Identifying schizophrenia in people with OCD

Among patients with obsessive-compulsive disorder (OCD), a few also have schizophrenia. But how can you tell if a person is suffering only from OCD or if he also has schizophrenia? This question is not as trivial as it sounds. Many of the symptoms of OCD are also found in people with both disorders (schizo-OCD), yet sufferers of these conditions require different treatments.

As the name suggests, people with OCD are riddled with obsessions (thoughts, images or impulses they can’t get rid of) and compulsions (the necessity to perform specific, repetitive actions). Schizophrenics usually have delusions and hallucinations. However, many people with schizophrenia also have OCD and perform the same ritualistic actions that OCD sufferers do. Luckily, according to a study by David Eilam and his colleagues from Tel Aviv University, there are differences that can be used to distinguish OCD from schizo-OCD.

Take a look at the video below. It compares the behavior of an OCD patient (left) and a schizo-OCD patient (right) preparing to leave their apartments. While they each feel compelled to perform many ritualistic actions before they can exit, there’s much more traveling around by the schizo-OCD patient.

The locations of the black circles show where an action took place, and the size of the circle indicates how many times an action was repeated at that spot. The OCD patient stands in the same place repeating the same action (like checking for his keys) up to ten times. Once he’s satisfied, his path to the front door is direct. In contrast, the person who also has schizophrenia travels all around his apartment, switching lights on and off, checking possessions, etc. An observer would have no idea that his ultimate goal was to exit the apartment.

Doctors might be able to use these differences in behavior to distinguish OCD patients from schizo-OCD patients. This is important because patients with schizophrenia require different and often more intense treatment than OCD patients.

Gershoni A, Hermesh H, Fineberg NA, & Eilam D (2013). Spatial behavior reflects the mental disorder in OCD patients with and without comorbid schizophrenia. CNS spectrums, 1-14 PMID: 23845600.