The Biology Behind OCD
In the last article, I explored the core dimensions of OCD. I want to now give a very brief overview of the bio-psycho-social components of OCD, to raise awareness about the predisposing, learned, and maintenance factors of the condition.
The Biology Behind OCD
The first thing you learn in every foundational psychology course is this idea of how everything psychological is simultaneously biological (and vice versa). Thus, there is a unique biological underpinning to each person’s experience of OCD. In fact, research indicates that OCD is linked to dysfunction in specific brain circuits, primarily those involving the cortico-striato-thalamo-cortical (CSTC) loop, as well as imbalances in key neurotransmitters like serotonin, dopamine, and glutamate (Harrison et al., 2013). Yes, these are big words, but they really just refer to different regions of the brain, which control different functions of our thinking, feeling and acting. The CSTC loop consists of connections between the orbitofrontal cortex (OFC), the striatum (caudate nucleus and putamen), the thalamus, and back to the cortex. Each of these regions of the brain are responsible for different aspects of our every day functioning, and explain some of the symptoms of OCD. The OFC is primarily responsible for decision making, evaluation of risk and threat perception. For people with OCD, the OFC is in overdrive, leading to heightened threat detections and perceptions of danger. You could think of the OFC as a mini-alarm system. The striatum is primarily responsible for filtering and regulating relevant and non-relevant thoughts into conscious awareness, and is also involved in the process of creating habits. In OCD, the striatum has a hard time filtering out intrusive thoughts, which allow them to persist and explains why they even rise up into conscious awareness in the first place. The thalamus, lastly, is like a relay station; It’s responsible for relaying sensory signals and stimuli (like sensations and even pre-conscious thoughts) from the body to the cortex for further processing and evaluation. The thalamus functions to spotlight sensations and thoughts, making them stand out more in conscious awareness. The implication: the OFC allows intrusive thoughts to surface in awareness and then the thalamus shines a massive spotlight on it, making them stand out. No wonder intrusive thoughts, images, and sensations are so damn scary - because they are more real to OCD sufferers. Interestingly, in a study published by Dr. Ben Harrison of the University of Melbourne found that severity of OCD symptoms depends on the connectivity between the OFC and the striatum (2013), which makes sense: a hypersensitive alarm system + porous filter + some other more complex brain things = OCD.
The Psychology of OCD: Learning and Reinforcement
Yet, it’s far from that simple of an equation. Biology sets the stage for learning to occur. Yes, people with different “presets” will see, perceive and interpret the world differently. However, what OCD looks like for each person - the specific intrusive thoughts, checking rituals, avoidance patterns - is vastly different, anchored in each person’s unique cultural background, history, and environment. What this implies then is that the range of OCD symptoms are the result of learned components of the condition (Greyson, 2014).
From the behaviorist perspective, there are two types of learning: classical and operant. Classical conditioning accounts for how our emotions and feelings become associated with certain neutral cues and stimuli; how different situations, stimuli, and cues make us feel. Classical conditioning, hence, is a kind of emotional learning. For instance, if every week a box of chocolates appeared on my door at 5:00 pm, over time I’d start to feel pretty stoked around 4:30. There was nothing special about the 4:30 - 5:00 time slot, but I’d learn to associate that time with getting chocolate and getting excited! Another way to think of classical conditioning is how triggers become "transferred". In this example, the trigger for my excitement for the chocolate was "transferred" to the time of day. In the case of the OCD sufferer, say if every time you see a loved one, you have an intrusive thought or image of harming them. Sooner or later, you will start to get super anxious about seeing them: the anxiety you experience from the intrusive thought gets associated (“transfers”) with the innocuous loved one. Hence, you’ve unknowingly “conditioned” yourself to respond with anxiety.
