Methamphetamine-induced psychosis is likely gated by genetic vulnerability, which can produce long-term changes in brain neurochemistry following repetitive use. Medication
Administration, or sometimes withdrawal, of a large number of medications may provoke psychotic symptoms. Drugs that can induce psychosis experimentally or in a significant proportion of people include stimulants, such as amphetamine and other sympathomimetics, dopamine agonists, ketamine, corticosteroids (often with mood changes in addition), and some anticonvulsants such as vigabatrin. Pathophysiology
Neuroimaging
The first brain image of an individual with psychosis was completed as far back as 1935 using a technique called pneumoencephalography (a painful and now obsolete procedure where cerebrospinal fluid is drained from around the brain and replaced with air to allow the structure of the brain to show up more clearly on an X-ray picture). Both first episode psychosis, and high risk status is associated with reductions in grey matter volume (GMV). First episode psychotic and high risk populations are associated with similar but distinct abnormalities in GMV. Reductions in the right middle temporal gyrus, right superior temporal gyrus (STG), right parahippocampus, right hippocampus, right middle frontal gyrus, and left anterior cingulate cortex (ACC) are observed in high risk populations. Reductions in first episode psychosis span a region from the right STG to the right insula, left insula, and cerebellum, and are more severe in the right ACC, right STG, insula and cerebellum.Another meta analysis reported bilateral reductions in insula, operculum, STG, medial frontal cortex, and ACC, but also reported increased GMV in the right lingual gyrus and left precentral gyrus.
Psychosis is an abnormal condition of the mind that results in difficulties determining what is real and what is not real. Symptoms may include delusions and hallucinations, among other features. Additional symptoms are incoherent speech and behavior that is inappropriate for a given situation. There may also be sleep problems, social withdrawal, lack of motivation, and difficulties carrying out daily activities. Psychosis can have serious adverse outcomes.As with many psychiatric phenomena, psychosis has several different causes. These include mental illness, such as schizophrenia or schizoaffective disorder, bipolar disorder, sensory deprivation and in rare cases, major depression (psychotic depression). Other causes include: trauma, sleep deprivation, some medical conditions, certain medications, and drugs such as cannabis, hallucinogens, and stimulants. One type, known as postpartum psychosis, can occur after giving birth. The neurotransmitter dopamine is believed to play an important role. Acute psychosis is considered primary if it results from a psychiatric condition and secondary if it is caused by a medical condition or drugs. The diagnosis of a mental health condition requires excluding other potential causes. Testing may be done to check for central nervous system diseases, toxins, or other health problems as a cause.Treatment may include antipsychotic medication, psychotherapy, and social support. Early treatment appears to improve outcomes. Medications appear to have a moderate effect. Outcomes depend on the underlying cause. In the United States about 3% of people develop psychosis at some point in their lives.