Another possibility is that problems of cultural identity are especially troublesome for second-generation members of immigrant families. Cross-cultural researchers use the term acculturation to describe the process of psychological transition that occurs when people move from one culture to another.42 According to one influential theory, proposed by Canadian psychologist John Berry, the outcome of this process can be of four kinds, depending on whether an individual chooses to identify with her culture of origin or with the host culture (see Table 18.1).43Integration occurs when the individual identifies with and exhibits some characteristics of both cultures. Assimilation occurs when the host culture is embraced and the culture of origin is disowned. Separation is the outcome when the individual retains the identity of her culture of origin and rejects the host culture. Finally, marginalization occurs when the individual feels uncommitted to either culture. Because the children of immigrants may be at special risk of becoming trapped between two identity groups and rejected by both, it is possible that they will be especially likely to experience this last outcome, which, according to Berry, is the most stressful of the four.
Table 18.1 The four types of acculturation identified by John Berry (1988).
Identification with host culture
Yes
No
Identification with culture of origin
Yes
Integration
Separation
NO
Assimilation
Marginalization
Cultural stressors and ethnic tension are not the only features of the social environment that seem to confer an increased risk of psychosis. In 1939, during the Great Depression, two American sociologists, Robert Faris and Warren Dunham, reported a survey carried out in Chicago, in which they attempted to identify areas with a high prevalence of schizophrenia patients. They found the highest rates in a slum area surrounding the centre of the city, which was occupied mainly by unskilled workers with low incomes. In areas further out from the centre, occupied by skilled workers, the rates were lower, and they were lower still in commuter areas occupied by middle-class professionals.44 This apparent relationship between the prevalence of schizophrenia and socio-economic status has since been observed in many other studies, and appears to be most evident in the largest cities.
The explanation of this phenomenon has been a matter of some debate. Although Faris and Dunham concluded that the stress associated with living in poor economic circumstances plays a causal role in schizophrenic symptoms, other researchers have suggested that the association between psychosis and poverty might be accounted for by downwards social drift.45 According to this theory, psychotic people are often unable to work, and so are forced to move to the poorer areas, where accommodation is cheaper.
The reality of social drift has been documented in a number of studies. A recent survey of psychiatric patients living in Inner London found that a large number of patients had moved into the area from outside the city.46 However, clear evidence that exposure to an urban environment can play a causal role in psychosis has recently emerged from a very large Danish study, in which data on childhood living circumstances and psychiatric difficulties in adulthood were collated for nearly2million people.47 The researchers found of a dose–response relationship between exposure to an urban environment in childhood and the development of psychosis in later life. It seems that the greater the proportion of childhood spent living in urban environments the greater the risk of madness, with those who spend their entire childhood in cities being most at risk in later life.
A recent World Health Organization study found that psychotic patients living in urban and rural environments tend to have different types of complaints.48 In rural areas, negative symptoms such as a loss of interest in appearance and cleanliness are most often observed, whereas urban patients are more likely to hear voices and to feel persecuted. These observations are quite easy to understand from a psychological perspective. Intrusive life events of the kind that are likely to induce paranoid thinking are especially likely to occur in city environments. On the other hand, social isolation, leading to the absence of the kind of social reinforcement that is necessary to maintain self-care skills, is more likely the occur in a rural environment.
Trauma
In this discussion of environmental influences on psychosis, I have left the contribution of trauma until last because, for many psychologists and psychiatrists at least, even to raise this issue is to court controversy. For this reason, I am going to outline the available evidence in quite a lot of detail.
Of course, many different kinds of disasters may befall us if we are unlucky. As children we may suffer physical or sexual abuse at the hands of our parents or other people. In adulthood, we may lose loved ones in sudden tragedies, find ourselves in conflict with the law, or suffer sudden reversals of our financial fortunes. If we are extremely unfortunate, we may become involved in civil unrest, warfare or other kinds of violent conflict. After Vietnam veterans persuaded American psychiatrists to include the diagnosis of post-traumatic stress disorder (PTSD) in the DSM, the effects of these kinds of experiences on mental health became the subject of vigorous research. The DSM-IV definition of PTSD points to three groups of symptoms commonly experienced by trauma victims. First, many complain that they persistently re-experience their traumatic experiences (for example, as intrusive and distressing memories or dreams). Second, many avoid stimuli associated with their trauma (for example, by never returning to the scene of an accident) or, alternatively, become emotionally numb (believed to be a form of psychological detachment that acts as a defence against intolerable feelings). Finally, many victims show symptoms of persistent physiological arousal (for example, insomnia and irritability).49 Although hallucinations and delusions do not fall within this definition, a few researchers have not been deterred from asking whether trauma can lead to psychotic breakdowns.
Some studies have examined the relationship between psychosis and sexual and physical abuse. Investigations of this sort are quite difficult to carry out. To begin with, there is considerable disagreement about the best way of defining abuse. Depending on the definition used, a larger or smaller proportion of the population can be said to be victims of assaults. Moreover, evidence of assault is usually obtained from descriptions given by patients during interviews. Recent debates about whether patients ever experience false memories of abuse testify to widespread suspicions that these kinds of descriptions are sometimes unreliable. However, it is also worth remembering that victims sometimes have powerful motives for not reporting this kind of trauma. They may be embarrassed or ashamed about what has happened to them, or expect others to blame them for allowing themselves to be victimized.
