OCD and Depression: Are They Related

Obsessive-Compulsive Disorder and Major Depressive Disorder are both common, and left untreated, potentially debilitating mental illnesses. While Obsessive-Compulsive Disorder (OCD) is widely categorized as an anxiety disorder, depression is a mood disorder. However, due to their biochemistry and most popular treatment recommendations, OCD and depression do share some relation to each other.

Difference Between Obsessions and Compulsions

Obsessive-compulsive disorder (OCD) presents primarily as patterns of unwanted and intrusive thoughts or fears that lead someone to perform repetitive or frequent behaviors. The thoughts and fears are considered the “obsessions” part of the namesake, and the repetitive behaviors are the “compulsions”. These obsessions and compulsions have the ability to interfere with daily activities and cause significant distress. Examples of common obsessions include:

  • Becoming ill or dying
  • Disturbing sexual thoughts, urges, images
  • Doubts about having done something right or forgetting things
  • Germs or contamination
  • Harming or having harmed someone
  • Anticipating something bad happening


Following experiencing the obsessions, compulsive behaviors can emerge. Examples of common compulsions can include:

  • Counting
  • Excessive checking that tasks were completed
  • Doing something over until it’s “right”
  • Excessive washing or cleaning
  • Repeatedly putting things in a certain order
  • Replicating routine behaviors
  • Seeking reassurance from others.


Breaking the OCD Cycle

Prior to seeking treatment, people often try to ignore or stop these obsessions or thoughts, but in a clinical case of OCD, ignoring them only increases distress and anxiety. As a result, there is often an overwhelming urge to perform the subsequent compulsive acts in an attempt to ease the distress. Despite efforts to ignore or get rid of bothersome thoughts or urges, they keep coming back. This leads to more ritualistic behaviors, which is ultimately the vicious cycle of OCD.



Major Depressive Disorder (MDD), on the other hand, is a common mood disorder that presents as any combination of the following symptoms that are present for at least a two week period of time:

  • Persistent sadness, anxiousness, “emptiness”, hopelessness, or pessimism
  • Irritability
  • Feelings of guilt, worthlessness, or helplessness
  • Loss of interest or pleasure in hobbies and activities
  • Decreased energy or fatigue
  • Moving or talking more slowly
  • Feeling restless or having trouble sitting still
  • Difficulty concentrating, remembering, or making decisions
  • Difficulty sleeping, early-morning awakening, or oversleeping
  • Appetite and/or weight changes
  • Thoughts of death or suicide, or suicide attempts
  • Aches or pains, headaches, cramps, or digestive problems


MDD can exist in one episode or as multiple episodes, lasting for periods of time up to months in length. There are a variety of other mood disorders that include varying degrees of depression as a symptom, such as Dysthymia or Postpartum Depression. The main difference between OCD and depression is that OCD is rooted in anxiety, and Major Depressive Disorder is a mood disorder. Although mood and anxiety are not the same, we know there is a link between the two conditions.


How Are OCD and Depression Connected? 

It’s believed that up to two-thirds of people diagnosed with OCD will experience a depressive episode throughout the course of their mental illness. Up to 40% will also be diagnosed with Major Depressive Disorder, according to some studies. It is important to recognize how distressing intrusive and unwanted thoughts or obsessions are. Depression has been found to be mostly related to the obsessions rather than the compulsive behaviors. Compulsions tend to bring immediate relief to anxiety, which is why they are performed, but overall perpetuate the cycle of OCD. Other potential triggers for a depressive episode include stress and biochemical changes that can alter moods and behavior. Depression can also be especially serious in people with OCD because the presence of a depressive episode can negatively impact their ability to treat their OCD symptoms.


A similar chemical imbalance that can cause OCD, also impacts depression. OCD and depression are both impacted by activity of serotonin, a neurotransmitter that impacts processes such as mood, memory, and digestion. Since they are both characterized by disruptions of serotonin, a common medication that targets it can help both OCD and Major Depressive Disorder. Selective Serotonin Reuptake Inhibitors (more commonly known as SSRIs) are a common form of medication treatment for both OCD and depression. In addition, other non-medication related therapies, such as Cognitive-Behavioral Therapy and TMS therapy, can be highly effective in the treatment of both conditions.


While their initial symptom presentation may not be similar, the presence of OCD puts someone at higher risk of having a depressive episode or a diagnosis of Major Depressive Disorder. Each mental illness can cause significant distress in someone’s life. Untreated, they can negatively impact personal relationships, work, and family dynamics. Luckily, treatments such as SSRIs, talk therapy and TMS therapy can be helpful for both OCD and depression. These are often covered by insurance companies and accessible as referrals from your primary care provider. Taking the time and energy to heal from either or both OCD and depression are an investment, but absolutely worth the effort.


Works Cited

Kelly, O. (2020, September 22). How Depression Complicates the Treatment of OCD. Retrieved November 12, 2020, from https://www.verywellmind.com/ocd-and-depression-2510591

Mayo Clinic. (2020, March 11). Obsessive-compulsive disorder (OCD) – Symptoms and causes. Retrieved November 12, 2020, from https://www.mayoclinic.org/diseases-conditions/obsessive-compulsive-disorder/symptoms-causes/syc-20354432

National Institute of Mental Health. (n.d.-e). NIMH » Depression. Retrieved November 11, 2020, from https://www.nimh.nih.gov/health/topics/depression/index.shtml

Rivier University. (2019, November 13). OCD and Depression. Retrieved November 12, 2020, from https://www.rivier.edu/academics/blog-posts/ocd-and-depression/

Salters-Pedneault, K. (2020, June 19). What Serotonin Is and How It Regulates Body Functions. Retrieved November 12, 2020, from https://www.verywellmind.com/what-is-serotonin-425327



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