Intermittent explosive disorder (IED) is characterised as extreme outbursts of aggressive behaviour that can lead to damage or destruction of property and physically injuring animals and/or people within a 12-month period and the behaviour is out of proportion to the circumstance.  The behaviour is short-lived and impacts social and vocational aspects of the individual’s life.  One example of IED behaviour is road rage as mentioned in the psychological literature.  

Over the years, research for IED has found that the disorder in the Diagnostic Statistical Manual I - IV was too narrow and each manual therefore broadened the disorder.  Initially the disorder excluded individuals who had generalised aggression between the explosive acts (DSM II), whereas in the DSM-5 it does allow these symptoms.  The implication for allowing generalised aggression between the explosive acts is that more people are able to become diagnosed and therefore receive appropriate treatment.  Another important change includes symptoms classified as severe to less severe meaning that IED is dimensional.  The challenges that researchers have found when reexamining the disorder was that there are over 200 meanings for aggression causing a lack of precision in creating measurement tools for research and that low prevalence rates did not provide enough participants for research purposes.  

Intermittent Explosive Disorder is not a part of another mental disorder but can be diagnosed in addition if it occurs when the other disorder is not present. Individuals with IED show characteristics of impatience, hostility, trait-anger, being assaultive and resentment.  They also have greater prevalence of mood disorder and higher levels of state and trait anxiety.  Individuals with IED tend to console their victims after the attack as they did not want the outburst to occur and became remorseful.

Research has found that individuals who have symptoms of IED are often in the correctional system and tend to miss out on treatment.  It is important to understand an individual's aggressive outbursts from a therapeutical point of view to correct the behaviour with the appropriate treatment.  

Sources:
American Psychiatric Association. Diagnostic and statistical manual of mental disorders (5th ed.).  Washington, DC:  Author, 2013.

Baron, R. A., & Richardson, D. R. (1994).  Human Aggression (2nd ed.). New York: Plenum Press.

Coccaro, E. F. (2010).  A family history study of intermittent explosive disorder.  Journal of Psychiatric Research, 44, 1101-1105.  

Coccaro, E. F., Kavoussi, R. J., Berman, M. E., & Lish, J. D. (1998).  Intermittent explosive disorder-revised: Development, reliability, and validity of research criteria.  Comprehensive Psychiatry, 39(8), 368-376.

Galovski,, T., & Blanchard, E. B. (2002).  Psychological characteristics of aggressive drivers with and without intermittent explosive disorder.  Behaviour Research and Therapy, 40, 1157-1168.

Saha, A. (2010).  A case of intermittent explosive disorder.  Industrial Psychiatry Journal, 19(1), 55-57.  doi: 10.4103/0972-6748.77639.

To obtain interpersonal competency you need to think about what you value and the cost and rewards the interaction is going to give you.

Interdependence Theory suggests that we consider the cost and rewards when mixing with other people. When considering the cost and rewards we will consider if the person can satisfy our highest value. The value is interchangeable and is used to compare, which means that I can choose to interact with somebody because they are confident but they talk too much. I value confidence highly and willing to overlook verbosity, therefore I am willing to compensate. The cost of "confidence" will provide me with rewards of positive energy: I am investing in good energy. To do this I will provide the other person with silence so they will be heard as they prefer being verbose. Therefore we are okay communicating as we are willing to compensate. Over time, the way I think will change because I realise that verbose people aren't that bad. Even though Attachment Theory suggests that the way we think is stable (some theorists do say it can change over time) Interdependence Theory says it is susceptible to change, depending on whether we are willing to compensate so we can gain the necessary rewards: the rewards is far greater than the cost.

In a nutshell, what Interdependence Theory suggests is that we are always assessing other people's styles because of the outcomes it produces. The outcomes will provide internal satisfaction (and exceed it). If the value the other person is not as satisfying then we will feel discontent and look for alternatives. We are also willing to compensate by overlooking styles that we don't really value as other parts of the person provides high intrinsic value; making us more flexible.

On the other hand we can become dependent (rather than remaining interdependent) on the other person, and overlook a quality that does not match our value. This is why some people choose to stay in abusive relationships or work with abusive colleagues. Even though they may value respect, they don't have enough or relevant education to get out of it and therefore feel they have to put up with it. To overcome this possibility, always consider what you value. If the person doesn't match it and leaves you feeling unhappy and dissatisfied, then consider what is the cost and rewards you are gaining. If the cost is your happiness and the reward is financial dependence/convenience, then decide is it really worth what you are missing out on and can you get that reward elsewhere. Interdependence Theory suggests that people start to explore opportunities for more satisfying outcomes by considering the rewards and costs. What is the reward going to cost you? Realise you have the power to decide what is best for you, especially after you learn what you value.

Source: Blackwell Handbook of Social Psychology: Interpersonal Processes, Edited by Garth Fletcher and Margaret Clark. Blackwell Publishing, 2003, USA.