Biomedical subjects

Louise C Johns

Publications and source records attributed to Louise C Johns.

11 recordsLinked to original sources

PubMed2007

Insight in individuals with an At Risk Mental State.

PURPOSE: On average, people with an At Risk Mental State (ARMS) for psychosis are more willing to seek and accept clinical help than patients with psychotic disorders, suggesting that insight in this group is relatively less impaired. We compared the level and quality of insight in the ARMS and in first episode psychosis. MATERIALS AND METHODS: Insight about illness was assessed in subjects with an ARMS and in patients with first episode psychosis (FEP) who were and were not help-seeking, using the Schedule for Assessment of Insight (SAI-E). RESULTS: Insight was impaired in ARMS subjects, but there was considerable variability in the insight displayed between subjects. Compared to FEP subjects, ARMS subjects showed greater insight, particularly with respect to Symptom Relabelling. ARMS subjects were more likely to interpret anomalous experiences as symptoms of illness, and to perceive themselves as needing treatment. CONCLUSIONS: Insight in people at high risk for psychosis is impaired, despite the fact that they are help-seeking. Insight varies between subjects, highlighting the need to comprehensively assess all aspects of insight in those with an ARMS. ARMS subjects are impaired in their ability to appraise anomalous experiences as symptoms of illness, but much less impaired than FEP subjects. This is consistent with cognitive models that propose that the way symptoms are appraised determines whether the individual develops a psychotic illness.

Adolescent↗

PubMed2006

Impaired verbal self-monitoring in psychosis: effects of state, trait and diagnosis.

BACKGROUND: Cognitive models propose that auditory verbal hallucinations arise through defective self-monitoring and external attribution of inner speech. We used a paradigm that engages verbal self-monitoring to examine how deficits in this process are related to symptoms and diagnosis in patients with psychosis. METHOD: We tested 45 patients with schizophrenia. Fifteen had current auditory hallucinations, 15 had a history of (but no current) auditory hallucinations, and 15 had delusions but neither current nor previous hallucinations. We also tested 10 patients with affective psychosis and current auditory hallucinations, and 20 healthy volunteers. Participants read single adjectives aloud while the source and the pitch of the on-line auditory verbal feedback was manipulated, then immediately identified the source of the speech they heard ('self'/'other'/'unsure'). RESULTS: When reading aloud with distorted feedback of their own voice, patients with schizophrenia who had auditory hallucinations were more likely than controls to misidentify its source as 'other'. Patients with delusions but no current hallucinations displayed a similar deficit, although there was a trend for this to be less marked. Patients with a history of hallucinations did not differ from controls. Patients with hallucinations in the context of an affective disorder made more unsure responses rather than misattributions. CONCLUSIONS: Difficulty with source monitoring was related to the acute psychotic state rather than a predisposition to hallucinations, and was evident in patients with affective psychosis as well as schizophrenia. External misattribution of source may reflect an impairment in verbal self-monitoring and/or the appraisal of ambiguous sensory material.

Adult↗

PubMed2005

What causes the onset of psychosis?

It has become increasingly clear that the simple neurodevelopmental model fails to explain many aspects of schizophrenia including the timing of the onset, and the nature of the abnormal perceptions. Furthermore, we do not know why some members of the general population have anomalous experiences but remain well, while others enter the prodrome of psychosis, and a minority progress to frank schizophrenia. We suggest that genes or developmental damage result in individuals vulnerable to dopamine deregulation. In contemporary society, this is often compounded by abuse of drugs such as amphetamines and cannabis, which then propel the individual into a state of dopamine-induced misinterpretation of the environment. Certain types of social adversity such as migration and social isolation, as well as affective change can also contribute to this. Thereafter, biased cognitive appraisal processes result in delusional interpretation of the abnormal perceptual experiences. Thus, a plausible model of the onset of psychosis needs to draw not only on neuroscience, but also on the insights of social psychiatry and cognitive psychology.

Brain↗

PubMed2005

Neural correlates of the misattribution of self-generated speech.

