Freud (1895/1966; 1900/1953; 1915/1957) has proposed that primary process functioning is typical for acute psychosis. A nonverbal method, the 'Geocat' (Brakel, Kleinsorge, Snodgrass, & Shevrin, 2000), measures primary processes operationalized as attributional categorization, which considers exemplars as similar if particular features match, even if these components are arranged in a quite different configuration. With the use of GeoCat we explored primary process mentation in 127 psychiatric patients. Results show that (1) there are substantially higher levels of attributional choices in our sample of psychiatric patients, independently of diagnosis, than in a non-patient population; (2) psychotic patients tend to have more attributional choices than non-psychotic patient; patients with acute psychotic symptoms show more attributional re-sponses than patients without acute psychotic symptoms; (3) this increase of attributional choices with the psychotic condition is independent of self-rated anxiety or medication intake. We propose that, instead, this increase of attributional levels in the acutely psychotic patients reflects a predominance of primary processing which is specifically tied to the acutely psychotic condition, as proposed by Freud. © 2012 American Psychological Association.