Autoimmune processes have been documented in both childhood and adulthood patients with obsessive-compulsive disorder (OCD), with the pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) representing the paradigm of this model.

Given the limited information available, the present study aimed at assessing the characteristics of adult patients with OCD exposed to a previous group A β-hemolytic Streptococcus infection, together with some peripheral inflammatory biomarkers.

Fifty-two subjects displaying antistreptolysin O (ASO) titer positivity were recruited from a sample of 247 adult OCD outpatients, diagnosed according to DSM-5 criteria and assessed by the Yale-Brown Obsessive-Compulsive Scale. Their clinical features were assessed and compared. The possible relationships between the different parameters were also examined.

Thirty-six subjects who were on medication for OCD showed significantly lower ASO titers than the other. The neutrophil count was positively and negatively related to, respectively, the “distress associated with obsessive thoughts” item and to the patients’ age. The lymphocyte count and folic acid levels were higher in 30 subjects with no perinatal insults.

These results seem to suggest that OCD subjects with ASO titer-positivity show a chronic inflammatory state, in spite of no symptoms or recall of bacterial infections, that might be involved in both the onset and the maintenance of OCD, with immunological alterations being related to symptom dimension to be identified. They also support the notion of possible anti-inflammatory effects of some psychotropic compounds.

Recently, some observational studies suggested that romantic love (RL) might influence the phenotypic expression of obsessive-compulsive disorder (OCD). The aim of the present study was to investigate the impact of different stages of RL on the clinical expression of OCD.

Two hundred and twelve patients with OCD onset related to the development or the termination of a romantic relationship (RR) and who were attending outpatient units at the University Psychiatric Clinic of Pisa, Italy, and seven specialized OCD clinics in Brazil were recruited. The assessment instruments were: the Structured Clinical Interview for DSM-5 Disorders (SCID-5), the Yale OCD Natural History Questionnaire, and the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Participants were divided into two groups (love-precipitated [LP-OCD] and break-up OCD [BU-OCD]).

The total Y-BOCS and obsessions and compulsions subscales scores were similar and indicative of severe OCD in the two groups. The average age of onset was significantly lower in the BU-OCD group, perhaps reflecting a vulnerability of the brain’s maturational stages to “undesirable” events in young individuals at risk for OCD. A trend towards aggression and symmetry, and ordering and rearrangement dimensions in BU-OCD patients emerged, possibly reflecting an amplification of some normal features of a RR.

Our findings suggest that different stages of RL may influence some features of OCD, namely the age of onset and specific dimensions. Again, RL poses the risk of developing this pathological condition in vulnerable individuals. Further research on the topic should be encouraged.

Blood platelets, due to shared biochemical and functional properties with presynaptic serotonergic neurons, constituted, over the years, an attractive peripheral biomarker of neuronal activity. Therefore, the literature strongly focused on the investigation of eventual structural and functional platelet abnormalities in neuropsychiatric disorders, particularly in depressive disorder. Given their impact in biological psychiatry, the goal of the present paper was to review and critically analyze studies exploring platelet activity, functionality, and morpho-structure in subjects with depressive disorder.

According to the PRISMA guidelines, we performed a systematic review through the PubMed database up to March 2020 with the search terms: (1) platelets in depression [Title/Abstract]”; (2) “(platelets[Title]) AND depressive disorder[Title/Abstract]”; (3) “(Platelet[Title]) AND major depressive disorder[Title]”; (4) (platelets[Title]) AND depressed[Title]”; (5) (platelets[Title]) AND depressive episode[Title]”; (6) (platelets[Title]) AND major depression[Title]”; (7) platelet activation in depression[All fields]”; and (8) platelet reactivity in depression[All fields].”

After a detailed screening analysis and the application of specific selection criteria, we included in our review a total of 106 for qualitative synthesis. The studies were classified into various subparagraphs according to platelet characteristics analyzed: serotonergic system (5-HT2A receptors, SERT activity, and 5-HT content), adrenergic system, MAO activity, biomarkers of activation, responsivity, morphological changes, and other molecular pathways.

Despite the large amount of the literature examined, nonunivocal and, occasionally, conflicting results emerged. However, the findings on structural and metabolic alterations, modifications in the expression of specific proteins, changes in the aggregability, or in the responsivity to different pro-activating stimuli, may be suggestive of potential platelet dysfunctions in depressed subjects, which would result in a kind of hyperreactive state. This condition could potentially lead to an increased cardiovascular risk. In line with this hypothesis, we speculated that antidepressant treatments would seem to reduce this hyperreactivity while representing a potential tool for reducing cardiovascular risk in depressed patients and, maybe, in other neuropsychiatric conditions. However, the problem of the specificity of platelet biomarkers is still at issue and would deserve to be deepened in future studies.