Lower levels of whole blood serotonin in obsessive-compulsive disorder and in schizophrenia with obsessive-compulsive symptoms

Neurobiological outcomes of cognitive behavioral therapy for obsessive-compulsive disorder: A systematic review

INTRODUCTION

Obsessive-compulsive disorder (OCD) is characterized by recurrent distressing thoughts and repetitive behaviors, or mental rituals performed to reduce anxiety. Recent neurobiological techniques have been particularly convincing in suggesting that cortico-striatal-thalamic-cortico (CSTC) circuits, including orbitofrontal cortex (OFC) and striatum regions (caudate nucleus and putamen), are responsible for mediation of OCD symptoms. However, it is still unclear how these regions are affected by OCD treatments in adult patients. To address this yet open question, we conducted a systematic review of all studies examining neurobiological changes before and after first-line psychological OCD treatment, i.e., cognitive-behavioral therapy (CBT).

METHODS

Studies were included if they were conducted in adults with OCD and they assessed the neurobiological effects of CBT before and after treatment. Two databases were searched: PsycINFO and PubMed for the time frame up to May 2022.

RESULTS

We obtained 26 pre-post CBT treatment studies performed using different neurobiological techniques, namely functional magnetic resonance imaging (fMRI), Positron emission tomography (PET), regional cerebral blood flow (rCBF), 5-HT concentration, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), Electroencephalography (EEG). Neurobiological data show the following after CBT intervention: (i) reduced activations in OFC across fMRI, EEG, and rCBF; (ii) decreased activity in striatum regions across fMRI, rCBF, PET, and MRI; (iii) increased activations in cerebellum (CER) across fMRI and MRI; (iv) enhanced neurochemical concentrations in MRS studies in OFC, anterior cingulate cortex (ACC) and striatum regions. Most of these neurobiological changes are also accompanied by an improvement in symptom severity as assessed by a reduction in the Y-BOCS scores.

CONCLUSION

Cognitive-behavioral therapy seems to be able to restructure, modify, and transform the neurobiological component of OCD, in addition to the clinical symptoms. Nevertheless, further studies are necessary to frame the OCD spectrum in a dimensional way.

Obsessive-compulsive symptoms in patients with schizophrenia: Relationships with olanzapine pharmacological parameters, psychopathology, and quality of life

Obsessive-compulsive symptoms (OCS) occur in a substantial portion of schizophrenia patients and have significant impacts on clinical course. This study was intended to investigate the relationships of OCS with pharmacological parameters of olanzapine, psychopathology, and quality of life. Totally 151 schizophrenia patients were recruited, and rated using Yale-Brown Obsessive-Compulsive scale (YBOCS), Positive and Negative Syndrome Scale (PANSS), Montgomery-Åsberg Depression Rating Scale (MADRS), and World Health Organization Questionnaire on Quality of Life: Short Form (WHOQOL-BREF). The concentrations of olanzapine and N-desmethylolanzapine were determined by HPLC. Twenty-five patients (16.6%) revealed the presence of OCS. OCS group had significantly higher olanzapine dose, more numbers of past hospitalizations, higher PANSS total, positive, negative, and general psychopathology scores, and higher MADRS score than those in non-OCS group. The WHOQOL-BREF physical subscale score in schizophrenia patients with OCS was significantly lower. Olanzapine dose, PANSS score, and MADRS score were significantly correlated with YBOCS score. Our findings highlight that OCS is highly prevalent in schizophrenia patients under olanzapine treatment, especially those at high doses. Schizophrenia patients with OCS had higher severity of psychotic and depressive symptoms and poorer quality of life. Clinicians should monitor OCS in patients with schizophrenia receiving olanzapine treatment.

Interleukin-3, symptoms and cognitive deficits in first-episode drug-naïve and chronic medicated schizophrenia

Previous studies consistently showed that IL-3 signaling may be involved in the pathophysiology of schizophrenia. However, investigations of associations between IL-3 and the neurocognitive impairments are lacking, including the study of how this may vary with stage of illness. We recruited 45 first-episode drug-naïve (FE-Sz), 35 chronic medicated schizophrenia (Ch-Sz) and 40 healthy controls (HC) and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and serum IL-3. Altered serum IL-3 levels were found in both patient groups compared with HC group (both p < 0.001). There were significantly lower neurocognitive scores on the RBANS and nearly all of its five subscales, except for Visuospatial/Constructional index in both FE-Sz and Ch-Sz patients vs healthy controls. Moreover, a significant reduction in Immediate memory index (p = 0.021) and a trend-level reduction in RBANS total score (p = 0.094) in Ch-Sz than FE-Sz patients. Interestingly, there was a significant negative correlation between IL-3 and the Immediate memory index only in Ch-Sz patients (p = 0.03). Our findings showed that neurocognitive impairments present in schizophrenia emerge during the first episode with further diminished functioning with disease progression, and IL-3 may be involved in the immediate memory deficits in the chronic phase of schizophrenia.

