ocd all about arranging your pens nice and neatly in colour order and washing your hands a few too many times right hey everyone welcome back to verity mind in this video we're looking at explanations for ocd we've seen in a previous video how it's easy for people to have a misunderstanding of what ocd is and to know what the real characteristics are in this video we're less focused on what it's really like to suffer from ocd and more focused on explaining where ocd comes from as we've said in previous videos there are different explanations for mental disorders like ocd depression and phobias but on the a-level psychology course the emphasis is just on one explanation for each condition so for ocd we're going to explore biological explanations the biological explanation for ocd is broken down into two parts firstly the role of genetics this explanation states that a person is more likely to develop ocd if a family member has it because of the genetics they have passed on this means that the dna they have inherited may give them a predisposition to developing ocd or what could be called a vulnerability to ocd research into the role of genetics in ocd has focused on two specific genes firstly there is the compt gene it's called the comp gene because it is involved in the production of catechol or methyl transferase but for you and me let's just stick with the comp gene the com gene is thought to regulate the production of a neurotransmitter you may have heard of called dopamine and the comp gene appears to have changed or mutated in individuals with ocd so that it's not working as it normally would be in people suffering from ocd then secondly there is the cert gene the cert gene stands for serotonin transporter and this cert gene appears to be changed or mutated in individuals with ocd this change in the search gene can lead to a decrease in the amount of another neurotransmitter you may have heard of called serotonin now you might be wondering if there's any evidence for the role of these genes well for the comp gene research by tukolital in 2013 compared 101 patients with ocd and 100 healthy control participants they found that compared to the healthy control participants the ocd patients had lower activity of the comp gene than normal and this was related to higher levels of dopamine for the cert gene or psychiatric in 2003 found a mutation in the search gene in two different families six of the seven family members with the mutated cert gene had ocd now there is lots of further supporting evidence for ocd and the role of biology but one of the key ways that psychologists can explore the role of genetics in human behavior is through studying twins there are two main types of twins monozygotic twins mono meaning one zygotic meaning egg these are identical twins who are from one fertilized egg and therefore share 100 dna then there are dizygotic twins die meaning two these are non-identical twins who are from two separate fertilized eggs and therefore share fifty percent of their dna in other words monozygotic twins are more genetically similar than dizygotic fred you next he's not fred i am honestly woman you call yourself our mother in twin study research concordance rates are compared as a reminder concordance rates are the degree of genetic similarity for a particular trait and the trait we're interested in is ocd supporting evidence for the role of genetics in ocd can be seen from twin city research by nest data in 2010 in their review of ocd and the role of genetics they showed that of all the twin study research published to date the concordance rate in monozygotic twins was higher than dizygotic twins now just so we're clear on this if ocd is genetic we should find a higher concordant rate for monozygotic twins than for dizygotic twins in other words if one twin has ocd the likelihood that the other twin develops ocd should be higher for monozygotics than for dizygotics and that's exactly what nest el reported monozygotics had a 68 concordance rate for ocd if one twin had it and dizygotic had a 31 concordance rate for ocd however whilst this research clearly shows the involvement of genetics in ocd it also indicates that it is not just genetics that's involved for example if ocd was purely genetic we would expect the concordant traits for monozygotics to be 100 because they're genetically identical however this is never the case so this suggests that there must be something else involved in ocd some other factor that is affecting the development of ocd and many have pointed to the influence of environmental factors more on that shortly so the first biological explanation of ocd was genetics in this second explanation we're going to explore the neural explanation the word neural relates to the nervous system so we're going to consider this in two parts firstly neurotransmitter levels and secondly an abnormal brain circuit some people have differing levels of a particular neurotransmitter neurotransmitter 1 dopamine high levels of dopamine have been associated with people with ocd and particularly linked to compulsive behavior for example k metal in 2007 gave ocd patients drugs that affected their dopamine levels and they found that this was correlated with less compulsion behaviors these findings suggest that the dopamine neurotransmitter system could play an important role in ocd patients neurotransmitter 2 serotonin low levels of serotonin have been associated with anxiety and ocd the idea here is that serotonin may be removed too quickly from the synapse before it has transmitted its signal now for more information about the how and the why of serotonin with ocd check out this next video on the biological treatments of ocd where we take a deeper look at synaptic transmission but for this video it's enough to understand that lower levels of serotonin are associated with ocd okay so how do we know this what research