In order to improve the outcome of schizophrenia, we must deepen our understanding of its heterogeneous aspect. At the same time, we must search for homogeneous subtypes characterized by consistent clinical aspects so that we may develop specific and more effective treatments. Researchers have long categorized schizophrenia as a syndrome manifested through a number of distinct subtypes that share the same morbid process but have sufficient differences to warrant distinct subtyping (Berman et al., 1995a; Fenton and McGlashan, 1986; Rosen, 1957; Stengel, 1945). Using genetic, neurological, biochemical and outcome markers, research continues to focus on the search for homogeneous subtypes (Goldstein and Tsuang, 1988).
In this article, we will discuss the significance of the obsessive-compulsive (OC) phenomenon in schizophrenia and focus on whether an OC subtype of schizophrenia makes clinical and theoretical sense. One of the yet unanswered questions is whether OC symptoms constitute the expression of schizophrenic psychosis or if they are the manifestation of obsessive-compulsive disorder (OCD). The answer to this question has both theoretical and clinical implications and would affect our understanding about the etiology and physiology of schizophrenia, as well as insights into outcome and treatment.
If OC symptoms in schizophrenia are expressions of OCD and are more than just manifestations of chronic psychosis, the treatment of many patients would be changed to include an anti-obsessional agent (Berman et al., 1995b). Increasing evidence suggests that OC symptoms are not simply expressions of persistent schizophrenic psychosis but that they actually constitute a cluster of symptoms that resembles OCD (Berman et al., 1998). The question then remains whether OC symptoms are manifestations of comorbid OCD or whether they are characteristics of a distinct subtype of schizophrenia.OC Symptoms in Schizophrenia
The answer to this question has been frequently hindered by the difficulty in differentiating between OCD and psychotic symptoms. Early authors have described the similarity between severe OCD and psychosis (Insel and Akiskal, 1986). For instance, both OCD and psychosis may include absurd or excessive ideas or beliefs. Moreover, when patients with OCD lose insight, their OC symptoms become psychotic; and, similarly, when psychotic symptoms become repetitive, intrusive and egodystonic, patients with schizophrenia begin to experience an OC-like phenomenon.
Consequently, these patients may suffer from obsessions and compulsions that are intertwined with the psychotic process. The current data suggest that a significant number of patients with schizophrenia (up to 50%) have OC-like symptoms coexisting with psychosis and that these symptoms can be easily overlooked by clinicians (Berman et al., 1998).
In order to understand the etiology of this phenomenon in patients with schizophrenia, we need to rely on pharmacologic, neurocognitive, genetic, brain imaging and biochemical data. The data about the significance of OC symptoms in schizophrenia, however, are limited to only a few studies about the phenomenology, epidemiology, psychopharmacology and neurocognition of OC phenomena in this patient population.Clinical Phenomenology
Early studies suggested that the association between OC symptoms and schizophrenia was a rare phenomenon and indicated a good outcome (Rosen, 1957; Stengel, 1945). More recent studies, however, have reported that the OC symptoms are seen in a significantly higher number of patients with schizophrenia than had been previously anticipated and that these patients have a poorer outcome. For instance, Fenton and McGlashan (1986) found that approximately 13% (21 out of 163) of patients with schizophrenia had significant OC symptoms and, compared to patients without obsessions or compulsions, were more socially isolated and had longer hospitalizations. Our group found similar results in a sample of patients from a community mental health center (Berman et al., 1995a). We found that approximately 25% of our patients had OC symptoms and that these patients with OC symptoms had an earlier onset of illness, were more socially isolated, spent more time in the hospital, had worse employment history and were thought by therapists to have a lower level of functioning. These findings were supported later by Bermanzohn et al. (1997) who reported that 20% to 50% of patients with schizophrenia had OC symptoms and that the presence of such symptoms indicated poor outcome. A similarly high prevalence (45%) was found by our group in a neuropsychological study in patients hospitalized at a long-term psychiatric hospital (Berman et al., 1998).