If you have OCD, you probably know that you are at a greater risk for developing other forms of mental illness. One of the most common mental illnesses to occur with OCD is major depressive disorder. Importantly, the presence of depression can often have a negative impact on the treatment of OCD symptoms.
What Is Major Depressive Disorder?
Before discussing the link between OCD and depression, let's take a moment to review the symptoms of the depression. Major depressive disorder is more than having the blues or feeling sad. To be diagnosed with major depressive disorder, you have to experience a sad or depressed mood or lose interest in things that used to be enjoyable for most of the day, nearly every day for at least two weeks.
In addition, you have to experience four of the following symptoms most of the day, nearly every day during this same two week period:
- Eating too much or too little
- Sleeping too much or too little
- Feeling either slowed down or excessively fidgety (usually so bad that it is noticed by others)
- Low energy
- Feelings of worthlessness or inappropriate guilt
- Problems thinking or concentrating
- Recurrent thoughts of death or suicide
Importantly, these symptoms are usually severe enough to cause problems at work or at home.
OCD and Depression
On average, about two thirds of people with OCD will experience an episode of major depression in their lifetime. In the majority of cases, depression occurs after the onset of OCD symptoms. This suggests that depression may often result from the on-going distress caused by the problems at work and at home that are often associated with symptoms of OCD.
However, it is also important to keep in mind that the close association between OCD and depression may also be related to shared biological and psychological factors. For example, both OCD and depression appear to involve alterations in the function of the serotonin system. Likewise, both OCD and depression seem to involve changes in brain regions related to processing of emotional experiences. As well, similar patterns of thinking that focus attention on negative aspects of a person’s experience may also be present in both illnesses.
There is also some evidence that symptoms of depression may be more likely to appear in response to disturbing obsessions than compulsions.
Being aware of and addressing depression when you have OCD is very important as it has been shown that the symptoms of depression – especially when severe – can interfere with psychological treatments for OCD including exposure and response prevention therapy. However, when the therapist is aware that depression is present, psychotherapy can be tailored so that both symptoms of depression and OCD are addressed. In severe cases, the therapist may have to treat the depression before addressing your OCD symptoms.
Depression doesn't seem to have the same impact on the effectiveness of medications used to treat OCD such selective serotonin reuptake inhibitors (SSRIs). This may be because SSRIs are also used as antidepressants.
If you are experiencing symptoms of depression be sure to tell your treatment provider. Effective treatments are available but are of little use unless your treatment provider is aware that you are experiencing these symptoms.
Abramowitz, J.S., “Treatment of obsessive-compulsive disorder in patients who have comorbid depression” Journal of Clinical Psychology 2004 60: 1133-1141.
Overbeek, T., Schruers, K., Vermetten, E., Griez, E. “Comorbidity of obsessive-compulsive disorder and depression: Prevalence, symptom severity, and treatment effect.” Journal of Clinical Psychiatry, 2002 63: 1106-1112.