Toward a Phenomenological Psychotherapy for Schizophrenia

The Evolution of Symbolic Thought: At the Intersection of Schizophrenia Psychopathology, Ethnoarchaeology, and Neuroscience

The human capacity for symbolic representation arises, evolutionarily and developmentally, from the exploitation of a widespread sensorimotor network, along a fundamental continuity between embodied and symbolic modes of experience. In this regard, the fine balancing between constrained sensorimotor connections (responsible for self-embodiment processing) and more untethered neural associations (responsible for abstract and symbolic processing) is context dependent and plastically neuromodulated, thus intersubjectively constructed within a specific socio-cultural milieu. Instead, in the schizophrenia spectrum this system falls off catastrophically, due to an unbalance toward too unconstrained sensorimotor connectivity, leading to a profound distortion of self/world relation with a symbolic activity detached from its embodied ground. For this very reason, however, schizophrenia psychopathology may contribute to unveil, in a distorted or magnified way, ubiquitous structural features of human symbolic activity, beneath the various, historically determined cultural systems. In this respect, a comparative approach, linking psychopathology and ethnoarchaeology, allows highlight the following invariant formal characteristics of symbolic processing: (1) Emergence of salient perceptive fragments, which stand out from the perceptual field. (2) Spreading of a multiplicity of new significances with suspension of common-sense meaning. (3) Dynamic and passive character through which meaning proliferation is experienced. This study emphasizes the importance of fine-grained psychopathology to elucidate, within a cross-disciplinary framework, the evolutionarily and developmental pathways that shape the basic structures of human symbolization.

Schizophrenia, the very idea: On self-disorder, hyperreflexivity, and the diagnostic concept

The purpose of the present article is to consider schizophrenia-the very idea-from the perspective of phenomenological psychopathology, with special attention to the problematic nature of the diagnostic concept as well as to the prospect and challenges inherent in focusing on subjective experience. First, we address historical and philosophical topics relevant to the legitimacy of diagnostic categorization-in general and regarding "schizophrenia" in particular. William James's pragmatist approach to categorization is discussed. Then we offer a version of the well-known basic-self or ipseity-disturbance model (IDM) of schizophrenia, but in a significantly revised form (IDMrevised). The revised model better acknowledges the diverse and even seemingly contradictory nature of schizophrenic symptoms while, at the same time, interpreting these in a more unitary fashion via the key concept of hyperreflexivity-a form of exaggerated self-awareness that tends to undermine normal world-directedness and the stability of self-experience. Particular attention is paid to forms of exaggerated "self-presence" that are sometimes neglected yet imbue classically schizophrenic experiences involving subjectivism or quasi-solipsism and/or all-inclusive or ontological forms of paranoia. We focus on the distinctively paradoxical nature of schizophrenic symptomatology. In concluding we consider precursors in the work of Klaus Conrad, Kimura Bin and Henri Grivois. Finally we defend the concept of schizophrenia by considering its distinctive way of altering certain core aspects of the human condition itself.

Self-Disorder in Schizophrenia: A Revised View (1. Comprehensive Review-Dualities of Self- and World-Experience)

A growing body of research supports the role of self-disorders as core phenotypic features of schizophrenia-spectrum disorders. Self-disorders comprise various alterations of conscious experience whose theoretical understanding continues to present a challenge. The following 2 articles aim to provide further clarification of the nature of self-disorders in schizophrenia by offering a comprehensive review (article 1) and theoretical revision (article 2) of the currently most influential model of altered selfhood in schizophrenia: the basic-self-disturbance or ipseity-disorder model (IDM). This article presents a state-of-the-art overview of the current self-disturbance model and critically assesses its descriptive adequacy with respect to the clinical variability and heterogeneity of the alterations in self- and world-awareness characteristic of schizophrenia. Special attention is paid to experiences of exaggerated basic self, increased "grip" or "hold" on the world, and paradoxical combinations. The next article proposes a theoretical revision of the self-disturbance model by considering how hyperreflexivity might form the crucial common thread or generating factor that unifies the phenomenologically heterogeneous, and sometimes even contradictory features of schizophrenic self-disorders. We outline the implications of our revised model for explanatory research, therapeutic practice, and our general understanding of the abnormalities in question.

