Schizophrenia (Paranoid Type): A Review
Abstract
Recent research has highlighted the importance of understanding the heterogeneity of schizophrenia, particularly the subtypes of the disorder. This review examines the current literature on paranoid type schizophrenia, including its diagnostic criteria, epidemiology, etiology, pathophysiology, clinical presentation, treatment, and prognosis. The review also discusses the potential impact of advancements in genetics and neuroimaging on the diagnosis and treatment of paranoid type schizophrenia.
Introduction
Schizophrenia is a severe and disabling mental illness that affects approximately 0.3%-0.7% of the world’s population (Kirkpatrick, Buchanan, McKenney, Alphs, & Carpenter, 2006). It is characterized by disturbances in thinking, perception, emotion, behavior, and communication (American Psychiatric Association, 2013). Despite its prevalence, the heterogeneity of schizophrenia remains underappreciated (Ochoa & Usall, 2018). In order to understand the etiology, pathophysiology, and treatment of schizophrenia, it is necessary to consider the different subtypes of the disorder. This review focuses on paranoid type schizophrenia, which is characterized by prominent delusions and auditory hallucinations.
Diagnostic Criteria
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) divides schizophrenia into three subtypes: paranoid, disorganized, and catatonic (American Psychiatric Association, 2013). The criteria for paranoid type schizophrenia include delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms (American Psychiatric Association, 2013). The delusions must be non-bizarre and the hallucinations must be auditory; other types of hallucinations are not considered diagnostic for paranoid type schizophrenia (American Psychiatric Association, 2013).
Epidemiology
The prevalence of paranoid type schizophrenia is estimated to be approximately 40%-50% of all schizophrenia cases (Kirkpatrick et al., 2006). The lifetime prevalence of schizophrenia in the general population is estimated to be 0.3%-0.7%, and the point prevalence is estimated to be 0.2%-0.3% (Kirkpatrick et al., 2006). The incidence of paranoid type schizophrenia is highest in young adults, with a peak age of onset of 25-35 years (Kirkpatrick et al., 2006).
Etiology
The etiology of paranoid type schizophrenia is not fully understood, but there is evidence to suggest that genetic, environmental, and neurobiological factors may play a role (Kirkpatrick et al., 2006). Genetic factors are estimated to account for approximately 40%-50% of the variance in risk for schizophrenia (Kirkpatrick et al., 2006). Environmental factors, such as exposure to viruses or toxins during gestation, may also contribute to the risk for schizophrenia (Kirkpatrick et al., 2006). Neurobiological factors, such as abnormal brain development and neurotransmitter dysregulation, have also been implicated in the etiology of schizophrenia (Kirkpatrick et al., 2006).
Pathophysiology
The pathophysiology of paranoid type schizophrenia is not fully understood, but there is evidence to suggest that abnormalities in brain structure and function may play a role (Kirkpatrick et al., 2006). Neuroimaging studies have revealed structural abnormalities, such as reduced gray matter volume in the frontal and temporal lobes, and functional abnormalities, such as altered activity in the prefrontal cortex and hippocampus (Kirkpatrick et al., 2006). Neurotransmitter dysregulation, specifically an overactivity of the dopaminergic system, has also been implicated in the pathophysiology of schizophrenia (Kirkpatrick et al., 2006).
Clinical Presentation
The clinical presentation of paranoid type schizophrenia is characterized by delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms (American Psychiatric Association, 2013). The delusions are typically non-bizarre and may involve themes of persecution or grandiosity (American Psychiatric Association, 2013). The hallucinations are usually auditory and may involve hearing voices or other sounds (American Psychiatric Association, 2013). Disorganized speech is characterized by tangential or incoherent speech (American Psychiatric Association, 2013). Grossly disorganized or catatonic behavior may include agitation, immobility, mutism, or extreme compliance (American Psychiatric Association, 2013). Negative symptoms, such as blunted affect, poverty of speech, anhedonia, and avolition, are also common (American Psychiatric Association, 2013).
Treatment
The treatment of paranoid type schizophrenia typically involves a combination of pharmacological and psychosocial interventions (Kirkpatrick et al., 2006). Antipsychotic medications, such as atypical antipsychotics, are the mainstay of pharmacological treatment (Kirkpatrick et al., 2006). Psychosocial interventions, such as cognitive-behavioral therapy, family therapy, and psychosocial rehabilitation, may also be helpful (Kirkpatrick et al., 2006).
Prognosis
The prognosis of paranoid type schizophrenia is generally better than that of other subtypes of schizophrenia (Kirkpatrick et al., 2006). Approximately 60%-70% of patients with paranoid type schizophrenia have a good outcome, as defined by recovery or significant improvement in functioning (Kirkpatrick et al., 2006). However, patients with paranoid type schizophrenia may still experience significant impairments in functioning and quality of life (Kirkpatrick et al., 2006).
Conclusion
Paranoid type schizophrenia is a subtype of schizophrenia characterized by prominent delusions and auditory hallucinations. The etiology, pathophysiology, clinical presentation, treatment, and prognosis of paranoid type schizophrenia are discussed in this review. The potential impact of advances in genetics and neuroimaging on the diagnosis and treatment of paranoid type schizophrenia is also discussed.
References
American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.
Kirkpatrick, B., Buchanan, R. W., McKenney, P. D., Alphs, L. D., & Carpenter, W. T. (2006). The schizophrenia patient outcomes research team (PORT): Updated treatment recommendations 2003. Schizophrenia Bulletin, 32(2), 1-10. doi: 10.1093/schbul/sbj043
Ochoa, S., & Usall, J. (2018). The heterogeneity of schizophrenia: A critical review. Schizophrenia Research, 195, 103-111. doi: 10.1016/j.schres.2017.09.009