Schizo-obsessive spectrum disorders: an update

The presence of obsessive-compulsive symptoms (OCS) and obsessive-compulsive disorders (OCD) in schizophrenia is frequent, and a new clinical entity has been proposed for those who show the dual diagnosis: the schizo-obsessive disorder. This review scrutinizes the literature across the main academic databases, and provides an update on different aspects of schizo-obsessive spectrum disorders, which include schizophrenia, schizotypal personality disorder (SPD) with OCD, OCD with poor insight, schizophrenia with OCS, and schizophrenia with OCD (schizo-obsessive disorder). An epidemiological discussion on the discrepancies observed in the prevalence of OCS and OCD in schizophrenia across time is provided, followed by an overview of the main clinical and phenomenological features of the disorder in comparison to the primary conditions under a spectral perspective. An updated and comparative analysis of the main genetic, neurobiological, neurocognitive, and pharmacological treatment aspects for the schizo-obsessive spectrum is provided, and a discussion on endophenotypic markers is introduced in order to better understand its substrate. There is sufficient evidence in the literature to demonstrate the clinical relevance of the schizo-obsessive spectrum, although little is known about the neurobiology, genetics, and neurocognitive aspects of these groups. The pharmacological treatment of these patients is still challenging, and efforts to search for possible specific endophenotypic markers would open new avenues in the knowledge of schizo-obsessive spectrum.

Integrin β3 Haploinsufficiency Modulates Serotonin Transport and Antidepressant-Sensitive Behavior in Mice

Converging lines of evidence have identified genetic interactions between the serotonin transporter (SERT) gene and ITGB3, which encodes the β3 subunit that forms the αIIbβ3 and αvβ3 integrin receptor complexes. Here we examine the consequences of haploinsufficiency in the mouse integrin β3 subunit gene (Itgb3) on SERT function and selective 5-hydroxytryptamine (5-HT) reuptake inhibitor (SSRI) effectiveness in vivo. Biochemical fractionation studies and immunofluorescent staining of murine brain slices reveal that αvβ3 receptors and SERTs are enriched in presynaptic membranes from several brain regions and that αvβ3 colocalizes with a subpopulation of SERT-containing synapses in raphe nuclei. Notably, we establish that loss of a single allele of Itgb3 in murine neurons is sufficient to decrease 5-HT uptake by SERT in midbrain synaptosomes. Pharmacological assays to elucidate the αvβ3-mediated mechanism of reduced SERT function indicate that decreased integrin β3 subunit expression scales down the population size of active SERT molecules and, as a consequence, lowers the effective dose of SSRIs. These data are consistent with the existence of a subpopulation of SERTs that are tightly modulated by integrin αvβ3 and significantly contribute to global SERT function at 5-HT synapses in the midbrain. Importantly, our screen of a normal human population for single nucleotide polymorphisms in human ITGB3 identified a variant associated with reductions in integrin β3 expression levels that parallel our mouse findings. Thus, polymorphisms in human ITGB3 may contribute to the differential responsiveness of select patients to SSRIs.

Associations of obsessive-compulsive symptoms with clinical and neurocognitive features in schizophrenia according to stage of illness

This study aimed to investigate the association of obsessive-compulsive symptoms with clinical and neurocognitive features in patients with schizophrenia. This study enrolled 163 people with schizophrenia who were receiving risperidone monotherapy. Comorbid obsessive-compulsive symptoms were assessed using the Yale-Brown Obsessive-Compulsive Scale, and subjects with a score ≥ 10 constituted the obsessive-compulsive symptom group (n=30, 18.4%). The learning index was significantly higher in patients with obsessive-compulsive symptoms than in those without such symptoms after adjusting for age, stage (early and chronic), duration of illness, and CDSS score. However, there was no significant interaction between obsessive-compulsive symptoms and stage of illness. Scores on Positive and Negative Syndrome Scale, Calgary Depression Scale for Schizophrenia, and Beck Depression Inventory were significantly higher in the obsessive-compulsive symptom group. In addition, the Subjective Well-being under Neuroleptic Treatment score was significantly lower in the obsessive-compulsive symptom group. In conclusion, comorbid obsessive-compulsive symptoms in patients with schizophrenia were associated with a higher learning ability without a significant interaction with stage of illness. However, schizophrenia patients with obsessive-compulsive symptoms had more severe psychotic and depressive symptoms and poorer quality of life.

