Psychosis refers to a loss of contact with reality, usually including delusions (fixed false beliefs) and hallucinations (hearing or seeing things that aren’t there). Psychosis can occur at any age, but most commonly emerges in late adolescence and early adulthood. However, psychosis can also develop later in life, even in individuals with no prior history of mental illness. Late onset psychosis, defined as onset after age 40, accounts for 15-20% of cases of schizophrenia. Understanding the causes of new onset psychosis in middle and late life is important for treatment and prevention.
What is psychosis?
Psychosis is characterized by two main types of symptoms – positive and negative:
Positive symptoms:
- Delusions – fixed false beliefs not shared by others in the person’s culture, such as paranoia or grandiose delusions.
- Hallucinations – usually hearing voices, but can also involve seeing, tasting, feeling or smelling things that are not really there.
- Disorganized thinking and speech.
- Grossly disorganized or abnormal motor behavior.
Negative symptoms:
- Lack of emotion or facial expressions.
- Lack of interest and motivation to engage in activities.
- Problems with focus and attention.
- Slowed thinking and problems with memory.
Psychosis causes significant distress and impairment in social, occupational, and other areas of functioning. It reflects a loss of contact with consensual reality.
What are the risk factors for late onset psychosis?
A number of medical, neurological, and psychosocial factors can increase the risk of developing psychosis later in life. These include:
Neurological conditions:
- Dementia – Alzheimer’s disease, Lewy body dementia, frontotemporal dementia
- Parkinson’s disease
- Stroke
- Brain tumor
- Huntington’s disease
- Multiple sclerosis
- HIV/AIDS
Medical conditions:
- Endocrine disorders – thyroid problems, adrenal disorders
- Vitamin deficiencies
- Electrolyte abnormalities
- Liver or kidney failure
- Autoimmune disorders
- Infections – neurosyphilis, HIV, encephalitis
- Sensory deficits – hearing loss, vision loss
Medications: Many prescription drugs can trigger psychotic symptoms, including:
- Corticosteroids
- Dopamine agonists
- Immunosuppressants
- Anticholinergics
- Antihistamines
- Antidepressants
- Stimulants
Genetics: Family history of psychosis or schizophrenia.
Stress: Major life stressors such as social isolation, bereavement, divorce or job loss.
Pre-existing mental illness: History of mood disorder or post-traumatic stress disorder.
Substance use: Alcohol or drug misuse.
Causes of psychosis in neurological conditions
Many neurological diseases that affect the brain can trigger the onset of psychosis in older adults.
Dementia
Dementia involves progressive decline in memory, thinking and behavior. Hallucinations and delusions are common symptoms that occur in many types of dementia, including:
- Alzheimer’s disease – delusions of theft or infidelity, misidentification delusions.
- Lewy body dementia – vivid visual hallucinations.
- Frontotemporal dementia – delusions and disinhibition.
- Vascular dementia – delusions of theft or persecution.
Dementia damages brain regions involved in memory, cognition and behavior regulation. This leads to psychotic symptoms emerging as the disease progresses.
Parkinson’s disease
Up to half of people with Parkinson’s disease experience mild psychotic symptoms like hallucinations or delusions. This is thought to result from the disease process affecting dopamine circuits in the brain. Dopamine dysregulation can lead to psychosis. Parkinson’s medications like levodopa may also trigger psychotic side effects.
Stroke
Psychosis can sometimes occur following a stroke, especially if the stroke damages areas like the temporal lobe and subcortical regions. Stroke-related brain damage may disrupt brain dopamine and neurotransmitter systems, impairing reality testing.
Brain tumors
Tumors in the brain can initiate psychosis in several ways, such as by:
- Direct damage to brain tissue.
- Increasing pressure and inflammation.
- Disrupting neurotransmitter balance.
- Causing seizures.
Psychotic symptoms often resolve if the tumor is successfully treated.
Huntington’s disease
Huntington’s is an inherited neurodegenerative disorder caused by a genetic mutation. It causes gradual damage to brain cells, leading to movement, cognitive and psychiatric problems. About 10% of people with Huntington’s experience psychotic symptoms like delusions and hallucinations.
Multiple sclerosis
Multiple sclerosis (MS) involves damage to the protective nerve sheaths. This disrupts communication between the brain and body. Psychosis affects a small percentage of people with MS, likely due to brain lesions and neurotransmitter imbalances induced by the disease.
HIV/AIDS
Psychosis can occur in people living with HIV/AIDS. It may result directly from HIV infection damaging the brain. Opportunistic infections and immune dysregulation may also contribute. Certain HIV medications have been associated with psychiatric symptoms.
Causes of psychosis in medical conditions
Many medical illnesses and conditions raise the risk for new onset psychosis in adults by causing disturbances in brain function.
Endocrine disorders
Endocrine system disorders like hypothyroidism, Cushing’s syndrome and Addison’s disease affect hormone regulation. Imbalances in thyroid, cortisol or adrenal hormones can impair brain function and trigger psychotic symptoms like hallucinations or delusions. Correcting the hormone abnormalities typically resolves psychosis.
Nutritional deficiencies
Deficiencies in vitamins like B12, niacin and folate can precipitate psychosis in older adults. These vitamins are essential for brain processes like neurotransmitter synthesis and myelin production. Supplementing vitamins often improves psychotic symptoms.
Electrolyte disturbances
Abnormal levels of body chemicals like sodium, calcium and potassium are linked to late life psychosis. Electrolyte imbalance alters brain cell functioning, which can cause thought disturbances. Restoring normal electrolyte levels is an important part of treatment.
