Litigious Paranoia (paranoia querulans)
The clinical form of litigious paranoia presents uniform characteristic features which are recognized in every civilized community. The basic emotion is vanity, but added to that is a strong element both of acquisitiveness and avarice. Moreover the subjects are, as regards character, persistent, opinionative and stubborn. When these qualities are superadded to a mind of the paranoiac type, which as has been pointed out, is more influenced by the passions or emotions than by ordinary rational considerations, it can readily be appreciated that the subjects are capable of creating difficulties and anxieties which sooner or later may lead to their forcible seclusion in the interests of social order.
It is important to observe that the rights such people lay claim to or the wrongs they complain of may not necessarily be imaginary. But, whether imaginary or real, the statement of their case is always made to rest upon some foundation of fact, and is moreover presented, if not with ability, at any rate with forensic skill and plausibility. As the litigants are persons of one idea, and only capable of seeing one side of the case - their own - and as they are actuated by convictions which preclude feelings of delicacy or diffidence, they ultimately succeed in obtaining a hearing in a court of law under circumstances which would have discouraged any normal individual. Once in the law courts their doom is sealed. Neither the loss of the case nor the payment of heavy expenses have any effect in disheartening the litigant, who carries his suit from court to court until the methods of legal appeal are exhausted. The suit may be raised again and again on some side issue, or some different legal action may be initiated. In spite of the alienation of the sympathy of his relations and the advice of his friends and lawyers the paranoiac continues his futile litigation in the firm belief that he is only defending himself from fraud or seeking to regain his just rights. After exhausting his means and perhaps those of his family and finding himself unable to continue to litigate to the same advantage as formerly, delusions of persecution begin to establish themselves. He accuses the judges of corruption, the lawyers of being in the pay of his enemies and imagines the existence of a conspiracy to prevent him from obtaining justice. One of two things usually happens at this stage. Though well versed in legal procedure he may one day lose self-control and resort to threats of violence. He is then probably arrested and may on examination be found insane and committed to an asylum. Another not uncommon result is that finding himself non-suited in a court of law he commits a technical assault upon, it may be, some high legal functionary, or on some person in a prominent social position, with the object of securing an opportunity of directing public attention to his grievances. The only result is, as in the former instance, his medical certification and incarceration.
A recent source
Paranoia querulans appears in a 2007 tabulation of mental disorders (see item 297.8). In other words, it is not like, say, "brain fever," a diagnosis that's been superseded in the light of improved knowledge, or "dementia praecox," a name now considered obsolete or imprecise.