A “conspiracy theorist” has been derided as a “conspiranoid” (conspiracy + paranoid) since at least June 1992. Conspiracy theorists questioned the truth about the 1963 assassination of U.S. President John F. Kennedy and the 1968 assassination of Martin Luther King, Jr. The 1991 film JFK repopularized some conspiracy theories.
 
Similar terms include “conspiracy nut” (since at least 1971), “conspirazoid” (since May 1996) and “conspiratard” (since October 2004).
 
 
Urban Dictionary
conspiranoid
A paranoia heightened by the belief that unseen forces are organized against one’s self or values, or against the general wellfare; persecution fantasy marked by belief that persons perceived negatively by the afflicted are operatives or dupes of real or imagined clandestine organizations.
“I can’t talk to that guy anymore; he’s gone so conspiranoid, he thinks our landlord is writing reports on his daily movements for the International Kommisariat of Screwing Over Delusional Nutjobs.”
by Stephen Couchman Nov 16, 2006
 
Merriam-Webster’s Online Dictionary
Main Entry: para·noid
Pronunciation: \ˈper-ə-ˌnȯid, ˌpa-rə-\
Variant(s): also para·noi·dal  \ˌper-ə-ˈnȯi-dəl, ˌpa-rə-\
Function: adjective
Date: 1904
1 : characterized by or resembling paranoia
2 : characterized by suspiciousness, persecutory trends, or megalomania
3 : extremely fearful
— paranoid noun
     
Google Groups: alt.politics.elections
Newsgroups: talk.politics.misc, alt.politics.elections
From: .(JavaScript must be enabled to view this email address) ()
Date: Tue, 23 Jun 1992 18:32:21 GMT
Local: Tues, Jun 23 1992 1:32 pm
Subject: Re: Conspiracies (was Re: Life under President Perot)
 
Now just a minute, there’s no reason to get conspiranoid over this!
     
Google Groups: alt.conspiracy.jfk
Newsgroups: alt.conspiracy.jfk
From: rharris@rt66,com (Robert Harris)
Date: 27 Nov 1994 16:05:12 GMT
Local: Sun, Nov 27 1994 11:05 am
Subject: Re: “Secrets of the Assassination”
 
Guess anybody would have to be a raving “Conspiranoid” (there’s a new stereotype name for you guys) to think the CIA had anything to do with that marriage, huh?
 
Google Books
Jamming the Media: a citizen’s guide
Reclaiming the tools of communication
By Gareth Branwyn
San Francisco, CA: Chronicle Books
1997
Pg. 30:
Overnight, this fringe culture had gone from almost complete obscurity to being a runaway media virus. The sales of conspiranoid media skyrocketed ... at least for fifteen minutes.
     
Google Groups: austin.general
Newsgroups: austin.general, austin.usenet.config
From: “David,”

Date: 1997/10/05
Subject: Re: Rosenthal: Net Censor
 
> By the way, the public on Usenet does indeed guide the rules.  There is an
> established process (vs. some ad hoc mechanism created last night to keep
> you silent, as much as your conspiranoid[1] mind may be attracted to that
> idea) by which newsgroups are created and maintained.