Mental health (psychiatric or psychologic) disorders involve disturbances in thinking, emotion, and/or behavior. Small disturbances in these aspects of life are common, but when such disturbances cause significant distress to the person and/or interfere with daily life, they are considered mental illness or a mental health disorder. The effects of mental illness may be long-lasting or temporary.
Anxiety is a feeling of nervousness, worry, or unease that is a normal human experience. It is also present in a wide range of psychiatric disorders, including generalized anxiety disorder, panic disorder, and phobias. Although each of these disorders is different, they all feature distress and dysfunction specifically related to anxiety and fear.
Occasionally everyone has minor problems integrating their memories, perceptions, identity, and consciousness. For example, people may drive somewhere and then realize that they do not remember the drive. They may not remember it because they are absorbed—with personal concerns, a program on the radio, or a conversation with a passenger—or are just daydreaming. Such problems, referred to as normal dissociation, typically do not disrupt everyday activities.
Mood disorders are mental health disorders that involve emotional disturbances consisting of long periods of excessive sadness (depression), excessive joyousness or elation (mania), or both. Depression and mania represent the two extremes, or poles, of mood disorders.
Paraphilias are frequent, intense, sexually arousing fantasies or behaviors that involve inanimate objects, children or nonconsenting adults, or suffering or humiliation of oneself or the partner. Paraphilic disorders are paraphilias that cause distress or cause problems functioning in the person with the paraphilia or that harm or may harm another person.
Schizophrenia and related psychotic disorders— brief psychotic disorder, delusional disorder, schizoaffective disorder, schizophreniform disorder, and schizotypal personality disorder—are characterized by psychotic symptoms, and often by negative symptoms and cognitive dysfunction.
Somatic symptom and related disorders are mental health disorders characterized by an intense focus on physical (somatic) symptoms that causes significant distress and/or interferes with daily functioning.