One hundred years ago, D'Arsonval and Beer first described the effects of magnetic fields on human brain function. Placing one's head into a powerful magnet produced phosphenes, vertigo or even syncopes (George & Belmaker, 2000). However, only since 1985 has the technology of fast discharging capacitors developed sufficiently to generate reproducible effects across the intact skull, with peak magnetic field strengths of about 1–2 tesla (Barker et al, 1985). The headline-grabbing news has been about therapeutic applications of transcranial magnetic stimulation (TMS), but in the meantime a revolution in functional brain research has taken place, based on the manipulation of brain activity by focused magnetic fields. TMS applied in this way is, in a manner of speaking, brain imaging in the reverse. While common modes of functional brain imaging, such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), demonstrate associations between brain metabolic activity and ‘brain tasks', the causal interpretation of such associations can be difficult. Is the frontal lobe activation observed during a memory task, for example, necessary for performing the task, or does it correspond to monitoring activity that runs parallel to task performance proper? If, on the other hand, focal brain activation during TMS results in a muscle twitch, there is no doubt that stimulation of at least some of the neurons within the magnetic field is sufficient cause for the observed movement. Functional neuroimaging is now often combined with TMS, carried out in the same session in order to exploit the complementary strengths of the methods. Although direct stimulation of association (as opposed to motor or sensory) cortex does not usually result in an observable response, TMS applied in repetitive trains can produce reversible ‘lesions'. By interfering with tasks that are dependent on the functioning of the stimulated neurons, it can thus contribute to the localisation of brain function.

There is little doubt that dementia is a very common cause of disability and dependency in our society. Since dementia of whatever type is usually more common with increasing age, then as population demographics change, so will the prevalence of dementia. Dementia is a generic term and the objective for clinicians, once dementia is suspected, is to attempt to define the cause. Alzheimer's disease is the most common cause of dementia, and in most centres vascular dementia would feature as the next most common aetiology. In some centres, Lewy body dementia is the second most common cause. Mixed Alzheimer's disease and vascular dementia would also feature high on the list at most centres.

Stalking (Box 1) has only recently been distinguished from a wide range of other socially inappropriate, intrusive and potentially distressing activities. It is now a specific form of criminal offending and has established itself as a recognised social problem (Meloy, 1998; Mullen et al, 2000). Stalking may well reflect, as Emerson et al (1998) argue, “intricate social processes”, but if the psychopathology of the stalker is a necessary, even if far from sufficient, cause then treating that psychopathology may end the stalking (Mullen & Pathé, 2001).

The targeting of services to groups with special needs is today commonplace in enlightened public health policies. To list men among the ‘minorities’ in need of such special help might have the semblance of satire. This air of levity is not really reduced by listing male's shorter life expectancy, higher infant mortality and higher rates of natural and unnatural deaths in all age groups (Drever & Bunting, 1997; Kelly & Bunting, 1998).

For the past 25 years, forensic psychiatry has been concerned with violent offenders with psychosis and/or personality disorder. If dual diagnosis or comorbidity meant anything to a forensic psychiatrist, it would be the ‘typical’ forensic case – an individual with schizophrenia and a premorbid dissocial personality who had been arrested for a violent crime. In this article I use comorbidity to describe the co-occurrence of two or more conditions (here a psychiatric disorder and health problems arising from substance misuse) rather than dual diagnosis. In fact, many violent offenders have multiple diagnoses. Williams & Cohen (2000) argue that dual diagnosis suggests a closer relationship, perhaps including cause and effect, and is a subset of comorbidity.

Assessment of development constitutes one of the core components of any psychiatric evaluation. This is because evaluation of psychopathology generally entails determining the extent to which behaviours and experiences are appropriate for an individual's age and stage of development and because developmental disorders are common and frequently associated with psychiatric and behavioural disorders. I will describe methods of evaluating and diagnosing developmental disorders, but the principles and techniques also apply to evaluating development during any comprehensive psychiatric assessment.

The association of life events with the onset of various psychiatric disorders is well-known. The body of evidence has highlighted the impact of negative or positive life events on the genesis of common mental disorders, especially depression. These findings have been replicated across different cultures, although the impact of different life events varies between cultures. In addition, the roles of chronic difficulties (defined in Life events and psychiatric disorders, below) and resulting ongoing chronic stress have been shown to contribute to vulnerability to certain mental illnesses. However, data on the impact of life events, especially those perceived as racial, on members of minority ethnic groups are rather sparse. The questions that need to be addressed concern the perception of life events as racial, the role of pervasive and perceived institutional and individual racism, and chronic difficulties.

