The term psychosocial refers to the psychological and social factors that influence mental health. Social influences such as peer pressure, parental support, cultural and religious background, socioeconomic status, and interpersonal relationships all help to shape personality and influence psychological makeup. Individuals with psychosocial disorders frequently have difficulty functioning in social situations and may have problems effectively communicating with others.

In the American Psychiatric Association it distinguishes 16 different subtypes (or categories) of mental illness. Although psychosocial variables arguably have some degree of influence on all subtypes of mental illness, the major categories of mental disorders thought to involve significant psychosocial factors include:

• Substance-related disorders. Disorders related to alcohol and drug use,abuse, dependence, and withdrawal.
• Schizophreniaand other psychotic disorders. These include the schizoid disorders (schizophrenia, schizophreniform, andschizoaffective disorder), delusional disorder, and psychotic disorders.
• Mood disorders. Affective disorders such as depression (major, dysthymic) and bipolar disorders.
• Anxietydisorders. Disorders in which a certain situation or place triggers excessive fear and/or anxiety symptoms (i.e.,dizziness, racing heart), such aspanic disorder, agoraphobia, social phobia,obsessive-compulsive disorder, post-traumatic stress disorder, and generalized anxiety disorders.
• Somatoform disorders. Somatoform disorders involve clinically significant physical symptoms that cannot be explained by a medical condition (e.g., somatization disorder, conversion disorder,paindisorder,hypochondriasis, and body dysmorphic disorder).
• Factitious disorders. Disorders in which an individual creates and complains of symptoms of a non-existent illness in order to assume the role of a patient (or sick role).
• Sexual and gender identity disorders. Disorders of sexual desire, arousal, and performance. It should be noted that the categorization ofgender identity disorderas a mental illness has been a point of some contention among mental health professionals.
• Eating disorders. Anorexia and bulimia nervosa.
• Adjustment disorders. Adjustment disorders involve an excessive emotional or behavioral reaction to a stressful event.
• Personality disorders. Maladjustments of personality, including paranoid, schizoid, schizotypal, anti-social, borderline, histrionic, narcissistic, avoidant, dependent, and obsessive-compulsive personality disorder (not to be confused with the anxiety disorder OCD).
• Disorders usually first diagnosed in infancy childhood, or adolescence. Some learning and developmental disorders (i.e., ADHD) may be partially psychosocial in nature.