OCD vs anxiety: how a psychologist tells them apart

Is OCD an anxiety disorder?

Not officially, since 2013. The DSM-5 moved OCD out of the anxiety disorders into its own chapter, Obsessive-Compulsive and Related Disorders, because the evidence showed it works differently. Anxiety is still central to OCD, and it often co-occurs with generalised anxiety and health anxiety, but the cycle of obsession and compulsion calls for a different treatment.

Three patterns that look alike

Imagine three people in Wellington who all describe themselves as "anxious all the time".

• The first lies awake running through the mortgage, her daughter's driving test, a work deadline and whether she offended a friend, one worry sliding into the next. That is the shape of generalised anxiety.
• The second has noticed a twinge in his side and spends evenings searching symptoms, pressing the spot, and planning a third GP visit despite two clear results. That is the shape of health anxiety.
• The third gets a sudden image of swerving her car into oncoming traffic, is horrified, and now avoids the motorway, replays every trip for evidence she's dangerous, and asks her partner whether she's a good person. That is the shape of OCD.

All three feel anxious. All three seek reassurance. But what the mind is doing, and what keeps the problem going, differs in ways that matter.

OCD vs generalised anxiety: worry versus obsession

Generalised anxiety disorder (GAD) is built on worry: a verbal, future-focused chain of "what ifs" about realistic life concerns such as money, work, health and family. The topics shift, the worry feels like problem-solving that never finishes, and the body stays tense and tired. Sleep suffers. There are no rituals, though reassurance-seeking and over-planning are common.

OCD is built on obsessions: intrusive thoughts, images or urges that feel alien, often improbable or taboo, and that return to the same theme. The person usually recognises the thought doesn't make sense yet can't shake the doubt. Obsessions are then followed by compulsions: visible ones like checking the stove or washing, and hidden ones like counting, mentally reviewing, praying or arguing with the thought. The compulsion brings brief relief, which teaches the brain the threat was real, and the cycle tightens.

Questions a psychologist would explore: Is the thought about something that could plausibly happen this month, or something that feels out of character? Do you do anything, physically or mentally, to make the feeling go away, and does it have to be done a certain way? Does the worry jump between topics, or circle one theme?

OCD vs health anxiety

Health anxiety is a preoccupation with having or developing a serious illness. Ordinary sensations get read as evidence; checking the body, researching symptoms, seeking tests and reassurance, or avoiding anything medical keep it going. It can look very like contamination OCD, and some people have both.

The differences are in the feared outcome and the function of the behaviour. In health anxiety the fear is usually "I already have, or am about to get, the illness", and checking is about detecting it. In contamination OCD the fear is often about contact, spreading or responsibility ("I'll bring something home and my kids will get sick"), and washing or avoiding is about preventing it or undoing it. OCD rituals also tend to have a "just right" quality: a set number of washes, a particular order.

Health anxiety has its own well-supported treatment. A 2017 meta-analysis found CBT for health anxiety produced a large effect compared with control conditions, with gains maintained at follow-up. Our health anxiety page describes that work.

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Why they often travel together

Having OCD doesn't protect you from ordinary worry, and a large US survey found OCD is associated with substantial comorbidity with anxiety and mood disorders. Living with intrusive thoughts is also exhausting, and low mood commonly follows. Panic attacks, social anxiety and specific phobias can also sit alongside OCD, each with its own treatment emphasis. The DSM-5's decision to give OCD its own chapter wasn't a claim that anxiety is irrelevant; it reflected evidence that OCD and its relatives (body dysmorphic disorder, hoarding, hair-pulling and skin-picking) share features that set them apart from the anxiety disorders.

When several things are present, a psychologist works out which is driving the most distress and disability and starts there, while keeping an eye on the rest.

How a psychologist tells them apart

It's done through a careful interview rather than a quiz. Alongside the questions above, your psychologist will ask for specific recent examples, how much time each day the thoughts and behaviours take, what you've started avoiding, and how convinced you are that the feared outcome is likely. Validated measures help: the OCI-R and Y-BOCS for OCD, with other questionnaires for worry and health anxiety where relevant.

Two features tilt the picture towards OCD: the presence of compulsions, including mental ones, and the sense that the thought is intrusive and unwanted rather than a reasonable concern. Two features tilt it towards GAD: worry that roams across realistic topics and a lack of rituals. Overlap is common, and the formulation your psychologist builds is more useful than any single label. Our OCD assessment page describes the process in full.

Why the label changes the treatment

This is why the distinction matters. The recommended treatments are different.

• For GAD, NICE recommends CBT or applied relaxation, typically 12 to 15 weekly sessions, targeting the worry process itself rather than any single feared thought.
• For OCD, NICE recommends CBT including exposure and response prevention: deliberately approaching the obsession and dropping the compulsion until the brain learns the fear is unnecessary.
• For health anxiety, CBT focuses on how body sensations are interpreted and on stopping the checking and reassurance that keep the fear alive.

Mixing them up has costs. Applying GAD-style techniques to OCD, such as reasoning through whether a feared event is likely, can become a mental compulsion. Treating OCD's checking as "just anxiety" can leave the rituals untouched. And treating ordinary worry with exposure to one feared scenario can miss the roaming nature of the problem. Getting the formulation right first saves time and money.

What to expect at Mindwell

Several of Mindwell's psychologists work with both anxiety disorders and OCD, which matters when the picture is mixed. ERP for OCD is delivered by four of our psychologists: Sandy Laurenson, Clinical Psychologist; Candice van der Merwe, Counselling Psychologist; Inge Prince, Clinical Psychologist; and Katherine Lee, Registered Psychologist. Sandy has ERP-specific training through the International OCD Foundation's Behavior Therapy Training Institute, and Katherine also works with sleep, relationships and perinatal mental health using CBT, ACT and schema therapy.

Assessment usually starts in your first 50-minute online session: what's happening, which pattern or patterns fit, and a plan agreed with you. How long it takes depends on you. Sessions are $199 + GST ($228.85 incl. GST), available anywhere in New Zealand to adults 18+, with no referral needed and first appointments typically within 7 days.

Related support: OCD assessment · Contamination OCD · Health anxiety · Anxiety therapy