Introduction Life becomes difficult for people with obsessive-compulsive disorder (OCD) as they tend to have persistent, upsetting thoughts (obsessions). In order to control the anxiety these thoughts produce they use rituals (compulsions). In other words OCD is a psychiatric anxiety disorder most commonly characterized by a subject’s obsessive, distressing, intrusive thoughts and related compulsions which try to neutralize the obsessions. In most of the cases of OCD it is the rituals that end up controlling them. For instance, if a person is obsessed with germs or dirt, they may develop a compulsion to wash their hands over and over again. There are cases when some keep checking if they have locked the door properly since they develop an obsession with intruders. Though performing such rituals is not pleasurable, it produces temporary relief from the anxiety created by obsessive thoughts. Even though most adults with OCD are aware of the fact that what they are doing is absurd, some adults and most children may not realize that their behaviour is out of the ordinary (NIMH, 2008). Obsessions can be defined as unwanted ideas, images, or impulses that repetitively enter a person’s mind. Although recognized as being self generated, they are experienced as “egodystonic” (out of character, unwanted, and distressing). Compulsions can be defined as repetitive stereotyped behaviours or mental acts determined by rules that must be applied rigidly. In general, they are intended to neutralise anxiety provoked by the obsessions (Heyman, 2006). It is estimated that approximately 2.3% of people between the ages of 18 and 54 in the world suffer from OCD (ocd-world.org.uk, N.D). This problem can be accompanied by eating disorders (Wonderlich and Mitchell,1997), other anxiety disorders, or depression (Regier et al., 1998). Studies have found that there is not much difference in the number between males and females and usually appears in childhood, adolescence, or early adulthood (Robins and Regier 1991). One-third of adults with OCD develop symptoms as children, and research indicates that OCD might be genetic in nature (NIMH, 1998). At some point of time the sufferer must realize that his/her obsessions or compulsions are unreasonable or excessive. Furthermore, the obsessions or compulsions must be time-consuming probable taking up more than one hour per day, cause distress, or cause harm in social, occupational, or school functioning (American Psychiatric Association, 2000). OCD often causes feelings similar to those of depression. This paper basically intends to review the presentation and assessment of OCD and discusses the current best treatment options. Causes and related disorders In the recent research the scientific community studying obsessive-compulsive disorder is split into two groups contradicting over the cause of OCD. One group believes that obsessive-compulsive behaviour is a psychological disorder; where as others thinks it has a neurological origin. A majority of researchers now believe in this neurological hypothesis. According to the studies conducted by Stanford University School of Medicine “although the causes of the disorder still elude us, the recent identification of children with OCD caused by an autoimmune response to Group A streptococcal infection promises to bring increased understanding of the disorder’s pathogenesis.” (Stanford University School of Medicine, 2008). Symptoms The f