The Link Between OCD and Major Depressive Disorder

Challenges in Managing the Dual Diagnosis of OCD and Depression

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People with obsessive-compulsive disorder (OCD) are at a greater risk of developing other forms of mental illness. One of the most common is major depressive disorder (MDD).

In fact, research suggests that as many as two-thirds of people living with OCD will experience a major depressive episode sometime during the course of their illness. The causes can be varied, ranging from reactive stress to obsessive or compulsive behaviors to biochemical changes in the brain that can alter moods and behavior.

Depression can be especially serious in people with OCD as it can affect their ability to adhere to the treatment of their OCD symptoms.

Understanding Major Depressive Disorder

Major depressive disorder is about more than just feeling sad. To be diagnosed with MDD, you need to experience a depressed mood and lose interest in things that used to be enjoyable to you for at least 2 weeks. In addition, four of the following symptoms must be present nearly every day during the same 2-week period:

  • Difficulty thinking or concentrating
  • Eating too much or too little
  • Feeling either slowed down or noticeably fidgety
  • Feelings of worthlessness or inappropriate guilt
  • Low energy
  • Recurrent thoughts of death or suicide
  • Sleeping too much or too little

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 988 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.

For more mental health resources, see our National Helpline Database.

Typically speaking, these symptoms will be severe enough to cause trouble at home or work.

Link Between OCD and Depression

Depression in people with OCD most often occurs after the onset of OCD symptoms; the inverse is not true. What this suggests is that depression may be related to the personal stress of living with OCD or troubles that have developed at home or work as the result of the disease. However, secure attachment seems to be protective against depression.

Scientists also believe there may be biochemical factors that contribute to depression. We know, for example, that OCD and MDD are both characterized by changes in the production and activity of serotonin, a chemical that relays signals between nerve cells.

With these biochemical changes can come associative behavioral ones, some of which are shared in people with OCD and MDD. As such, OCD may perpetuate MDD simply by enhancing an underlying biochemical imbalance.

Most evidence also suggests that symptoms of depression are more actively linked to disturbing obsessions (negative thoughts you can't get rid of) rather than compulsions (repetitive behaviors you can't control).

Managing a Dual Diagnosis

On their own, OCD and MDD require specific care and treatment delivered over the long term. When they both occur together, they may complication therapy.

But this is really only the tip of the problem. By its very nature, major depression tends to affect a person's ability to maintain adherence to drug therapy, not only those related to OCD but any chronic medication that requires daily drug-taking.

Oftentimes, feelings of persistent hopelessness can lead people to ask "what's the point?" If this happens, the person will usually be less interested in taking their drugs, grooming, eating properly, or interacting with others.

This can be seriously problematic for those undergoing OCD treatment. Insofar as many psychotropic drugs require high levels of adherence to achieve the desired effect, any gap in treatment can take back the gains a person may have made. To mitigate this concern, the therapist will often need to treat the depression first before addressing the OCD.

On the other hand, the use of selective serotonin reuptake inhibitors (SSRIs), commonly used to treat depression, is also known to be effective in managing many of the symptoms of OCD.

In the end, if you have been diagnosed with OCD and believe you have depression, do not wait for the feelings of sadness to pass. Speak with your doctor or mental health provider. Treatment plans can be adjusted to meet your needs and prevent the worsening of symptoms.

2 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Tibi L, Van oppen P, Van balkom AJLM, et al. The long-term association of OCD and depression and its moderators: A four-year follow up study in a large clinical sample. Eur Psychiatry. 2017;44:76-82. doi:10.1016/j.eurpsy.2017.03.009

  2. Pallanti S, Grassi G, Sarrecchia ED, Cantisani A, Pellegrini M. Obsessive-compulsive disorder comorbidity: clinical assessment and therapeutic implications. Front Psychiatry. 2011;2:70. doi:10.3389/fpsyt.2011.00070

Additional Reading

By Owen Kelly, PhD
Owen Kelly, PhD, is a clinical psychologist, professor, and author in Ontario, ON, who specializes in anxiety and mood disorders.