Second generation antipsychotic-induced obsessive-compulsive symptoms in schizophrenia: a review of the experimental literature

Second generation antipsychotics (SGAs) have been implicated in the de novo emergence and exacerbation of obsessive-compulsive symptoms (OCS) in patients with schizophrenia. Among SGAs, clozapine, olanzapine, and risperidone are the most prominent agents associated with these sequelae, according to case reports. Comorbid OCS can impede recovery by compromising treatment benefits, medication compliance, and clinical prognoses. Previous reviews of SGA-induced OCS have predominantly focused on descriptive case reports, with limited attention paid toward experimental findings. To address this paucity of data, we sought to review the effects of SGAs on OCS in schizophrenia in the experimental literature, while addressing the role of different treatment (duration, dose, serum levels) and pharmacogenetic factors. Our findings suggest that clozapine confers the greatest risk of OCS in schizophrenia, with 20 to 28% of clozapine-treated patients experiencing de novo OCS, in addition to 10 to 18% incurring an exacerbation of pre-existing OCS. Clozapine can also yield full threshold obsessive-compulsive disorder (OCD), in some cases. Olanzapine is another high risk drug for secondary OCS which occurs in 11 to 20% of schizophrenic patients receiving olanzapine therapy. At this time, there is insufficient experimental evidence to characterize the effects of other SGAs on OCS. Despite some experimental support for the involvement of longer treatment duration and genetic factors in mediating drug-induced OCS, more research is needed to clearly elucidate these associations. Based on these results, schizophrenic patients should be routinely monitored for OCS throughout the course of SGA treatment, particularly when clozapine or olanzapine is administered.

Anxiety comorbidity in schizophrenia

Diagnostic and treatment hierarchical reductionisms have led to an oversight of anxiety syndromes in schizophrenia. Nevertheless, recent data have indicated that anxiety can be a significant source of morbidity in this patient group. This paper reviews current knowledge concerning anxiety comorbidity in schizophrenia, its epidemiology, course, and treatment. A computerized search of the literature published from 1966 to July 2012 was conducted on Medline. Comorbid anxiety disorders are present in 38.3% of subjects with schizophrenia spectrum disorders. The most common anxiety disorder is social phobia followed by post-traumatic stress disorder and obsessive compulsive disorder. The presence and severity of symptoms of anxiety are associated with more severe clinical features and poorer outcomes. Available literature on the treatment consists primarily of case reports and open trials. Fragments of data support the notion of treating these anxiety states and syndromes as co-occurring clinical conditions with adjunctive medications and psychosocial interventions. However, additional work remains to be done on this issue before firm conclusions can be drawn.

Interleukin 18 and cognitive impairment in first episode and drug naïve schizophrenia versus healthy controls

Alterations in the inflammatory and immune systems have been documented to occur from the earliest stages of schizophrenia, and have been associated with neurodevelopmental changes. Cognitive impairment is a core feature in the pathology of schizophrenia, and recent studies showed a significant increase in serum IL-18 in schizophrenia, and a putative role of IL-18 in neuroprogression and thus neurocognitive defects. The purpose of this study was to examine the association of IL-18 with cognitive deficits in schizophrenia. We recruited 77 first episode and drug naïve schizophrenic patients and 75 healthy control subjects and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and serum IL-18 in both groups. Schizophrenic symptoms were assessed using the positive and negative syndrome scale (PANSS). We found that IL-18 levels were non-significantly higher in patients than controls (206.0±92.9 pg/ml vs 193.2±41.8 pg/ml, p=0.28). Cognitive scores on the RBANS and nearly all of its five subscales (all p<0.05) except for the Visuospatial/Constructional index (p>0.05) were significantly lower in schizophrenic patients than normal controls. For the patients, IL-18 was positively associated with the Visuospatial/Constructional domain of cognitive deficits in schizophrenia. Our findings suggest that cognitive deficits occur during the acute stage of a schizophrenic episode, and IL-18 may be involved in Visuospatial/Constructional deficits of these patients.

