Understanding Diagnosis Code F: Mental, Behavioral, and Neurodevelopmental Disorders in ICD-10

In the International Classification of Diseases, 10th Revision (ICD-10), diagnosis codes are used by healthcare professionals and medical coders to classify and code all diagnoses, symptoms, and procedures recorded in conjunction with hospital care in the United States. Among these, Diagnosis Code F marks a significant chapter, dedicated to “Mental, Behavioral and Neurodevelopmental disorders”. This category is crucial for accurately documenting and understanding a wide spectrum of conditions affecting the mind and behavior. This article provides an expanded overview of the ICD-10 “F” codes, offering a more detailed look at each major group within this classification.

F01 to F09: Mental Disorders Due to Known Physiological Conditions

This section of diagnosis code f encompasses mental disorders that are directly attributed to specific physiological conditions. These are not primary psychiatric illnesses but rather mental disturbances arising as a consequence of a known physical health issue.

F01 Vascular dementia: Dementia caused by cerebrovascular disease, such as after a stroke or due to chronic ischemia.
F02 Dementia in other diseases classified elsewhere: This includes dementias that are symptomatic of other underlying diseases like Parkinson’s disease, Huntington’s disease, HIV disease, or Creutzfeldt-Jakob disease.
F03 Unspecified dementia: Used when a diagnosis of dementia is clear, but the underlying cause is not specified or known.
F04 Amnestic disorder due to known physiological condition: Memory impairment that is a direct consequence of a physiological condition, such as head trauma or surgery.
F05 Delirium due to known physiological condition: A state of acute confusion and disturbed consciousness and cognition that is caused by a physiological condition, like infection or medication side effects.
F06 Other mental disorders due to known physiological condition: This is a broader category for various mental disturbances that are directly linked to physical health problems, which don’t fit neatly into the other F01-F05 categories.
F07 Personality and behavioral disorders due to known physiological condition: Personality changes or behavioral issues that arise because of a physiological condition, often involving brain injury or disease.
F09 Unspecified mental disorder due to known physiological condition: A catch-all code when a mental disorder is known to be due to a physiological condition, but the specific nature of the mental disorder is not specified.

F10 to F19: Mental and Behavioral Disorders Due to Psychoactive Substance Use

This extensive category within diagnosis code f addresses disorders resulting from the use of psychoactive substances, including alcohol, opioids, cannabis, sedatives, cocaine, stimulants, hallucinogens, nicotine, inhalants, and other substances. Each code range within F10-F19 specifies the substance involved and the nature of the disorder (e.g., dependence, withdrawal, psychosis).

F10 Alcohol-related disorders: Covers a spectrum of conditions from acute intoxication and harmful use to dependence and withdrawal states related to alcohol.
F11 Opioid-related disorders: Includes disorders related to opioids such as heroin, morphine, and prescription pain relievers, encompassing dependence, withdrawal, and opioid-induced psychosis.
F12 Cannabis-related disorders: Disorders linked to cannabis use, including dependence, withdrawal, and psychotic disorders induced by cannabis.
F13 Sedative, hypnotic, or anxiolytic related disorders: This category includes disorders caused by sedatives, hypnotics (like sleeping pills), and anxiolytics (anti-anxiety medications), covering dependence and withdrawal.
F14 Cocaine-related disorders: Disorders associated with cocaine use, including dependence, withdrawal, and cocaine-induced psychotic disorder.
F15 Other stimulant-related disorders: Covers disorders related to stimulants other than cocaine, such as amphetamines and methamphetamines, addressing dependence, withdrawal, and stimulant-induced psychosis.
F16 Hallucinogen-related disorders: Disorders resulting from hallucinogen use, including hallucinogen persisting perception disorder (HPPD) and hallucinogen-induced psychosis.
F17 Nicotine dependence: Specifically for disorders related to nicotine dependence, primarily from tobacco use.
F18 Inhalant-related disorders: Disorders caused by inhalant use, such as volatile solvents, aerosols, and gases, including dependence and inhalant-induced neurocognitive disorder.
F19 Other psychoactive substance-related disorders: This category is used when the psychoactive substance is not specified or falls into multiple categories, covering a range of substance-related disorders.

F20 to F29: Schizophrenia, Schizotypal, Delusional, and Other Non-Mood Psychotic Disorders

This section of diagnosis code f is dedicated to psychotic disorders that are not primarily mood-related. These are severe mental disorders that cause abnormal thinking and perceptions.

F20 Schizophrenia: A chronic brain disorder that affects a person’s ability to think, feel, and behave clearly. It is characterized by positive symptoms (like hallucinations and delusions) and negative symptoms (like flat affect and social withdrawal).
F21 Schizotypal disorder: A personality disorder characterized by severe social anxiety, thought disorder, paranoia and often unconventional beliefs. It is considered to be on the schizophrenia spectrum.
F22 Delusional disorders: Characterized by persistent delusions that are not bizarre, without other symptoms of schizophrenia. Delusions are fixed false beliefs.
F23 Brief psychotic disorder: Sudden onset of psychotic symptoms, such as delusions, hallucinations, or disorganized speech or behavior, lasting for at least a day but less than a month, with eventual full return to premorbid functioning.
F24 Shared psychotic disorder: (Folie à deux) A rare condition where delusions are shared between two or more people who have a close relationship.
F25 Schizoaffective disorders: A condition characterized by symptoms of both schizophrenia and mood disorders (like bipolar disorder or depression).
F28 Other psychotic disorder not due to a substance or known physiological condition: This category is for psychotic disorders that do not meet the criteria for schizophrenia, schizoaffective disorder, or delusional disorder, and are not due to substance use or a medical condition.
F29 Unspecified psychosis not due to a substance or known physiological condition: Used when psychosis is present but does not meet criteria for any specific psychotic disorder and is not attributable to substance use or a medical condition.

F30 to F39: Mood (Affective) Disorders

This category of diagnosis code f addresses mood disorders, also known as affective disorders, characterized by disturbances in mood or emotion.

F30 Manic episode: A distinct period of abnormally and persistently elevated, expansive, or irritable mood, increased activity or energy, and other symptoms like inflated self-esteem and decreased need for sleep.
F31 Bipolar disorder: A disorder characterized by episodes of both mania and depression, with periods of normal mood in between. Types include Bipolar I (primarily manic episodes with or without major depressive episodes) and Bipolar II (hypomanic and major depressive episodes).
F32 Major depressive disorder, single episode: Characterized by one or more major depressive episodes. Symptoms include persistent sadness, loss of interest or pleasure, changes in appetite or sleep, fatigue, and feelings of worthlessness or guilt.
F33 Major depressive disorder, recurrent: Characterized by recurrent major depressive episodes.
F34 Persistent mood (affective) disorders: Includes chronic mood disturbances, such as cyclothymia (milder form of bipolar disorder) and dysthymia (persistent mild depression).
F39 Unspecified mood (affective) disorder: Used when a mood disorder is present but does not meet the criteria for any specific mood disorder.

F40 to F48: Anxiety, Dissociative, Stress-Related, Somatoform and Other Nonpsychotic Mental Disorders

This diverse section of diagnosis code f includes a range of nonpsychotic mental disorders, from anxiety disorders to those related to stress and bodily symptoms.