Liver or kidney disease
Liver dysfunction like cirrhosis can produce psychosis by causing a buildup of toxins that damage the brain. Kidney failure allows waste products to accumulate, also inducing neurotoxic effects. Dialysis treatment for kidney disease may improve mental status.
Infections
Infections like neurosyphilis, HIV, herpes encephalitis and Lyme disease can all lead to psychotic symptoms. The infectious agents cross into the brain, triggering inflammation, delirium and psychosis. Treating the underlying infection is critical.
Sensory deficits
Untreated vision or hearing loss, common in the elderly, deprives the brain of sensory stimulation. This sensory deprivation can cause distortions in perception that manifest as psychotic-like experiences. Restoring sensory input through vision aids or hearing devices can help correct the problem.
Medication-induced psychosis
Many medications used to treat medical conditions can also provoke psychotic side effects, including:
Corticosteroids
Corticosteroid medications like prednisone are used to reduce inflammation in conditions like asthma, allergies and arthritis. They carry risks of side effects like mania, mood swings, hallucinations and confusion. Psychosis usually resolves with discontinuation.
Dopamine agonists
Parkinson’s drugs like pramipexole and ropinirole act on dopamine receptors. This can elevate dopamine neurotransmission too much, leading to psychotic symptoms. Reducing the medication dosage often minimizes side effects.
Immunosuppressants
Drugs that suppress the immune system, like chemotherapy agents and biologics used in autoimmune conditions, are associated with delirium and psychosis, likely resulting from their effects on the brain.
Anticholinergics
Anticholinergic medications block acetylcholine activity in the nervous system. Drugs with anticholinergic effects include some antihistamines, tricyclic antidepressants, bladder antispasmodics, antiparkinson agents and muscle relaxants. Anticholinergic side effects include confusion, memory loss, hallucinations and delirium.
Stimulants
Stimulant medications for conditions like ADHD and narcolepsy can trigger psychosis at higher doses by overactivating dopamine receptors. Amphetamines and methylphenidate carry risks of psychotic symptoms like paranoia and hallucinations.
Genetic factors
Genetics play a role in late life psychosis. Having a close family member with schizophrenia increases risk, suggesting shared genetic vulnerability. Specific gene variants affecting dopamine function may contribute. However, genes alone cannot explain most psychosis cases starting after middle age. Environmental triggers and risk factors are still required for illness to develop.
Stress as a trigger
Major stressful life events can act as triggers precipitating psychosis in predisposed older adults. Stress impacts hormone levels, neurotransmitters, inflammation and brain activity in ways that may destabilize thinking. Significant individual stressors linked to late life psychosis include:
- Bereavement or grief
- Social isolation or loneliness
- Divorce or family conflict
- Job loss or retirement
- Financial stressors
- Changes in living situation
- Medical illness or disability
Stress often interacts with genetic, biological and cognitive vulnerabilities to instigate psychosis later in life.
Effects of pre-existing mental illness
Individuals with a history of mental health conditions like major depression or PTSD may experience their first psychotic episode later in life, triggered by factors like stress, aging or medical illness.
Previous depressive or manic episodes are linked to greater psychosis risk in older populations. Mood disorders can sensitize brain pathways, priming the individual for psychosis when additional insults occur.
PTSD also heightens psychosis vulnerability. Trauma exposure changes brain function in ways that can lower the threshold for hallucinations and reality distortions under stress.
Effective treatment of underlying mood and trauma disorders may help prevent late life psychosis from developing.
Substance use problems
Alcohol and drug misuse frequently contribute to new onset psychosis in middle-aged and older adults. Substance use is associated with neurological changes and vitamin deficiencies that can trigger psychotic breaks. Specific substance-related risks include:
- Alcohol – alcohol misuse is linked to psychotic disorders like Korsakoff’s syndrome.
- Cocaine and amphetamines – stimulant use can provoke paranoia and hallucinations.
- Cannabis – frequent cannabis use may precipitate psychosis in vulnerable individuals.
- Prescription drug misuse – medications like opioids carry psychosis risks.
Getting substance use problems under control through counseling, 12-step programs, or residential treatment can help prevent recurrent psychosis.
When to seek help
New onset of psychotic symptoms like delusions or hallucinations after age 40 requires prompt medical evaluation. Early treatment maximizes the chances of uncovering reversible causes and achieving an optimal recovery.
Seeking help is crucial because untreated psychosis tends to worsen over time. Prompt treatment also helps minimize risks and distress to the individual experiencing psychosis.
Evaluation for new psychosis involves a complete medical workup, neurologic examination, cognitive testing, assessment of medications and substance use, and mental health interview. Input from friends and family members is extremely helpful.
The cause of psychosis dictates the appropriate treatment approach. Treatment can involve medications, therapy, correcting medical conditions, changing medications, brain stimulation, skills training, and family support.
With personalized, integrated treatment, many people with late life psychosis experience significant improvement and enhanced quality of life. While some cases are progressive, early intervention provides the best opportunity for recovery.
Conclusion
The onset of psychosis later in life has a wide range of potential causes, spanning from neurologic illnesses like dementia to medication side effects and stress. Medical evaluation aims to uncover any reversible factors fueling psychosis. Integrated, individually tailored treatment can help most people achieve stabilization and restoration of functioning. Increased awareness and recognition of late life psychosis allows for earlier intervention and better outcomes. Ongoing research continues to advance our understanding of biological and environmental contributors in order to inform prevention and support healthy aging.