The Blake Marsh lecture, an annual lecture on learning disability, was endowed in 1963 in memory of Dr Blake Marsh, the former medical superintendent of Bromham House Colony in Bedford. The first lecture was given in 1967.

To review the speciality of the psychiatry of learning disability and how it is currently practised in the UK.

Clinical, service, research and educational issues in learning disability psychiatry are reviewed and illustrated.

Key issues which emerge in all four areas include the importance of communication skills, consultation with users and carers, professional education and partnership.

The psychiatry of learning disability is a complex, varied and stimulating branch of psychiatry with a strong developmental focus.

Studies in schizophrenia suggest that a longer initial period of untreated illness is associated with a poorer clinical outcome.

To determine whether, in first-episode schizophrenia, a longer duration of untreated psychosis (DUP) or of untreated illness (DUI) (DUP plus any prodrome) is associated with clinical variables that could mediate a poor prognosis.

Clinical, social, neuropsychological and oculomotor function data on 53 patients with first-episode schizophrenia were related to the DUP and DUI.

Comparing short and long DUP groups split around the median showed no statistically significant differences (except age); patients in the latter group tended to perform worse on an executive attentional set-shifting task, and were more likely to be unemployed, and living alone or homeless.

There was little evidence of any association between either DUP or DUI and progressive deterioration in the schizophrenic illness or the development of resistance to initial drug treatment. Social variables that augur a poor prognosis may be associated with delayed presentation of schizophrenia to psychiatric services.

The excess mortality of schizophrenia is well recognised, but its precise causes are not well understood.

To measure the standardised mortality ratio (SMR) and examine the reasons for any excess mortality in a community cohort with schizophrenia.

We carried out a 13-year follow-up of 370 patients with schizophrenia, identifying those who died and their circumstances.

Ninety-six per cent of the cohort was traced. There were 79 deaths. The SMRs for all causes (298), for natural (232) and for unnatural causes (1273), were significantly higher than those to be expected in the general population, as were the SMRs for disease of the circulatory, digestive, endocrine, nervous and respiratory systems, suicide and undetermined death. Smoking-related fatal disease was more prominent than in the general population.

Some of the excess mortality of schizophrenia could be lessened by reducing patients' smoking and exposure to other environmental risk factors and by improving the management of medical disease, mood disturbance and psychosis.

It has been proposed that breast-feeding might have a protective effect against the development of adult schizophrenia.

To test this hypothesis.

Using prospective data from two UK national birth cohorts, the feeding histories of those who later developed schizophrenia were compared with the remaining population at risk. Analyses in each cohort were considered to be independent tests of the hypothesis.

There were no differences in feeding histories. In the 1946 birth cohort (n=4447) 30 cases of DSM–III–R schizophrenia arose by age 43; 24.1% of cases v. 23.6% of controls were entirely bottle-fed; 17.3% v. 12.3% were breast-fed for under I month; 58.6% v. 64.1% were breast-fed beyond I month. In the 1958 cohort (n=18 856), 40 cases of CATEGO nuclear schizophrenia arose by age 28; 24.1% of cases v. 31.7% of controls were entirely bottle-fed; 27.6% v. 24.9% were breast-fed for under 1 month; 48.3% v. 43.4% were breast-fed beyond 1 month.

These findings provide no evidence of any effect of breast-feeding in protecting against the risk of later schizophrenia.

The regional cerebral blood flow (rCBF) response to the Wisconsin Card Sort Test (WCST) has been used to assess the functional integrity of the prefrontal cortex in patients with schizophrenia.

In this study, patients were divided into two groups according to whether they had made few or many perseverative errors on a modified version of the WCST. A control group consisted of normal volunteers. The groups were then compared with respect to rCBF response to WCST activation.

rCBF was measured during administration of a modified version of the WCST and during a card sorting control task, using single photon emission computerised tomography (SPECT).