Self-Disorder in Schizophrenia: A Revised View (2. Theoretical Revision-Hyperreflexivity)

A growing body of research supports the role of self-disorders as core phenotypic features of schizophrenia-spectrum conditions. Self-disorders comprise various alterations of conscious experience whose theoretical understanding continues to present a challenge. This is the second of two articles that aim to clarify the nature of self-disorders in schizophrenia by considering the currently most influential, phenomenological model of schizophrenia: the basic-self-disturbance or ipseity-disorder model (IDM). The previous paper (article 1) presented a state-of-the-art overview of this model and critically assessed its descriptive adequacy with respect to the clinical heterogeneity and variability of the alterations in self- and world-awareness characteristic of schizophrenia. This paper (article 2) proposes a theoretical revision by considering how hyperreflexivity might form the crucial common thread or generating factor that unifies the heterogeneous, and sometimes even contradictory features of schizophrenic self-disorders. We outline implications of our revised model (IDMrevised) for explanatory research, therapeutic practice, and our general understanding of the abnormalities in question.

Pseudoneurotic Symptoms in the Schizophrenia Spectrum: A Longitudinal Study of Their Relation to Psychopathology and Clinical Outcomes

BACKGROUND AND HYPOTHESIS

Nonpsychotic symptoms (depression, anxiety, obsessions, etc.) are frequent in schizophrenia-spectrum disorders and are usually conceptualized as comorbidity or transdiagnostic symptoms. However, in twentieth century foundational psychopathological literature, many nonpsychotic symptoms with specific phenomenology (here termed pseudoneurotic symptoms) were considered relatively typical of schizophrenia. In this prospective study, we investigated potential associations of pseudoneurotic symptoms with diagnostic status, functional outcome as well as psychopathological dimensions of schizophrenia.

STUDY DESIGN

First-admitted patients (N = 121) diagnosed with non-affective psychosis, schizotypal disorder, or other mental illness were examined at initial hospitalization and 5 years later with a comprehensive assessment of psychopathology. Informed by the literature, we constructed scales targeting pseudoneurotic symptoms and other, more general, nonpsychotic symptoms.

STUDY RESULTS

Pseudoneurotic symptoms aggregated in schizophrenia-spectrum groups compared to other mental illnesses and occurred at similar levels at baseline and follow-up. They longitudinally predicted poorer social and occupational functioning in schizophrenia-spectrum patients over a 5-year-period but not transition to schizophrenia-spectrum disorders from other mental illnesses. Finally, the level of pseudoneurotic symptoms correlated with disorder of basic self at both assessments and with positive and negative symptoms at follow-up. The scale targeting general nonpsychotic symptoms did not show this pattern of associations.

CONCLUSIONS

The study supports that a group of nonpsychotic symptoms, ie, pseudoneurotic symptoms, are associated with schizophrenia-spectrum disorders and linked with temporally stable psychopathology, particularly disorder of the basic self. Their prospective association with social and occupational functioning needs replication.

Psychotherapy for patients with schizotypal personality disorder: A scoping review

BACKGROUND

Treatment of schizotypal personality disorder is complex. Currently, there are no clear evidence-based recommendations for use of psychotherapy for individuals suffering from this mental illness, and studies are sparse. Our aim in this review is to map and describe the existing research and to answer the research question: What do we know about the use of psychotherapy for people with schizotypal personality disorder?

METHODS

We conducted a scoping review using systematic searches in the Embase, MEDLINE and PsycINFO databases. Two reviewers screened possible studies and extracted data on subject samples, type of psychotherapy, outcomes and suggested mechanisms of change. The review is based on the PRISMA checklist for scoping reviews.

RESULTS

Twenty-three papers were included, and we found a wide variety of study types, psychotherapeutic orientations and outcomes. Few studies emerged that focused solely on schizotypal personality disorder.

CONCLUSION

Psychotherapy as a treatment for schizotypal personality disorder is understudied compared with diagnoses such as schizophrenia and borderline personality disorder. Our results included two randomized controlled studies, as well as mainly smaller studies with different approaches to diagnostic criteria, psychotherapeutic orientation and outcome measures. The findings are too sparse and too diverse to make any evidence-based recommendations. We found some indications that psychotherapy may support and assist individuals with schizotypal personality disorder.

