Schizophrenia or attention deficit hyperactivity disorder: drug abuse as a cause of wrong diagnosis

Introduction It is common to find patients with overlapping attention deficit hyperactivity disorder (ADHD) and substance abuse disorder, specially alcohol, cannabis and cocaine. The anxiety, impulsivity and even psychosis derived from consumption often induce wrong diagnosis of patients, due to the camouflage of the basic psychopathology of ADHD. Objectives Analyze a clinical case in order to point out the difficulty of diagnosis existent in ADHD patients with substance abuse disorder comorbidity. Aims To gain insight in the psychopathology of ADHD patients, to make the right discernment and to improve the quality of their lives. Methods Thirty-four-year-old man, ex-drug user of cannabis and cocaine, diagnosed with paranoid schizophrenia several years ago on an outpatient basis. Currently in prison, with regular follow-up by psichiatry in the last year. The toxic withdrawal, the collection of medical history and the successive consultations finally orientated the diagnosis to ADHD-combined subtype, receiving treatment with atomoxetine instead of antipsychotics. After few months of observation, we confirmed an excellent general clinical response and a better adaptation to the prison environment. Results Psychoticism disappeared with drug abstinence. Antipsychotics were interrupted due to the absence of psychopathology of schizophrenia. Free of psychotropic drugs, ADHD symptoms became apparent. Conclusions Due to ADHD comorbidity, it is important to pay attention to the profile to make the right discrimination between different entities for therapeutic and prognosis implications.