Psychosis and Cannabis: Rethink “Users Always Think Worse”

In 105 psychiatric inpatients with psychotic disorders, cannabis users had higher MoCA (Montreal Cognitive Assessment, a brief test of thinking skills) scores than non-users. The highest MoCA performance was reported among daily users. Cannabis use was also associated with being male, younger age, and earlier psychosis onset compared with non-use.

This was a cross-sectional observational study, meaning the team measured cannabis use and cognition at the same time without assigning or controlling exposure. Researchers recruited 105 inpatients with psychotic disorders from one hospital in Tirana and collected demographic and clinical information. Cognitive performance was measured with MoCA (a short screening test), and symptom severity was rated with BNSS (negative symptoms), CDSS (depression in schizophrenia), PSYRATS (psychotic symptom ratings), and TLC (thought and language disturbance). The biggest weakness is timing: because exposure and outcome were measured at once, the direction of the association between cannabis use and MoCA scores cannot be determined.

Cognition (thinking skills like memory and attention) is a core driver of disability in chronic psychotic disorders, and it is also one of the most debated areas in cannabis research. By 2026, many studies in the general population had linked cannabis exposure with worse cognitive performance, but psychosis samples often look different because illness severity, medication, and hospitalization can dominate test scores. This study directly targeted a common clinical contradiction: high cannabis use rates in psychosis alongside mixed findings on whether users test worse, the same, or sometimes better on cognitive screening tools.

A headline could read as if cannabis use is linked to better cognition in psychosis, but this study only shows an association in a single inpatient cohort, not an effect of cannabis on brain function. The same dataset also linked cannabis use to younger age, more males, and earlier psychosis onset, which means the user and non-user groups were not comparable at baseline, and those differences can track with cognitive test performance. This finding sits in tension with broader general-population research where heavier cannabis exposure is often linked to lower cognitive scores, so selection effects (who continues using and still functions well enough to complete testing), reverse causation (people with better cognition being more likely to use), or illness-subtype differences could explain the pattern. The abstract also mentions daily use as having the most favorable MoCA outcomes, but without THC to CBD ratios, dose, or timing of last use, readers cannot tell whether the signal reflects long-term traits, recent intoxication or withdrawal states, or unmeasured clinical factors.

Cannabis exposure was not quantified in the abstract with amounts, timing, or objective biomarkers, and THC or CBD content was not measured, even though the interpretation hinges on these details. The sample came from a single inpatient hospital in Tirana, which can differ sharply from community or outpatient psychosis populations in symptom severity and medication patterns. MoCA is a brief screen and may not capture specific cognitive domains that longer neuropsychological testing can detect.