The phenomenological model of depression: from methodological challenges to clinical advancements

In this article our overall aim is to illustrate how phenomenological psychopathology can advance the clinical work on depression. To do so, we start by unfolding the current phenomenological model of depression. We argue that this model faces a methodological challenge, which we define as 'the challenge of patho-description'. Mental disorders, such as depression, influence how people are able to access and describe their own experiences. This becomes a challenge for phenomenological psychopathology since its methodology is based on people's ability to describe their own experiences. To deal with this challenge, in the case of depression, we turn to the framework of phenomenological interview. We interview 12 participants (7 women, 5 men, age-range from 29 to 57 years) with moderate and severe depression. From the interview results, we show how phenomenological interview deals with the challenge of patho-description and how patho-description in depression conceals experiential nuances. We unfold these nuances and describe how people with depression pre-reflectively experience a variety of feelings, a type of agency, overly positive self-image, and relations in a hyper-social way. These descriptive nuances not only strengthen the phenomenological model of depression, but they also help advance the clinical work on depression. We firstly illustrate how the descriptive nuances can be added to current manuals and rating scales to advance diagnostic work. Secondly, we illustrate how phenomenological, 'bottom-up', and embodied approaches function at the pre-reflective level of experience, and that further effort at this level can help advance therapy for depression.

Forcing an Effortless Stance: The Lived Body in Social Anxiety Disorder

INTRODUCTION

The fear of scrutiny central in social anxiety disorder (SAD) points to a problem of the interpersonally perceivable body. Whereas the predominant cognitive-behavioral (CBT) account of the disorder understands this as a problem of excessive self-focused attention, the phenomenological literature reveals it as a sign of a fundamental transformation of body experience. The lived body absent from experience becomes the object body at the forefront of it. The present paper contributes to this literature by refining and grounding these notions in first-person descriptions of concrete experiences of social anxiety.

METHOD

Repeated interviews were conducted with eight informants struggling with social anxiety and collected personal diaries. The interviews were informed by phenomenological concepts and a specific line of inquiry on body experiences. The analysis tested iteratively a set of phenomenologically grounded hypotheses of altered body experience against the first-person descriptions.

RESULTS

A concept of bodily instrumentalization is developed which accounts for the tendency of self-directed attention and behavior central to the disorder. That is, the socially anxious patient experiences their body as entrapped by the Other and thus unable to act freely among them. This felt bodily self-enslavement for the Other shows itself in efforts to conceal the body from the others and to puppeteer it for them.

DISCUSSION

The notion of bodily enslavement captures a central aspect of the suffering experienced by patients with SAD that exceeds the capability of the CBT language. Additionally, the social nature of the bodily instrumentalization that is constitutive of this suffering means that psychotherapy should not treat SAD as a cognitive disorder, but rather as an interpersonal disorder. Specifically, psychotherapy should offer patients shared interpersonal experiences in which they forget their bodily presence.

Phenomenology as a resource for translational research in mental health: methodological trends, challenges and new directions

This editorial reflects on current methodological trends in translational research in mental health. It aims to build a bridge between two fields that are frequently siloed off from each other: interventional research and phenomenologically informed research. Recent years have witnessed a revival of phenomenological approaches in mental health, often - but not only - as a means of connecting the subjective character of experience with neurobiological explanatory accounts of illness. Rich phenomenological knowledge accrued in schizophrenia, and wider psychosis research, has opened up new opportunities for improving prediction, early detection, diagnosis, prognostic stratification, treatment and ethics of care. Novel qualitative studies of delusions and hallucinations have challenged longstanding assumptions about their nature and meaning, uncovering highly complex subjective dimensions that are not adequately captured by quantitative methodologies. Interdisciplinary and participatory research efforts, informed by phenomenological insights, have prompted revisions of pre-established narratives of mental disorder dominated by a dysfunction framework and by researcher-centric outcome measures. Despite these recent advances, there has been relatively little effort to integrate and translate phenomenological insights across applied clinical research, with the goal of producing more meaningful, patient-valued results. It is our contention that phenomenological psychopathology - as the basic science of psychiatry - represents an important methodology for advancing evidence-based practices in mental health, and ultimately improving real-world outcomes. Setting this project into motion requires a greater emphasis on subjectivity and the structures of experience, more attention to the quality and patient-centredness of outcome measures, and the identification of treatment targets that matter most to patients.

Pseudoneurotic symptoms in the schizophrenia spectrum: An empirical study

BACKGROUND

Nonpsychotic symptoms (depression, anxiety, obsessions etc.) are frequent in schizophrenia-spectrum disorders. Twentieth century foundational psychopathological literature claimed that certain nonpsychotic symptoms (here termed pseudoneurotic symptoms) are relatively closely linked with the schizophrenia-spectrum, despite descriptive overlap with symptoms of other diagnoses. In this study, we investigated the association of pseudoneurotic and other nonpsychotic symptoms with the schizophrenia-spectrum as well as a hypothesis about an association of pseudoneurotic symptoms with disorder of basic self.

