14 September 2015

Loop the loop

While the exact cause of OCD has yet to be identified, studies by neuroscientists indicate that it may have a biological basis. The BBC's Horizon programme 'OCD: A Monster in my Mind' took a look at some recent research and I found one experiment particularly interesting.

Electrodes were placed on the hands of people both with and without the condition and mild electric shocks administered if they provided the incorrect response to images presented to them: one picture correlated to their left hand and the other their right, and they had to tap a panel with the corresponding foot.

After a while, the electrode was removed from one hand. Although participants were aware that they no longer needed to tap the matching foot to avoid a shock, those with OCD continued to do so. The explanations each of them gave later as to why they had carried on tapping were always along the lines of 'Just in case' and 'Because it seemed better to.' A clear parallel, therefore, with the 'reasoning' behind compulsions. 

Scans conducted during this experiment showed that, in those with the disorder, there was a higher level of activity in the region of the brain known as the basal ganglia. In this area, messages are sent backwards and forwards in a series of 'closed loops' and the hyperactivity noted in some of these is what makes it hard for sufferers to filter out certain thoughts.

Image courtesy of renjith krishnan/
These loops are part of an evolutionary safety mechanism, related to looking for hidden dangers, but in OCD sufferers, there seems to be no natural stop to this. However, the programme introduced viewers to a technique called Deep Brain Stimulation (DBS), which it is claimed can provide some control.

We met a Dutch woman, Nanda, who was housebound by her obsessions and compulsions, even after 14 years of cognitive behaviour therapy (CBT), which is the recognised treatment for the condition. Such extreme cases, where all else has failed, are candidates for DBS in the Netherlands - the procedure is not available in the UK - where it has apparently brought relief to 60% of the 50 patients treated, with some going into complete remission.

This procedure involves implanting an electrode in the brain, which is hooked up to a battery pack stitched into the patient's chest. The pack allows the electrode to be 'tuned' to reduce the hyperactivity in the basal ganglia. Nanda felt an immediate reduction in her anxiety levels, although, at the close of the documentary, fine-tuning was still required to address her symptoms completely.

While her doctor hopes that this treatment could assist with other mental health conditions, at present the electrical stimulation affects a relatively large area of the brain and work is ongoing to find a way to target specific neurons.

Expert feedback to the show, on social media, indicated a high level of scepticism as to the efficacy of this very invasive, and potentially risky, treatment and commentators reiterated the fact that CBT delivers a successful outcome for most. The programme did acknowledge that the mind can change the way that the brain functions, without the need for extreme surgical intervention.

For me, the lasting image was of those never-ending brain loops. It seems some of us really are just wired differently!


Anonymous said...

Thanks for this great information, Helen, and as you say, it seems that such a drastic measure as DBS should be reserved for only the most severe, treatment-resistant cases of OCD. All this research is certainly interesting though and, as you say, shows those with OCD are wired differently!

Helen Barbour said...

ocdtalk, it certainly looked, from the scenes of surgery they showed, to be a brutal physical intervention. You would have to be pretty desperate to contemplate it.

Helen Poskitt said...

I haven't seen the surgery, but it brought ECT to mind due to the reference to electricity.

Gosh, roll on the day someone invents a FUN way of 'rewiring' those of us with OCD - e.g eating delicious puddings - as I was struck by the thought'loops' too.

Helen Barbour said...

Helen, what a great idea - if only delicious puddings were the cure!