Background

The comorbidity of attention deficit hyperactivity disorder (ADHD) and schizophrenia poses a considerable diagnostic challenge due to significant symptom overlap, and represents a highly debilitating condition for the patient. This case report aims to present the history of a 19-year-old patient suffering from these two diagnostic entities, and thereby seeks to elucidate diagnostic and therapeutic approaches for this condition.

Methods

The Diagnostic and Statistical Manual of Mental Disorders (fourth edition) criteria for ADHD and schizophrenia were used to establish clinical diagnoses. Furthermore, an in-depth clinical interview with the patient’s mother was carried out. Finally, a clinical interview was conducted with the patient and the Wender Utah Rating Scale was applied to assess ADHD symptoms retrospectively.

Results

Outcomes of the mentioned diagnostic approaches confirmed the diagnosis of ADHD in the patient suffering from schizophrenia. As amphetamines would be contraindicated in the described patient, atomoxetine, a drug approved for the treatment of ADHD due to its efficacy as a selective norepinephrine reuptake inhibitor, was chosen. Following a 6-week interval after treatment initiation, a clinical re-evaluation was carried out, which showed an improvement of symptoms according to the International Classification of Diseases (tenth revision) criteria.

Conclusion

The present case report indicates that atomoxetine may be effective in treating symptoms of ADHD in patients with schizophrenia, without increasing psychotic symptoms. Results are discussed in terms of diagnostic and therapeutic implications.