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When Doubt Won’t Let Go: Obsessive-Compulsive Disorder (OCD)

9 min readEvidence-based
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Obsessive-Compulsive Disorder (OCD) involves unwanted thoughts, images or urges that keep coming back (obsessions), and repeated actions or mental rituals done to ease the distress (compulsions). These can take up a lot of time, cause real distress and get in the way of daily life. Liking a tidy desk, or saying you're "a bit OCD", is not the same thing.

OCD is more common than many people think. A national survey found that 3.6% of Australians aged 16–85 had OCD in the past year. It often starts in childhood, the teenage years or early adulthood. Many people wait years before getting help, often because they feel ashamed of their thoughts. The good news is that OCD responds well to treatment.

Obsessions and compulsions

Obsessions are intrusive thoughts, images or urges. They cause anxiety, disgust or a feeling that something is "not right". They often clash with what the person values. Compulsions are actions or mental routines used to reduce the distress or prevent something bad happening. Some are visible. Others happen only in the mind.

Common themes include:

  • Contamination: fear of germs, illness or dirt, leading to washing, cleaning or avoiding things.
  • Harm and responsibility: fear of causing harm by mistake, such as leaving the stove on, leading to checking.
  • Unwanted taboo thoughts: upsetting thoughts about violence, sex or religion, followed by mental reviewing, seeking reassurance or avoidance.
  • Order and "just right": a need for things to be even or exact, leading to arranging, repeating or counting.
  • Relationships and identity: constant doubt about whether you truly love your partner, or about your sexuality or morals.

Intrusive thoughts are normal. The response is what matters

Research across six continents found that almost everyone has unwanted intrusive thoughts at times, including disturbing ones. In OCD, the difference is how these thoughts are understood and responded to. A thought like "What if I hurt someone?" may be taken as a sign of danger or bad character. That leads to urgent efforts to cancel it out.

A thought is not a wish or an intention. In fact, people with OCD are often upset precisely because the thought goes against what they value. A psychologist will not judge you for the content of your thoughts.

Why relief doesn't last

Imagine checking that a door is locked, then going back because it doesn't feel completely certain. Checking again brings relief. But it also teaches the brain that uncertainty is unbearable and needs another ritual. Over time, the rules get stricter and the relief gets shorter.

Many people know their response is excessive, yet find it very hard to resist. That's why "just stop worrying" rarely helps. Reassurance from family, given with love, can also become part of the cycle.

What causes OCD?

OCD develops from a mix of factors. It runs in families, and genes play a part. Brain research suggests differences in circuits involved in spotting errors and shifting attention. Stress, big changes in responsibility (such as becoming a parent) and learned beliefs about thoughts and danger may also play a role. OCD is not caused by weakness or poor parenting.

OCD often occurs alongside anxiety and depression, and sometimes with tics, ADHD or autism. Related conditions include body dysmorphic disorder, hoarding disorder, and hair-pulling or skin-picking.

How is OCD treated?

OCD responds well to treatment. Our psychologists often draw on three approaches: CBT with Exposure and Response Prevention (ERP), ACT and IFS. Each offers a different way of understanding the OCD cycle, and they can be combined. Medication can also help, and is discussed with your GP or a psychiatrist.

Cognitive Behavioural Therapy (CBT) and Exposure and Response Prevention (ERP)

CBT sees OCD as a cycle. An intrusive thought triggers distress. A compulsion brings relief. That relief teaches the brain that the ritual was needed, so the cycle grows. CBT also looks at the beliefs that fuel the cycle, such as "Having this thought means I'm dangerous" or "If I don't check and something happens, it's my fault".

ERP is the leading form of CBT for OCD. In therapy, your psychologist might help you:

  • Map the cycle, including visible rituals and hidden mental ones, such as reviewing or praying to cancel a thought.
  • Build a ladder of steps, from mildly to more challenging triggers.
  • Face triggers gradually while resisting rituals, learning that distress and uncertainty rise and fall on their own.
  • Test beliefs about responsibility, danger and the importance of thoughts.
  • Reduce reassurance, including with family, in a supportive way.

The work is planned together, with no surprise challenges. Your psychologist should explain the reason for each step, and you stay in control of the pace. Research consistently supports ERP as a first-line treatment for OCD.

