Intervention: Trazodone
Trial phase: Phase 4
ATC code: N06AX05
SMILES: O=c1n(CCCN2CCN(c3cccc(Cl)c3)CC2)nc2ccccn12
Sex: All
Age groups: Adult | Older Adult
Healthy volunteers: No
Participants at risk: 1
Group description: Veterans switching from quetiapine to trazodone for the treatment of insomnia.

Trazodone: Veterans willing to switch from quetiapine to trazodone for the treatment of insomnia will receive up to 400mg of trazodone daily.
Eligibility criteria:
Inclusion/Exclusion Criteria (PHASE 1):

Identified by their VA prescribing provider as taking quetiapine primarily as a sedative/hypnotic agent for some form of insomnia for at least 1 month
Identified by their VA prescribing provider as having dual diagnosis; a lifetime history of substance use disorder and a mental disorder
Willing to meet with a research assistant to answer several questions regarding their use of and experience with quetiapine.
Appear not to be regularly on any medication which would be an exclusion for Part II (see Part II exclusion criteria).

Inclusion Criteria (PHASE 2):

Willing to provide written informed consent.
Provider reports that primary use of quetiapine is for insomnia for at least one month and not primary or augmentation treatment of mood, anxiety disorder, psychosis, or mood stabilization.
Have a self-identified and provider confirmed lifetime history of mental health and substance use disorder (dual diagnosis).
Currently taking Quetiapine up to 300mg daily for the primary purpose of treating insomnia, and have been taking it for at least 1 month (30 days).
Use of an acceptable method of birth control by female patients who have a possibility of becoming pregnant.
The provider should review the patients from the identified charts, and fill out information about the patient and why they are on the drug, and provider should consent to us approaching the client and potentially switching them; the investigators will not approach and begin enrollment for part II on subjects if their provider feels it is not appropriate for them for any reason.

Exclusion Criteria (PHASE 2):

Physiologic substance dependence requiring detoxification in the past 30 days (substance abuse is not an exclusion).
Concomitant administration of: other sedative hypnotics, benzodiazepines, prazosin, other atypical antipsychotics, stimulants, ketoconazole and other inhibitors of cytochrome P450 3A (e.g., itraconazole, fluconazole, erythromycin, and protease inhibitors), phenytoin or other strong inducers of cytochrome P450 enzymes.
Intolerance or hypersensitivity to trazodone.
Pregnant or lactating women or women planning to become pregnant.
Hepatic or renal problems AST or ALT (>3 times upper limit of normal);
Elevated bilirubin (>1.2), BUN (>24), creatinine (>1.7).
Unstable, serious medical condition or one requiring acute medical treatment, or anticipation of hospitalization for extended care.
Dementia, epilepsy, insulin-dependent diabetes, anticoagulation with coumadin.
Legal entanglements or pending legal charges with potential of incarceration.
Recent (i.e., past 3 months) assault or suicide gesture currently needing acute intervention.
Concurrent participation in another clinical trial with an investigational drug during the last 30 days.