In panic disorder, intense anxiety is the predominant symptom, virtually always accompanied by severe somatic symptoms that include the following:
- Shortness of breath.
- Tingling sensations.
- Fears of going crazy or that a heart attack is occurring.
Panic disorder is characterized by discrete panic "attacks" that are experienced as happening suddenly, often without a specific trigger, and become intense very quickly. Attacks or discrete periods of intense discomfort generally last for several minutes or longer, but the discomfort generally lasts for hours. A common complication is agoraphobia or avoidance of open places, caused by fear of situations that might trigger attacks. Patients with panic attacks often present with symptoms that can be difficult to differentiate from other medical disorders, though a known history of panic disorder can help clarify the diagnosis. Panic disorder in patients with cancer is most often managed with benzodiazepines and antidepressant medications  but also responds well to CBT.
Generalized anxiety disorder
Generalized anxiety disorder is characterized by ongoing, unrealistic, and excessive anxiety and worry about two or more life circumstances, to a degree that is pervasive and does not respond to either reassurance or contrary evidence. The following physical symptoms may be reported but do not have the sudden onset or intensity of panic attacks:
- Motor tension (restlessness, muscle tension, and being easily fatigued).
- Autonomic hyperactivity (shortness of breath, heart palpitations, sweating, and dizziness).
- Vigilance in scanning (feeling keyed up and on edge, irritability, and having exaggerated startle responses).
Some examples of generalized anxiety disorder are patients' fears that no one will care for them, even though they have adequate and willing social support; and the fear of exhausting their finances, even though adequate insurance and financial coverage is available. Frequently, a generalized anxiety disorder is preceded by a major depressive episode.
Obsessive-compulsive disorder (OCD) is characterized by persistent thoughts, ideas, or images (obsessions) and by repetitive, purposeful, and intentional behaviors (compulsions) that a person performs to manage his or her intense distress. To qualify as OCD, the obsessive thoughts and compulsive behaviors must be time-consuming and sufficiently distracting to interfere with the person's ability to function in employment, academic, or social situations.
Patients with cancer who have a history of OCD may engage in compulsive behaviors such as hand washing, checking, or counting to such an extent that they cannot comply with treatment. For such patients, normal worry about the cancer diagnosis and prognosis can develop into full obsessive-compulsive symptoms and be severely disabling. OCD is most often managed with serotonergic antidepressant medications (selective serotonin reuptake inhibitors [SSRIs] and clomipramine) and CBT. Milder obsessive thoughts or use of rituals that are not interfering might be addressed with CBT, but medications are not indicated. This disorder is rare in cancer patients who do not have a premorbid history.