Auditory hallucinations are thought to arise through the misidentification of self-generated verbal material as alien. The neural mechanisms that normally mediate the differentiation of self-generated from nonself speech are unclear. We investigated this in healthy volunteers using functional MRI. Eleven healthy volunteers were scanned whilst listening to a series of prerecorded words. The source (self/nonself) and acoustic quality (undistorted/distorted) of the speech was varied across trials. Participants indicated whether the words were spoken in their own or another person's voice via a button press. Listening to self-generated words was associated with more activation in the left inferior frontal and right anterior cingulate cortex than words in another person's voice, which was associated with greater engagement of the lateral temporal cortex bilaterally. Listening to distorted speech was associated with activation in the inferior frontal and anterior cingulate cortex. There was an interaction between the effects of source of speech and distortion on activation in the left temporal cortex. In the presence of distortion participants were more likely to misidentify their voice as that of another. This misattribution of self-generated speech was associated with reduced engagement of the cingulate and prefrontal cortices. The evaluation of auditory speech involves a network including the inferior frontal, anterior cingulate, and lateral temporal cortex. The degree to which different areas within this network are engaged varies with the source and acoustic quality of the speech. Accurate identification of one's own speech appears to depend on cingulate and prefrontal activity.

Acoustic Stimulation↗

PubMed2005

Hallucinations in the general population.

Although hallucinations occur in a range of organic and psychiatric conditions, they are not invariably a sign of illness and also occur in "normal" individuals. Evidence indicates that psychotic hallucinations lie on a continuum with normal experiences, and many more people experience hallucinations than meet criteria for clinical psychosis. In addition to a symptomatic continuum between normal individuals and patients with psychosis, there is evidence that hallucinatory experiences in nonclinical and clinical samples may share the same underlying etiologic influences, including sociodemographic risk factors and neurocognitive mechanisms. Predictors of patient status include beliefs about hallucinations, negative mood, and perceived lack of control.

Brief Psychiatric Rating Scale↗

PubMed2005

Outreach and support in south London (OASIS): implementation of a clinical service for prodromal psychosis and the at risk mental state.

BACKGROUND: While recent research points to the potential benefits of clinical intervention before the first episode of psychosis, the logistical feasibility of this is unclear. AIMS: To assess the feasibility of providing a clinical service for people with prodromal symptoms in an inner city area where engagement with mental health services is generally poor. METHOD: Following a period of liaison with local agencies to promote the service, referrals were assessed and managed in a primary care setting. Activity of the service was audited over 30 months. RESULTS: People with prodromal symptoms were referred by a range of community agencies and seen at their local primary care physician practice. Over 30 months, 180 clients were referred; 58 (32.2%) met criteria for an at risk mental state, most of whom (67.2%) had attenuated psychotic symptoms. Almost 30% were excluded due to current or previous psychotic illness, of which two-thirds were in the first episode of psychosis. The socio-demographic composition of the 'at risk' group reflected that of the local population, with an over-representation of clients from an ethnic minority. Over 90% of suitable clients remained engaged with the service after 1 year. CONCLUSION: It is feasible to provide a clinical service for people with prodromal symptoms in a deprived inner city area with a large ethnic minority population.

Adult↗

PubMed2004

Misattribution of external speech in patients with hallucinations and delusions.

BACKGROUND: One of the main cognitive models of positive symptoms in schizophrenia proposes that they arise through impaired self-monitoring. This is supported by evidence of behavioural deficits on tasks designed to engage self-monitoring, but these deficits could also result from an externalising response bias. We examined whether patients with hallucinations and delusions would demonstrate an externalising bias on a task that did not involve cognitive self-monitoring. METHOD: Participants passively listened (without speaking) to recordings of single adjectives spoken in their own and another person's voice, and made self/nonself judgements about their source. The acoustic quality of recorded speech was experimentally manipulated by altering the pitch. Fifteen patients with schizophrenia who were currently experiencing hallucinations and delusions, 13 patients with schizophrenia not experiencing current hallucinations and delusions and 15 healthy controls were compared. RESULTS: When listening to distorted words, patients with hallucinations and delusions were more likely than both the group with no hallucinations and delusions and the control group to misidentify their own speech as alien (i.e. spoken by someone else). Across the combined patient groups, the tendency to misidentify self-generated speech as alien was positively correlated with current severity of hallucinations but not with ratings of delusions or positive symptoms in general. CONCLUSIONS: These findings indicate that patients with hallucinations and delusions are prone to misidentifying their own verbal material as alien in a task which does not involve cognitive self-monitoring. This suggests that these symptoms are related to an externalising bias in the processing of sensory material, and not solely a function of defective self-monitoring.

Acoustic Stimulation↗

PubMed2004

Prevalence and correlates of self-reported psychotic symptoms in the British population.