F40 Phobic anxiety disorders: Characterized by excessive and persistent fear of specific objects, situations, or places, leading to avoidance behavior. Includes specific phobias, social anxiety disorder, and agoraphobia.
F41 Other anxiety disorders: Covers other forms of anxiety that do not meet criteria for phobias, such as generalized anxiety disorder (GAD) and panic disorder.
F42 Obsessive-compulsive disorder (OCD): Characterized by recurrent, unwanted thoughts (obsessions) and/or repetitive behaviors or mental acts (compulsions) that an individual feels driven to perform.
F43 Reaction to severe stress, and adjustment disorders: Includes disorders that develop in response to significant life stressors, such as post-traumatic stress disorder (PTSD), acute stress reaction, and adjustment disorders.
F44 Dissociative and conversion disorders: Dissociative disorders involve disturbances in identity, memory, or consciousness. Conversion disorder (functional neurological symptom disorder) involves neurological symptoms without a neurological cause, believed to be psychologically driven.
F45 Somatoform disorders: Characterized by physical symptoms that suggest a medical condition but cannot be fully explained by a medical condition, substance use, or another mental disorder. Includes somatic symptom disorder and illness anxiety disorder (hypochondriasis).
F48 Other nonpsychotic mental disorders: A residual category for other nonpsychotic mental disorders that do not fit into the above categories.

F50 to F59: Behavioral Syndromes Associated with Physiological Disturbances and Physical Factors

This section of diagnosis code f includes behavioral syndromes linked to physiological disturbances and physical factors, covering eating, sleep, sexual, and postpartum-related disorders.

F50 Eating disorders: Characterized by abnormal eating habits and disturbed body image, such as anorexia nervosa and bulimia nervosa.

Alt text: Diagram illustrating the key characteristics of anorexia nervosa and bulimia nervosa, two major eating disorders, highlighting differences in weight status and compensatory behaviors.

F51 Sleep disorders not due to a substance or known physiological condition: Primary sleep disorders not directly caused by substances or medical conditions, such as insomnia, narcolepsy, and sleep apnea (if not due to a medical condition alone).
F52 Sexual dysfunction not due to a substance or known physiological condition: Sexual disorders that are not due to medical conditions or substances, including erectile dysfunction, female orgasmic disorder, and premature ejaculation (when psychological factors are primary).
F53 Mental and behavioral disorders associated with the puerperium, not elsewhere classified: Mental disorders related to childbirth, such as postpartum depression and postpartum psychosis.
F54 Psychological and behavioral factors associated with disorders or diseases classified elsewhere: Used when psychological or behavioral factors are believed to have played a significant role in the etiology, course, or outcome of physical diseases classified elsewhere.
F55 Abuse of non-psychoactive substances: For the abuse of substances that are not typically considered psychoactive but may be misused, like laxatives or antacids.
F59 Unspecified behavioral syndromes associated with physiological disturbances and physical factors: Used when a behavioral syndrome related to physiological or physical factors is present, but does not fit a more specific category.

F60 to F69: Disorders of Adult Personality and Behavior

This category within diagnosis code f addresses personality and behavior disorders that are typically established patterns of behavior and inner experience that deviate markedly from the norms of an individual’s culture.

F60 Specific personality disorders: Includes various personality disorders such as paranoid, schizoid, borderline, antisocial, histrionic, narcissistic, avoidant, dependent, and obsessive-compulsive personality disorders.

Alt text: Infographic showing the three clusters of personality disorders – Cluster A (odd or eccentric), Cluster B (dramatic, emotional, or erratic), and Cluster C (anxious or fearful), with examples of personality disorders within each cluster.

F63 Impulse disorders: Disorders characterized by the failure to resist an impulse, drive, or temptation to perform an act that is harmful to the person or others, such as pathological gambling, kleptomania, and pyromania.
F64 Gender identity disorders: Disorders related to gender identity, including gender dysphoria.
F65 Paraphilias: Sexual disorders characterized by recurrent, intense sexual urges, fantasies, or behaviors involving unusual objects, activities, or situations.
F66 Other sexual disorders: Other specified sexual disorders, not elsewhere classified.
F68 Other disorders of adult personality and behavior: A residual category for other personality and behavior disorders that do not fit into the specific categories.
F69 Unspecified disorder of adult personality and behavior: Used when a disorder of adult personality and behavior is present, but does not meet criteria for a specific disorder.

