Investigation into the relationship between OCS and positive and negative is needed to understand whether, as noted by Lysaker and Whitney (2009), OCS may serve as an indicator for a separate subtype of schizophrenia (as will be further discussed in the conceptualization section) that has its own pathophysiology or as Bleuler (1911/1950) suggested, OCS may simply aggravate the symptoms of schizophrenia rather than be a separate form of schizophrenia. Additionally, it continues to be unclear whether or not OCS exacerbates schizophrenia symptoms or serves as a protective factor against further deterioration.

Early studies examining the relationship between OCS and positive and negative symptoms produced contradictory results. Some studies have found no significant correlations (Berman et al. 1997; Borkowska et al. 2003; Poyurovsky et al. 2001), whereas others have noted that schizophrenia with OCD in younger individuals is associated with lesser levels of negative symptoms (Poyurovsky et al. 1999; Tibbo et al. 2000). Furthermore, other early studies support an association between OCS and positive and negative symptoms (Hwang and Hollander 1993; Lysaker et al. 2000).

On the other hand, both Byerly et al. (2005) and Sevincok et al. (2007) did not find associations between positive symptoms and OCS and OCD in participants with schizophrenia. In examining the clinical profiles of 55 participants with comorbid schizophrenia and OCD, Rajkumar et al. (2008) found that they had more paranoia and first-rank symptoms than those without comorbid OCD. In a meta-analysis of 18 studies between 1998 and 2006, Cunill et al. (2009) found no significant differences in symptom severity between groups of individuals with schizophrenia with OCD and schizophrenia without OCD. However, when comparing schizophrenia with OCS and without OCS, Cunill et al. found schizophrenia with OCS to be associated with greater global and positive symptoms compared to schizophrenia without OCS. Tiryaki and Ozkorumak (2010) also found more severe psychotic symptoms in participants with schizophrenia and OCS compared to participants without OCS.

More recent studies have failed to find a significant relationships between OCS and positive symptoms. Nasrollahi et al. (2012) did not find a relationship between OCS and positive symptoms of schizophrenia as assessed by the Y-BOCS and PANSS, respectively, in participants in a psychiatric hospital. Further, in a prospective study of the 5-year course of comorbid OCS and OCD in 172 patients with first-episode schizophrenia and related disorders, de Haan et al. (2013b) did not find a relationship among positive symptoms of schizophrenia and OCD/OCS, as assessed by the Y-BOCS. In a 12-month longitudinal study, Schirmbeck et al. (2013) also used the Y-BOCS and PANSS and found that individuals with schizophrenia and comorbid OCS did not have significantly higher scores in positive symptoms than individuals without OCS.

Nasrollahi et al. (2012) found a significant negative correlation between negative symptoms of schizophrenia and obsessive symptoms as assessed by the PANSS and Y-BOCS, respectively. Further, the authors found that more obsessive symptoms predicted less negative symptoms. Nasrollahi and colleagues suggested that obsessions could serve as a protective factor against developing negative symptoms of schizophrenia, and obsessions do not necessarily mean poorer prognosis. De Haan et al. (2013b) did not find a correlation between positive symptoms of schizophrenia and comorbid OCD/OCS nor between negative and disorganized symptoms of schizophrenia and OCD/OCS in a study of first-episode schizophrenia patients followed for 5 years. On the contrary to the previously discussed studies, Schirmbeck et al. (2013) found individuals with schizophrenia and comorbid OCS had significantly higher scores in negative symptoms and general psychopathology, but not in their positive symptoms.

Overall, there no consistent relationship between OCS/OCD and psychotic symptoms has emerged from the literature. While some studies have found higher levels of OCS/OCD were linked with more severe positive symptoms others have failed to replicate this. The majority of studies, on the other hand, have found little evidence of a relationship between negative symptoms and OCS/OCD. Among the studies in support for a relationship between OCS/OCD and psychotic symptoms, the relationship between OCS and psychotic symptoms (i.e., both positive and negative symptoms) is more consistently found than between OCD and psychotic symptoms. Additionally, a few studies have supported a negative correlation between OCS and negative symptoms.

The literature tends to be clearer in regard to the comorbidity of schizophrenia and OCS and affective symptoms, with the majority of studies supporting a positive correlation between OCS and depressive symptoms. Individuals with schizophrenia and OCS tend to demonstrate significant depressive symptoms, which is not surprising given that major depressive episodes are the most common comorbid disorder in OCD individuals (Murphy et al. 2010).

