Neurological abnormalities and cognitive ability in first-episode psychosis

Dazzan, Paola; Lloyd, T A; Morgan, Kevin; Zanelli, Jolanta; Morgan, Craig; Orr, Kenneth G.; Hutchinson, Gerard; Fearon, Paul; Allin, Matthew; Rifkin, Larry; McGuire, Philip; Doody, Gillian A.; Holloway, John; Leff, Julian; Harrison, Glynn; Jones, Peter B.; Murray, Robin M.

doi:10.1192/bjp.bp.107.045450

Cited by 58 publications

(35 citation statements)

References 27 publications

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“…As expected, the current IQ of patients was lower than their premorbid IQ on average (see also Dazzan et al, 2008). We calculated a difference score (IQ minus premorbid IQ) in order to see whether the estimated deterioration was associated with cannabis use (see also Leeson et al, 2011), and found this to be the case.…”

Section: Difference Between Iq and Premorbid Iq In Relation To Cannabmentioning

confidence: 80%

Cannabis users have higher premorbid IQ than other patients with first onset psychosis

Ferraro

Russo

O’Connor

et al. 2013

Schizophrenia Research

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a b s t r a c t a r t i c l e i n f oBackground: A number of studies have reported that patients with psychosis who use cannabis have better cognitive performance than those who do not. This is surprising as cannabis can impair cognition in healthy subjects. An obvious question is whether the better current performance of psychotic patients who have used cannabis is a reflection of their having a higher premorbid IQ than those psychotic patients who haven't used cannabis. Aim: In a sample of patients at their first episode of psychosis, we tested the hypothesis that patients who smoked cannabis would have a higher premorbid IQ than patients who did not. Methodology: 279 participants (119 patients and 160 healthy controls) were assessed in order to obtain current and premorbid IQ measures and detailed information on cannabis use. We examined the association between cannabis use and both premorbid and current IQ in patients and controls. Results: Patients who had ever smoked cannabis had significantly higher current (p b .001) and premorbid IQ (p = .004) compared to patients who had never used cannabis. This difference was not found among controls. Conclusions: These findings suggest that the better cognitive performance of patients with their first episode of psychosis who have used cannabis compared with those who haven't is due to the better premorbid IQ of the former.

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Section: Difference Between Iq and Premorbid Iq In Relation To Cannabmentioning

confidence: 80%

Cannabis users have higher premorbid IQ than other patients with first onset psychosis

Ferraro

Russo

O’Connor

et al. 2013

Schizophrenia Research

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“…Being one of the common neuropsychological tests to assess the executive function of mental set shifting, the TMT B is required to search for and connect targets containing digits and letters with a pencil in ascending order, alternating between digits and letters. In order to exclude that the observed results are due to neurological soft signs that have been reported in schizophrenia (Chan and Gottesman 2008;Dazzan et al 2008;Gupta et al 1995), we compared the results to the association between Crus I/II and TMT A. TMT A involves the connection of targets but consisting of digits only, so that the task switching component is absent but the motoric component is present as well. Interestingly, we only found a significant association between GM in Crus I/II and the Brain Struct Funct (2012) 217:523-529 527 TMT B, not TMT A.…”

Section: Discussionmentioning

confidence: 92%

Reduction of cerebellar grey matter in Crus I and II in schizophrenia

et al. 2011

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Structural deficiencies within the cerebellum have been associated with schizophrenia. Whereas several region-of-interest-based studies have shown deviations in cerebellar volume, meta-analyses on conventional whole-brain voxel-based morphometry (VBM) studies do not implicate abnormalities in the cerebellum. Since this discrepancy could be due to methodological problems of VBM, we used a cerebellum-optimized VBM procedure. We acquired high-resolution MRI scans from 29 schizophrenia patients and 45 healthy controls and used a VBM approach utilizing the Spatially Unbiased Infratentorial toolbox (Diedrichsen in Neuroimage 33:127-138, 2006). Relative to healthy controls, schizophrenia patients showed reductions of grey matter volume in the left cerebellum Crus I/II that were correlated with thought disorder (p < 0.05; one-sided) and performance in the Trail-making test B (p < 0.01). No cerebellar group differences were detected employing conventional whole-brain VBM. The results derived from the cerebellum analysis provide evidence for distinct grey matter deficits in schizophrenia located in Crus I/II. The association of this area with thought disorder and Trail-making performance supports the previously suggested role of the cerebellum in coordination of mental processes including disordered thought in schizophrenia. The failure of conventional VBM to detect such effects suggests that previous studies might have underestimated the importance of cerebellar structural deficits in schizophrenia.

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“…in subjects who do not respond to treatment. Relevant to this notion is the observation that neurological soft signs, often considered to be an index of neurodevelopmental disturbances in schizophrenia, 67 are related to both reduced gyrification 68 and poor response to antipsychotics in psychosis. 69 Moreover, unlike responders, the nonresponders showed no diagnostic differences in gyrification.…”

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confidence: 97%

Cortical Folding Defects as Markers of Poor Treatment Response in First-Episode Psychosis

et al. 2013

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IMPORTANCE At present, no reliable predictors exist to distinguish future responders from nonresponders to treatment during the first episode of psychosis. Among potential neuroimaging predictors of treatment response, gyrification represents an important marker of the integrity of normal cortical development that may characterize, already at illness onset, a subgroup of patients with particularly poor outcome.OBJECTIVE To determine whether patients with first-episode psychosis who do not respond to 12 weeks of antipsychotic treatment already have significant gyrification defects at illness onset.DESIGN Case-control study with 12 weeks' longitudinal follow-up to determine treatment response.SETTING Secondary psychiatric services in an inner-city area (South London, England).PARTICIPANTS A total of 126 subjects, including 80 patients presenting with first-episode psychosis and 46 healthy controls. Patients were scanned at the outset and received various antipsychotic medications in a naturalistic clinical setting. They were followed up for 12 weeks and classified as responders or nonresponders if they reached criteria for symptom remission, evaluated with the Psychiatric and Personal History Schedule.OBSERVATION Patients were exposed to naturalistic antipsychotic treatment for 12 weeks following a magnetic resonance imaging scan. MAIN OUTCOMES AND MEASURESCortical gyrification was assessed using local gyrification index in a vertexwise fashion across the entire cortical surface with correction for multiple testing using permutation analysis. Differences in local gyrification index were assessed between responders, nonresponders, and healthy controls. The effect of diagnosis (affective vs nonaffective psychosis) on the local gyrification index was also investigated in responders and nonresponders.RESULTS Patients with first-episode psychosis showed a significant reduction in gyrification (hypogyria) across multiple brain regions compared with healthy controls. Interestingly, nonresponders showed prominent hypogyria at bilateral insular, left frontal, and right temporal regions when compared with responders (all clusters significant at P < .05). These effects were present for both affective and nonaffective psychoses.CONCLUSIONS AND RELEVANCE Gyrification appears to be a useful predictor of antipsychotic treatment response. Early neurodevelopmental aberrations may predict unfavorable prognosis in psychosis, irrespective of the existing diagnostic boundaries.

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Neurological abnormalities and cognitive ability in first-episode psychosis

Abstract: Higher rates of primary and motor coordination signs are not associated with lower cognitive ability, and are specific to the presence of psychosis.

Cited by 58 publications

References 27 publications

Cannabis users have higher premorbid IQ than other patients with first onset psychosis

Cannabis users have higher premorbid IQ than other patients with first onset psychosis

Reduction of cerebellar grey matter in Crus I and II in schizophrenia

Cortical Folding Defects as Markers of Poor Treatment Response in First-Episode Psychosis

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