Performance of the modified WCST was associated with a widespread and substantial increase in rCBF, particularly in the frontal region. The poorly performing group of patients with schizophrenia showed only a modest increase in rCBF in the left anterior cingulate region.

Subjects with schizophrenia are able to respond to specific neuropsychological challenge with activation of the frontal regions.

We present a revised Beliefs About Voices Questionnaire (BAVQ–R), a self-report measure of patients' beliefs, emotions and behaviour about auditory hallucinations.

To improve measurement of omnipotence, a pivotal concept in understanding auditory hallucinations, and elucidate links between beliefs about voices, anxiety and depression.

Seventy-one participants with chronic auditory hallucinations completed the BAVQ–R, and 58 also completed the Hospital Anxiety and Depression Scale.

The mean Cronbach's α for the five sub-scales was 0.86 (range 0.74–0.88). The study supports hypotheses about links between beliefs, emotions and behaviour, and presents original data on how these relate to the new omnipotence sub-scale. Original data are also presented on connections with anxiety and depression.

The BAVQ–R is more reliable and sensitive to individual differences than the original version, and reliably measures omnipotence.

Many patients suffering from psychosis are unaware of their disorder and symptoms.

To investigate whether insight changes with time, and how it relates to patients' psychopathology, and to examine the correlations between insight scales in patients with psychoses.

Seventy-five consecutively admitted in-patients with schizophrenia, affective disorder with psychotic symptoms, or schizoaffective disorder were examined after remission of an acute episode and at follow-up (>6 months). Three different scales were used to assess insight.

To some extent, insight into past episodes improved over time in patients with psychosis, regardless of diagnosis. Few significant relationships between insight and psychopathology remained stable at follow-up. The higher the negative and disorganisation dimensions at baseline, the less did attitudes to treatment vary when tested at follow-up. No predictive value for variability of psychopathological dimensions was found for insight dimensions. The insight scales used were highly intercorrelated, suggesting that they measure the same construct.

Insight and psychopathology seem to be semi-independent domains.

Persons of African – Caribbean origin are more frequently imprisoned, and increasing evidence suggests they are detained more frequently in psychiatric hospitals, following offending behaviour.

To estimate population-based prevalence rates of treated mental disorder in different ethnic groups compulsorily admitted to secure forensic psychiatry services.

A survey was recorded of 3155 first admissions, from 1988 to 1994, from half of England and Wales, with 1991 census data as the denominator adjusted for under-enumeration.

Compulsory admissions for Black males were 5.6 (CI 5.1–6.3) times as high as, and for Asian males were half, those for White males; for Black females, 2.9 (CI 2.4–4.6) times as high and for Asian females one-third of those for White females. Admissions of non-Whites rose over the study period. Patterns of offending and diagnoses differed between ethnic groups.

Variations in compulsory hospitalisation cannot be entirely attributed to racial bias. Community-based services may be less effective in preventing escalating criminal and dangerous behaviour associated with mental illness in African–Caribbeans.

More treatment for substance misuse should be provided within prisons.

To examine differences between prisoners on remand with substance misuse problems and other prisoners on remand.

Random selection and interview of unconvicted male prisoners (n=750, a 9.4% sample), plus examination of the prison medical record.

Of the sample of 750, 253 subjects (33.7%) reported either drug- or alcohol-related health problems or dependency. Compared with other prisoners on remand, they reported more childhood adversity, conduct disorder, self-harm, past psychiatric treatment and current mood disorder, and had fewer qualifications, were more likely to be unemployed and have more housing difficulties.

One-third of unconvicted men in prison report substance-related problems, and these are a marker for vulnerability within a disadvantaged population. Health care providers should involve this group in treatment and rehabilitation, both inside prison and following release.

The identification of fluctuating confusion is central to improving the differential diagnosis of the common dementias.

To determine the value of two rating scales to measure fluctuating confusion.

The agreement between the clinician-rated scale and the scale completed by a non-clinician was determined. Correlations between the two scales were calculated; variability in attention was calculated on a computerised cognitive assessment and variability in delta rhythm on an electroencephalogram (EEG).

The Clinician Assessment of Fluctuation and the computerised cognitive assessment were completed for 155 patients (61 Alzheimer's disease, 37 dementia with Lewy bodies, 22 vascular dementia, 35 elderly controls). A subgroup (n=40) received a further evaluation using the One Day Fluctuation Assessment Scale and an EEG. The two scales correlated significantly with each other, and with the neuropsychological and electrophysiological measures of fluctuation.

Both scales are useful instruments for the clinical assessment of fluctuation in dementia.

There is little available literature on the effect of suicide methods on brain weight.

To explore variations in postmortem brain weight in different methods of fatal self-harm (FSH) and in deaths from natural causes.

A review of a sample of coroners' records of elderly persons (60 and above). Verdicts of suicide, misadventure and open verdicts were classified as FSH. Post-mortem brain weight for 142 FSH victims and 150 victims of unexpected, sudden or unexplained death due to natural causes, and from various methods of FSH, were compared.

Brain weight of victims of FSH was significantly higher than of those who died of natural causes (P<0.01); brain weights in both groups were within the normal range for this age group. There was no significant difference in brain weight between different methods of FSH (P>0.05).

The findings require critical examination and further research, to include data from younger age groups. A regional or national suicide neuropathological database could be set up if all victims of FSH underwent routine neurohistochemical post-mortem examination.

Treatments in different settings have different costs. A dilemma arises if expensive treatments lead to better outcomes.

To investigate conflicts between the priorities of cost minimisation, clinical effectiveness, and cost-effectiveness in the detoxification of opiate addicts.

Cost and clinical effectiveness were examined using published outcome data. The main outcome measures were: achieving a drug-free state on completion of detoxification; the economic costs of treatment.

In terms of simple cost, in-patient detoxification is much more expensive than out-patient treatment (ratio, 24:1). With adjustment for successful outcome, the costs are almost identical (ratio, 0.9:1). Comparison of specialist and general psychiatry in-patient settings showed that even when adjusted for clinical outcomes, the specialist setting is more costly (ratio, 1.9:1), although the outcomes are better.

Naïve adherence to cost and cost-containment considerations is dangerous. Discussion of treatment costs is misleading if not informed by, and adjusted for, evidence of effectiveness. This is especially important where marked differences in outcome between treatment options exist.

The York resource allocation formula includes a calculation of the amount needed to purchase mental health services equitably in each health authority in England. However, the amount which is actually spent on services is at the discretion of the authority.

To compare expenditure on mental health services with allocation, and test the hypothesis that differences between them are to the disadvantage of services in deprived areas.

A comparison of routine expenditure and allocation data, and linear regression modelling of the ratio of expenditure to allocation.

The ratio of expenditure to allocation varies widely. Relative underspending occurs more frequently in deprived areas, although not in the four inner-London health authorities.

The intentions of the York formula are not achieved in practice. The implications of the formula for mental health should be made explicit to health authorities, and shortfalls in mental health expenditure relative to allocation should be justified at a local level.

The interaction between psychosis and violence in adults is an important area of research receiving attention. To date there is little available data examining this relationship in adolescence.

To investigate the possible relationships between criminally violent types of behaviour, and psychopathology and social factors, among adolescents suffering from a psychotic disorder.

A retrospective case note study of 39 in-patients diagnosed as having a psychotic disorder and admitted to one of two adolescent psychiatry units (one secure, one open). Cases were divided into a ‘violent’ and a ‘non-violent’ group, and these two groups were then compared for social and psychopathological variables.

There was no association between recorded psychopathology and criminally violent behaviour. Criminally violent behaviour was associated with a history of emotional or physical abuse, contact with social or mental health services, and previous criminal behaviour.

These findings fail to echo results of studies in adult schizophrenia; they suggest that violent behaviour in psychosis is associated more closely with social factors than with specific symptoms of the psychotic illness. Potential explanations are discussed.