| Study | 
        Underlying disorder (N) | 
        Methods | 
        Outcome | 
        Concomitant medication | 
      
      
        | Ahmed et al. [74] | 
        Bipolar disorder (1) | 
        Case report;  Duration: 7 days (1mg/day) | 
        Acute manic episode   | 
        mianserin    (90 mg/day), oxazepam (10    mg/day), acetylsalicylic acid (80 mg/day), barnidipine (20    mg/day), hydrochlorothiazide (12.5    mg/day), perindopril (8    mg/day) and rosuvastatin (5    mg/day)  | 
      
      
        | Francois et al. [75] | 
        None (1) | 
        Case report;  Duration: 7 days (dose not specified) | 
        Grandiose delusions, agitation,    insomnia, rapid speech | 
        None | 
      
      
        | Freedman,  [76] | 
        Schizophrenia (1)  | 
        Case report;  Duration: 5 days (1 mg BID) | 
        Exacerbation of psychotic symptoms | 
        Thiothixene (1015mg/day) | 
      
      
        | Hussain et al. [77] | 
        History of mild depression (1) | 
        Case report;  Duration: approximately three weeks    (0.5mg/day) | 
        Manic episode | 
        Oxycodone (up to 12 pills/day),    diazepam (10mg/day) | 
      
      
        | Ismail et al. [78] | 
        Schizophrenia (1) | 
        Case report;  Duration: 20 days (1 mg BID) | 
        Significant reduced smoking and    self report craving to smoke. Polydipsia and hyponatremia  | 
        Depot risperidone (25mg /2 weeks) | 
      
      
        | Kohen and Kremen,  [79] | 
        Bipolar disorder (1) | 
        Case report;  Duration: 7 days (2mg/day) | 
        Exacerbation of manic episode | 
        valproic acid (dose not specified) | 
      
      
        | Morstad, [81] | 
        Bipolar II disorder, polysubstance    abuse (1) | 
        Case report;  Duration: approximately one month (2mg/day) | 
        Hypomanic episode with suicidal    ideation | 
        bupropion XL (300 mg/day), clonazepam (1 mg/day),    oxcarbazepine (450 mg/day), quetiapine (100 mg/day), montelukast (10 mg/day),    pantoprazole (40 mg/day)  | 
      
      
        | Popkin, [82] | 
        Major depression | 
        Case report;  Duration: 6 weeks (2mg/day) | 
        Hypersomnia, unusual dreams,    decreased appetite, irritability, sadness and guilt | 
        Fluoxetine (20mg/day), asprin,    niacin and metoprolol | 
      
      
        | Waldo et al. [83] | 
        Schizophrenia (6) | 
        Pilot study; Duration: 2 hours (1    mg, once) | 
        Varenicline did not improve P50 gating.    Study discontinued due to emergence of suicidal ideation, aggressive, erratic    behavior | 
        Atypical APDs | 
      
      
        | Anghelescu, [86] | 
        Schizophrenia (1) | 
        Case report;  Duration: 2     weeks (1 mg BID) | 
        Complete abstinence confirmed with    expired CO level, improvement of negative symptoms 45 to 22 via PANSS | 
        Depot risperidone (37.5mg/2 weeks) | 
      
      
        | Fatemi, [87] | 
        Schizophrenia (1) | 
        Case report;  Duration: >24 weeks (1 mg BID) | 
        Meaningful reduction in number of    cigarettes smoked | 
        Clozapine (700mg/day) and    citalopram (40 mg/day) | 
      
      
        | Evins and Goff, [88] | 
        Schizophrenia (16) | 
        Case series;  Duration: 12 weeks (1 mg BID) | 
        Reduced craving to smoke, 13    patients quit smoking (expired CO level <9 ppm), self report abstinence    ≥12 weeks | 
        Various antipsychotics | 
      
