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Dopamine and Insulin in Psychosis

ConditionFirst Episode Psychosis (FEP)
Trial statusNot yet recruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-40
SponsorMedical University of Vienna

About this trial

Patients with schizophrenia have a high risk of developing metabolic disorders and current evidence points to an overlap in mechanisms underlying psychiatric symptoms and metabolic disturbances. The main goal of this study is to investigate effects of brain insulin on dopamine signaling and energy metabolism in patients with schizophrenia experiencing their first psychotic episode (FEP). To this end, patients with schizophrenia and healthy volunteers will undergo two \[11C\]-(+)-PHNO positron emission (PET) scans to measure the changes in dopamine receptor availability after nasally applied insulin, as well as single proton magnetic resonance spectroscopy (1H-MRS) to assess the impact of intranasal insulin on levels of glucose and glutamate in the hippocampus.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

age 18-40

Body mass index (BMI) range 18-25

good general health according to physical examination and medical history

absence of relevant abnormalities in laboratory screening, electrocardiogram (ECG) or vital signs

Disqualifiers

severe or unstable medical or neurological illness or clinically significant abnormality on screening laboratory studies or ECG

established diagnosis of type 1 or type 2 diabetes

current substance use disorder or regular recreational drug abuse (except nicotine and caffeine)

pregnancy or breastfeeding

Trial design

Design model

Crossover

Treatments tested in this trial

  • Intranasal Insulin

    Drug

    160 IU intranasal insulin is administered using precision air pumps twice: 15 min prior to the PET scan and 35 min prior to the 1H-MRS scan

  • Placebo

    Drug

    Insulin-free dilution buffer is administered using precision air pumps 15 min prior to the PET scan

  • Low dose insulin infusion

    Drug

    2.5 mU/kg insulin in 100 ml isotonic saline is infused intravenously over 15min prior to PET scan when placebo is administered intranasally

  • Placebo infusion

    Drug

    100 ml saline is infused intravenously over 15min prior to PET scan when insulin is administered intranasally

  • [11C] (+)-4-propyl-(+)-4-propyl-9-hydroxynaphthoxazine (PHNO)

    Radiation

    Each participant undergoes a 90-min \[11C\]-(+)-PHNO scan twice

Treatment groups

46 Participants
are divided into 3 treatment groups
Group A: Schizophrenia groupExperimental treatment 5 interventions
Group B: Healthy volunteer groupExperimental treatment 5 interventions
Group C: Test-retest groupOther 1 intervention

Trial outcomes

Primary outcomes

1

[11C]-(+)-PHNO BPND values

Dopamine D2/3 receptor availability after intranasal insulin or placebo administration

Time frame
Assessed on two separate study visits within 5-12 days (scan duration: 90 min)
2

Hippocampal glucose and glutamate concentrations

Hippocampal glucose and glutamate concentrations before and after intranasal insulin administration

Time frame
Assessed during a single study visit (scan duration: 40 min in total)

Secondary outcomes

1

Changes in blood-based parameters of energy metabolism

Changes in concentrations of selected metabolic parameters (blood glucose, insulin, c-peptide, total cholesterol, HDL, LDL, trigycerides, ketone bodies) following intranasal insulin/placebo administration, assessed by venous blood sampling

Time frame
Assessed at baseline and at 15min intervals after instranasal insulin/placebo administration over a period of up to 90min
2

Hippocampal volumetric parameters

Whole hippocampus and hippocampal subfield volumes assessed with structural MRI

Time frame
Assessed during a single study visit, at baseline (scan duration: 10min)

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Medical University of Vienna

Lead sponsor

Source ClinicalTrials.gov

This trial is not recruiting at the moment. You can still explore other options: