MC, a 21-year-old university law student, came to a first appointment at a private psychiatric outpatient clinic referred by her psychologist who followed her for a clinical picture of borderline personality disorder. She reported having difficulties in maintaining concentration during classes as her attention was diverted by frequent experiences of "voices of other people making negative comments about me", compatible with auditory verbal hallucinations (AVH). Although AVHs first presented when MC was 16 years, they were not continuous, and their intensity was higher during periods of greater anxiety. Nonetheless, MC had good insight to these phenomena, recognizing "they sound real, but I know they are a product of my head". In addition, MC referred sometimes to having thoughts that "other people are saying bad things about me", especially when those people do not give her the attention, she considers necessary, perceiving their attitude as they are abandoning her when she most needs. This in turn leads to feelings of rage and depression as well as anger outbursts that often result in loss of friendships or the end of relationships. MC describes that when relationships come to an end, she is "filled with overwhelming emotional pain" which only has some relief when she performs self-harm behaviors like doing small cuts on her arms. She recognized placing high expectations in relationships and becoming enamored of people very quickly and very intensely as a way of dealing with her low self-esteem and chronic feelings of emptiness that have been present for as long as she could remember.
Psychiatric assessment concluded that the patient met the DSM-5 criteria for BPD. Differential diagnosis included major depressive disorder with mixed features, bipolar disorder, and schizophrenia spectrum disorders. The first two diagnostic hypothesis were ruled out as the pattern of interpersonal problems that MC described was longstanding and the mood symptoms were triggered by interpersonal conflicts. Schizophrenia and related disorders were excluded since, beyond AVHs, other symptoms necessary to meet diagnostic criteria were not present and AVHs were not present continuously or reached a duration threshold for diagnosis. Moreover, use of psychoactive substances was denied by the patient and therefore a diagnosis of substance-induced psychosis as an explanation for the occurrence of AVHs was excluded. Diagnostic hypothesis of a comorbid psychotic disorder due to a medical condition was excluded since symptoms or signs of systemic disease were absent.
At the time of presentation, MC was not under any pharmacological treatment. Ongoing treatment included individual third generation cognitive-behavioral psychotherapy (dialectical behavioral therapy) started 1 year before. The patient acknowledged having acquired more adequate coping strategies to deal with periods of intense negative emotional states, reporting that self-harm behaviors now occurred very rarely. However, she described still having significant emotional fluctuation and no improvement in what was concerned with the frequency or impact of AVHs. Treatment with cariprazine 3 mg once every day was prescribed. A month later, MC reported an important reduction in the occurrence of AVHs, allowing her to concentrate better during university classes. In addition, she described having less moodiness and no anger outbursts. This meant a reduction of the CGI-S global severity from a score of 5 (Markedly ill) before starting cariprazine to a score of 3 (Mildly ill) after 4 weeks of treatment (Table 1). Cariprazine was well tolerated as MC denied any adverse effect.