Treatments for OCD
We have seen how OCD is linked to brain functions, and especially how it is linked to imbalances in how the frontostriatal loops work. But how do the existing treatments for OCD try to change these imbalances?
Various brain processes can be off-balance in people living with OCD. Similarly, different OCD therapies may influence the frontostriatal loops in different ways. This may be why treatments work more or less well for different people with OCD. In this section, we will explore the commonly recommended treatments for OCD and what we know about how they work. There are also other treatments that affect the brain, many of which are not as well established yet, or scientific evidence is still being collected for them. We do not cover other OCD treatments here, but you can read more about them here. Please note, the availability and approval of treatments varies between countries and is subject to change.
Cognitive-behavioural therapy (CBT) with exposure and response prevention (ERP)
The most common way to treat OCD, especially in young people, is using evidence-based therapies, such as cognitive-behavioural therapy (CBT) with exposure and response prevention (ERP). CBT refers to a specific form of therapy, in which trained psychotherapists guide the person to alter behaviours and thought patterns. ERP is the most important type of CBT for people living with OCD, as it directly challenges the OCD cycle of obsessions and compulsions.
Here, the person with OCD is put into situations that may normally trigger their OCD symptoms (like compulsions), but then tries to not carry out the compulsive acts. For example, in a person that experiences OCD focused on harm, they might be asked to experience exposures involving their triggers, such as handling sharp objects or looking at a photograph of an accident. With the guidance of the therapist, they confront the situation, embracing the discomfort or anxiety it may cause and resist the urge to engage with compulsive behaviours. By doing this, their brain learns that the situation itself is not truly threatening and over time, and that it does not always have to react with the same feelings (distress) and behaviours (compulsions) in those specific situations. Therefore, CBT with ERP changes the workings of the brain through the power of talking, learning and practicing changes in behavioural patterns. This approach is often challenging, but highly effective. For more information, see our OCD Resources section.
How does it work?
Engaging in ERP means that we can indirectly change imbalances in the frontostriatal loops through the power of plasticity – the brain's ability to change and adapt. We can do this by changing the anxiety linked to a situation, introducing new ways of responding to an obsession, and enabling re-learning of what to do in these OCD-related situations. Brain imaging research studies have indeed suggested that ERP does change how the frontrostriatal loops work (scientific journals on the subject can be found here and here).
Changing the levels of chemicals in the brain
A second way of altering these loop imbalances is by changing the level of brain chemicals called neurotransmitters, which influence the balance of frontostriatal loops. There are different medications that alter different neurotransmitters. The most commonly approved and prescribed medications affect a neurotransmitter called serotonin (so called SSRIs or SRIs). Sometimes additional medications that affect a neurotransmitter called dopamine are also prescribed.
How does it work?
Even though we know these drugs are safe and work well for OCD, the exact mechanisms behind how these drugs re-balance frontostriatal loops are not known. Neurotransmitters have many roles in the brain which means it is unclear to pinpoint what exactly has changed. However, we do know that they have a direct impact on how information is being processed in brain areas that are part of the frontostriatal loops. If you think back to our traffic example, you can imagine that changing the levels of a neurotransmitter such as serotonin influences this entire system – just like changing how long traffic lights are on green can change how smoothly cars flow through traffic.
Changing brain activity
There are more experimental approaches to change frontostriatal loop imbalances too. However, these methods are still currently being assessed, and/or are reserved for people who do not respond to commonly recommended treatments. These methods directly alter brain activity, such as deep brain stimulation (DBS), where an internal electrical stimulator (similar to a pacemaker for a heart) is implanted in the brain or transcranial magnetic stimulation (TMS), where an external device using magnetic coils is positioned over the head.
How do they work?
DBS and TMS work by changing activity in one area of the brain. Imagine that this is like changing just one specific traffic light in our traffic system. Just like traffic, our brain is all connected and changing the activity of one brain region has an impact on the entire network, in a similar way that one signal failure can affect traffic across the entire city.
Summary
OCD is much more treatable than many people assume and treatments benefit the majority of people living with OCD. However, it is important to note that none of these treatments are perfect or have a 100% success rate. People respond differently to treatment, and it may be challenging and a long journey for many. It is likely that some amount of imbalance in the brain will remain and for some people, the OCD symptoms might not go away completely or might come back after some time. Because the human brain is so complex, these treatment options can also affect different functions of the brain, leading to side effects. However, researchers are working hard to improve the treatments so that they help to reduce OCD symptoms as much as possible with minimal side effects.
Exactly which treatments work best for whom is a question that researchers are currently exploring. It could well be that people with different types of imbalances in the frontostriatal loops will benefit from different or a combination of treatments. This is why researchers are looking into which imbalances exist, how they can be measured, and whether we can predict who will benefit from which treatment.
