Clinical trial NCT01907568: Understanding Hallucinations (Part I)
Official title: Understanding Hallucinations (Part I) - Phenomenology and Cognition
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Hallucinations
No Hallucinations
Lead sponsor: UMC Utrecht
Sponsor class: OTHER
Collaborators: name: University Medical Center Groningen
name: Free University Medical Center
name: Parnassia Groep
First posted: 2013-07-25
Enrollment: 700
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: We aim to include subjects of each of the following diagnostic groups, both with and without psychotic symptoms:

1. patients with schizophrenia spectrum disorders
2. patients with borderline personality disorder (BPD)
3. patients with hearing impairment
4. patients with visual loss
5. patients with Parkinson's disease (PD)
6. patients with Alzheimer's disease (AD)
7. patients with Lewy Body dementia (DLB)
8. patients with post-traumatic stress disorder (PTSD)
9. patients with delirium
10. healthy individuals
11. patients with mood disorder

Brief summary: Psychotic symptoms (hallucinations and delusions) are present in several psychiatric and neurological disorders as well as in the general population. Effective treatment strategies for these symptoms in all patients are lacking and treatment-response can presently not be predicted. To date, the exact pathophysiological mechanism of these symptoms remains unknown. By investigating (subtypes) of hallucinations and delusions in all populations, a common pathway may be found, leading to more effective treatment options. Alternatively, different subtypes may be associated with different pathophysiological mechanisms.


Eligibility criteria: Inclusion Criteria:

* age \> 18 years
* mentally competent
* in case of delirium: family member able to give informed consent
* Individuals with hallucinations will have to experience at least one episode of hallucinations over the last month.
* Individuals without hallucinations: no current hallucinations and a history of maximum 1 episode of hallucinations with a maximum duration of 1 week, at least two years ago.

Exclusion Criteria:

* Age \<18)
* Participants that cannot read, speak or understand Dutch
* For all included diagnostic groups except delirium: Mentally incompetent individuals who are not capable to provide informed consent, as determined by their treating physician.

Primary outcomes:
measure: The number of clusters of patients with shared symptom profiles as determined by latent class analysis, and the difference in scores on cognitive assessment between these identified clusters.
timeFrame: Three years
Secondary outcomes:
measure: The internal consistency, test-retest reliability, inter-rater reliability, criterion validity and construct validity of a newly developed questionnaire.
timeFrame: Two years
measure: The difference in scores on cognitive assessment between participant groups with and without psychotic symptoms.
timeFrame: Three years
Other outcomes:
Locations:
city: Amsterdam
country: Netherlands
facility: VU Medical Center
city: Den Haag
country: Netherlands
facility: Parnassia Bavo Groep
city: Groningen
country: Netherlands
facility: UMC Groningen
city: Utrecht
country: Netherlands
facility: UMC Utrecht
Study officials:
affiliation: UMC Utrecht
name: Iris Sommer, Prof, MD, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: UMC Groningen
name: Teus van Laar, MD, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Amsterdam UMC, location VUmc
name: Philip Scheltens, Prof, MD, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Parnassia Groep
name: Karin Slotema, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: