The people involved in agriculture differ from the general population in the types and frequencies of the behavioral health problems they typically experience.  There are commonalities as well, but the differences are the most important for farmers and their healthcare providers to understand.   

This and next week’s article examine these matters.  Today’s message about chronic mental illnesses (CMIs) and personality disorders adopts the National Institute for Occupational Safety and Health’s definition of farmer, which also includes ranchers, farm laborers, seasonal farm workers, commercial fishers and lumber harvesters as farmers. 

CMIs include any of the recurrent psychoses, such as schizophrenia.  Psychosis is identified by its primary symptoms: delusions, hallucinations, and disordered thinking and speech; the latter may seem nonsensical to other persons but not to the person with the illness. 

Psychotic illnesses usually are genetically inclined, but may be due to other causes, such as neurological injuries, drug addictions and exposures to toxic chemicals.  Infrequently, but occasionally, psychotic behaviors accompany severe bipolar disorder, major depression and anxiety disorders, but generally these disorders do not become so severe as to lead to delusions, hallucinations, and seriously disturbed thinking. 

Prevalence rates of CMIs in the U.S.  A National Institute of Mental Health (NIMH) report indicates that 1.1 percent of Americans develop schizophrenia sometime during their lives.  The NIMH has indicated a lifetime prevalence rate of about 3 percent for bipolar disorder and prevalence rates for depression and anxiety disorders in the 11-20 percent range, depending on the study. 

Schizophrenia tends to run in families.  Onset usually occurs in late adolescence or early adulthood.  A 2015 collaborative report of more than 100 scientists indicated 108 genetic markers linked to schizophrenia.

Bipolar disorder, major depression and anxiety disorders also have genetic markers but their phenotypic expressions vary considerably.  Depression and anxiety, in particular, are highly associated with the amount of stress experienced by the persons who develop them.   

Prevalence of CMIs in the agricultural population.  I directed a study of 7,238 persons involved in agriculture in the Upper Midwest, and who sought professional behavioral healthcare assistance during the period from September 1, 2005 to October 31, 2007.   

Our team of researchers tallied the diagnoses that were provided by the caregivers for the case sample. The prevalence of a diagnosis of schizophrenia was .6 percent. 

There are few farmers with schizophrenia, because their proneness to hallucinations and disordered thinking incapacitates them to such a degree they cannot carry on the highly stressful work of farming.  The medications commonly used to treat severe psychosis often hamper the operation of machinery and the ability to make complex decisions.

The prevalence rates for other CMIs experienced by the agricultural population are less well established.  Although CMIs may also include recurrent, severe, behavioral health conditions like bipolar disorder, major depression, and severe anxiety disorders, these conditions are usually treatable, and seldom incapacitate individuals to such a degree they cannot farm successfully. 

Most farmers with CMIs usually cannot hold down permanent and adequate-paying jobs to care for themselves and families.  Usually they have to depend on financial resources, like Supplemental Security Income, and on other people for assistance with daily living.

Persons with personality disorders also seldom are able to farm successfully.  Let’s define personality and personality disorder.

Drawing on the research of Dr. Walter Mischel and other psychology experts, personality is a behavior pattern that is consistent across various situations and over time.  For example, some people tend to be gregarious and seemingly “talk all the time” wherever they are and with whomever they interact. 

Personality disorders are enduring behavior patterns that seriously and regularly disrupt personal, social and occupational functioning.  Like personality, personality disorders often are formed during childhood, and usually in response to adverse experiences like abuse, rather than the positive childhoods most behaviorally healthy children experience. 

The latest Diagnostic and Statistical Manual of Mental Disorders (DSM 5), published by the American Psychiatric Association in 2013, lists ten personality disorders: Paranoid, Schizoid, Schizotypal, Antisocial, Borderline, Histrionic, Narcissistic, Avoidant, Dependent and Obsessive-Compulsive. 

The prevalence rates of personality disorders using the DMS 5 have not been fully established.  The NIMH estimated the prevalence rates of personality disorders using its predecessor, the DSM IV, at 9.1 percent of the general population for any type of personality disorder.  About half the persons with personality disorders also had one or more co-occurring mental illnesses, such as–but not limited to–substance abuse, anxiety and depression. 

My colleagues and I also used the DSM IV when we followed the diagnoses of 7,238 farm people in the Upper Midwest.  We found a 1.5 percent prevalence rate for any type of personality disorder. 

Farm people and their behavioral health caregivers need to be aware of the differences in CMIs and personality disorders for farm people and the general population.

Next week’s article will be devoted to the most common behavioral health issues of farm people, which are stress-related and usually manageable.  


Dr. Rosmann is a clinical psychologist and farmer at Harlan, Iowa.  Contact him at: www.agbehavioralhealth.com.