The Link Between OCD and Schizophrenia

If being diagnosed with obsessive-compulsive disorder (OCD) isn’t challenging enough, imagine how it would feel to be faced with a separate mental disorder that affects your very ability to think, feel, or behave rationally.

Schizophrenia is a serious mental disorder, and it's estimated that as many as 25% of people with schizophrenia also experience obsessive-compulsive symptoms (OCS). About 12% fulfill the diagnostic criteria for obsessive-compulsive disorder. Schizophrenia and OCD are entirely independent of each other, both in their cause and symptoms, but share characteristics that place some individuals at higher risk of both.

Understanding Schizophrenia

Schizophrenia is a chronic disorder characterized by abnormal social behavior and difficulty grasping what is real and what is not. A person diagnosed with schizophrenia may experience an array of symptoms including hallucinations, delusions, and disorganized thinking and speech.

There are many different types of schizophrenia, some of which may be experienced with extreme paranoid and other with an unresponsive (catatonic) state. People with schizophrenia often have great difficulty in establishing and maintaining relationships as they struggle with distortions of reality and are less able to connect thought cohesively.

Less than one percent of the world population is diagnosed with schizophrenia. It is a major cause of disability in the U.S. with 85% of those affected unable to maintain employment. Suicide rates are high among people with schizophrenia, about 12 times greater than that of the general population.

OCD and Schizophrenia Causes

While the causes for the association remain unclear, OCD and schizophrenia do share a number of key similarities. Both disorders tend to manifest with symptoms around the end of adolescence.

Interestingly, people who have been diagnosed with both conditions commonly report OCD symptoms as their first sign of mental illness with symptoms usually appearing in the early teens.

The disorders are also associated with imbalances in serotonin and dopamine, the nerve-transmitting chemicals that regulates everything from your emotional state to memory and sleep. They also share links to a specific genetic mutation (known as SLC1A1) which predisposes some individuals to these illnesses, and is more likely to co-occur in individuals with high levels of consanguinity.

On the flip side, the use of certain atypical antipsychotic drugs has been known to cause OCD symptoms in some people with schizophrenia. Antipsychotics, which are typically used to treat schizophrenia, can also be used to treat OCD in cases that are otherwise unresponsive to the usual medication treatments.

Comparing Delusions and Obsessions

Scientists have long studied the relationship between OCD and schizophrenia, as a great many of their symptoms overlap. Doctors can often differentiate the disorders by the delusions seen in schizophrenia and the obsessions seen in OCD.

• Delusions are defined as false thoughts that are held to be true despite evidence to the contrary. Often times, the affected person will feel that they possess special powers, is being persecuted, or has an extraordinary connection to events, people, or objects that don’t exist. Moreover, persons experiencing a delusion will usually not recognize the irrationality of their thoughts.
• Obsessions, by contrast, are similar in that they are also irrational but are more related to concepts of uncleanliness, disorder, or asymmetry. And, unlike schizophrenic delusions, persons experiencing an obsession are usually aware of their irrationality and are simply unable to control it.

While this is not always the case, of course, it does provide a framework by which psychiatrists can individually identify and treat the two co-existing conditions.