Study register · detailQuerschnittsstudie · Psychosis Risk · 2010
Symptomatology and neuropsychological functioning in cannabis using subjects at ultra-high risk for developing psychosis and healthy controls.
Korver et al.·Australian & New Zealand Journal of Psychiatry
HarmGRADELow53 citations
Samplen = 121 Pat.
ControlNon-using UHR patients and healthy non-users
EndpointUHR symptomatology and…
Blindingn.a.
DesignQuerschnittsstudie
Routeinhalativ
”Key finding
Cannabis use is associated with more subclinical psychosis symptoms and neuropsychological functional impairments, also in healthy control persons.
Summary
n=63 UHR patients (34 cannabis users) + n=58 controls (28 cannabis users), cross-sectional; cannabis-using UHR patients had more basic symptoms than non-using UHR patients; healthy cannabis users achieved verbal memory and fluency performance at UHR level; frequency of cannabis use correlated with severity of several UHR symptoms. Cross-sectional design limits causal conclusions.
P
PopulationPersons with Ultra-High-Risk (UHR) for psychosis and healthy control persons aged 12–35 years; n=121 (63 UHR patients, of whom 34 cannabis users; 58 control persons, of whom 28 cannabis users)
I
InterventionCannabis use (≥4 joints/week in the control group; self-report in the UHR group)
C
ControlNon-using UHR patients and healthy non-users
O
OutcomeCannabis-using UHR patients showed more basic symptoms than non-using UHR patients; healthy cannabis users showed more subclinical UHR/basic symptoms as well as poorer verbal memory and word fluency performance (at UHR group level); frequency of cannabis use correlated with the severity of several UHR symptoms
Confidence in the evidence
Very lowLowModerateHigh
Low
The second of four GRADE levels, the effect estimate is of limited reliability.
Quality profile
Sample size★★★★★
Blinding—
Effect sizeHarm
Citations / year★★★★★
Authors
Korver N, Nieman DH, Becker HE, van de Fliert JR, Dingemans PH, de Haan L, Spiering M, Schmitz N, Linszen DH.
<h4>Objective</h4>The relationship between cannabis use and psychosis has been studied intensively. Few data, however, are available on the relationship between cannabis use, ultra-high risk for developing psychosis and neurocognition. The aim of the present cross-sectional study was therefore to investigate the relationship between cannabis use, ultra-high-risk (UHR) symptoms and cognitive functioning in UHR patients and healthy controls.<h4>Methods</h4>A total of 63 ultra-high-risk patients (34 cannabis users) and 58 control subjects (28 cannabis users) were assessed with clinical measures and a neuropsychological test battery. Patients were eligible for the study if they were between the ages of 12 and 35 years and if they fell into one or more of the following inclusion groups: familial risk and reduced functioning, attenuated psychotic symptoms, brief limited intermittent psychotic symptoms and basic symptoms. Control subjects were eligible for the study if they were between the ages 12 and 35, had no present or past psychiatric illness, no family history of psychiatric illness, no drug use in the non-cannabis-using group, and use of at least four joints per week in the cannabis-using control group.<h4>Results</h4>In the UHR and the control group, cannabis users experienced more basic symptoms and UHR symptoms than the non-cannabis users. Moreover, cannabis users in the control group performed at the level of the UHR subjects on a test of verbal memory and verbal fluency. Frequency of cannabis use correlated with severity of several UHR symptoms.<h4>Conclusions</h4>Cannabis-using UHR patients have more basic symptoms than non-using patients. In addition, healthy cannabis users have more subclinical UHR and basic symptoms and more neuropsychological dysfunctions than non-cannabis users. More frequent cannabis use was related to increased severity of certain UHR symptoms.