An evidenced-based approach to psychiatry is playing an increasingly prominent role in treatment decision-making for individual patients and for populations. Many doctors are now critical of the emphasis being placed on ‘the evidence’ and concerned that clinical practice will become more constrained.

To demonstrate that evidence-based medicine is not new, sources of evidence are limited and psychosocial aspects of medicine are neglected in this process.

Some of the literature is reviewed. Ideas and arguments are synthesised into a critical commentary.

These are considered under four headings: evidence-based medicine is not new; what evidence is acceptable; the doctor as therapist; and the emergence of a new utilitarian orthodoxy.

It is agreed that a degree of professional consensus is necessary. However, too great an emphasis on evidence-based medicine oversimplifies the complex and interpersonal nature of clinical care.

There is an ethical imperative to evaluate service and policy initiatives, such as those highlighted in the recent National Service Framework, just as there is to evaluate individual treatments.

To outline the best methods available for evaluating the delivery and organisation of mental health services.

We present a narrative methodological overview, using salient examples from mental health services research.

Cluster randomised studies involve the random allocation of groups of clinicians, clinical teams or hospitals rather than individual patients, and produce the least biased evaluation of mental health policy, organisation or service delivery. Where randomisation is impossible or impractical (often when services or policies are already implemented), then quasi-experimental designs can be used. Such designs have both strengths and many potential flaws.

The gold standard remains the randomised trial, but with due consideration to the unit of randomisation. Use of quasi-experimental designs can be justified in certain circumstances but should be attempted and interpreted with caution.

Depression in childhood or adolescence often has morbidity implications continuing into adulthood, generating needs for specialist services and support.

To estimate the patterns of service use and costs in adulthood of former patients.

Service use and other cost-related data were collected from former patients. Comparisons were made between those people with and without comorbid conduct disorder in childhood and with data for the general population.

Data on 91 people with depression (only) and 49 with comorbid conduct disorder revealed high adulthood service utilisation rates and costs. Inpatient care and criminal justice services were used more frequently by the comorbid group and total costs were significantly higher. There were also indications of higher service use by the comorbid group than the general adult population.

The high and enduring long-term costs associated with childhood depression and conduct disorder give further reason for early and effective intervention.

Neuroendocrine studies of brain serotonin (5-HT) function in depression generally show evidence of impaired 5-HT function but it is disputed whether or not this impairment resolves with clinical recovery.

To use the endocrine response to the selective 5-HTreuptake inhibitor, citalopram, to study brain 5-HT function in acute and recovered depressed subjects relative to healthy controls.

We used a double-blind, placebo-controlled design to measure the prolactin and cortisol responses to citalopram (10 mg intravenously) in patients with major depression, in unmedicated subjects recovered from depression and in healthy controls.

The prolactin responses to citalopram were blunted similarly in both acutely depressed and recovered subjects. The cortisol responses were blunted in the acutely depressed patients but not in the recovered subjects.

Our data support the proposal that some aspects of impaired 5-HT neurotransmission may be trait markers of vulnerability to depression. The recovery of the cortisol response to citalopram may indicate resolution of hypothalamic – pituitary-adrenal axis dysfunction.

Up to three-quarters of patients with fatigue syndromes have comorbid mood or anxiety disorders, suggesting that chronic fatigue is a forme fruste of anxiety or depressive states.

To establish whether the association of chronic fatigue with psychological distress is causal or due to a common genetic or environmental factor.

69 monozygotic (MZ) and 31 dizygotic (DZ) female twin pairs, with only one co-twin reporting at least 6 months of fatigue, completed questions on fatigue, the General Health Questionnaire (GHQ) and a structured psychiatric interview. We examined the effects of three progressively more stringent definitions of chronic fatigue on four GHQ sub-scales.

Fatigued MZ and DZ twins by all definitions were significantly more depressed, anxious, somatically preoccupied and socially dysfunctional than their non-fatigued co-twins. Intrapair differences were similar in DZ and MZ twins, but non-significant differences were observed for the somatic symptoms and anxiety/insomnia sub-scales.

In this sample, chronic fatigue and psychological distress are strongly associated without evidence for genetic covariation, implying that the association is environmental, or due to overlapping definitions. Any genetic covariation missed is likely to involve anxiety rather than depression.

Schneider's first-rank symptoms are given particular weight when making a diagnosis of schizophrenia, but the nuclear syndrome, characterised by one or more first-rank symptoms, has been found previously to have no heritability.

To estimate the heritability of the nuclear syndrome.

A total of 224 twin pairs (106 monozygotic, 118 same-gender dizygotic) were ascertained from the Maudsley Twin Register in London via probands with any psychosis. Lifetime-ever first-rank symptoms were rated using the OPCRIT checklist. Probandwise concordance rates were calculated for the nuclear syndrome and a heritability estimate was derived from biometric model fitting.

Probandwise concordance rates were 13/49 (26.5%) for monozygotic and 0/45 to 2/46 (0.0–4.3%) for dizygotic pairs. The heritability estimate for the best-fitting model was 71% (95% CI 57–82).

These results indicate that the nuclear syndrome shows substantial heritability, although this is slightly lower than that for schizophrenia as defined by the DSM and ICD systems.