Does clozapine cause or worsen obsessive compulsive symptoms? An analysis and literature review

BACKGROUND

Clozapine is the most effective antipsychotic in treatment-resistant schizophrenia but its use portends with a high burden of adverse reactions. One adverse event reported both in case reports and cross-sectional surveys is the emergence or worsening of obsessive compulsive symptoms (OCS).

OBJECTIVES

This study presents a retrospective review of a UK cohort of clozapine-treated individuals with the aim to further investigate the complex relationship between clozapine and OCS.

METHODS

An extensive review of the medical records of 49 patients receiving clozapine in the Southampton area was undertaken. We searched for a diagnosis of obsessive compulsive disorder, signs or symptoms of obsessive compulsive disorder or the prescribing of selected antidepressants the year before clozapine initiation and the year after.

RESULTS

Fifteen patients (31%) had reports of OCS during the 2-year data collection period. Twelve patients (24%) had OCS before clozapine initiation while only 7 (14%) had symptoms after clozapine was initiated. De novo OCS were reported in three (6%) cases after 5-9 months of clozapine treatment.

CONCLUSIONS

As with previous studies it was not possible to establish a definitive link between clozapine and OCS. Clinicians should be mindful of the common comorbidity of OCS and schizophrenia and the possible increased risk incurred when starting clozapine.

Effects of genetic group selection against mortality on behavior and peripheral serotonin in domestic laying hens with trimmed and intact beaks

Severe feather pecking is a maladaptive behavior in laying hens that may result in cannibalism and ultimately death of the victims. Selection methods in which the genetic effect of an animal on the survival of its group members is taken into account, i.e. 'group selection', have been shown to be very effective in reducing mortality due to feather pecking and cannibalism in laying hens. It has been suggested that fearfulness and serotonergic functioning are involved in the causation and development of feather pecking. We investigated effects of selection based on survivability in non-beak trimmed groups on fear-related behavior and peripheral 5-HT concentration and uptake in hens with trimmed or intact beaks, in a 2 x 2 factorial arrangement. Hens from the second generation of the low mortality line showed less fear-related behavior than control line hens. In addition, they displayed higher whole blood 5-HT concentrations and a lower platelet 5-HT uptake, indicating differences in functional activity of the 5-HT system. Beak trimming resulted in lowered levels of fear, and in a reduction of feather damage. Hens with trimmed and intact beaks did, however, not differ in peripheral 5-HT. The results imply that fearfulness and 5-HT activity are related to feather pecking without distinguishing between cause and effect. However, given that selection altered fear-related behaviors and peripheral 5-HT concentration and uptake, whereas beak trimming affected fearfulness and feather damage, but not 5-HT parameters, we suggest that peripheral 5-HT activity might reflect the predisposition to develop severe feather pecking under adverse conditions in laying hens.

Obsessive-compulsive disorder in UK clozapine-treated schizophrenia and schizoaffective disorder: a cause for clinical concern

The association between schizophrenia and obsessive-compulsive disorder (OCD) is complex. This study systematically examined a UK cohort of clozapine-treated individuals with schizophrenia/schizoaffective disorder. Fourteen of 59 cases (24%) scored positively on item H of the Mini-International Neuropsychiatric Interview (MINI) for OCD. The mean Yale- Brown Obsessive-Compulsive Scale (Y-BOCS) score in MINI-positive cases was 17.6 (SD+/-6.3). Sixty-four percent scored 16 or more on the Y-BOCS, representing clinically meaningful illness severity. Seven (50%) patients with OCD had previously received the diagnosis by their treating clinicians and were already receiving with selective serotonin re-uptake inhibitors (SSRIs) treatment. OCD cases scored significantly worse than their non-OCD counterparts on the Abnormal Involuntary Movement Scale (P=0.01) and the Simpson Angus Scale (SAS; P=0.01). There was also a non-significant trend toward higher ratings for OCD cases on the Clinical Global Impression-Schizophrenia scale (P=0.06). Comparing the OCD cases taking SSRI (n=7) with those not on SSRI (n=7), significant differences emerged on the SAS (P=0.03). Our results suggest that OCD is common among patients receiving clozapine for schizophrenic disorders and that the comorbidity is associated with greater motoric impairment. The role of medication in this condition remains unclear.