Mood Swings and Cognitive Changes

Printer Friendly

Behavior is the way in which a person responds to a certain set of conditions. Changes in personality and behavior occur in the majority of patients with brain tumors at some point during their treatment.


In some cases, these changes are so subtle that the patients themselves are more aware of their difficulties than are those around them. In others, it is the caregiver rather than the patient who first recognizes that something is different.


Common cognitive changes and personality-related problems and difficulties experienced by patients with brain tumors are usually associated with:

  • Language and Communication: Difficulty with verbal fluency; speaking, reading, and/or writing.
  • Emotion and Personality: Psychiatric symptoms such as depression, anxiety, or obsessive-compulsive behaviors; changes in emotional control such as irritability, mood swings, or withdrawal; socially inappropriate behavior; and/or denial that behavior is a problem.
  • Learning and Memory (particularly short-term memory): Difficulty processing, storing, and remembering information; short-term memory loss.
  • Attention and Concentration: Confusion, easy distraction, difficulty multitasking and planning.
  • Executive Functioning/General Intellectual Abilities: Decreased reasoning ability, impaired judgment, inability to connect cause and effect.

The area of the brain affected by the tumor is often linked to the symptoms experienced. The diagram below shows some of the different areas of the brain that are directly related to behavior.

  • Frontal lobe: Movement, intelligence, reasoning, behavior, memory, personality, planning, decision making, judgment, initiative, inhibition, mood.
  • Temporal lobe: Speech, behavior, memory, hearing, vision, emotions.
  • Parietal lobe: Intelligence, reasoning, telling right from left, language, sensation, reading.


It is estimated that more than half of all patients with malignant brain tumors experience some behavioral changes.


A number of factors can lead to changes in behavior in patients with brain tumors. The location, size, and rate of growth of the tumor can have a lot to do with how a patient behaves. Treatments such as radiation, surgery, and chemotherapy can also affect how the patient feels and acts. The psychological and emotional effects of brain tumors are important to consider as well.


Patients with brain tumors should be encouraged to undergo a complete neuropsychological evaluation. This detailed evaluation of a patient’s behavioral, cognitive, and emotional status can help identify issues so that the best treatment can be provided.

Different behavioral issues are addressed in different ways:

  • Language and Communication: Typically managed with speech and language therapy, as well as cognitive rehabilitation therapy*.
  • Emotional and Personality: Typically managed with cognitive rehabilitation therapy*, psychotherapy, and medication.
  • Learning and Memory: Typically managed with cognitive rehabilitation therapy* and speech and language therapy.
  • Attention and Concentration: Typically managed with cognitive rehabilitation therapy* and medication.
  • Executive Functioning/General Intellectual Abilities: Typically managed with cognitive rehabilitation therapy* and problem-solving therapy.

*Cognitive rehabilitation is specialized therapy designed to help patients regain as much of their mental, physical, and emotional abilities as possible.

It is not unusual for brain tumor symptoms to change over time. Be sure to discuss any new symptoms or changes in existing symptoms with your doctor or nurse as soon as possible.

It is important to note that the information provided here is basic and does not take the place of an in-person assessment by a physician. If there is any question about the seriousness of changes in behavior or any other symptom experienced, please contact your doctor.