Despite these difficulties, there is consistent evidence that a history of physical or sexual abuse is unusually common in psychotic women. In a review of the research on this topic, American psychologists Linda Goodman, Kim Mueser and their colleagues were able to identify thirteen adequately conducted studies.50 For the purpose of their review, they defined physical abuse as acts, ‘intended to produce severe pain or injury, including repeated slapping, kicking, biting, choking, burning, beating, or threatening with or using a weapon’. They defined sexual abuse as, ‘forcible touching of breasts or genitals or forcible intercourse, including anal, oral or vaginal sex’. The highest estimates of abuse were obtained in those studies that Goodman and her colleagues judged to be most meticulously executed. Across the thirteen studies, between 51 and 97 per cent of women reported some form of physical or sexual abuse in their lifetime, suggesting that perhaps the majority of mentally ill women have been victimized in this way.
Although most studies have focused on abuse during childhood, high levels of assaults during adulthood have also been reported. In a study published several years after they completed their review, Mueser and Goodman estimated that 52 per cent of 153 severely ill female patients they interviewed had experienced sexual abuse during childhood
, but nearly 64 per cent had suffered sexual abuse in later life.51 These figures suggest that many psychotic women have been victimized on more than one occasion. As Mueser and Goodman’s figures are so much higher than even the highest estimates for the general population (between 14 and 34 per cent for abuse in adulthood, and between 15 and 33 per cent for childhood sexual abuse, according to their own figures) I do not think they can be easily dismissed. Nor is this association restricted to schizophrenia patients; higher than expected rates of abuse have recently been reported for patients diagnosed as suffering from bipolar disorder.52
Comparable evidence of an association between trauma and psychosis has emerged from studies of men. In Mueser and Goodman’s research, 35.5 per cent of male patients reported being sexually assaulted in childhood, and 25.9 per cent reported that they had been sexually assaulted as adults. Seventeen per cent had witnessed an attack leading to the killing or serious injury of another person during childhood, and the comparable figure for adult life was nearly 47 per cent. These findings are supported by the results of studies that have focused on the psychological impact of armed conflict. Follow-up investigations of American soldiers taken prisoner by the Japanese during the Pacific campaign of the Second World War, carried out in the 1970s, found higher than expected rates of schizophrenia in the most severely traumatized, although elevated rates were not found in prisoners taken by the Germans.53 (This difference may reflect the comparative harshness of the treatment given to the POWs in the two theatres. A survey of POWs living in Minnesota, USA, found that, overall, 1.9 per cent met the DSM-III criteria for schizophrenia whereas, among those who had lost more than 35 per cent of their body weight while in captivity, the rate was 4.2 per cent, about four times the expected rate in the general population.)54 Similarly, in two studies conducted by Kim Mueser, high levels of auditory hallucinations and delusions were found in Vietnam veterans diagnosed as suffering from PTSD.55 The severity of these symptoms correlated with the severity of their combat experience. (Of course, combatants are not the only psychological casualties of warfare or political conflict. Psychotic reactions have also been reported in Nazi concentration camp victims56 and, more recently, in survivors of Pol Pot’s regime in Cambodia.)57
It might be argued that the high level of trauma reported by patients sometimes reflects events that have befallen them after they have become ill. On this view, patients whose judgement is impaired may be especially likely to place themselves in situations of risk, may be unable to take adequate avoiding actions if attacked, or may be forced by economic necessity to live in unsafe environments. At a push, the findings from veterans might even be interpreted this way (a sceptic might argue that a mentally unstable soldier is especially likely to be captured by an enemy). However, a recent large-scale survey of patients experiencing their first admission for psychosis carried out in the United States found very high levels of trauma that were comparable to those reported by patients who had been ill for some time. When the researchers took steps to exclude from their analyses any traumatic events that could be a consequence of psychotic behaviour, only 5 per cent of incidents could be accounted for in this way.58
If trauma does play an important role in the development of psychosis, many psychotic patients should also suffer from post-traumatic symptoms. Mueser and Goodman found that, although fewer than 3 per cent of the patients they surveyed had a PTSD diagnosis recorded in their medical notes, 40 per cent of those with a primary diagnosis of bipolar disorder, 37 per cent of those with a diagnosis of schizoaffective disorder and 28 per cent of those with a diagnosis of schizophrenia also met the DSM criteria for PTSD. By comparison, they estimated the risk of developing PTSD in the lifetime of an average member of the population to be less than 9 per cent.
