-four of these had completed the same neurocognitive battery at index admission. Comparisons with normative data showed impaired executive function in a proportion of the first episode (FE) sample at baseline. Significant deterioration was seen over the follow-up period in three of nine sub-tests: object assembly, picture completion and memory for designs. Neurocognitive impairments at outcome, but not baseline, correlated with clinical outcome. Poor outcome was associated with a decline in performance on visuo-spatial tasks and a failure to improve on frontal-temporal tasks during the follow-up period. Executive deficits may be present in the FE, but do not progress over 10-12 years. Visuo-spatial function is spared in the FE but may deteriorate over time. Changes in both these patterned deficits are predictive of clinical outcome.

Adolescent↗

The relationship between predisposing factors, premorbid function and symptom dimensions in psychosis: an integrated approach.

BACKGROUND: Increasing evidence suggests psychosis may be more meaningfully viewed in dimensional terms rather than as discrete categorical states and that specific symptom clusters may be identified. If so, particular risk factors and premorbid factors may predict these symptom clusters. AIMS: (i) To explore, using principal component analysis, whether specific factors for psychotic symptoms can be isolated. (ii) To establish the predictors of the different symptom factors using multiple regression techniques. METHOD: One hundred and eighty-nine inpatients with psychotic illness were recruited and information on family history, premorbid factors and current symptoms obtained from them and their mothers. RESULTS: Seven distinct symptom components were identified. Regression analysis failed to identify any developmental predictors of depression or mania. Delusions/hallucinations were predicted by a family history of schizophrenia and by poor school functioning in spite of normal premorbid IQ (F = 6.5; P < 0.001); negative symptoms by early onset of illness, developmental delay and a family history of psychosis (F = 4.1; P = 0.04). Interestingly disorganisation was predicted by the combination of family history of bipolar disorder and low premorbid IQ (F = 4.9; P = 0.003), and paranoia by obstetric complications (OCs) and poor school functioning (F = 4.2; P = 0.01). CONCLUSION: Delusions and hallucinations, negative symptoms and paranoia all appeared to have a developmental origin though they were associated with different childhood problems. On the other hand, neither mania nor depression was associated with childhood dysfunction. Our most striking finding was that disorganisation appeared to arise when a familial predisposition to mania was compounded by low premorbid IQ.

Adolescent↗