The Trouble With Psychosis....

Alcohol misuse and drug misuse can trigger a psychotic episode.

A person can also experience a psychotic episode if they suddenly stop drinking alcohol or taking drugs after

using them for a long time. This is known as withdrawal.

It's also possible to experience psychosis after drinking large amounts of alcohol or if you're high on drugs.
Drugs known to trigger psychotic episodes include:

• cocaine
• amphetamine (speed)
• methamphetamine (crystal meth)
• mephedrone (MCAT or miaow)
• MDMA (ecstasy)
• cannabis
• LSD (acid)
• psilocybins (magic mushrooms)
• ketamine
  

In rare situations, psychosis can also occur as a side effect of some types of medication, or as a result of an overdose of that medication.
For example, levodopa, a medication that's used to treat Parkinson's disease, can sometimes cause psychotic episodes. However, any medicine that acts on the brain can cause psychosis with an overdose.
Read more at My Addicted Mind.com

Reference:

Psychosis - Causes, (2014), Causes of psychosis. Retrieved from http://www.nhs.uk/Conditions/Psychosis/Pages/Causes.aspx