Ian Medley

The functional anatomy of auditory hallucinations in schizophrenia.

We used continuous whole brain functional magnetic resonance imaging (fMRI) with a 3-T magnet to map the cerebral activation associated with auditory hallucinations in four subjects with schizophrenia. The subjects experienced episodes of hallucination whilst in the scanner so that periods of hallucination could be compared with periods of rest in the same individuals. Group analysis demonstrated shared areas of activation in right and left superior temporal gyri, left inferior parietal cortex and left middle frontal gyrus. When the data were examined on an individual basis, the temporal cortex and prefrontal cortex areas were activated during episodes of hallucination in all four subjects. These findings support the theory that auditory hallucination reflects abnormal activation of normal auditory pathways.

Increased incidence of psychotic disorders in migrants from the Caribbean to the United Kingdom

BACKGROUND Several studies have replicated the finding of increased incidence of schizophrenia and related psychoses in first and second generation migrants from the Caribbean. The finding has remained consistent in studies employing different methods, but concern has been expressed about indirect methods of calculating the population at risk. This study aims to overcome these short-comings. METHOD A further prospective study was undertaken in Nottingham assembling an inception cohort of psychotic patients (N = 168) presenting from a defined catchment area. The 1991 census, which includes codings for self-ascribed ethnic origin, was used to calculate the denominator, employing correction factors for potential under-enumeration. Case-ascertainment was based upon all service contacts and subjects had in-depth assessments including the SCAN. Collateral history was obtained from informants. RESULTS Subjects born in the Caribbean, or who had one or both parents born in the Caribbean, had a greatly elevated risk (incidence ratios above 7) for all psychotic disorders and for ICD-10 (DCR)-defined F20 Schizophrenia. CONCLUSIONS The size of the increase and the methodological safeguards employed support the validity of this now highly replicated finding. A personal or family history of migration from the Caribbean is a major risk factor for psychosis; the consistency of this finding justifies a systematic evaluation of potential aetiological factors. Any hypothesis derived from the evidence so far must explain: increased incidence in first and second generation migrants; increased risk for all psychoses (including affective psychoses); and an effect specifically associated with a migration history from the Caribbean to Northern Europe.

Is the incidence of psychotic disorder in decline? Epidemiological evidence from two decades of research

BACKGROUND It is unclear whether the incidence of first episode psychoses is in decline. We had the opportunity to determine whether incidence had changed over a 20-year period in a single setting, and test whether this could be explained by demographic or clinical changes. METHODS The entire population at-risk aged 16-54 in Nottingham over three time periods (1978-80, 1993-95 and 1997-99) were followed up. All participants presenting with an ICD-9/10 first episode psychosis were included. The remainder of the population at-risk formed the denominator. Standardized incidence rates were calculated at each time period with possible change over time assessed via Poisson regression. We studied six outcomes: substance-induced psychoses, schizophrenia, other non-affective psychoses, manic psychoses, depressive psychoses and all psychotic disorders combined. RESULTS Three hundred and forty-seven participants with a first episode psychosis during 1.2 million person-years of follow-up over three time periods were identified. The incidence of non-affective or affective psychoses had not changed over time following standardization for age, sex and ethnicity. We observed a linear increase in the incidence of substance-induced psychosis, per annum, over time (incidence rate ratios: 1.15; 95% CI 1.05-1.25). This could not be explained by longitudinal changes in the age, sex and ethnic structure of the population at-risk. CONCLUSIONS Our findings suggest psychotic disorders are not in decline, though there has been a change in the syndromal presentation of non-affective disorders, away from schizophrenia towards other non-affective psychoses. The incidence of substance-induced psychosis has increased, consistent with increases in substance toxicity over time, rather than changes in the prevalence or vulnerability to substance misuse. Increased clinical and popular awareness of substance misuse could also not be excluded.

Residence of incident cohort of psychotic patients after 13 years of follow up

Objective :To establish the residential history of an incident cohort of psychotic patients 13 years after their first contact with the psychiatric services. Design :Tracing of all patients admitted to the WHO study on determinants of outcome of severe mental disorders in Nottingham between 1978 and 1980. Patients were assessed using standardised and comparable instruments, and extra information was obtained from key informants and medical records. Setting :Catchment area of Nottingham psychiatric services. Main outcome measures :Main place of residence over the previous two years and residential history over 13 years in terms of homelessness, imprisonment, and use of high dependency psychiatric facilities. Results :95 patients were traced. At the point of follow up no patients were in long stay psychiatric wards, two were in supervised residence, none was homeless, and none was in prison or a high security hospital. 85 patients were living either independently alone or with their family or friends in the community. Of these, 44 had had no contact with the psychiatric services at the point of follow up. Conclusions :Although many patients experienced a difficult early course of illness, the longer term outcome of the disorder was associated with remarkably low periods of homelessness and imprisonment and low use of intensive care facilities. These findings offer some reassurance, given the concerns about the effectiveness of community oriented care for this potentially most vulnerable group of psychiatric patients.