BACKGROUND: The psychosis phenotype is generally thought of as a categorical entity. However, there is increasing evidence that psychosis exists in the population as a continuum of severity rather than an all-or-none phenomenon. AIMS: To investigate the prevalence and correlates of self-reported psychotic symptoms using data from the 2000 British National Survey of Psychiatric Morbidity. METHOD: A total of 8580 respondents aged 16-74 years were interviewed. Questions covered mental health, physical health, substance use, life events and socio-demographic variables. The Psychosis Screening Questionnaire (PSQ) was used to identify psychotic symptoms. RESULTS: Of the respondents, 5.5% endorsed one or more items on the PSQ. Factors independently associated with psychotic symptoms were cannabis dependence, alcohol dependence, victimisation, recent stressful life events, lower intellectual ability and neurotic symptoms. Male gender was associated with paranoid thoughts, whereas female gender predicted hallucinatory experiences. CONCLUSIONS: Self-reported psychotic symptoms are less common in this study than reported elsewhere, because of the measure used. These symptoms have demographic and clinical correlates similar to clinical psychosis.

Adolescent↗

PubMed2003

Establishing the reliability of a verbal self-monitoring paradigm.

BACKGROUND: Auditory hallucinations in schizophrenia are associated with defective monitoring of inner speech. This process can be examined using a computerised task of verbal self-monitoring. Cognitive therapy for voices aims to improve the patients' self-monitoring ability, and changes in self-monitoring could be assessed using this task. Before using the paradigm in this way, we sought to determine its test re-test reliability. SAMPLING AND METHODS: 20 normal volunteers were tested on the paradigm on two occasions, 3 months apart. The task involved reading single adjectives under the following randomized conditions: reading aloud; reading aloud with acoustic distortion of their own voice; reading aloud with alien feedback (someone else's voice), and reading aloud with distorted alien feedback. Immediately after articulating each word, the participants were required to identify the source of the speech they heard ('self'/'other'/'unsure') via a button press. Response choice and reaction time were recorded. RESULTS: There was no change in error rate over the two testing occasions; however, participants had faster reaction times when tested for the second time. This reduction in reaction time was not specific to type of response (correct, error, unsure). CONCLUSIONS: Participants showed no evidence of practice on the paradigm in terms of making fewer errors or responding faster for correct responses. The overall reduction in reaction times on the second occasion may reflect increased familiarity with the task. The verbal self-monitoring paradigm appears to be a reliable measure, which could be used to evaluate changes in self-monitoring ability in hallucinators following psychological therapy.

Adolescent↗

PubMed2002

Occurrence of hallucinatory experiences in a community sample and ethnic variations.

BACKGROUND: Hallucinations typically are associated with severe psychiatric illness but also are reported by individuals with no psychiatric history. AIMS: To examine the prevalence of hallucinations in White and ethnic minority samples using data from the Fourth National Survey of Ethnic Minorities. METHOD: Interviews of 5196 ethnic minority and 2867 White respondents were carried out. The respondents were screened for mental health problems and the Psychosis Screening Questionnaire asked about hallucinations. Those who screened positive underwent a validation interview using the Present State Examination. RESULTS: Four per cent of the White sample endorsed a hallucination question. Hallucinations were 2.5-fold higher in the Caribbean sample and half as common in the South Asian sample. Of those who reported hallucinatory experiences, only 25% met the criteria for psychosis. CONCLUSIONS: The results provide an estimate of the annual prevalence of hallucinations in the general population. The variation across ethnic groups suggests cultural differences in these experiences. Hallucinations are not invariably associated with psychosis.

Adolescent↗

PubMed2002

A comparison of auditory hallucinations in a psychiatric and non-psychiatric group.

OBJECTIVES: To compare auditory hallucinations in a psychiatric and non-psychiatric sample. DESIGN: Between-participants group design: a psychiatric group of 14 patients with schizophrenia, and a non-psychiatric group of 16 participants with tinnitus. METHOD: Participants were interviewed using the Mental Health Research Institute Unusual Perceptions Scale (MUPS). RESULTS: The type of hallucinations differed: participants with tinnitus predominantly heard music, whereas the patients with schizophrenia heard voices speaking. The groups also differed in their explanations of the hallucinations. However, there were similarities in contributory factors, emotional responses and coping strategies. CONCLUSIONS: The study highlights the multi-dimensional nature of the auditory hallucinatory experience, and opportunities for intervention.

Adaptation, Psychological↗