An interventional study of (R)-3-hydroxybutyl (R)-3-hydroxybutyrate) and Maltodextrin, Fructose, Pectin, Sodium alginate, Sodium chloride in Schizophrenia and Related Disorders, Psychosis and Bipolar and Related Disorders, sponsored by Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA). Completed at 1 site in Netherlands. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-04-27.
Sponsored by Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA) · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to learn if a ketone drink can improve signs and symptoms of patients with a schizophrenia-spectrum disorder (SSD), or a bipolar-spectrum disorder (BD).
The main questions it aims to answer are:
Does a ketone drink improve information processing in patients with SSD/BD?
Other questions it aims to answer are:
Does a ketone drink improve cognitive functioning in patients with SSD/BD? Does a ketone drink improve metabolism and inflammation in patients with SSD/BD? Does a ketone drink affect circadian rhythm in patients with SSD/BD?
Research will compare the effects of the ketone drink with that of an isocaloric carbohydrate drink in the same patients ('cross-over').
Participants will:
drink a ketone drink and (after a wash-out period) an isocaloric control drink (randomized order); after each drink:
for 5 consecutive days:
3,563 studies on the registry are indexed under Schizophrenia; 491 are open to participants now.
This study's enrollment of 28 is below the median of 71 across 2,944 interventional studies indexed under Schizophrenia.
Browse Schizophrenia studies →Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA) is the lead sponsor of 532 studies on the registry; 183 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
1x50 g dGK ketone drink
Dietary Supplement: (R)-3-hydroxybutyl (R)-3-hydroxybutyrate)
1x isocaloric carbohydrate control drink
Other: Maltodextrin, Fructose, Pectin, Sodium alginate, Sodium chloride
1x50g ingestion of pure dGK
Also known as: delta G Ketones (dGK)
Isocaloric carbohydrate control (active control)
Also known as: Maurten Drink Mix 160
Prepulse Inhibition (PPI) - change dGK vs isocaloric control
PPI: an event-related potential (ERP) representing information processing (known to be disrupted in schizophrenia and bipolar disorder). The PPI task is an auditory paradigm featuring a total of 10 trials split evenly into two conditions: prepulse (PP) and non-prepulse (NP) in blocks. Startle pulses are 100dB at 40 ms, which is shown to provide significant startle visible in EEG126. Prepulse stimuli are 70 dB and 50 ms in duration, presented 50ms prior to the startle pulse. There is a 12 to 18 (avg: 15 s) interstimulus interval. All stimuli are white-noise blips. A calibrated apparatus is used to present the stimuli. Total estimated time is 20 min.
Time frame: measured 45 minutes (Tmax) after ingestion of intervention 1 (dGK) and 45 minuts after ingestion of intervention 2 (isocaloric carb control)
P300 Event Related Potential (change dGK vs isocaloric control)
The P300 task consists of 160 stimuli in the oddball paradigm and requires the subjects to press a button on detection of the rare target (32/160). The common nontarget stimuli are 500 Hz, 100 ms duration. The rare target stimuli are 700 Hz. Both are 100 ms duration at 80 dB with variable interstimulus interval of 1.2 to 1.5 s. Preceded by 10 practice trials. This task has minimal burden and requires about 10 minutes.
Time frame: measured 65-75 minutes after ingestion of intervention 1 (dGK) and 75 minutes after ingestion of intervention 2 (isocaloric carb control); NB: directly after PPI.
Cognitive test: 15 Word Test (15WT) - change dGK vs isocaloric control
15WT is a measure of verbal/episodic memory. The 15WT consists of 15 words, which have to be learned during three trials. After every trial the respondent is asked to recall as many words as possible. After a distraction period of 20 minutes, the respondent is asked to name the words they have learned before, again. Immediate recall after 1 test: maximum 15 words (minimum 0) Immediate recall after 3 test: maximum 45 words (minimum 0). Retention score after 20 minutes: 1. percentage of correctly remembered words in the delayed recall-trial, relative to the number of words correctly remembered in the third immediate recall-trial 2. percentage of correctly remembered words in the delayed recall-trial, relative to the maximum score in the immediate recall-trials Higher 15WT scores indicate better verbal/episodic memory, lower scores the opposite.
Time frame: measured 75-85 minutes after ingestion of intervention 1 (dGK) and 75 minutes after ingestion of intervention 2 (isocaloric carb control); NB: directly after P300.
Cognitive test: Trail Making Test A (TMT-A) - change dGK vs isocaloric control
TMT-A is a measure of (visual) attention. TMT-A outcome is the duration of time required to finalize test (including the time needed for the correction of errors prompted by the examiner), with a maximum of 5 minutes. The average TMT-A score in healthy adults is 29 seconds; a deficient score is greater than 78 seconds. Higher scores on TMT-A indicate worse (visual) attention.
Time frame: measured 75-85 minutes after ingestion of intervention 1 (dGK) and 75 minutes after ingestion of intervention 2 (isocaloric carb control); NB: directly after P300.
