Obsessive compulsive disorder, often abbreviated as OCD, results in invasive thoughts that drive patients to perform repetitive behaviors. Patients with OCD have a cycle of symptoms: They perform the compulsions to reduce the obsessions, but the obsessions become more persistent, causing anxiety to increase. OCD patients can have other psychological disorders. Stanford University School of Medicine notes that 31 percent of OCD patients also have major depression, a disorder marked by persistent sadness.
Changes in Thinking
Both OCD and depression affect how patients think. For example, depression causes slowed thinking and decreased concentration. These thinking problems affect a patient's memory abilities, her capacity to form new memories and remember past information. Depression can also affect decision-making abilities, resulting in indecisiveness and issues with problem solving. With OCD, the anxiety-causing obsessions take over a patient's thinking. The Mayo Clinic's website points out that these obsessions are persistent and unwanted and usually follow a theme. For example, a patient's obsessions can focus on dirt; in which case, all of her thoughts would consist of dealing with germs and maintaining cleanliness. Another patient's obsessions may focus on keeping order. Some patients might have aggressive or sexual obsessions, which could scare them.
Changes in Behavior
Patients can have noticeable changes in their behavior. With OCD, patients have compulsions, or repetitive behaviors, that they feel they must perform in order to reduce their anxiety levels. Just like the obsessions, the compulsions also follow a theme. For example, if a patient's obsessions focus on dirt and germs, he may wash his hands excessively as his compulsion. Some patients may feel they always have to have things in a certain order. Other patients need to count or check certain things before they feel they can continue with their activities for the day. The Mayo Clinic's website describes how these patients feel powerless to stop these behaviors, which decrease their quality of life. With depression, patients lose interest in activities they used to enjoy. For example, a patient suffering from depression might have a reduced sex drive. Depression can also cause changes in appetite and sleep, such as a decreased appetite and increased need for sleep. These behavioral changes from depression might cause a lack of energy in some patients.
Mood Changes
Depression affects a patient's emotions, but the controlling symptoms of OCD can as well. During a depressive episode, some patients might feel sad or unhappy and experience crying spells. Other patients might feel irritable instead. Still others might suffer guilt and focus on mistakes they made earlier in their lives. In severe cases of depression, patients might have thoughts of death. The Mayo Clinic's website explains that OCD may cause patients to feel distressed and embarrassed by their condition.