points to the potential influence of serotonin in ocd some row italian 2009 reviewed 17 studies into drug treatment for ocd these 17 studies combined over 3 000 participants and these studies compared drugs that affected serotonin levels in the brain with placebos the results showed that these drugs that altered serotonin levels were more effective in reducing ocd symptoms basically the ocd patients were given drugs that increased serotonin and these patients reported less ocd symptoms part two abnormal brain circuits one area of the brain thought to be involved with ocd is called the orbitofrontal cortex the orbital frontal cortex is the area of the prefrontal cortex that sits just above the orbits also known as the eye sockets the orbital frontal cortex is sometimes referred to as the worry circuit this circuit involves the orbital frontal cortex the basal ganglia specifically a part of it called the caudate nucleus the thalamus and then back to the orbital frontal cortex the orbital frontal cortex is involved in our perception of the world and when we are worried it sends the signal that we are worried to the thalamus the thalamus is thought to be the center of our perception of pain among other things this worry signal is normally suppressed or filtered by the caudate nucleus in the basal ganglia but if there is something abnormal about the circuit at this point then the thalamus becomes alerted to the signal quite strongly and confirms the worry back to the orbital frontal cortex which is about logical thinking and making decisions he's now going to start thinking or we could say obsessing about this worry in other words this worry circuit is over active and that then might lead to compulsive behaviors to cope with this anxiety and worry evidence for the role of this worry circuit and specifically the orbital frontal cortex in ocd comes from buick etal in 2013 they looked at ocd patients who were on medication and ocd patients not on medication they found that non-medicated ocd patients showed greater activity and connectivity in the orbital frontal cortex the level of activity in the orbital frontal cortex was also positively correlated with how severe their ocd symptoms were in other words the more severe their ocd symptoms were the more active was the orbital frontal cortex so now we've looked at two biological explanations genetics with the content cert gene and neural explanations with the neurotransmitters dopamine and serotonin and then the abnormal brain circuit involving the orbital frontal cortex now having outlined all of that let's discuss this biological explanation for ocd in terms of its strengths and limitations one practical application of the biological explanation of ocd relates to treatments if one of the key factors involved in ocd is for example lower levels of serotonin because of the mutation of the search gene then this knowledge can lead to drugs being prescribed to correct this imbalance one particular form of drugs that have been used are called ssris which stand for selective serotonin reuptake inhibitors ssri medication has been successfully used to reduce ocd symptoms and therefore shows the value that the biological explanation has in helping to improve the lives of people suffering from ocd for more information on ssris and how these drugs work check out the next video on treatments of ocd an alternative explanation for ocd is the diathesis stress model what this model does is propose an explanation for how biological and environmental factors may be interconnected it suggests that genetics may be involved that they create a predisposition of vulnerability for ocd in other words some people may have the specific genes which makes it more likely that they develop ocd but ocd may never develop unless there is an environmental trigger a stressor the diathesis stress model suggests that environmental factors can trigger or increase the risk of developing ocd some research suggests that ocd may be more common in people who have been bullied abused or neglected and it sometimes starts after an important life event such as childbirth or a bereavement chromatal in 2007 found that over 50 percent of the ocd patients in their sample had a traumatic event in their past therefore this suggests that the biological explanation alone is not sufficient to fully explain ocd and that the diathesis stress model helpfully offers an explanation for how biology and the environment may be both involved finally one great way to discuss the biological explanation relates to the debates you learn about in psychology the biological explanation for ocd has been criticized for being deterministic this is because it states that ocd is determined or caused by internal biological factors such as genetics or neural factors as a result people who are suffering with ocd have no control over their behavior they have no free will and are unable to change this is a rather pessimistic view of the condition as it implies that they can't improve and that their obsessive thoughts and compulsive behaviors are inevitable perhaps it could be argued that taking a deterministic view could actually further add to the anxiety that those suffering with ocd already experience therefore this suggests that the biological explanation's rather limited in its view of ocd because of the lack of choice it sees people have to manage it if you like this video and want to be a top psychologist consider giving me some positive reinforcement with that like button and perhaps leave a comment below for more on the topic of psychopathology and mental disorders check out this playlist for more and if you would like more information relating to mental health whether to help you or others do check out the links in the description for some helpful online resources and support services i hope you found this video helpful and we'll see you in the next one