Membrane phospholipid abnormalities in people with schizophrenia, measured with 31P magnetic resonance spectroscopy (31P-MRS), have been previously reported in brain regions involved in this disorder.

In this 4.0 Tesla 31P-MRS study of people with schizophrenia, membrane phospholipid metabolism was examined in brain regions previously inaccessible due to their small volumes.

Three-dimensional chemical-shift imaging (3D–CSI) examined 15 cc volumes in 12 brain regions in 11 people with chronic schizophrenia and 11 healthy control volunteers.

Glycerophosphoethanolamine was decreased in the anterior cingulate, right prefrontal cortex and left thalamus, but increased in the left hippocampus and cerebellum in those with schizophrenia. Phosphoethanolamine and glycerophosphocholine were decreased in the right prefrontal region and phosphocholine was decreased in the anterior cingulate. No significant difference in membrane phospholipid levels existed between groups in the parieto-occipital and posterior cingulate regions.

Altered membrane phospholipid metabolism was demonstrated in all regions implicated in schizophrenia.

In the rating scales commonly used for assessing response to antipsychotic treatment, individual items embrace symptoms that apparently arise from distinguishable pathophysiological processes and might be expected to respond differently to treatment.

To test the reliability sensitivity to change and factor structure of a new scale for the assessment of the Signs and Symptoms of Psychotic Illness (the SSPI).

Interrater reliability was evaluated by determining the intraclass correlation for the ratings of 63 patients. Sensitivity to change was assessed in a longitudinal study of 33 patients. Factor structure was determined from scores for 155 patients.

The intraclass correlation was satisfactory for all individual items and excellent for the total score. Scores were sensitive to change. A change in Clinical Global Impression of one unit corresponded to an SSPI total score change of 31%. Factor analysis revealed five clusters of symptoms.

The SSPI provides a sensitive and reliable measure of the five major clusters of symptoms that occur commonly in psychotic illness.

An acceptable, standardised outcome measure to assess efficacy and effectiveness is needed across multiple disciplines offering psychological therapies.

To present psychometric data on reliability, validity and sensitivity to change for the CORE–OM (Clinical Outcomes in Routine Evaluation – Outcome Measure).

A 34-item self-report instrument was developed, with domains of subjective well-being, symptoms, function and risk. Analysis includes internal reliability, test–retest reliability, socio-demographic differences, exploratory principal-component analysis, correlations with other instruments, differences between clinical and non-clinical samples and assessment of change within a clinical group.

Internal and test–retest reliability were good (0.75–0.95), as was convergent validity with seven other instruments, with large differences between clinical and non-clinical samples and good sensitivity to change.

The CORE–OM is a reliable and valid instrument with good sensitivity to change. It is acceptable in a wide range of practice settings.

The Health of the Nation Outcomes Scales (HoNOS) have been developed to measure outcomes in people with mental health problems.

Frequent impaired social functioning, problems with communication and associated physical conditions meant that a bespoke instrument was needed for people with learning disabilities. We describe the development of the Health of the Nation Outcomes Scales for People with Learning Disabilities (HoNOS–LD).

HoNOS-LD was piloted at 26 sites. Two raters, at two points in time, rated 372 subjects. Analysis determined acceptability, ease of use, interrater reliability, sensitivity to change and reliability with the Aberrant Behavior Checklist (ABC).

The resulting 18-item instrument demonstrated good reliability and validity characteristics and is generally acceptable to clinicians.

HoNOS-LD is an appropriate instrument for measuring outcome in people with learning disabilities with additional mental health needs.

Confusional states associated with medical and surgical conditions require more study and biochemical explanation.

To understand impairment of consciousness, cognition and memory.

A psychiatrist reports experience of his changing mental state over 5 days from notes made immediately on recovery.

A prodromal phase of declining consciousness, understanding and memory registration over perhaps 48 h was difficult to detect. During unconsciousness there were four brief partial reversals with arousal, and some mental functioning (memory, formation of beliefs) occurred.

Self-report can be a useful addition in clinical study and patients with renal failure require psychological and psychiatric study. Comparison with the mental effects of benzodiazepine or of an anaesthetic such as nitrous oxide might throw light on the pathology.

A high rate of maternal depression and associated disturbance in the mother–infant relationship has been found in an indigent peri-urban South African community Khayelitsha. The question arises whether a community-based intervention could be beneficial.

To train community workers to deliver an intervention to mothers and infants in Khayelitsha, and to compare mothers and infants receiving this intervention with a sample receiving no such intervention.

Four Khayelitsha women were trained in a mother-infant intervention, which they delivered to 32 women recruited in late pregnancy. At 6 months post-partum, maternal mood, the mother–infant relationship and infant growth were assessed. The findings were compared with a matched group of 32 mothers and infants.

There was no reliable impact of the intervention on maternal mood. However, compared with the comparison sample, the quality of mother – infant engagement was significantly more positive for those who had received the intervention.

The pilot study produced preliminary evidence of a benefit of a community-based mother – infant intervention delivered by trained, but otherwise unqualified, community workers, sufficient to warrant a formal controlled evaluation of this treatment.