Treatment Response in Non-Affective Psychosis

Recruitment & Eligibility

Status: Pending

Sex: Not specified

Target Recruitment: 63

Inclusion Criteria

1) First or later episode of psychosis, provided that the patient has not used antipsychotics for at least one year and that lifetime use of antipsychotics does not exceed 6 months (Patients only).
2) A rating of at least 5, corresponding to moderate severe, on two or more items of the positive symptom subscale of the PANSS at the moment that the patient enters the mental health services (Patients only).
3) Age: 18-35 years.
4) Within the first 5 years after onset of the first psychotic episode (Patients only).

Exclusion Criteria

1) Antipsychotic use longer than 9 weeks at the moment of the PET scan (Patients only).
2) Current neurological disorder or history of neurological disorder (e.g. epilepsy) or history of severe head trauma (contusio cerebri).
3) Current psychotic disorder or history of any psychotic disorder (Controls only).
4) First-degree relative with schizophrenia spectrum disorder (Controls only).
5) Incompetence (Dutch: wilsonbekwaamheid) according to the responsible physician or researcher. Participants should be able to understand the purpose of the study (understanding what happens in the brain and the development of a tool to select the best medication for a particular individual), the associated benefit (none for them), burden (hours of time) and risk (minimal, but not zero).
6) Patients who resist or oppose antipsychotic medication (Patients only).
7) Primary diagnosis of bipolar disorder with psychotic features or major depressive disorder with psychotic features at the moment that the patient enters the mental health services (Patients only).
8) Psychotic disorder due to another medical condition or substance/medication-induced psychotic disorder (Patients only).

Exclusion criteria related to alcohol, soft/hard-drugs, and medicinal drugs:
1) Lifetime history of DSM-5 diagnosis of any Substance Use Disorder (SUD; except tobacco use disorder and alcohol use disorder, mild) or substance use which would have met the DSM-5 criteria for SUD.
2) Current use of substances other than tobacco or alcohol, such as XTC, cannabis, cocaine, amphetamine, opioids or GHB. A) Use of cocaine, amphetamine, GHB or opioids in the past is allowed, if last use occurred at least three months before the study and if the substance was used only once in the past year. B) Use of XTC in the past is allowed, if last use occurred at least three months before the study and if substance was used on no more than five occasions in the past year. C) Use of cannabis in the past is allowed, if last use occurred at least one month before the study and if there was no disorder in the use of cannabis in the past.
3) Positive urine drug screen at the baseline assessment. Participants will be tested on cannabis, amphetamine, XTC, cocaine, and opiates.
4) Positive urine drug screen at the test day (Controls only). Participants will be tested on cannabis, amphetamine, XTC, cocaine, and opiates.
5) Current or recent (less than 3 months ago) use of other psychotropic drugs that may influence the dopamine system (e.g. sodium valproate, lithium or methylphenidate). The use of benzodiazepines, hypnotics and antidepressants in amounts within the therapeutic range is allowed.

Exclusion criteria directly related to MRI and PET/CT scanning:
1) Smoking during the period of three hours prior to the PET/CT scan and eating or using caffeinated drinks during the period of six hours prior to the PET/CT-scan.
2) Participation in a scientific examination where radiation was used, in the last year.
3) In women: positive pregnancy test on the day of the MRI and/or PET/CT scans and lactation.
4) Metal objects in or around the body (e.g. pacemaker and ferromagnetic implants) or claustrophobia.

Study & Design

Study Type: Observational non invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
- [18F]-DOPA influx (Ki) values in the whole striatum and its associative, limbic, and sensorimotor subregions (assessed in subgroup).<br>- Glutamate/Creatine and Glx/Creatine ratios on 1H-MRS in the ACC.<br>- GABA concentration on 1H-MRS in the ACC.<br>- Degree of change of positive symptoms on the CGI-SCH at the first and second follow-up compared to the start of non-clozapine antipsychotic treatment.<br>- AEA and 2-AG plasma concentrations at the day of the MRI/PET scans.<br>

Secondary Outcome Measures

Name	Time	Method
- Percentage change in positive symptom score on the PANSS following 4-6 weeks of non-clozapine treatment at adequate dose (first follow-up) and 6 months after the start of antipsychotic medication (second follow-up).<br>- Percentage change of total PANSS score between the baseline assessment and the first and second follow-up.<br>- Neuromelanin contrast ratio on NM-MRI.