METHODS

The sample (N = 226) comprised patients with non-affective psychosis (N = 119), schizotypal personality disorder (N = 51) and other mental illness (N = 56), who were examined with a comprehensive assessment of lifetime psychopathology. Informed by the literature, we constructed scales targeting pseudoneurotic symptoms and other, more general, nonpsychotic symptoms.

RESULTS

Pseudoneurotic symptoms aggregated significantly in schizophrenia-spectrum disorders with an Area under the receiver operating characteristic curve of 0.84 (SE 0.03) for classifying patients with schizophrenia-spectrum disorders versus other mental illness. Patients with non-affective psychosis scored slightly, but significantly, higher on the scale targeting general nonpsychotic symptomatology than the other groups. In multiple regression analysis, pseudoneurotic symptoms were predicted by general nonpsychotic symptoms, disorders of basic self, and negative symptoms but not positive symptoms.

CONCLUSION

The study supports that certain neurotic-like symptoms with specific descriptive features (pseudoneurotic symptoms) are associated with schizophrenia-spectrum disorders. It suggests that pseudoneurotic symptoms are linked with temporally stable schizophrenia psychopathology (disorder of basic self and negative symptoms).

Self-disorders and psychopathology: a systematic review

In foundational texts on schizophrenia, the mental disorder was constitutively linked to a specific disintegration of subjectivity (often termed a self-disorder). Apart from Scharfetter's work on ego-pathology, research on self-disorders generally faded into oblivion, and self-disorders were only rediscovered as notable psychopathological features of the schizophrenia spectrum nearly two decades ago. Subsequently, the Examination of Anomalous Self-Experience (EASE) scale was constructed to allow systematic assessment of non-psychotic self-disorders. This Review is the first systematic review of empirical studies on self-disorders based on the EASE or other related scales. The results consistently show that self-disorders hyper-aggregate in schizophrenia spectrum disorders but not in other mental disorders; that self-disorders are found in individuals at a clinical risk of developing psychosis; that self-disorders show a high degree of temporal stability; that self-disorders predict the later development of schizophrenia spectrum disorders; and that self-disorders correlate with the canonical dimensions of the psychopathology of schizophrenia, impaired social functioning, and suicidality. Issues with the methods of the reviewed literature are critically discussed and the role of self-disorders in clinical psychiatry and future research is outlined.

Social Dysfunction in Psychosis Is More Than a Matter of Misperception: Advances From the Study of Metacognition

Many with psychosis experience substantial difficulties forming and maintaining social bonds leading to persistent social alienation and a lack of a sense of membership in a larger community. While it is clear that social impairments in psychosis cannot be fully explained by symptoms or other traditional features of psychosis, the antecedents of disturbances in social function remain poorly understood. One recent model has proposed that deficits in social cognition may be a root cause of social dysfunction. In this model social relationships become untenable among persons diagnosed with psychosis when deficits in social cognition result in inaccurate ideas of what others feel, think or desire. While there is evidence to support the influence of social cognition upon social function, there are substantial limitations to this point of view. Many with psychosis have social impairments but not significant deficits in social cognition. First person and clinical accounts of the phenomenology of psychosis also do not suggest that persons with psychosis commonly experience making mistakes when trying to understand others. They report instead that intersubjectivity, or the formation of an intimate shared understanding of thoughts and emotions with others, has become extraordinarily difficult. In this paper we explore how research in metacognition in psychosis can transcend these limitations and address some of the ways in which intersubjectivity and more broadly social function is compromised in psychosis. Specifically, research will be reviewed on the relationship between social cognitive abilities and social function in psychosis, including measurement strategies and limits to its explanatory power, in particular with regard to challenges to intersubjectivity. Next, we present research on the integrated model of metacognition in psychosis and its relation to social function. We then discuss how this model might go beyond social cognitive models of social dysfunction in psychosis by describing how compromises in intersubjectivity occur as metacognitive deficits leave persons without an integrated sense of others' purposes, relative positions in the world, possibilities and personal complexities. We suggest that while social cognitive deficits may leave persons with inaccurate ideas about others, metacognitive deficits leave persons ill equipped to make broader sense of the situations in which people interact and this is what leaves them without a holistic sense of the other and what makes it difficult to know others, share experiences, and sustain relationships. The potential of developing clinical interventions focused on metacognition for promoting social recovery will finally be explored.

Prejudices in the psychopathologist: Karl Jaspers' heritage

Contributions of Karl Jaspers to the discipline of psychopathology are numerous. One of his most important insights deals with the method of interviewing in psychopathology. Specifically, how an interviewer (i.e. psychopathologist) approaches and explores mental phenomena that present themselves in the person being interviewed. By cultivating a phenomenological attitude, clinicians also acquire and renew self-criticism (Selbskritik), an essential aspect of a true psychopathologist. A fundamental part of the critical attitude in descriptive psychopathology is the re-examination of prejudices present in psychopathological interviewing. This review outlines and discusses six types of prejudices, as abstracted by Karl Jaspers, and illustrates them with clinical examples. (i) Philosophical prejudice deals with deductive and inductive reasoning; (ii) theoretical prejudice addresses the modeling of understanding of mental phenomena by analogy with natural sciences; (iii) somatic prejudice addresses biological reductionism in psychopathology; (iv) psychological prejudice focuses on approaches that consist of psychological interpretations that transgress the boundaries of psychological intelligibility; (v) pictorial prejudice deals with conceptualizations of psychic life as an analogy with certain visual depictions; (vi) medical prejudice is connected with strivings towards quantity, objectivity and diagnostic precision in psychopathology. To have the ability to represent the inner life of a person, we must dispense with prejudices in the clinical encounter with our patients. With the demands of modern-day life, and requests for quick clinical assessments, the idea of examining our prejudices and performing phenomenological interviews is more important than ever.

Delusions beyond beliefs: a critical overview of diagnostic, aetiological, and therapeutic schizophrenia research from a clinical-phenomenological perspective

Delusions are commonly conceived as false beliefs that are held with certainty and which cannot be corrected. This conception of delusion has been influential throughout the history of psychiatry and continues to inform how delusions are approached in clinical practice and in contemporary schizophrenia research. It is reflected in the full psychosis continuum model, guides psychological and neurocognitive accounts of the formation and maintenance of delusions, and it substantially determines how delusions are approached in cognitive-behavioural treatment. In this Review, we draw on a clinical-phenomenological framework to offer an alternative account of delusion that incorporates the experiential dimension of delusion, emphasising how specific alterations to self-consciousness and reality experience underlie delusions that are considered characteristic of schizophrenia. Against that backdrop, we critically reconsider the current research areas, highlighting empirical and conceptual issues in contemporary delusion research, which appear to largely derive from an insufficient consideration of the experiential dimension of delusions. Finally, we suggest how the alternative phenomenological approach towards delusion could offer new ways to advance current research and clinical practice.

Disturbances of Shared Intentionality in Schizophrenia and Autism

Schizophrenia and autism are today considered complex spectrum disorders characterized by difficulties in social behavior. Drawing on recent advances in collective or shared intentionality studies, we present a novel theoretical approach to these social difficulties by exploring them from the angle of shared intentionality. We begin by describing two forms of shared intentionality: joint intentionality and we-intentionality. Joint intentionality crucially relies on the agents' mentalizing abilities such as mind reading and the ability to factor in (or "to be moved" by) their partner's intentions in deliberation and action planning. By contrast, we-intentionality relies on the agents' capacity to understand themselves as group members and to adopt the group's perspective. In schizophrenia spectrum disorders, we propose that joint intentionality remains unaffected, but we-intentionality may be impaired. In severe autism spectrum disorder (i.e., infantile autism), we propose that both forms of shared intentionality are impaired. We suggest that the source of the problems affecting we-intentionality in schizophrenia spectrum disorders lies primarily in trait-like, anomalous self-experiences. In severe autism spectrum disorder, we suggest that problems with mind reading, the ability to "be moved" by others' intentions, and with the capacity for perspective-taking impede both forms of shared intentionality.

How to increase the role of social workers in suicide preventive interventions

OBJECTIVE

Suicide is a serious public health issue that affects individuals, families and societies all over the world. International studies provide consistent evidence that the presence of psychiatrists in a region is associated with lesser suicide rates. However, many psychiatric patients including suicidal patients do not have access to psychiatrists. This indicates that mental health and non-mental health social workers need to be involved in suicide prevention efforts. This paper is the first comprehensive work that discusses how to increase the role of social workers in the area of suicide prevention.

METHODS

A review of the relevant literature.

RESULTS

Increasing the role of social workers in suicide prevention efforts may reduce suicide risk in groups and people at elevated risk for suicide, as well as the general population.