F70 to F79: Intellectual Disabilities

This section of diagnosis code f covers intellectual disabilities (previously termed mental retardation), characterized by significantly subaverage intellectual functioning and deficits in adaptive behavior.

F70 Mild intellectual disabilities: Individuals in this category have some limitations in intellectual functions but can still achieve independence in many areas of daily life, particularly with support.
F71 Moderate intellectual disabilities: Individuals require more support than those with mild intellectual disability and may have limitations in academic and social functioning.
F72 Severe intellectual disabilities: Individuals in this category require substantial support and supervision in most areas of daily life.
F73 Profound intellectual disabilities: Individuals require constant care and supervision and have very limited capacity for independent functioning.
F78 Other intellectual disabilities: Used when intellectual disability is diagnosed but does not clearly fit into the categories of mild, moderate, severe, or profound.
F79 Unspecified intellectual disabilities: Used when intellectual disability is diagnosed, but the severity cannot be assessed.

F80 to F89: Pervasive and Specific Developmental Disorders

This section of diagnosis code f includes disorders that are characterized by impairments in specific areas of development, often evident in early childhood.

F80 Specific developmental disorders of speech and language: Includes disorders like expressive language disorder, receptive language disorder, and phonological disorder.
F81 Specific developmental disorders of scholastic skills: Includes learning disabilities such as dyslexia (reading disorder), dysgraphia (disorder of written expression), and dyscalculia (mathematics disorder).
F82 Specific developmental disorder of motor function: Developmental coordination disorder, characterized by marked impairment in motor coordination.
F84 Pervasive developmental disorders: A spectrum of disorders characterized by widespread impairments in social interaction and communication and restricted, repetitive patterns of behavior, interests, or activities. This category includes autism spectrum disorder (including Asperger’s syndrome and childhood autism).

Alt text: Visual representation of the Autism Spectrum, showing the range of conditions included under Autism Spectrum Disorder and highlighting the variability in symptom presentation.

F88 Other disorders of psychological development: A residual category for other disorders of psychological development that do not fit into the specific categories.
F89 Unspecified disorder of psychological development: Used when a disorder of psychological development is present but does not meet criteria for a specific disorder.

F90 to F98: Behavioral and Emotional Disorders with Onset Usually Occurring in Childhood and Adolescence

This section of diagnosis code f addresses disorders that typically manifest in childhood or adolescence, focusing on behavioral and emotional disturbances.

F90 Attention-deficit hyperactivity disorders (ADHD): Characterized by inattention, hyperactivity, and impulsivity, significantly impacting academic, social, or occupational functioning.
F91 Conduct disorders: Characterized by a repetitive and persistent pattern of behavior in which the basic rights of others or major age-appropriate societal norms or rules are violated.
F93 Emotional disorders with onset specific to childhood: Includes disorders like separation anxiety disorder, phobic anxiety disorder of childhood, and social anxiety disorder of childhood.
F94 Disorders of social functioning with onset specific to childhood and adolescence: Includes reactive attachment disorder and disinhibited social engagement disorder.
F95 Tic disorder: Includes Tourette’s syndrome and other tic disorders, characterized by sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations.
F98 Other behavioral and emotional disorders with onset usually occurring in childhood and adolescence: A residual category for other behavioral and emotional disorders of childhood and adolescence.

F99 to F99: Unspecified Mental Disorder

F99 Mental disorder, not otherwise specified: This is a general code used when a mental disorder is diagnosed, but it does not meet the criteria for any specific disorder within the “F” category, and there is insufficient information to be more specific.

Understanding diagnosis code f is essential for healthcare professionals, especially those in psychiatry, psychology, and primary care, as well as for medical coders and billers. Accurate coding ensures proper documentation, facilitates research, and is crucial for healthcare administration and reimbursement. This overview serves as a guide to the breadth and depth of mental, behavioral, and neurodevelopmental disorders classified under the “F” codes in ICD-10.