the term  cancer  refers to a set of conditions that have the growth of cells that invade tissues and organs of the human body in common . the causes of cancer are varied , but psychological and behavioral factors such as chronic stress , depression , and social isolation may contribute to the initiation and progression of certain cancers [ 2 , 3 ] . conversely , cancer is a risk factor for the development of mental disorders . symptoms of psychological and physical distress may emerge during cancer treatment in combination with disease systems [ 46 ] . attention to the psychosocial aspects of the disease is equally important to cancer treatment , especially regarding psychopathologies because they significantly impact morbidity , low adherence to treatment , hospitalization duration , prognosis , quality of life , and patient survival [ 811 ] . the estimated prevalence of psychiatric disorders in individuals with cancer is approximately 20 to 50% [ 1214 ] , and depression exhibits the highest rates [ 1518 ] . psychiatric disorders and symptoms may represent an adjustment reaction to the disease condition , and these symptoms may also be associated with a general medical condition , such as delirium . clinical complications and metabolic changes , such as hypercalcemia , anemia , vitamin b12 deficiency , and electrolyte imbalance , are also risk factors for mental disorders in cancer patients , especially depression . therefore , the impact of the cancer and the associated clinical conditions may promote the development of psychiatric disorders , especially mood disorders and psychotic symptoms [ 20 , 21 ] . pathological anxiety may be present in physical diseases , medication and drug use , alcohol withdrawal , central nervous system depressants , and the so - called anxiety disorders [ 22 , 23 ] . the prevalence of anxiety in cancer patients varies between 10 and 30% [ 24 , 25 ] , and it is often associated with the diagnosis stage , procedure performance , and uncertainty about the future [ 20 , 21 ] . the abuse of psychoactive substances is directly associated with physical diseases , such as cirrhosis , cancer , and cardiovascular disease . the consumption of alcohol and tobacco is a well - established and prominent etiological factor in patients with malignancy in the lungs and esophagus . mental disorders may appear as comorbidities with the clinical condition , which may negatively impact disease diagnosis and treatment and emotional and financial costs [ 911 ] . however , oncology clinicians poorly identify mental disorders and their most common symptoms , despite the good responses to pharmacological and/or psychosocial interventions [ 2831 ] . knowledge of the prevalence of psychiatric disorders in this specific population may increase awareness and identification and mobilize resources for prevention and treatment [ 6 , 32 ] . early screening for behavioral and/or psychological / psychiatric disorders in patients seen in health care settings positively affects health care quality and decreases suffering and institutional operational costs . this study evaluated a statistically estimated sample of cancer outpatients at a hospital specializing in cancer according to the presence / absence of major mental symptoms / disorders using simple and quick screening instruments across different oncology specialties . statistical calculations determined that a minimum sample size of 1,155 subjects was required with an error rate of 3% . the subjects were recruited from a single hospital specializing in cancer , and all subjects were receiving outpatient care ( new or return cases ) in different oncology specialties . the following exclusion criteria were adopted : severe cognitive impairment as qualitatively evaluated by the applicator and the absence of clinical conditions that would affect responses to the instruments . the following self - assessment scales were used for data collection : patient health questionnaire-4 ( phq-4 ) screens for depression ( phq-4 d  brief version of phq-9 ) and anxiety ( phq-4 a  brief version of gad-7 ) indicators experienced during the prior two weeks . copyright 2005 ) translated this version into brazilian portuguese;generalized anxiety disorder ( gad-7 ) screens for typical indicators of anxiety disorders experienced during the prior two weeks . this instrument includes the two items from phq-4 a and more five items that enable screening of generalized anxiety disorder . copyright 2005 ) translated this version into brazilian portuguese;fast alcohol screening test ( fast ) evaluates risky , harmful use and alcohol dependence syndrome . this version was translated and validated for brazilian portuguese ; fagerstrm test for nicotine dependence ( ftnd ) measures the degree of physical dependence on nicotine . this version was translated and validated into brazilian portuguese .sociodemographic and clinical questionnaire assesses information about sociodemographic data ( gender , schooling , civil status , professional situation , and religion ) and treatments in mental health . patient health questionnaire-4 ( phq-4 ) screens for depression ( phq-4 d  brief version of phq-9 ) and anxiety ( phq-4 a copyright 2005 ) translated this version into brazilian portuguese ; generalized anxiety disorder ( gad-7 ) screens for typical indicators of anxiety disorders experienced during the prior two weeks . this instrument includes the two items from phq-4 a and more five items that enable screening of generalized anxiety disorder . copyright 2005 ) translated this version into brazilian portuguese ; fast alcohol screening test ( fast ) evaluates risky , harmful use and alcohol dependence syndrome . this version was translated and validated for brazilian portuguese ; fagerstrm test for nicotine dependence ( ftnd ) measures the degree of physical dependence on nicotine . sociodemographic and clinical questionnaire assesses information about sociodemographic data ( gender , schooling , civil status , professional situation , and religion ) and treatments in mental health . the subjects were selected randomly in reference to the scheduling system of the hospital according to the medical consultation dates . process no . 537/2011 ) and technical recommendations and entered into a database for analysis . descriptive ( e.g. , mean , standard deviation , and percentage ) and parametric statistics ( e.g. , student 's t - test , chi - square , and pearson correlation test ) were used for data analysis the sample included adult individuals ( mean = 50.3 ; dp = 13.9 ) of both genders with a slight predominance of women ( 55.8% ) . the sample included subjects with incomplete / completed elementary school ( 59% ) , married or in a stable relationship ( 67.4% ) , with children ( 86.7% ) , and not active from a labor viewpoint ( 61.3% ) . a total of 79.5% of the sample followed some type of religion , most often catholicism ( 68% ) . approximately 80% of the sample had no previous psychiatric / psychological history or psychiatric antecedents . the prevalence of different indicators of psychiatric disorders in the total sample and according to different oncology specialties is shown in table 1 . anxiety 's symptoms rates between 21.4% and 27.3% were observed for the total group , and gynecology , mastology , and thorax specialties were prominent ( table 1 ) . the prevalence of depression indicators was 18.5% for the total group , and gynecology , orthopedics , and thorax exhibited the highest rates . the percentage prevalence of these abuse rates was higher in the upper digestive , thorax , head and neck , and urology specialties , reaching levels in excess of 30% . prevalence indicators for different sociodemographic characteristics of the sample are shown in tables 2 and 3 . women had higher anxiety indicators prevalence rates than men , and unmarried subjects exhibited higher anxiety rates than married subjects . this difference according to marital status was observed using the phq-4 a instrument , but it was not confirmed using the gad-7 instrument . higher rates of symptoms of depression were associated with females , unmarried , and widowed subjects and subjects who were professionally inactive . the rates of substance abuse ( alcohol and tobacco ) were more significant in men , married , and divorced individuals , subjects with less education , subjects who were not professionally active , and subjects who did not follow any religion ( table 3 ) . the comorbidity rate in the total sample and among different oncology specialties is also noteworthy : 27.1% of the sample exhibited at least one comorbidity , with a prevalence of cooccurrence of anxiety and depression of 11.8% , and 6.6% of the sample had more than two comorbidities . a total of 43.4% of patients in the thorax / lung specialty , 33.5% of the upper digestive specialty , and 29.8% of the urology specialty exhibited indicators of more than one mental disorder . cancer and psychiatric symptoms / disorders are strongly associated , and the present study evaluated this association in cancer outpatients undergoing treatment . screening instruments evaluated symptoms of depression , anxiety , and substance abuse / chemical dependence . the data showed depression indicators prevalence of 18.5% , which is greater than a previous brazilian epidemiological study of 9.4%   but similar to a meta - analysis that reported a 16.3% depression rate in cancer patients at clinics and cancer hospitals . these data corroborate previous reports of the prevalence of depression in this clinical group . the prevalence of anxiety indicators varied between 21.4% and 27.3% , which are similar to primary care users ( 27.9% ) as determined using observer - assessment interviews . these data reinforce the important association between physical disease and anxiety , regardless of treatment context . moreover , the rate of anxiety indicators in this study is high compared to a previous study that diagnosed 7.6% of cancer patients with an anxiety disorder using a diagnostic interview . however , the choice of instrument may explain this difference , and the present study used screening instruments that measure anxiety symptoms rather than specific disorders . this level is higher than patients admitted to general medical specialties ( 9.8% ) and hospitalized cancer patients ( 15.5% ) , who were all evaluated using a screening instrument . the