Autoimmune psychosis is a distinct medical condition where the body’s immune system mistakenly attacks the brain, leading to symptoms that affect a person’s thoughts, perceptions, and behaviors. This condition differs from traditional psychiatric disorders because it has an identifiable physical cause within the body.
What Is Autoimmune Psychosis?
Psychosis generally refers to a break from reality, where individuals may experience hallucinations or delusions. Autoimmune psychosis is a unique form of this condition because it stems from the body’s own immune system attacking its brain cells or disrupting normal brain function. It is considered a physical, neurological condition rather than solely a mental health disorder. This means it requires a medical diagnosis. This form of psychosis differs from primary psychiatric conditions, which do not have a clear physical cause.
How the Immune System Causes Psychosis
The underlying mechanism of autoimmune psychosis involves the immune system producing specific proteins called autoantibodies. These autoantibodies mistakenly target and bind to healthy receptors or proteins in the brain. For instance, in anti-NMDA receptor encephalitis, autoantibodies attack the NMDA receptors in the brain. These receptors are involved in various brain functions, including thinking, movement, and mood regulation.
When these autoantibodies bind to their targets, they can cause inflammation and disrupt the normal communication between neurons, leading to neuronal dysfunction. This immune system misbehavior can arise in conditions such as autoimmune encephalitis, where the brain itself becomes inflamed, or in systemic autoimmune diseases that affect multiple body systems, including the brain. Systemic Lupus Erythematosus (SLE) and Hashimoto’s encephalopathy are examples of such conditions that can manifest with psychotic symptoms.
Common Signs and Symptoms
The symptoms of autoimmune psychosis can vary, often including typical psychotic features like hallucinations, delusions, disorganized thoughts, and paranoia. These symptoms can develop acutely or subacutely, meaning they appear rapidly over days to weeks, which often distinguishes them from the more gradual onset seen in primary psychiatric disorders. Beyond these psychiatric manifestations, individuals may also experience other neurological or systemic symptoms.
These additional symptoms can involve cognitive changes such as memory loss, confusion, and difficulty concentrating. Seizures are also a common occurrence, as are various movement disorders, including abnormal facial movements or involuntary body movements. Sleep disturbances, headaches, and fever can also be present. In some cases, there might be changes in consciousness, ranging from lethargy to a catatonic state, along with rapid mood swings or other behavioral changes like agitation or inappropriate conduct.
Identifying and Treating Autoimmune Psychosis
Diagnosis
Diagnosing autoimmune psychosis involves a comprehensive evaluation to identify the specific immune-mediated cause. This process typically begins with a thorough medical history and a neurological examination to assess symptoms and pinpoint any neurological deficits. Blood tests are often performed to screen for the presence of autoantibodies, such as anti-NMDA receptor antibodies, LGI1, CASPR2, or anti-thyroid peroxidase antibodies (TPOAb) which are associated with Hashimoto’s encephalopathy.
A lumbar puncture is frequently conducted to collect cerebrospinal fluid (CSF) for analysis. CSF analysis can reveal signs of inflammation, such as an elevated white blood cell count, or the presence of specific autoantibodies within the fluid surrounding the brain and spinal cord. Brain imaging, such as magnetic resonance imaging (MRI), is used to identify structural changes or areas of inflammation in the brain, although MRI results can appear normal in about half of patients with certain types of autoimmune encephalitis. Electroencephalography (EEG), which measures brain electrical activity, can detect abnormal patterns or epileptic discharges, commonly seen in these conditions.
Treatment
Treatment for autoimmune psychosis primarily focuses on modulating the immune system to reduce the autoimmune attack on the brain. First-line immunotherapies commonly include corticosteroids, which help suppress inflammation. Intravenous immunoglobulin (IVIg) is administered to neutralize autoantibodies and provide anti-inflammatory effects. Plasma exchange (PLEX) is another first-line treatment that involves removing the patient’s plasma and replacing it with donor plasma or a substitute.
For patients who do not respond adequately to initial treatments or have more severe cases, second-line immunosuppressants may be used. These can include medications like rituximab or cyclophosphamide, which target specific immune cells to further suppress the autoimmune response. In addition to immunotherapies, supportive treatments are often used to manage acute psychotic symptoms. Antipsychotic medications can help control hallucinations and delusions, and benzodiazepines may be used for agitation or seizures. These symptomatic treatments are typically used in conjunction with immunotherapy, rather than as the sole treatment, to address both the symptoms and the underlying immune cause.