PurposeIn addition to neurological symptoms glioblastoma (GBM) patients can experience psychiatric complaints, which are often hard to recognize and difficult to treat. Research on psychiatric symptoms during glioblastoma treatment is limited, but can have significant impact on quality of life, treatment processes and even survival. The aim of this study is to explore the incidence of clinically relevant psychiatric symptoms, during glioblastoma treatment and active surveillance.MethodsMedical records of 302 GBM patients were reviewed from diagnostic surgery until discontinuation of treatment or active surveillance. Clinical relevance was defined as psychiatric symptoms that interfered with the oncological treatment and required referral to a psychiatrist. “Referred” versus “non-referred” GBM patients were compared using the Pearson Chi-Square test, Fisher’s Exact Test or Mann Whitney-U test.ResultsPsychiatric symptoms occurred in 11.5% of patients during glioblastoma treatment or active surveillance, most often mood or behavioral symptoms, followed by psychotic symptoms. Referral occurred mainly during concomitant chemoradiation or adjuvant chemotherapy (64.3%). In 28.6% of patients psychiatric symptoms were thought to be attributive to medication. Treatment was discontinued in 17.9% of patients and temporarily interrupted in 3.6%. Possible risk factors included male gender, history of psychiatric disorder, postoperative delirium, non-frontal tumor location, anti-epileptic drug use at baseline and corticosteroid initiation during treatment.ConclusionThe found incidence of 11.5% and the high number of patients discontinuing treatment due to psychiatric symptoms justify more research in this, to date, understudied topic in scientific literature. Further prospective studies are needed to identify risk factors and unravel possible effects on survival.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11060-023-04326-2.