Epilepsy is a neuropsychiatric disease [1]. One in three people with epilepsy will suffer from a psychiatric disorder (depression, anxiety, psychotic disorder) during their lifetime, linked to biological and psychosocial factors. The risk is two to five times higher than in the general population [2]. Psychotic disorders are characterized by symptoms belonging to one or more of the following five categories: delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms that progress with preserved consciousness (DSM-5) [3]. The relationship between epilepsy and psychotic disorders is complex. An epileptic seizure may be the direct cause of a psychotic disorder; psychotic disorders may be a comorbidity of epilepsy; epileptic seizures and psychotic disorders may be symptoms of the same genetic condition. Moreover, the relationship between epilepsy and psychotic disorders is bidirectional: the existence of psychosis increases the risk of subsequent development of epilepsy, and the existence of epilepsy increases the risk of psychotic disorders [4]. However, epileptic psychoses are not recognized as an entity in the DSM-5, where they are classified under the heading “Psychotic disorder due to another medical condition”, specifying “epilepsy” with the mental disorder coding. The lack of individualization of epileptic psychoses in international classifications complicates the management of disorders situated on the borderline between neurology and psychiatry. For example, they are poorly understood by French neurologists and psychiatrists [5]. Epilepsy encompasses a wide range of heterogeneous syndromes, all of which have in common the spontaneous recurrence of epileptic seizures [6]. The psychotic disorders observed in epilepsy are logically classified according to their chronology of onset in relation to the seizures in four main frameworks [7]: (i) ictal psychoses, in which psychotic symptoms are the expression of the epileptic discharge itself; (ii) post-ictal psychoses, in which psychotic symptoms follow the seizures after a free interval during which the patient returns to normal functioning; (iii) interictal psychoses, where psychotic symptoms are related to the existence of epilepsy (still active or in remission) but without any chronological relationship with the seizures; (iv) psychoses related to complete seizure control (concept of forced normalization). Psychoses related to the use of antiepileptic drugs transcend classification, and can be observed in any of the above 4 settings. The existence of epilepsy modifies symptom semiology, complicating clinical diagnosis and the use of DSM-5 criteria [8]. Moreover, certain clinical syndromes are only observed in epilepsy [8]. The assessment and management of psychiatric disorders in epilepsy requires specific training for psychiatrists and psychologists, in close interaction with epileptologists. The acronym EPI-PSY has been proposed in France to define the scope of this interaction and formalize neuropsychiatric collaboration in the management of epilepsy [9]. To date, there is no satisfactory neurobiological model explaining the relationship between epilepsy and psychosis (or, to keep it simple, between epileptic seizures and psychotic symptoms), but recent data show that a common neurobiological substrate is highly probable. The practical approach is based on expert consensus, owing to the lack of controlled trials. An algorithm for diagnostic orientation and management is shown in Fig. 1 [10].