Psychiatric Disorders - Merck Manuals Professional Edition

Approach to the Patient With Mental Symptoms

Patients with mental complaints or concerns or disordered behavior present in a variety of clinical settings, including primary care and emergency treatment centers. Complaints or concerns may be new or a continuation of a history of mental problems. Complaints may be related to coping with a physical condition or be the direct effects of a physical condition on the central nervous system. The method of assessment depends on whether the complaints constitute an emergency or are reported in a scheduled visit. In an emergency, a physician may have to focus on more immediate history, symptoms, and behavior to be able to make a management decision. In a scheduled visit, a more thorough assessment is appropriate.
Anxiety and Stressor-Related Disorders

Anxiety disorders are characterized by persistent and excessive fear and anxiety and the dysfunctional behavioral changes a patient may use to mitigate these feelings. Anxiety disorders are differentiated from one another based on the specific objects or situations that induce the fear, anxiety, and associated behavioral changes.
Dissociative Disorders

Many people occasionally experience a failure in the normal automatic integration of memories, perceptions, identity, and consciousness. For example, people may drive somewhere and then realize that they do not remember many aspects of the drive because they were preoccupied with personal concerns, a program on the radio, or conversation with a passenger. Typically, such a failure, referred to as nonpathologic dissociation, does not disrupt everyday activities.
Eating Disorders

Eating disorders involve a persistent disturbance of eating or of behavior related to eating that
Mood Disorders

Mood disorders are emotional disturbances consisting of prolonged periods of excessive sadness, excessive elevated mood, or both. Mood disorders can occur in adults, adolescents, or children (see Depressive Disorders in Children and Adolescents and Bipolar Disorder in Children and Adolescents).
Obsessive-Compulsive and Related Disorders

Obsessive-compulsive disorder (OCD) is characterized by recurrent, persistent, unwanted, and intrusive thoughts, urges, or images (obsessions) and/or by repetitive behaviors or repetitive mental acts that patients feel driven to do (compulsions, rituals) to try to lessen or prevent the anxiety the obsessions cause. Diagnosis is based on history. Treatment consists of psychotherapy (specifically, exposure and response prevention plus, in many cases, cognitive therapy), pharmacologic therapy (specifically, selective serotonin reuptake inhibitors [SSRIs] or clomipramine), or both.
Paraphilias and Paraphilic Disorders

Paraphilic disorders are recurrent, intense, sexually arousing fantasies, urges, or behaviors that are distressing or disabling and that involve inanimate objects, children or nonconsenting adults, or suffering or humiliation of the person or a partner, with the potential to cause harm.
Personality Disorders

Personality disorders in general are pervasive, enduring patterns of thinking, perceiving, reacting, and relating that cause significant distress or functional impairment. Personality disorders vary significantly in their manifestations, but all are believed to be caused by a combination of genetic and environmental factors. Many gradually become less severe with age, but certain traits may persist to some degree after the acute symptoms that prompted the diagnosis of a disorder abate. Diagnosis is based on clinical criteria. Treatment is with psychosocial therapies and sometimes with medications.
Schizophrenia and Related Disorders

Schizophrenia and related psychotic disorders— brief psychotic disorder, delusional disorder, schizoaffective disorder, schizophreniform disorder, and schizotypal personality disorder—are characterized most prominently by psychotic symptoms and often by negative symptoms and cognitive dysfunction.
Gender Incongruence and Gender Dysphoria
- Gender Incongruence and Gender Dysphoria
Somatic Symptom and Related Disorders

Somatization is the expression of mental phenomena as physical (somatic) symptoms. Disorders characterized by somatization extend in a continuum from those in which symptoms develop unconsciously and nonvolitionally to those in which symptoms develop consciously and volitionally. This continuum includes
Suicidal Behavior and Self-Injury

Suicide is death caused by an act of self-harm that is intended to be lethal. Suicidal behavior encompasses a spectrum of behavior from suicide attempt and preparatory behaviors to completed suicide. Suicidal ideation refers to the process of thinking about, considering, or planning suicide.
- Suicidal Behavior
- Nonsuicidal Self-Injury (NSSI)
Substance-Related Disorders

Substance-related disorders involve substances that directly activate the brain's reward system. The activation of the reward system typically causes feelings of pleasure; the specific characteristics of the pleasurable feelings evoked vary widely depending on the drug. These drugs are divided into 10 different classes that have different, although not completely distinct, pharmacologic mechanisms. The classes of drugs include
- Overview of Substance Use
  - Scheduled drugs
- Substance Use Disorders