Cognitive test: Trail-Making Test B (TMT-B) - (change dGK vs isocaloric control)
TMT-B is a measure of (frontal) executive functioning. TMT-B outcome is the duration of time required to finalize test (including the time needed for the correction of errors prompted by the examiner), with a maximum of 5 minutes. Average TMT-B score is 75 seconds; a deficient score is greater than 273 seconds. Higher scores on TMT-B indicate worse (frontal) executive functioning.
Time frame: measured 75-85 minutes after ingestion of intervention 1 (dGK) and 75 minutes after ingestion of intervention 2 (isocaloric carb control); NB: directly after TMT-A.
Cognitive test: Digit Span Test (DST) (change dGK vs isocaloric control)
DST is a measure for working memory. DST outcome is the maximum number of sequential digits correctly reproduced. In average healthy adults, the digit span is around 7 +/- 2. Minimum score is 0, maximum score is 9. Lower DST score indicate worse working memory.
Time frame: measured 75-85 minutes after ingestion of intervention 1 (dGK) and 75 minutes after ingestion of intervention 2 (isocaloric carb control); NB: directly after TMT-B.
Patient experience outcome on Mood, energy level, focus (change dGK vs isocaloric control)
visual analog scale (VAS) is used with a scale of 0 to 10 to measure patient-experiences effects of the interventions on their mood (0=extremely depression, 10 = extremely happy/euforic), energy level (0=completely exhauster, 10= extremely energetic) and ability to focus (0=completely unable to focus, 10=perfect focus).
Time frame: measured circa 120 minutes after ingestion of intervention 1 (dGK) and circa 120 minutes after ingestion of intervention 2 (isocaloric carb control)
Immune function: blood markers (change dGK vs isocaloric control)
sequential blood sampling through intravenous line: concentration (pg/ml) of inflammatory biomarkers relevant for immune function: * IL-1b * IL-6 * IL-8 * IL-10 * TNF-a * IFN-g * hsCRP Comparison between dGK and isocaloric control at the same time points (see below).
Time frame: first blood sample before ingestion (dGK or isocaloric control) (T0), then every 20 minutes in first hour after ingestion; afterwards every 30 minutes (max. 3 hours)
Immune function: blood RNA markers (change dGK vs isocaloric control)
RNA expression analysis (immune panel nCounter, Nanostring) in whole blood: comparison dGK vs isocaloric control only at T0 plus 90 minutes.
Time frame: first blood sample before ingestion (dGK or isocaloric control) (T0), next at T0+90 minutes
Immune function: passive sweat IL-6 (change dGK vs isocaloric control)
continuous measurement of IL-6 (pg/ml) in passive sweat (EnLiSense device)
Time frame: Full 5 days of the study
Immune function: passive sweat TNF-a (change dGK vs isocaloric control)
continuous measurement of TNF-a (pg/ml)in passive sweat (EnLiSense device)
Time frame: Full 5 days of study
Metabolic function: Indirect Calorimetry (change dGK vs isocaloric control)
Resting energy expenditure (REE) is measured by gaseous exchange (indirect calorimetry). Oxygen consumption and CO2 production are measured during 20 minutes using a ventilated hood system (Q-NRG, Cosmed). Subjects lie flat on their backs and breathe into a canopy for 20 minutes. REE and Respiratory Quotient (RQ) are calculated with these measurements. The RQ represents the ratio of CO2 exhaled to the amount of 02 consumed by the individual and represents whole body substrate oxidation (glucose, fat and protein oxidation).
Time frame: circa 90-120 minutes after ingestion of intervention 1 (dGK) and intervention 2 (isocaloric control); directly after finalizing cognitive tests.
Metabolic function: blood biomarkers - change dGK vs isocaloric control
Sequential blood sampling through intravenous line, to determine the plasma and serum concentrations of: * Glucose * Ketones * acylcarnitine profile * growth hormone (GH) * superoxide dismutase (SOD) * gluthione S-transferase (GST) * soluble intercellular adhesion molecule 1 (sICAM1) Comparison between dGK and isocaloric control at the same time points (see below).
Time frame: first blood sample before ingestion (both dGK and isocaloric control) (T0), then every 20 minutes in first hour after ingestion; afterwards every 30 minutes (max. 3 hours)
Metabolic function: continuous glucose monitor (CGM) - change dGK vs isocaloric control
continuous glucose monitor (CGM; Abbott Libre Sense); continuous concentration in mM.
Time frame: Full 5 days of the study.
Circadian rhythm: passive sweat cortisol (change dGK vs isocaloric control)
continuous measurement of cortisol (pg/ml) in passive sweat (EnLiSense device)
Time frame: Full 5 days of study
Circadian rhythm: passive sweat melatonin (change dGK vs isocaloric control)
continuous measurement of melatonin (pg/ml) in passive sweat (EnLiSense device)
Time frame: Full 5 days of study
Ran from Dec 2024 to primary completion in Apr 2026, 16 months.
Of 753 non-industry interventional studies with no phase under Schizophrenia, half reached primary completion within 33 months of starting (the median), counting those still running; a quarter within 17 and three quarters within 56. This study's 16 months is below that.
Counting every sponsor, half of 766 studies reached it within 32 months; a quarter within 16 and three quarters within 56.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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