Corpus callosum agenesis (CCA) is a rare congenital disorder in which there is a partial or complete absence of the corpus callosum. Within the framework of an anatomoclinical approach to schizophrenia, a few studies have focused on its association with neurological disorders, including CCA.

In this perspective, we report a rare case of an adolescent with intellectual disability, with whose complete CCA was revealed by a recent-onset schizophrenia.

A case report and literature review.

The teenager M.A. is from a first degree consanguineous marriage. He had no family history, no special habits and no history of seizures. Since early childhood, he had had a psychomotor acquisition delay and relationship difficulties that tended to worsen later. At school, he was teased by his peers and failed 4 times in different rows. At the age of 15, he dropped out of school. Verbal and physical aggressiveness, soliloquy, unmotivated laughter and vague ideas of persecution suddenly appeared, hence his psychiatric consultation one month later. Neuropsychological tests indicated current low Intelligence Quotient (60). Brain imaging revealed complete ACC (see Figure 1). He was diagnosed with schizophrenia and put on antipsychotic treatment at adequate doses and durations, with poor therapeutic response.

Our observation provides additional support for neurodevelopmental models of schizophrenia, and confirms literature data indicating that severe structural brain abnormalities would lead to early onset psychotic symptoms which are often refractory to pharmacological treatments

There is a clear need for effective interventions to reduce cannabis use in patients with first-episode psychosis. This follow-up of a randomized trial examined whether an intervention for parents, based on motivational interviewing and interaction skills (Family Motivational Intervention, FMI), was more effective than routine family support (RFS) in reducing cannabis use in patients with recent-onset schizophrenia.

In a single-blind trial with 75 patients in treatment for recent-onset schizophrenia, 97 parents were randomly assigned to either FMI or RFS. Assessments were conducted at baseline and at 3 and 15 months after the interventions had been ended. Analyses were performed on an intention-to-treat basis using mixed-effect regression models.

From baseline to the 15-month follow-up, there was a significantly greater reduction in FMI compared to RFS in patients’ quantity (p = 0.01) and frequency (p < 0.01) of cannabis use. Patients’ craving for cannabis use was also significantly lower in FMI at 15 months follow-up (p < 0.01). Both groups improved in parental distress and sense of burden; however, only FMI parents’ appraisal of patients’ symptoms showed further improvement at the 15-month follow-up (p < 0.05).

The results support the sustained effectiveness of FMI in reducing cannabis use in patients with recent-onset schizophrenia at 15 months follow-up. Findings were not consistent with regard to the long-term superiority of FMI over RFS in reducing parents’ distress and sense of burden.