Acceptance and Commitment Therapy (ACT)

ACT sees the problem in OCD as the struggle with intrusive thoughts and uncertainty. The more you try to get rid of a thought or feel completely certain, the more stuck you become. Rituals are a way of trying to win that struggle.

In therapy, your psychologist might help you:

  • Step back from intrusive thoughts, seeing "what if I left the stove on?" as a thought, not an instruction.
  • Make room for uncertainty and discomfort, instead of trying to fix them.
  • Notice urges without acting on them, letting them rise and pass.
  • Clarify what matters, such as family, work or fun, that OCD has been taking time from.
  • Choose values-based actions, such as returning to a conversation instead of checking.

For example, you might notice the urge to check the lock again, say "there's the doubt", and head off to spend time with your kids anyway. ACT is often combined with exposure. A 2018 trial found that ERP with added ACT and ERP alone both led to lasting improvement.

Internal Family Systems (IFS)

IFS sees the mind as made up of different "parts". IFS clinicians Martha Sweezy and Melissa Mose describe OCD this way. Worrying protectors respond to an intrusive thought with urgent "what ifs", such as "What if you're a bad person?" Ritual protectors step in when anxiety gets too high, using checking, washing, counting or reassurance to put out the emotional "fire". Vulnerable parts, called exiles, may carry burdens such as "I'm dangerous" or "it will be my fault", which make protectors work even harder. These protectors are trying to keep you safe, but they have taken on extreme roles.

IFS also describes a Self: a calm, clear and compassionate core that can tell a real threat from "brain noise". In therapy, your psychologist might help you:

  • Notice worrying and ritual parts from Self, with curiosity rather than fear.
  • Understand what they fear, and let them know they don't have to carry the job alone.
  • Help hurt parts release burdens, such as "I'm bad".
  • Do "Self-led ERP": facing triggers and resisting rituals, with compassion for the parts that feel afraid.

This can make exposure feel less like a battle and more like building trust inside, so the system can work together in harmony.

What does the research show?

Research consistently supports ERP as a first-line treatment for OCD. Medication, usually a type of antidepressant called an SSRI, also helps. A 2022 review found that ERP plus medication improved symptoms more than medication alone. Intensive formats, such as the Bergen 4-Day Treatment, have also shown promising results. Talk to your GP or a psychiatrist about medication.

Progress doesn't have to mean no intrusive thoughts at all. It may mean far less time spent on rituals, less distress and more freedom to live your life.

Supporting someone with OCD

It is natural to want to reassure or help with rituals. But this can keep the cycle going. Instead, acknowledge their distress, show confidence that they can cope with uncertainty and encourage treatment. Where possible, agree as a family, ideally with a psychologist's help, how to gradually reduce reassurance. Avoid anger or teasing. The person is not choosing their symptoms.

When to seek help

If checking, reassurance-seeking, mental reviewing or avoidance is taking over your time or relationships, an assessment can help. You don't need to name every symptom, or share every thought, to start that conversation. Psychologists who work with OCD have heard a wide range of intrusive thoughts.

Getting support at Invision Psychology

Our psychologists offer CBT and ERP for OCD at our clinics in Rockhampton (2/72 Bolsover Street) and Yeppoon (3/26 James Street), and by telehealth for people across Central Queensland and beyond.

  • You don't need to know which therapy you want. Your first appointment is a chance to talk about what's happening and what you'd like to change.
  • Medicare: with a Mental Health Treatment Plan from your GP, you may be able to claim a Medicare rebate for up to 10 sessions each calendar year. See our fees.
  • NDIS: we work with self-managed and plan-managed NDIS participants.

Make an enquiry or call 07 5641 4888.

If you need help now

If you or someone else is in immediate danger, call 000. For 24/7 support:

  • Lifeline: 13 11 14
  • Beyond Blue: 1300 22 4636
  • 13YARN (Aboriginal and Torres Strait Islander people): 13 92 76
  • Kids Helpline (ages 5–25): 1800 55 1800

An appointment enquiry is not an emergency service.

About the author

Alex Parkes BPsychSci, GradDipPsych, MPsych, MAAPi
Founder and Principal Psychologist, Invision Psychology. Level 1 trained Internal Family Systems practitioner.

Published September 2026 · Last reviewed September 2026 · Next review due September 2027

This article gives general information based on published research. It is not a substitute for personalised advice from a qualified health professional.

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