tobacco abuse rate for the total sample was 40.2% , which was similar to the prevalence of 44% in patients admitted to gastroenterology and pulmonology wards using screening scales and diagnostic interviews . these findings suggest tobacco use as a possible risk factor , especially for oncological diseases of the respiratory system . the gynecology , mastology , and thorax specialties showed the highest rates of depression and anxiety indicators . one possible explanation for this finding is the exclusive presence of women in the first two specialties . other evaluation studies of cancer patients reported that women subjects admitted to general hospitals or the general population exhibit high rates of depression and anxiety symptoms [ 31 , 4145 ] . it is possible too that , in thorax specialty , the poorer prognosis can favor these rates . one study evaluated 987 patients with lung cancer and found depressive symptoms in most subjects . another study evaluated patients with lung cancer using a self - administered hospital anxiety and depression scale ( hads ) and found that 37% had depression symptoms . one possible explanation for this result is suggested by two other studies that showed an increased likelihood of depressive episodes in subjects during nicotine withdrawal , and an even greater likelihood for patients with a history of previous depressive episodes [ 49 , 50 ] . therefore , patients with lung cancer may begin a process of reduction or remission of their smoking habit and develop withdrawal symptoms , which promotes the onset of depression and anxiety symptoms . men predominated among patients abusing alcohol and tobacco , which has also been demonstrated in previous evaluations in the general population in different countries [ 39 , 5153 ] . therefore , these high rates and the behaviors associated with the male gender , who care less about health and engage in more risky behavior [ 5458 ] , support the use of these substances as a risk factor for disease development [ 27 , 5963 ] . the higher prevalence rates of alcohol and tobacco abuse in thorax / lung and upper digestive specialty patients and patients with tumors in the head and neck confirm this hypothesis . the data presented are consistent with the previous literature and attest to the high prevalence of indicators of psychiatric disorders in cancer patients , especially compared to the prevalence in the general population . these results support the conclusion that individuals with cancer are more vulnerable to the onset and development of psychiatric disorders . conversely , the association between substance abuse and certain cancers indicates that substance abuse can be also a risk factor for disease development . this study was conducted using a large and statistically estimated sample , but the psychiatric indicators were evaluated using screening instruments . these instruments were validated previously and show adequate sensitivity and specificity , but they only provide the prevalence of indicators but do not indicate disorders per se . the subjects ' self - perception also influences these instruments , which may be overestimated or underestimated , and this fact should be considered in data interpretation as well as the fact that all the patients come from a single treatment center . the high rates indicate the need to screen for psychiatric disorders in cancer patients , especially because of the damaging effects that psychiatric symptoms may exert on patient treatment . active monitoring and early detection of symptoms may facilitate treatment adherence , decrease the duration of hospital stay , and assist in disease coping . the study also highlights the need for greater investment in prevention campaigns that discourage the use of legal substances , such as alcohol and nicotine , because these substances are risk factors in cancer development .
objective . 
 this study evaluated the prevalence of various indicators of psychiatric disorders in brazilian outpatients with cancer and assessed possible associations with sociodemographic indicators . 
 materials and methods . 
 a total of 1,385 patients were evaluated using the following instruments : patient health questionnaire-4 ( phq-4 ) , generalized anxiety disorder ( gad-7 ) , fagerstrm test for nicotine dependence ( ftnd ) , and fast alcohol screening test ( fast ) . 
 results . 
 the sample was composed of both genders with a slight predominance of women ( 55.8% ) , subjects with incomplete / completed elementary school ( 59% ) , married ( 67.4% ) , with children ( 94% ) , not active from a labor viewpoint ( 61.6% ) , and following some type of religion ( 79.5% ) . 
 the prevalence of anxiety for the total sample varied between 21.5 and 27.4% . 
 the prevalence of depression was 21.1% , tobacco abuse / dependence was 40.2% , and alcohol was 20.3% . 
 women had significantly higher levels of anxiety and depression than men . 
 men had higher levels of substance abuse / dependence indicators than women . conclusion . 
 these results are consistent with the literature , which attests to the high prevalence of psychiatric disorder indicators in cancer patients , especially compared to the general population .