Managing Cancer-Related Mood Shifts & Emotional Distress

This page is for families and caregivers of someone with cancer who has become angry, suspicious or unlike themselves. It explains the common medical causes and when to get help.

Families often describe the same thing in different words. He has become cruel. She says things she would never have said. He is suspicious of me. She cannot be reasoned with. It is frightening. It is also one of the most misread parts of cancer care. The natural reading is that the person has chosen to become someone else.

Very often, they have not. Anger, suspicion, disinhibition (losing the usual brakes on behavior), flat indifference and sudden agitation are frequently symptoms with medical causes. Those causes can be identified, and in many cases treated. Report the change to the oncology team. That is far more useful than absorbing it.

The sections below walk through the main causes, one at a time.

Delirium is a confused mental state. It involves changes in awareness, thinking, judgment, sleep patterns and behavior. It typically develops over hours or days rather than gradually, and it fluctuates. That is why families often report that the person was fine in the morning and unrecognizable by evening.

It takes three forms. Hyperactive delirium looks like restlessness, anxiety, agitation and refusal to cooperate. Hypoactive delirium looks like sleepiness or depression, and is often missed entirely. Mixed delirium alternates between the two.

Common triggers in cancer include advanced disease and brain tumors. Medicines are another, particularly high doses of opioids. So are dehydration, infection, and stopping or withdrawing a medicine. Older age raises the risk. This part matters: many episodes are caused by medication or dehydration, and they are reversible once the cause is corrected.

Dexamethasone and prednisone are used widely in cancer care. MedlinePlus lists restlessness, trouble sleeping, depression and anxiety among the side effects of dexamethasone, and extreme changes in mood and changes in personality among those of prednisone. It says to tell your doctor if these are severe or do not go away. Do not stop or change a steroid on your own, but do raise it with the care team early rather than enduring it.

Cancer in or near the brain can change behavior directly. NCI lists changes in personality, mood, ability to focus or behavior among the symptoms of brain tumors. The person may not be aware anything has changed.

Not everything is neurological. Uncontrolled pain makes people short-tempered. Severe fatigue removes the reserve people normally use to be gracious. Fear, loss of independence and the humiliation of needing help with intimate tasks all come out as irritation. The person nearest is the one who receives it.

Whatever the cause seems to be, the team needs a clear picture. Describe the change the way you would describe a fever. What is new. When it started. Whether it comes and goes. What else changed around the same time. Useful details include:

• any new medicine or dose change in the preceding week
• whether the person is drinking
• whether they are constipated or short of breath
• whether sleep has reversed
• whether they know the date and where they are

Ask directly whether delirium has been considered. Ask whether any current medicine could be responsible. Ask whether the steroid dose can be reviewed.

Understanding the medical cause does not mean accepting anything. Driving, access to firearms, wandering, cooking unsupervised and physical aggression are safety issues rather than things to manage at home. The section below sets out who to call, and how fast.

It is also possible to hold both facts at once. The illness is producing the behavior. And the behavior is doing real harm to the people absorbing it. Both deserve attention.

• Call 911 or go to an emergency department if the person strikes someone or threatens someone with a weapon. Do the same if they are set on driving or leaving the house while confused and cannot be redirected. Move yourself and anyone else out of reach first, then call.
• Call 911 or go to an emergency department if the confusion arrived over a few hours, the person cannot be kept awake or roused, or they have a seizure. Do the same if a fever of 100.4°F (38°C) or higher appears during chemotherapy. That fever is an emergency by itself (CDC).
• Call the oncology team right away if confusion, suspicion or agitation came on over days, or comes and goes across the day. Ask outright whether this could be delirium. Say what medicine or dose changed in the week before.
• Call the oncology team right away if irritability, sleeplessness or agitation began after starting or raising a steroid such as dexamethasone. Ask whether the dose can be reviewed.
• Call the oncology team within a day or two if judgment, impulse control or warmth has drifted over weeks, and the person does not seem to notice it themselves. Ask whether the brain has been imaged.
• Call within a day or two if the person has stopped drinking, is newly constipated, or is sleeping in the day and awake all night. Each of these can be feeding the confusion, and each can be treated.

• NCI — Delirium (PDQ)
• MedlinePlus — Dexamethasone
• MedlinePlus — Prednisone
• NCI — Adult Central Nervous System Tumors Treatment (PDQ)
• NCI — Last Days of Life (PDQ)
• NCI — Emotions and Cancer