The combination of pharmacotherapy with cognitive therapy integrates treating the possible underlying biological problems and decreasing the symptoms with psychotherapy as well. Psychotherapy has been said to be the most useful form of treatment because of the trust formed in a patient and therapist relationship.Supportive therapy has also been shown to be helpful. Its goal is to facilitate treatment adherence and provide education about the illness and its treatment. Furthermore, providing social skills training has been found to be helpful for many people. It can promote interpersonal competence as well as confidence and comfort when interacting with those individuals perceived as a threat.Insight-oriented therapy is rarely indicated or contraindicated; yet there are reports of successful treatment. Its goals are to develop therapeutic alliance, containment of projected feelings of hatred, powerlessness, and badness; measured interpretation as well as the development of a sense of creative doubt in the internal perception of the world. The latter requires empathy with the patients defensive position. Epidemiology
Delusional disorders are uncommon in psychiatric practice, though this may be an underestimation due to the fact that those with the condition lack insight and thus avoid psychiatric assessment. The prevalence of this condition stands at about 24 to 30 cases per 100,000 people while 0.7 to 3.0 new cases per 100,000 people are reported every year. Delusional disorder accounts for 1–2% of admissions to inpatient mental health facilities.
In light of this, a combined approach to laboratory diagnosis is required to reach a differential diagnosis.CBS deficiency may be diagnosed by routine metabolic biochemistry. Genetic testing may be used to screen for known SNPs (mutations). In the first instance, plasma or urine amino acid analysis will frequently show an elevation of methionine and the presence of homocysteine. Many neonatal screening programs include methionine as a metabolite. The disorder may be distinguished from the re-methylation defects (e.g., MTHFR, methionine synthase deficiency, or the cobalamin defects) in lieu of the elevated methionine concentration. Additionally, organic acid analysis or quantitative determination of methylmalonic acid should help to exclude cobalamin (vitamin B12) defects and vitamin B12 deficiency giving a differential diagnosis.The laboratory analysis of homocysteine itself is complicated because most homocysteine (possibly above 85%) is bound to other thiol amino acids and proteins in the form of disulphides (e.g., cysteine in cystine-homocysteine, homocysteine in homocysteine-homocysteine) via disulfide bonds. Since as an equilibrium process the proportion of free homocystene is variable a true value of total homocysteine (free + bound) is useful for confirming diagnosis and particularly for monitoring of treatment efficacy. To this end it is prudent to perform total homocyst(e)ine analysis in which all disulphide bonds are subject to reduction prior to analysis, traditionally by HPLC after derivatisation with a fluorescent agent, thus giving a true reflection of the quantity of homocysteine in a plasma sample.