Operant conditioning, however, accounts for how we behave in response to those cues and stimuli, a form of behavioral learning. In this type of learning, we learn to do or not do things depending on the consequences of our actions. In the case of the chocolate example, say that in order for me to get the chocolates at 5:00 pm every day, I had to go on a walk for 10 minutes in the morning. Then, I’d be pretty darn likely to go and do that 10 minute walk so that I’d get my chocolate. When a behavior is increased or supported as a result of a consequence, it is reinforced, which can happen in two ways: when something good is “added” or something unpleasant is taken away, bringing relief. In confusing technical psychology speak, when something is “added” that’s what’s meant by positive reinforcement, and when something is “taken away” that’s what is meant by negative reinforcement. For example, social media is so addictive because of both of these reinforcement mechanisms: it not only feels good to scroll (positive reinforcement), but especially when doing so helps me feel less anxious or bored (negative reinforcement). In the case of OCD, compulsions and safety behaviors are negatively reinforcing, meaning that they are more easily cemented into habit because they (temporarily) remove the stressors of uncertainty and anxiety triggered by both intrusive thoughts and other classically conditioned stimuli.
ERP in a Nutshell
How do we “unlearn” these associations then? Enter Exposure and Response Prevention. ERP is, at its most fundamental level, a structured process for what it means to “face your fears”. Exposure involves intentionally and voluntarily confronting the specific triggers of your fears and Response Prevention involves refraining from engaging in compulsions/safety behaviors after confronting your fears. How would confronting the things that scare you and refraining from seeking safety even be considered a form of treatment, let alone help promote learning? Let’s go back to classical and operant learning.
Remember, classical conditioning is a kind of emotional learning, pairing our emotional responses with certain cues in the environment. In the case of exposure, by confronting our fears, repeatedly and consistently, we begin “unpair” our anxiety with the cue. This doesn’t mean that that cue will never be uncomfortable or distressing: it still will be. But you’ll begin to tolerate it with less distress and even with a sense of non-importance. This process is known as habituation, the reduction in anxiety after repeated exposure to a fear cue. Not only, exposing ourselves to our fears and refraining from safety behaviors, gives us the opportunity to promote safety learning about our fears. Those intrusive thoughts of say choking a loved one; of being responsible for some future catastrophe; of getting a terminally ill disease, don’t seem as scary and threatening. Afterall, they are just thoughts, nothing more, nothing less, and in fact don’t reflect something about your “true” nature, but are just weird, random, annoying, confusing workings of the mind. And in approaching, rather than avoiding, we learn new ways of interacting with the world and our triggers, throwing a wrench in the cycle of negative reinforcement. Also, doing things that scare you, and getting through it, also can be an immensely profound and rewarding experience, promoting self-efficacy (the fancy psychology word for self-confidence). These three components: habituation, promoting safety learning, and increasing self-confidence, are the main theories for why ERP works.
It is common for most sufferers to want to pinpoint and address the root cause of their OCD symptoms, to understand the elusive why? This is a useful thread to explore, understanding the moments and circumstances surrounding the onset of someone's OCD symptoms. However the conditions that lead in the development of a behavior or condition are often different that the factors that continue to maintain it (Abramowitz, Deacon, & Whiteside, 2019). It is these maintenance factors that are the main target of ERP therapy, specifically compulsions and safety behaviors. There are profound implications for engaging in response prevention. Refraining compulsions puts one face to face with the inherent uncertainty of our lives and the world. This is and always will be deeply unsettling. I will write more about uncertainty and this implication in the coming articles. But also, refraining from compulsions allows us to reclaim the life we have lost to OCD, granting us more time and attention to focus our efforts on things that are truly meaningful for us. Afterall, all we truly have is our time and attention.
Coming Up
In the coming articles, I am going to explore each subtype of OCD in more depth, as well as explore the key to OCD recovery: acceptance of uncertainty. And as always, thanks so much for your time and attention. See you next week.
References
Abramowitz, J. S., Deacon, B. J., & Whiteside, S. P. H. (2019). Exposure therapy for anxiety: Principles and practice (2nd ed.). Guilford Press.
Grayson, J. (2014). Freedom from obsessive-compulsive disorder: A personalized recovery program for living with uncertainty (Updated ed.). Berkley Publishing Group.
Harrison, B. J., Pujol, J., Cardoner, N., Deus, J., Alonso, P., López-Solà, M., ... & Soriano-Mas, C. (2013). Brain corticostriatal systems and the major clinical symptom dimensions of obsessive-compulsive disorder. Biological psychiatry, 73(4), 321-328.
