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Credit: Buckyball Design, Melissa Thomas Baum Source: International OCD Foundation
OCD is a Brain Disorder which presents with intrusive, unwanted thoughts known as obsessions and some behaviour or counter thoughts to neutralise the obsessions. These countering thoughts or behaviours are known as compulsions.Let us see the kind of brain dysfunction and changes that occur with OCD. Parts of the brain, including the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), and thalamus and basal ganglia, have been pointed out in the neurobiology of OCD.
The orbitofrontal cortex is a structure involved in modulating autonomic reactions, learning, prediction, and decision-making regarding emotions and reward-related behaviours. The area known as the anterior cingulate cortex is involved in tolerating pain, regulating emotions, focusing, and making decisions.
The Thalamus is like a station that receives sensory information and movement from the body and relates it to the brain. Several cortical and subcortical circuits exist in the brain. OCD is also related tothe Basal Ganglia.Basal Ganglia structures were traditionally thought to regulate movement (that is, prevent unwanted movements and encourage wanted movements). Hence,the Basal Ganglia has been implicated in movement disorders such as Tourette’s Syndrome, Huntington’s chorea, Sydenham’s chorea, and Parkinson’s disease.
Interestingly, studies have shown that OCD is increased in people presenting with these disorders (Alex S. S. Freire Maia,1999). Let us understand what Basal Ganglia is. Basal Ganglia are a group of structures in the base of the brain. The structures that make up the basal Ganglia are the Caudate, putamen, globus pallidus (Cerebrum), Substantia Nigra (Midbrain) and subthalamic nucleus (diencephalon).
Apart from movement and motor functions, we now know that the basal ganglia have several other functions related to cognition, learning, behaviours, emotions, executive functions,etc. In addition to the loops with the cortex, the basal ganglia have loops with the prefrontal cortex. The prefrontal cortex involves attention, impulse control, memory, and cognitive flexibility.
When there is a dysfunction in this loop between the basal ganglia and pre-frontal cortex, the ability to suppress unwanted thoughts is lost, which may be implicated in unwanted, intrusive thoughts not within one’s control. OCD results from dysfunction in a neuronal loop running from the orbital frontal cortex (which is part of the prefrontal cortex) to the cingulate gyrus, striatum (caudate nucleus and putamen), globus pallidus, thalamus, and back to the frontal cortex.
In OCD, maladaptive brain circuitry is implicated (Grant E Joe et al. 2020). There is a loss of top-down control over inhibitions. There is evidence of reduced grey matter (substance and cells in the brain) in the cortical region and increased grey matter in the subcortical region in OCD.
The good news is that these changes are reversible with medications, Cognitive Behaviour Therapy and mindfulness. There is no evidence to say that only serotonin dysfunction causes OCD. However, several neurotransmitters, including GABA, glutamate and dopamine, apart from serotonin, are imbalanced in OCD.
In Chennai Minds, we offer exclusive treatment for OCD and have several options for treatment, including medications, psychoeducation, CBT, and mindfulness. Chennai Minds, the Best Psychiatrist in Chennai, is now also offering Telepsychiatry, including Online Counselling for Depression and OCD.
