OCD medication and therapy in NZ: how the two fit together

What are the main treatments for OCD?

Clinical guidelines recommend two first-line treatments for OCD: exposure and response prevention (ERP), a specific form of cognitive behavioural therapy, and medication from the SSRI class of antidepressants. Either can be used alone, and they are often combined when OCD is severe or one approach hasn't been enough. In New Zealand, SSRIs are prescribed by GPs and psychiatrists, not psychologists.

What the guidelines recommend

The UK's NICE guideline on OCD matches treatment to how much the OCD is affecting your life:

• Mild impairment: a low-intensity psychological treatment including ERP, up to about 10 therapist hours.
• Moderate impairment: a choice between a course of an SSRI and more intensive CBT including ERP (more than 10 therapist hours).
• Severe impairment: combined treatment with an SSRI and CBT including ERP.

The American Psychiatric Association's practice guideline takes a similar view: CBT with ERP and SSRIs are both safe and effective first-line treatments, with the choice depending on severity, your preferences, previous treatment and whether skilled CBT is available. A 2013 review of the evidence concluded the guideline remained substantially correct, and that within psychological treatments ERP has the strongest evidence.

A large network meta-analysis in The Lancet Psychiatry (54 trials, 6,652 participants) found that psychological treatments, especially behavioural therapy, had larger effects than medication alone, while noting that most psychotherapy trials allowed participants to continue antidepressants. The authors suggested combining the two is likely to be more effective for severe OCD.

SSRIs for OCD: general information

SSRIs (selective serotonin reuptake inhibitors) are the medication class recommended first for OCD. NICE names fluoxetine, fluvoxamine, paroxetine, sertraline and citalopram. In New Zealand, Healthify lists citalopram, escitalopram, fluoxetine, paroxetine and sertraline as the SSRIs available here, all funded by Pharmac, and notes they are used for OCD as well as depression and other anxiety conditions.

A few points from the guidelines are worth knowing before you talk to your doctor:

• SSRIs can take time to work for OCD. NICE advises patients that there is commonly a delay in the onset of effect of up to 12 weeks, so a fair trial is judged over weeks rather than days.
• Early side effects can include nausea, sleep disturbance, sweating and restlessness, and some people experience increased agitation, or thoughts of self-harm or suicide, in the first weeks. Healthify advises talking to your doctor straight away if this happens.
• If an SSRI helps, NICE recommends continuing it for at least 12 months to reduce the chance of relapse.
• SSRIs should not be stopped suddenly, because withdrawal symptoms can occur; reductions are planned gradually with your prescriber.
• Clomipramine, an older antidepressant, is an alternative that guidelines reserve for when SSRIs haven't worked.

None of this is advice to start, change or stop a medication. Your GP or psychiatrist knows your history and can weigh benefits and risks for you.

ERP on its own

Many people choose to treat OCD with ERP alone, and for mild to moderate OCD the guidelines support that choice. ERP involves gradually facing the situations and thoughts that trigger obsessions while resisting the compulsions, so that the brain learns the feared outcome doesn't follow and the anxiety settles. It's structured, collaborative and practised between sessions: at the kitchen bench, the front door, the car park at the kids' school, wherever your OCD operates. A typical course runs weekly or fortnightly over a few months, with the first sessions spent mapping your particular obsessions and compulsions before exposures begin.

The appeal is that the skills are yours afterwards. You learn how OCD works and how to respond when it flares, which many people value for the long run. Our ERP therapy page explains the process in detail.

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Combining medication and ERP

Guidelines suggest combination when OCD is severe, when one treatment alone hasn't produced enough change, or when depression or another condition that responds to SSRIs is also present. In practice, some people find medication lowers the baseline intensity enough to make exposure work manageable, while the ERP gives them tools that medication alone doesn't. Sequencing varies: some people start therapy first and add medication only if progress stalls; others begin medication through their GP while waiting to start ERP, then taper later with medical guidance once the skills are established.

If you're already taking an SSRI when you start therapy, there's no need to change anything; ERP works alongside it. If you're considering starting, your psychologist can describe how the therapy is going and what they're observing, with your consent, to help your prescriber's decision, but the decision stays with you and your doctor.

Who prescribes in New Zealand

Psychologists in New Zealand don't prescribe. Medication for OCD is prescribed by:

• Your GP, who can prescribe the funded SSRIs, monitor side effects and adjust doses. For most people this is where medication starts.
• A psychiatrist, usually by GP referral to your local Health NZ community mental health service (free if accepted, with criteria that generally prioritise more significant difficulties) or privately. A 2025 fee guide quoted private psychiatrist assessments in Auckland at around $550 an hour.

If your GP is less familiar with OCD, it can help to take along a written summary of your symptoms, and to mention that the APA guideline sets out dosing and trial-length guidance specific to OCD. Our finding an ERP therapist page covers the wider system.

How Mindwell psychologists work alongside your GP

With your consent, your psychologist can write to your GP to share the assessment, the treatment plan and your progress on measures like the Y-BOCS. GP letters and reports are quoted and agreed in advance. If you'd rather keep therapy separate from your medical record, that is your choice, and nothing is shared without your permission, except where the law requires or allows it.

What we won't do is tell you whether to start, stop or change medication. We can help you prepare for the conversation with your doctor, explain the general evidence, and keep working on ERP whatever you decide. If something changes with your medication during therapy, let your psychologist know so the plan can take it into account.

Questions to take to your GP

• Is an SSRI appropriate for my OCD, and which one would you suggest for me?
• How long should I give it before we judge whether it's working?
• What side effects should I watch for in the first few weeks, and when should I contact you?
• If it helps, how long would I stay on it, and how would we eventually reduce it safely?
• I'm doing ERP with a psychologist. Can we share information so you both know what's happening?
• If I'm pregnant, planning a pregnancy or breastfeeding, what does that change?
• Would a referral to a psychiatrist be useful, and what would that involve?

Related support: ERP therapy for OCD · OCD assessment · Cost and funding · Find an ERP therapist