9 Substance-Induced Disorders says...
Withdrawal results in agitation, severe body aches, gastrointestinal symptoms, dysphoria, and craving to use more opioids. Symptoms during withdrawal vary—some will become acutely anxious and agitated, while others will experience depression and anhedonia.
It adds that even with complete abstinence that these symptoms can last for weeks.
The paper sites Levinson et al. 1995 and Zukin and Zukin (1992) under the Opioid section, and also talks about PCP and it's effects such as an acute psychotic state.
PCP may have been included there as Drugs.com states:
PCP is a noncompetitive NMDA/glutamate receptor
antagonist, but also interacts with other receptor sites, and may have
effects with dopamine, opioid and nicotinic receptors.
Opioids and the Treatment of Chronic Pain: Controversies, Current Status, and Future Directions also explores opioid usage. They say that there are some people on opioids who have problematic behaviour that isn't related to the drugs. They do say that people who actually need the opioids act differently than people who are abusing the opioids, but it's not mutually exclusive. "[...] some patients who are treated for pain do develop severe behavioral disturbances indicative of a comorbid addictive disorder."
- Levinson I, Galynker II, Rosenthal RN. Methadone withdrawal
psychosis. Journal of Clinical Psychiatry. 1995;56:73–76. PubMed
- Zukin, S.R., and Zukin, R.S. Phencyclidine. In: Lowinson, J.H., Ruiz,
P., Millman, R.B., and Langrod, J.G., eds. Substance Abuse: A
Comprehensive Textbook. Baltimore: Williams & Wilkins, 1992. pp.
Continued research suggests that the only psychological effect that opioids have are psychological addiction. Although it can act as a sedative according to Benyamin et al. (but it is listed as a side effect).
In this study, they concluded that long-term use actually reduced functional connectivity in the brain. Although the patients that they were compared against had to be of clear health physically and mentally.
I was unable to find anything that suggested that it would help with psychosis. Most data suggests that it should only be used on a short term basis and long term use actually can cause detrimental effects mentally and physical dependance.
According to Treatment4Addiction.com withdraw actually causes psychosis and other detrimental effects, most of the research has been focused on getting away from opioids. It would probably be a bad idea to treat psychosis with a drug whose withdraw symptoms include psychosis.