Consultation–liaison psychiatry in renal medicine provides a unique experience for the psychiatrist. There is the opportunity to work with a specialist multi-disciplinary team managing patients with chronic and complex physical problems in in-patient and out-patient settings. We aim to consider the common psychiatric problems experienced by renal patients and the particular problems that face the renal team and the liaising psychiatrist in relation to assessment and treatment.

Growth and development are at the core of paediatric practice and are the fundamental factors that make medical work with children different from adult medicine. All paediatricians must have an understanding of the basic science of growth and development and how to measure them. This is fairly straightforward with regard to physical characteristics, but more difficult for mental development. However, it is a skill that must be familiar to children's doctors working in the fields of neurological disease and mental health and, arguably, to all paediatricians.

“Evidence-based medicine builds upon, rather than disparages or neglects, the evidence gained from good clinical skills and sound clinical experience.” (Sackett, 1995: p. 840)

Acute mental disturbance associated with physical illness is well described in early medical literature, but it was not until 1 AD that Celsus coined the term ‘delirium’ (Lindesay, 1999). Although delirium has many synonyms that are applied in particular clinical settings (Box 1), all acute disturbances of global cognitive functioning are now recognised as ‘delirium’, a consensus supported by both ICD–10 (World Health Organization, 1992) and DSM–IV (American Psychiatric Association, 1994) classification systems. Delirium is a complex neuropsychiatric syndrome that typically involves a plethora of cognitive and non-cognitive symptoms, resulting in a broad differential diagnosis dominated by mental disorders. Psychiatrists' skills in assessing cognitive function and psychopathology, coupled with their knowledge of psychotropic agents, make them well suited to improving detection, coordinating management and facilitating research into this understudied disorder.

Acquired brain damage in children is not uncommon, head injuries being the most frequent cause. Brain injury may also occur during the very vulnerable periods of rapid growth of the foetal brain from prenatal trauma/strokes, during a difficult birth, or postnatally from strokes, infections (e.g. meningitis and encephalitis), metabolic disturbances (e.g. phenylketonuria), treatment (e.g. central nervous system (CNS) surgery or radiotherapy for leukaemia) or toxins (e.g. alcohol and valproate). This paper concentrates on the assessment of and interventions following acquired brain injury sustained after the first 2 years of life, that is, after a period of relatively normal development when there has been an expectation that a child will follow the usual trajectory in development and learning throughout childhood and adolescence. Acquired brain injury in younger children tends to have global and profound effects, for instance, from CNS radiation (Said et al, 1989) or head injury (Levin et al, 1995). Injury in older children may result in more specific or focal problems depending on the mechanism of injury.

The most important psychiatric implication of experiencing trauma during war is post-traumatic stress disorder (PTSD). The core symptoms of PTSD are intrusive re-experiencing of traumatic events, hyperarousal in reaction to minor stimuli and avoidance of trauma-related triggers. In this paper we describe the phenomenon of intrusive reexperiencing, of which the post-traumatic nightmare (PTNM) is an impressive manifestation that causes considerable distress (Mellman et al, 1995; Schreuder, 1996; Ørner & de Loos, 1998; Schreuder et al, 1998).

Diversion from custody is a policy supporting the removal of people with mental disorders from the criminal justice system to hospital or a suitable community placement where they can receive treatment. There are three principal reasons why such a policy is necessary. First, when those with mental disorders fall through the net of psychiatric services they tend to gravitate towards the criminal justice system; second, the standard of health care provided in prison is, generally speaking, poor; and third, because prison health care centres are not recognised as hospitals for the purposes of the Mental Health Act (MHA) 1983, treatment for mental disorder cannot be given against a prisoner's will unless this can be justified under common law.

Dependence on alcohol or other drugs is a depressing experience. The way of life of the individual who is dependent on alcohol is replete with incidents that are demoralising, waking daily with a hangover or with tremor and retching, coupled with amnesia for events of the night before, a sense of inability to face the day ahead and awareness of recriminations at work and at home. Little wonder that depressed mood is common in such circumstances. Similarly, the drug addict, when life is dominated by the daily problem of obtaining supplies of a substance that brings transient relief or pleasure but also experiences of an impoverished existence and low mood. Add to this the fact that the biological action of many commonly misused substances can induce depression then it is hardly surprising that depression is common in this population. There are also a smaller number who use alcohol or illicit drugs to cope with primary depression. Teasing out the interplay of affect and substance misuse is a challenge for the general psychiatrist and the addiction specialist.

Somatising disorders, characterised by complaints of unexplained physical symptoms, are common presentations in children and adolescents, both in primary and secondary care settings. They have significant impact on the children themselves and on health care resources: as in adults, there is a wide range of severity and resulting handicaps.