By now the reader might be wondering whether crises more mundane than assaults or warfare can lead to madness. In fact, one particular type of commonplace trauma has long been known to trigger psychotic episodes. This trauma is, of course, the experience of giving birth to a child. In the nineteenth century, Esquirol carried out the first quantitative studies of puerperal psychosis, describing a series of 92 cases.59 He noted that unmarried mothers seemed to be at special risk, presumably because, at that time, they suffered from many additional stresses and disadvantages. Modern studies – such as those by Robert Kendell in Edinburgh,60 and by Ian Brockington in Manchester61 – suggest that about 1 in every 1000 births is followed within three months by a psychotic reaction in the mother. Consistent with Esquirol’s much earlier observations, these studies have also shown that additional stressors contribute to the risk of breakdown. For example, both separation from a husband and a stillbirth seem to increase the risk of psychosis.
In a detailed (and fascinating) historical review of research on puerperal psychosis, Ian Brockington has noted that some clinicians have assumed it to be a disease entity in its own right, whereas others have argued that it is a variant of one of the diagnostic categories defined within the Kraepelinian system. Brockington’s own preference is to regard puerperal psychosis as a form of manic depression, because manic features are often evident. However, he notes that a minority of cases appear more schizophrenic, according to conventional definitions.62
The similarity between puerperal psychosis and mania is perhaps understandable when it is remembered that new mothers frequently experience sleep loss in the months following the birth of a child. However, in the case of other types of trauma, delusions and especially hallucinations have been more frequently recorded. For example, in two studies carried out by Colin Ross and his colleagues in Canada, the number of Schneiderian first-rank symptoms experienced by female inpatients correlated strongly with measures of how severely they had been sexually abused.63 In a more recent study carried out by University of Auckland psychologist John Read, the case notes of 92 patients with a documented history of sexual and physical abuse were compared with the case notes of 108 who had not, and hallucinations stood out as the symptom most strongly predicted by a history of trauma.64 To test whether this specific association is confined to schizophrenia patients, Paul Hammersley, in my own department, recently examined therapists’ reports on nearly 100 bipolar disorder patients participating in a clinical trial of a new form of psychological treatment.65 As part of the trial procedure, a group of research assistants had independently interviewed the patients about their lifetime history of symptoms. Although only a minority of the patients reported hallucinations, Paul found that these patients were especially likely to have disclosed to their therapists that they had been sexually abused.66
Overall, then, and contrary to received wisdom, the evidence that trauma can play a causal role in psychosis appears to be surprisingly strong. However, we are still left with a couple of unresolved questions. First, it is difficult to explain why (with the possible exception of the trauma of childbirth) there should be a specific association between trauma and hallucinations. Second, it is also difficult to explain why the effects of adverse experiences are sometimes delayed (so that, for example, sexual abuse in early life increases the risk of psychosis in adulthood).
We will not be able to answer these questions properly until we have an adequate understanding of how the cognitive processes responsible for hallucinations develop during childhood and afterwards. However, once again child psychologists have provided us with a few clues, which may point us in roughly the right direction. Recall, first of all, that hallucinations are the consequence of failing to monitor accurately the source of thoughts and images. It is therefore especially interesting that British developmental psychologists Charles Ferny-hough and James Russell have recently found an association between efficiency at source monitoring in early childhood and the use of private speech in social settings – children who speak a lot to themselves when other people are present tend to be good at discriminating between their thoughts and other people’s voices.67 Perhaps children learn to tell the difference between the external (‘real’) and the cogn
itive (‘imaginary’) relatively easily in circumstances in which both types of events can readily be contrasted. Opportunities for this kind of learning might include not only private speech in social settings but also, for example, waking from vivid dreams, or situations in which the child learns to use mental imagery to solve complex visual problems. Speculating, as I would hardly dare to when writing a paper in a psychiatric journal, it is possible that some children who (for whatever reason) are relatively deprived of these kinds of experiences never become completely efficient at source monitoring.
On this account, it becomes possible to see why trauma might later lead to hallucinatory experiences. In Chapter 14 we saw that source-monitoring failures tend to occur when we experience intrusive or automatic thoughts. (This is because the effort taken to generate a thought acts as a cue telling us that the thought is self-generated.) It follows that a person who has poor source-monitoring skills will be most vulnerable to hallucinations when experiencing a flood of intrusive thoughts and images. Trauma (we know from the research literature on post-traumatic stress disorder) often has exactly this effect.
It is less easy to explain the delay that often occurs between trauma and the onset of hallucinations. One possibility is that this happens when there is a delay in the production of intrusive thoughts and images. This might happen, for example, when an individual initially copes well with a traumatic experience but is later reminded of it by a further trauma or period of severe stress. Many of the patients interviewed by Marius Romme and his colleagues in Holland reported being retraumatized in this way.68 (I can think of several of my own patients whose life stories fit this picture; for example a young man who was sexually abused by his stepfather, who coped very well until his long-term girlfriend suddenly deserted him for another man, and who then became very depressed and lost his job, after which he began to hear threatening voices.) Another possibility is that stressful events some time after a trauma lead to a further reduction in the individual’s already compromised source-monitoring ability, so that mental events that are initially experienced as intrusive thoughts are later experienced as hallucinations. (Again, I can think of patients who have complained of progressing from intrusive thoughts to hallucinations, but I have no evidence that this happens very often.)
Madness Explained Page 55