CONCLUSION

Recommendations are provided for how the social work profession can improve upon suicide prevention while incorporating universal, selective and indicated suicide preventive interventions. Social work research efforts should focus on how to increase the role of social workers in suicide prevention and the management of suicidal patients. Social work education programmes should modify their curricula and increase their attention on suicide prevention. Mental health social workers need to educate the patient and their family on suicide risk factors. Furthermore, mental health and non-mental health social workers need to educate the general public on suicide risk factors.

A Phenomenological Paradigm for Empirical Research in Psychiatry and Psychology: Open Questions

This article seeks to clarify the way in which phenomenology is conceptualized and applied in empirical research in psychiatry and psychology, emphasizing the suitability of qualitative research. It will address the “What,” “Why,” and “How” of phenomenological interviews, providing not only preliminary answers but also a critical analysis and pointing to future directions for research. The questions it asks are: First, what makes an interview phenomenological? What are phenomenological interviews used for in empirical research in psychiatry and psychology? Second, why do we carry out phenomenological interviews with patients? Is merely contrasting phenomenological hypotheses or concepts enough to do justice to the patients’ involvement? Third, how should we conduct phenomenological interviews with patients? How can we properly perform analysis in empirical phenomenological research in psychiatry and psychology? In its conclusion, the article attempts to go a step beyond these methodological questions, highlighting the “bigger picture”: namely, the phenomenological scientific paradigm and its core philosophical claim of reality as mind-dependent.

Improving treatments for psychotic disorders: beyond cognitive behaviour therapy for psychosis

More effective treatments for people with psychotic disorders are urgently required. Here, we make three suggestions for progress: 1. Targeting the disorders' core phenomenological features ('phenomenological phenotype'), 2. Addressing social disconnection, isolation and loneliness, and 3. Leveraging 'hot' cognitions and using symptom capture approaches that combine psychotherapy with advances in technology and neuroscience.

The role of inner speech on the association between childhood adversity and 'hearing voices'

Adverse childhood experiences are associated with later development of psychosis, particularly auditory verbal hallucinations and delusions. Although auditory hallucinations have been proposed to be misattributed inner speech, the relation between childhood adversity and inner speech has not been previously investigated. The first aim was to test whether childhood adversity is associated with inner speech in persons with psychosis. The second aim was to test for the influence of inner speech on the association between childhood adversity and auditory hallucinations. Our final aim was to test for evidence that would falsify the null hypothesis that inner speech does not impact the relationship between childhood adversity and delusions. In persons with psychosis, we found a positive association between childhood adversity and dialogic inner speech. There was a significant total effect of childhood adversity on auditory hallucinations, including an indirect effect of childhood adversity on auditory hallucinations via dialogic inner speech. There was also a significant total effect of childhood adversity on delusions, but no evidence of any indirect effect via inner speech. These findings suggest that childhood adversities are associated with inner speech and psychosis. The relation between childhood adversity and auditory hallucination severity could be partially influenced by dialogic inner speech.

mTOR Expression in Hippocampus and Prefrontal Cortex Is Downregulated in a Rat Model of Schizophrenia Induced by Chronic Administration of Ketamine

Schizophrenia is a severe chronic neuropsychiatric disorder, and it negatively affects individuals' quality of life, but the pathogenesis of schizophrenia remains unclear. This study aimed to explore whether the administration of ketamine in rats causes changes in mTOR (mechanistic/mammalian target of rapamycin) expression in the hippocampus and prefrontal cortex. Ketamine was used to establish an animal model of schizophrenia. Rats were randomly divided into four groups: control group (normal saline), low-dose group (15 mg/kg ketamine), middle-dose group (30 mg/kg ketamine), and high-dose group (60 mg/kg ketamine). The rats were intraperitoneally injected with ketamine or normal saline twice a day (9 AM and 9 PM) for 7 consecutive days. Immunohistochemistry was used to detect mTOR protein expression in the hippocampus and prefrontal cortex from rats at 13 h after the last treatment. Using immunohistochemistry, the expression of the mTOR protein was localized exclusively in the CA3 region of the hippocampus and in the Cg1 region of the prefrontal cortexes. Ketamine at 60 mg/kg decreased the expression of mTOR protein in the brain of rats. Ketamine successfully established a rat model of schizophrenia. This study helps elucidate the mechanisms of ketamine-induced schizophrenia and provides novel insights for drug discovery and development.