OCD and Depression: Why OCD Is Often Misdiagnosed

Many people living with OCD spend years — sometimes decades — not receiving a diagnosis of OCD, despite seeing multiple providers. This post explains why that happens, what the research shows, and what an accurate diagnosis and effective treatment plan can look like.

Why OCD Gets Misdiagnosed as Depression

Diagnosing Obsessive-Compulsive Disorder (OCD) can take years before individuals receive an accurate diagnosis. The average delay in diagnosis is 6 to 10 years from the onset of symptoms (Torres et al., 2018). One reason for this delay is the complexity of OCD symptoms, which can vary widely in severity and presentation, making it challenging for clinicians to recognize. Additionally, many individuals with OCD may feel embarrassed about their symptoms, leading them to conceal their struggles.

The symptoms of OCD can present very differently across individuals, which can make it difficult to spot as a clinician.  When a patient presents primarily with symptoms of depression — common secondary effects of living with untreated OCD — clinicians may reasonably focus on depression without probing further for the obsessions and compulsions driving it or that exist alongside it.  OCD is essentially hidden in the shadow of the depression.

An Example

Mary recently sought us out for "treatment resistant depression" after decades of medication and psychotherapy failure. After a thorough assessment, Mary learned that she had OCD, which had gone unrecognized by dozens of providers. After receiving medications targeted to the OCD and ERP therapy, Mary has shown improvements in almost every domain of her life, including her depression.

Mary's case is not unusual. Patients who have seen multiple providers without sustained improvement are worth re-evaluating from the ground up. A diagnosis anchored early in treatment can persist long past its usefulness — particularly when subsequent providers inherit and defer to prior records rather than reassessing independently.

How Depression and OCD Interact

Depression commonly co-occurs with OCD, further complicating the diagnostic process. Research suggests that up to two-thirds of individuals with OCD experience comorbid depression at some point during their illness (Pallanti et al., 2011). The presence of depressive symptoms can overshadow the OCD symptoms and lead clinicians to focus solely on treating depression, delaying the identification of underlying OCD.

The relationship between the two conditions is bidirectional. OCD is exhausting — the mental effort of managing intrusive thoughts and the time consumed by compulsions takes a significant toll. Depression often develops as a secondary consequence. Conversely, depressive symptoms such as impaired concentration, guilt, and withdrawal can amplify obsessional thinking, creating a cycle that worsens both conditions simultaneously. Treating depression alone, without addressing the OCD maintaining it, rarely produces durable improvement.

Treatment Options: ERP, SSRIs, and Ketamine

Treatment for OCD commonly involves Exposure and Response Prevention (ERP). ERP is the gold-standard psychotherapy for OCD, with decades of controlled research supporting its efficacy. It works by systematically exposing patients to feared stimuli while preventing the compulsive responses that temporarily relieve anxiety — gradually weakening the obsessive-compulsive cycle. Patients who understand the rationale behind ERP and engage with it consistently tend to achieve the most durable outcomes. It is not a comfortable process, but it is a reliably effective one.

Although psychotherapy is first-line treatment for OCD, medication can also be helpful.  Selective serotonin reuptake inhibitors (SSRIs) are the first-line medications. For patients who don't respond adequately to SSRIs, off-label medications such as memantine, naltrexone, or neuroleptics (e.g. aripiprazole) may be added. Treating the co-occurring depression is essential, as it not only compounds the burden of OCD but can also impair treatment response.  SSRIs serve a dual role in this capacity, targeting both OCD and depressive symptoms (Pittenger et al., 2015).

Ketamine has shown promise in treating OCD.  Studies have shown that ketamine therapy can lead to significant reductions in OCD severity, particularly in treatment-resistant cases (Bloch et al. 2012).  A preliminary study presented at the Ketamine Conference in Oxford found that ketamine rapidly reduced the severity of OCD symptoms compared to placebo, and the effects of a single treatment were sustained for 3 weeks (van Roessel, 2024).  While the precise mechanisms underlying ketamine's therapeutic effects in OCD are still being studied, its ability to modulate glutamate neurotransmission and promote neuroplasticity may contribute to its efficacy. Incorporating ketamine treatment into comprehensive OCD management plans may offer hope for individuals who have not responded to traditional therapies.

At Point Loma Clinic, ketamine treatment is not administered in isolation. When clinically appropriate, we combine it with psychotherapy — including ERP — timed to take advantage of the neuroplasticity window ketamine opens. For patients with OCD who have not responded to multiple prior treatments, this integrated approach represents one of the more promising options currently available.

Key Points

• Diagnosing OCD often faces delays of 6 to 10 years due to symptom complexity and stigma.

• Depression commonly co-occurs with OCD, complicating its recognition and treatment.

• SSRIs are primary for OCD treatment, with alternatives like memantine and aripiprazole used for non-responders.

• Ketamine shows promise in rapidly reducing severe OCD symptoms, especially in resistant cases.

• OCD symptoms often precede and drive depressive symptoms — treating depression alone, without addressing OCD, rarely produces lasting results.

• ERP is the evidence-based psychotherapy of choice for OCD and has been shown to improve depressive symptoms alongside OCD symptoms.

You can learn more about OCD and where to get help at the International OCD Foundation.

If you or someone you know has had limited success with prior treatment for depression, a thorough evaluation that includes screening for OCD may be a productive next step. Contact Point Loma Clinic to speak with one of our providers.