      
        | Smith et al. [90] | 
        Schizophrenia (9);                Schizoaffective (3) | 
        Case series;  Duration: 9 weeks (1 mg BID) | 
        Significant decrease in plasma    cotinine (p <0.01), expired CO level (p<0.05), self reported smoking    urges, number of cigarettes smoked and nicotine level. Improvement in some    cognitive test  score | 
        Various antipsychotics | 
      
      
        | Weiner et al. [91] | 
        Schizophrenia (8) | 
        Double blind randomized trial;  Duration: 12 weeks (1 mg BID) | 
        Sustained abstinent and significant    reduction in CO level <10 ppm (p=0.02)in Varenicline group | 
        Atypical antipsychotics | 
      
      
        | Dutra et al. [93] | 
        Schizophrenia or Schizoaffective    disorder (53) | 
        Trial combined with CBT; Duration:    12 weeks (1 mg BID) | 
        60.4% attained abstinence,    significantly reduced CO levels (p<0.001) compared with baseline | 
        Various antipsychotics | 
      
      
        | Pirmoradi et al. [100] | 
        Alcohol abuse and MDD (1) | 
        Case report;  Duration: 7 days (1mg/day) | 
        Experience of severe anxiety | 
         eszopiclone (2    mg/day), fluoxetine (20 mg/day), bupropion hydrochloride (300 mg/day),    lisinopril (10 mg/day) and hydrochlorothiazide 12.5 mg/day)   | 
      
      
        | Pumariega et al.  [101] | 
        MDD (1) | 
        Case report;  Duration: 90 days (dose not specified) | 
        Creation of manic episode | 
        Sertraline (dose not specified) | 
      
      
        | DiPaula and Thomas, [102] | 
        Bipolar disorder (1) | 
        Case report;  Duration: 2 days (2mg/day) | 
        Exacerbation of psychotic symptoms    and agitation | 
        Hallopridol, olanzapine, lorazpam    and diphenhydramine (dose not specified) | 
      
      
        | Liu et al.          [103] | 
        Schizoaffective disorder (1) | 
        Case report;  Duration: 13 days (dose not specified) | 
        Exacerbation of mania episode with    psychotic features | 
        clothiapine (160 mg/day) and    lithium (1,200 mg/day)  | 
      
      
        | Lyon, [104] | 
        MDD, GAD, BLPD and marijuana use    (1) | 
        Case report;  Duration: One month (2mg/day) | 
        Paranoia and irritability | 
        Topiramate (200 mg/day), duloxetine    (120 mg/day), modafinil (400 mg/day) and clonazepam (2mg/day) | 
      
      
        | Alhatem et al. [105] | 
        Bipolar and Adult ADHD disorder (1) | 
        Case report;  Duration: 2 weeks (dose not specified) | 
        Exacerbation of mania | 
        Quetiapine and    amphetamine salts (dose not specified)  | 
      
      
        | Kutscher et al. [106] | 
        None (1) | 
        Case report;  Duration: 10 weeks (dose not specified) | 
        Paranoia, anxiety and suicidal    ideation | 
        Oral contraceptive | 
      
      
        | Raidoo et al. [107] | 
        PTSD, depression, alcohol    dependence (1) | 
        Case report;  Duration: 19 days (2mg/day) | 
        Visual hallucination | 
        fluoxetine (20 mg/day),    nortriptyline (25 mg/day), quetiapine (50 mg/day), prazosin (1 mg/day),    pramipexole (0.5 mg/day), terazosin (5 mg/day), atenolol (50 mg/day) and    spironolactone (50 mg/day) | 
      
      
        | Cinemre et al. [108] | 
        Brief episode of atypical psychosis    (1) | 
        Case report;  Duration: 30 days (dose not specified) | 
        Creation of psychotic symptoms | 
        None | 
      
    
    
    ADHD: Attention  deficit hyperactivity disorder; BLPD: Borderline personality disorder; GAD:  Generalized anxiety disorder; MDD, Major depressive disorder;   PTSD, post-traumatic stress disorder