Universität zu Köln

Zubair, Alina (2025). Vulnerability, Cognition and Resilience in Cannabis Consumers: A comparison across healthy and psychosis groups. PhD thesis, Universität zu Köln.

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Abstract

Cannabis is one of the most widely used drugs globally. The increasing consumption underscores the necessity of research into its effects and consequences.. Cannabis-induced psychosis (CIP) is one of the possible consequences of using cannabis and has received little research attention. The risk pathways and cognitive impairments in primary schizophrenia and psychosis are well established. Risk factors include environmental exposures such as childhood trauma, bullying, depression and lack of resilience. Cognitive impairment is the most common shared symptom in psychosis patients. Research into cognitive impairment in healthy Cannabis Consumers (CC) is mixed and partly contradictory. Some studies suggest that cannabis consumption has long-lasting negative effects on cognition, while others argue that these effects disappear after abstinence. The frequency and dose of cannabis also plays an important role in cognitive impairment. The role of risk factors and cognitive impairment in CIP remains mostly unclear. The purpose of this study was to compare cognitive impairment, resilience and the vulnerability factors of childhood trauma, bullying, depression, and an environmental risk score for psychosis between n = 49 Cannabis-induced psychosis (CIP) patients, n = 70 recent-onset psychosis (ROP) patients, n = 120 healthy controls (HC), and n = 25 healthy cannabis consumers (CC). Behavioural data was collected through standardised selfreporting questionnaires: the Resilience Scale for Adults (RSA), the Beck Depression Inventory II (BDI-II), the Childhood Trauma Questionnaire (CTQ), and the Bullying Scale (BS). Using the questionnaire manuals, subdomains and total scores were calculated. The exposome score for schizophrenia (EC-SCZ) calculates a sum score of weighted exposure factors and was calculated based on the factors cannabis use, winter birth, childhood trauma and bullying. Neurocognitive data was collected using the PRONIA neurocognitive test battery. The cognitive subdomains of Social Cognition, Speed of Processing, Working Memory, Verbal Learning, and Attention were calculated, as well as a global cognition score. Two-way ANOVAS with the factors cannabis and psychosis were used to compare the four study groups. Based off previous research in psychosis and cannabis, we expected CIP, ROP, and CC to show less resilience, more vulnerability factors and more cognitive impairment than HC. Results showed that cognitive impairment was only associated with the presence of psychosis (global cognition: F(1, 260) = 75.698, p < 0.001). This is in line with existing research about cognitive impairment in schizophrenia. Unlike most previous research, CC showed no cognitive impairment compared to HC, ROP or CIP. Interaction of cannabis and psychosis was associated with higher depression scores (F(1, 251) = 5.768, p = 0.017), higher emotional abuse scores (F(1, 245) = 7.151, p = 0.008) and a lack of social resources11 (F(1, 244) = 27.640, p < 0.001) as part of an overall lack of resilience (F(1, 228) = 4.133, p = 0.043). These interactions might point towards these vulnerability factors being more specific risk pathways for CIP, than just overall psychosis. Longitudinal data would be needed to further establish causal links between suggested risk pathways and CIP. This might help to establish prevention programs specifically for CIP.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Zubair, Alina zubair.alina@outlook.de UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-790511
Date:	2025
Language:	English
Faculty:	Faculty of Medicine
Divisions:	Faculty of Medicine > Psychiatrie und Psychotherapie > Klinik und Poliklinik für Psychiatrie und Psychotherapie
Subjects:	Psychology Medical sciences Medicine
Uncontrolled Keywords:	Keywords Language Cannabis induced psychosis English Psychosis English Cannabis English Cognition English Resilience English Vulnerability English
Date of oral exam:	12 September 2025
Referee:	Name Academic Title Kambeitz-Ilankovic, Lana Privatdozentin Dr Huys, Daniel Privatdozent Dr. med.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/79051