GENES, NEURONS AND SCHIZOPHRENIA

This month's issue covers a wide range of schizophrenia research activity, from genes and genetic epidemiology through to cell neuropathology and treatment. The rare genetic disorder velo-cardio-facial syndrome (VCFS) is associated with a higher than expected rate of schizophrenia; approximately 30% of subjects with a deletion of the 22q11 gene develop psychotic symptoms. This rate has been suggested to be higher in patients with psychotic illness with an early age of onset. Ivanov et al () demonstrate that there is no increase in the prevalence of VCFS in a sample of 192 patients with schizophrenia with onset before the age of 18 years. They conclude that screening for VCFS is not justified in all patients with psychosis, or in those with an early onset of illness. However, patients with cleft lip or palate, characteristic dysmorphology, learning disability, congenital heart disease or hypocalcaemia should be screened for this disorder.

From an epidemiological perspective, increasing paternal age has been found to be associated with an increased risk of developing schizophrenia. Zammitt et al () report the results from a Swedish cohort of over 50 000 adolescent males. They found a ‘dose-dependent’ relationship between paternal age and schizophrenia, which was not associated with maternal age. They were able to exclude the effects related to social integration, drug use and low IQ, suggesting that this paternal age factor was most likely to be due to an increase in paternal germ cell mutations with increasing age.

Hippocampal pyramidal cell size does not differ between patients with schizophrenia and comparison subjects. Highley et al () performed a neuropathological study estimating the pyramidal cell volume in the hippocampi of patients and controls and found no significant differences. Previous structural imaging studies have consistently suggested a reduction in hippocampal volume within the hippocampi of patients with schizophrenia, but neuropathological studies have been less definitive. The authors suggest that the structural volume reductions reported in other cortical regions may also require reassessment.

PSYCHOLOGICAL TREATMENT IN DUAL DIAGNOSIS

The benefits of cognitive–behavioural therapy (CBT) for patients with schizophrenia have included lower relapse rates and improved functioning. Haddock et al () address an important, yet relatively neglected, area of combined treatment using CBT and motivational interviewing in dual diagnosis patients with both schizophrenia and substance misuse. They demonstrate that this combined approach improved patient functioning and that this benefit was maintained at 18-month follow up. They add a caveat to their findings; that they are only applicable to patients in contact with their families and were uncontrolled for therapeutic time additional to that received by the routine care group. In an accompanying editorial, Clark & Mueser () discuss the economic implications of the study and note that these benefits may still be apparent for patients who continue to use drugs or alcohol – important for general harm reduction.

SEXUAL ABUSE AND LEARNING DISABILITY

A history of sexual abuse is associated with a range of detrimental behavioural and mental health problems. Sequeira et al () fill a gap in the research by examining a group of adults with learning disability and demonstrating that a subgroup with proven or probable history of sexual abuse demonstrated an increased rate of mental illness and behavioural problems – predominantly aggressive and agitated behaviour, with sudden changes in mood and temper outbursts. The abused group also showed increased rates of self-injurious and stereotypical behaviours. In keeping with findings from the general population, increased severity of abuse was associated with increased levels of symptomology.

DEATH BY CHOKING

The risk of choking to death is increased in schizophrenia and, unsurprisingly, in organic psychiatric illness, regardless of the medication administered. Ruschena et al () linked the register of deaths with a psychiatric case registry in Victoria, Australia, and revealed that a significantly increased proportion of people who died by choking had had contact with mental health services, the majority with a diagnosis of schizophrenia. The authors propose that patients with schizophrenia may be at increased risk, either because they may have disordered physiology related to swallowing and reflux, or because of behaviours that place them at increased risk.

DEVELOPING RESEARCH IN SRI LANKA

Psychiatry around the world provides a useful example of the mutual benefits of international collaboration in psychiatric research. Sumathipala et al () describe the collaborative research approach necessary to build research capacity in Sri Lanka. They use the setting up of the Sri Lankan twin registry as an example, highlighting the need for parallel development of bioethical guidelines designed to protect the national interest from commercial exploitation but to permit sufficient flexibility to support the development of new ideas.