De Haan et al. (2005) found more severe depressive symptoms in patients with comorbid OCD as assessed with the Montgomery-Asberg Depression Rating Scale (MADRS; Montgomery and Asberg 1979). In the opposite direction, Sevincok et al.’s (2007) study that has been previously referred to found no relationship between OCD and depressive symptoms in individuals with schizophrenia in addition to finding no links with positive and negative symptoms. Ongür and Goff (2005) found schizophrenia participants with OCS had more depressive symptoms in addition to positive symptoms as previously mentioned. In regard to individuals with schizophrenia in an inpatient unit and/or under treatment, Kayahan et al. (2005) found that increased levels of OCS, as assessed with the Y-BOCS, had a significant relationship with depressive symptoms as assessed by the Calgary Depression Rating Scale for Schizophrenia (Addington 1990). In addition to Rajkumar et al. (2008) finding schizophrenia patients with comorbid OCD to have greater associations with more paranoia and first-rank symptoms compared to patients without OCD, they found that participants with both comorbid schizophrenia and OCD had greater depression scores on both the Hamilton Rating Scale for Depression (HAM-D; Hamilton 1960) and the depression subscale of the PANSS and more comorbid anxiety disorders.

In a prospective study of the 5-year course of comorbid OCS and OCD in 172 patients with first-episode schizophrenia and related disorders, de Haan et al. (2013b) found that comorbid OCD, but not OCS, as assessed by the Y-BOCS, was associated with more severe depressive symptoms at follow-ups. Additionally, Schirmbeck et al. (2013) found individuals with comorbid schizophrenia and OCS did not have increased levels of depressive symptoms compared to those without OCS.

Overall, the literature more clearly suggests a trend toward an association between the comorbidity of schizophrenia and OCS/OCD and depressive symptoms. Additionally, studies more frequently find correlations between depressive symptoms and persons with schizophrenia and OCD than with schizophrenia and OCS.

In regard to general functioning/psychosocial functioning, the research demonstrates that the relationship between OCS and functioning appears to be clearer than the relationship between OCS and symptoms; overall, OCS are associated with greater levels of impairment. This association between OCS and functional impairments may be explained by the fact that OCS can be debilitating in and of itself, which may hence exacerbate other symptoms. On the other hand, OCS in schizophrenia may be a separate subtype of schizophrenia with its own pathophysiology, which is linked with higher levels of maladaptive behaviors (Lysaker and Whitney 2009). In an early retrospective study, Fenton and McGlashan (1986) found OCS in schizophrenia to be associated with poorer social and global functioning as well as less employment. Additionally, the study demonstrated that persistent OCS in schizophrenia predicted poorer prognosis. These findings have been replicated in participants with chronic schizophrenia (Berman et al. 1995; Poyurovsky et al. 2001).

In order to further examine the effects of OCS in individuals with schizophrenia, Lysaker et al. (2006) examined participants’ coping mechanism and hope. The study used the Y-BOCS to assess severity of OCS, the PANSS to assess severity of positive and negative symptoms, the Ways of Coping Questionnaire to assess coping preference (Folkman and Lazarus 1988), and the Beck Hopelessness Scale (Beck et al. 1974) to assess hope. Lysaker and colleagues found that participants with greater levels of OCS were more likely to engage in an avoidance coping skills, have less hope for their future, and give up. Further, the participants with both negative symptoms and OCS had greater pessimistic views about their future and greater avoidance coping strategies than the participants with similar levels of negative symptoms but no OCS.

Regarding the issues of suicide, Sevincok et al. (2007) found inpatient and outpatient participants with comorbid OCD and schizophrenia (N = 24) had more suicide attempts and ideations than those without comorbid OCD (N = 33). Additionally, results showed that those with comorbid OCD and schizophrenia had a greater number of previous suicidal attempts and ideations. In participants with severe OCS as measured by the Y-BOCS, a positive correlation with suicide attempts was found. Hagen et al. (2013) found higher rates of suicidal ideations and attempts in participants with comorbid OCD and first-episode psychosis. Likewise, DeVylder et al. (2012) also found social impairments and more suicidal ideations in psychosis-risk participants with OCS than those without OCS. On the contrary, when comparing schizophrenia patients with and without OCS/OCD, Hosseini et al. (2012) found no association between OCS/OCD and suicidal ideations. Hosseini et al. (2012) also used the Y-BOCS and PANSS to assess severity of OCS and symptoms of schizophrenia. They used the Beck Scale for Suicide Ideation (Beck and Steer 1991).

Additional studies have continued to consistently find a relationship between lower levels of psychosocial functioning and OCS in schizophrenia. Considering life satisfaction, Huppert and Smith (2005) investigated the association between self-reported OCS using the Obsessive-Compulsive Inventory (Foa et al. 1998) and quality of life using the Lehman Quality of Life Interview (Lehman 1988). Results demonstrated that lower levels of OCS were related to greater quality of life. In addition, Tiryaki and Ozkorumak (2010) examined the quality of life of 62 schizophrenia patients with and without OCS. The study utilized the Scale for the Assessment of Negative Symptoms, Scale for the Assessment of Positive Symptoms, Y-BOCS, and the Quality of Life Scale (QOLS; Heinrichs et al. 1984). Tiryaki and Ozkorumak (2010) found that schizophrenia patients with OCS had lower quality of life scores compared to schizophrenia patients without OCS. Additionally, DeVylder et al. (2012) found lower levels of subjective quality of life in first-episode schizophrenia participants with OCS compared to those without OCS. Further, Zink et al. (2014) found patients with at-risk mental states for psychosis and OCS had higher levels of psychosocial impairments.