This study aims to investigate whether specific non-coding RNAs, molecules involved in the regulation of gene expression, are altered in individuals with psychiatric disorders such as schizophrenia, bipolar disorder, major depressive disorder, panic disorder, and obsessive-compulsive disorder. Researchers will compare the expression levels of these molecules in patients who are drug-naïve or have been free from psychiatric treatment for at least six months with those observed in healthy volunteers.

The study will also evaluate whether the expression of these non-coding RNAs changes after approximately five months of standard psychiatric treatment. Blood samples collected during routine clinical care will be used to measure the expression levels of selected non-coding RNAs using reverse transcription quantitative polymerase chain reaction (RT-qPCR), a laboratory technique used to assess gene expression.

This is an observational study and does not assign specific treatments. All therapies will be prescribed according to standard clinical practice.

The main objective is to determine whether alterations in non-coding RNA expression may serve as biological markers of psychiatric disorders and whether these markers may help monitor treatment-related changes over time. The findings may contribute to a better understanding of the biological mechanisms underlying major psychiatric disorders and support the future development of more accurate diagnostic and therapeutic approaches.

This is a multicenter, prospective, observational case-control study designed to evaluate the expression of selected non-coding RNAs in psychiatric disorders. The study will include adult drug-naïve or drug-free patients diagnosed with Bipolar Disorder type I or II, Panic Disorder, Major Depressive Disorder, Obsessive-Compulsive Disorder or Schizophrenia, as well as healthy volunteers recruited from transfusion services.

Patients will be assessed at baseline (T0) and again after at least five months of pharmacological treatment (T1). Healthy controls will be assessed at baseline only. No treatments will be assigned for the purposes of the study. All pharmacological therapies will be prescribed according to routine clinical practice.

Peripheral blood serum samples will be collected from patients and healthy controls. For patients, residual peripheral venous blood collected during routine laboratory investigations will be used for study purposes. Serum samples will be centrifuged, stored at -80 °C, and subsequently transferred on dry ice to the Cellular and Molecular Biology Laboratories of the University of Messina.

Total RNA will be extracted from serum samples and reverse-transcribed into cDNA. Expression levels of selected miRNAs and lncRNAs will be analyzed using RT-qPCR. Relative expression levels will be quantified using the 2^-ΔΔCt method.

The study aims to identify possible ncRNA expression abnormalities in major psychiatric disorders, evaluate treatment-related changes over time, and explore the potential role of ncRNAs as biomarkers for diagnosis and treatment monitoring.

Inclusion Criteria (patients):

• Age between 18 and 55 years;
• Male sex or female sex in the mid-luteal phase of the menstrual cycle;
• Clinical presentation consistent with diagnostic criteria for:
• Bipolar Disorder type I or II,
• Panic Disorder,
• Major Depressive Disorder,
• Obsessive-Compulsive Disorder,
• Schizophrenia;
• First diagnosis and drug-naive status, or absence of psychopharmacological treatment for at least 6 months prior to enrollment.

Inclusion Criteria (Healthy Control):

• Age between 18 and 55 years;
• Male sex or female sex in the mid-luteal phase of the menstrual cycle;
• No treatment with psychotropic medications;
• Absence of clinical elements supporting a diagnosis of Bipolar Disorder, Panic Disorder, Major Depressive Disorder, Obsessive-Compulsive Disorder, Schizophrenia;
• Absence of clinical or laboratory evidence of infectious or internal medicine diseases;
• Absence of autoimmune diseases;
• HAM-D score < 8;
• MRS score < 11;
• Y-BOCS score < 7;
• BPRS score = 18;
• No significant stressful life events during the previous 6 months.

Exclusion Criteria (patients):

• Current immunosuppressive, antibiotic, or hormone replacement therapy;
• Relevant medical comorbidities, including autoimmune or internal medicine disorders;
• Active infectious diseases or infections resolved less than 3 weeks before enrollment;
• Relevant psychiatric comorbidities;
• Current psychopharmacological treatment or discontinuation of psychopharmacological therapy less than 6 months before enrollment.

The study population will consist of adult psychiatric inpatients and day-hospital/day-service patients recruited from the Psychiatry Units of the University Hospitals of Catania, Messina, Palermo, and the Psychiatry Unit of Umberto I Hospital in Enna. Eligible participants will include drug-naive or drug-free subjects diagnosed with Bipolar Disorder type I or II, Major Depressive Disorder, Panic Disorder, Obsessive-Compulsive Disorder, or Schizophrenia. Healthy controls will consist of volunteer blood donors recruited from the transfusion services of the participating university hospitals.

Individual participant data (IPD) will not be shared.