Overview of Mental Illness
Mental illness is a term that refers collectively to all of the diagnosable mental disorders. Mental disorders are characterized by abnormalities in cognition, emotion or mood, or the highest integrative aspects of behavior, such as social interactions or planning of future activities. These mental functions are all mediated by the brain.
Symptoms related to behavior or our mental lives clearly reflect variations or abnormalities in brain function. On the more difficult side of the ledger are the terms disorder, disease, or illness. There can be no doubt that an individual with schizophrenia is seriously ill, but for other mental disorders such as depression or attention-deficit/hyperactivity disorder, the signs and symptoms exist on a continuum and there is no bright line separating health from illness, distress from disease.
Moreover, the manifestations of mental disorders vary with age, gender, race, and culture. The thresholds of mental illness or disorder have, indeed, been set by convention, but the fact is that this gray zone is no different from any other area of medicine.
Persons suffering from any of the severe mental disorders present with a variety of symptoms that may include inappropriate anxiety, disturbances of thought and perception, dysregulation of mood, and cognitive dysfunction. Many of these symptoms may be relatively specific to a particular diagnosis or cultural influence. Similarly, severe disturbances in expression of affect and regulation of mood are most commonly seen in depression and bipolar disorder. Symptoms associated with mood, anxiety, thought process, or cognition may occur in any patient at some point during his or her illness.
Anxiety is one of the most readily accessible and easily understood of the major symptoms of mental disorders. Each of us encounters anxiety in many forms throughout the course of our routine activities. Anxiety is aroused most intensely by immediate threats to one’s safety, but it also occurs commonly in response to dangers that are relatively remote or abstract. Intense anxiety may also result from situations that one can only vaguely imagine or anticipate.
Anxiety has evolved as a vitally important physiological response to dangerous situations that prepares one to evade or confront a threat in the environment. The appropriate regulation of anxiety is critical to the survival of virtually every higher organism in every environment.
The mechanisms that regulate anxiety may break down in a wide variety of circumstances, leading to excessive or inappropriate expression of anxiety. Specific examples include phobias, panic attacks, and generalized anxiety. In phobias, high-level anxiety is aroused by specific situations or objects that may range from concrete entities such as snakes, to complex circumstances such as social interactions or public speaking. Panic attacks are brief and very intense episodes of anxiety that often occur without a precipitating event or stimulus. Generalized anxiety represents a more diffuse and nonspecific kind of anxiety that is most often experienced as excessive worrying, restlessness, and tension occurring with a chronic and sustained pattern. In each case, an anxiety disorder may be said to exist if the anxiety experienced is disproportionate to the circumstance, is difficult for the individual to control, or interferes with normal functioning.
Obsessive-compulsive disorder and post-traumatic stress disorder are generally believed to be related to the anxiety disorders. In the case of obsessive-compulsive disorder, individuals experience a high level of anxiety that drives their obsessional thinking or compulsive behaviors. When such an individual fails to carry out a repetitive behavior such as hand washing or checking, there is an experience of severe anxiety. Post-traumatic stress disorder is produced by an intense and overwhelmingly fearful event that is often life-threatening in nature. The characteristic symptoms that result from such a traumatic event include the persistent reexperience of the event in dreams and memories, persistent avoidance of stimuli associated with the event, and increased arousal.
Common signs of acute anxiety
- Feelings of fear or dread
- Trembling, restlessness, and muscle tension
- Rapid heart rate
- Lightheadedness or dizziness
- Cold hands/feet
- Shortness of breath
Disturbances of perception and thought process fall into a broad category of symptoms referred to as psychosis. The threshold for determining whether thought is impaired varies somewhat with the cultural context. Like anxiety, psychotic symptoms may occur in a wide variety of mental disorders. They are most characteristically associated with schizophrenia, but psychotic symptoms can also occur in severe mood disorders.
One of the most common groups of symptoms that result from disordered processing and interpretation of sensory information are the hallucinations. Hallucinations are said to occur when an individual experiences a sensory impression that has no basis in reality. This impression could involve any of the sensory modalities. Thus hallucinations may be auditory, olfactory, gustatory, kinesthetic, tactile, or visual. For example, auditory hallucinations frequently involve the impression that one is hearing a voice. In each case, the sensory impression is falsely experienced as real.
A delusion is a false belief that an individual holds despite evidence to the contrary. A common example is paranoia, in which a person has delusional beliefs that others are trying to harm him or her. Attempts to persuade the person that these beliefs are unfounded typically fail and may even result in the further entrenchment of the beliefs.
Hallucinations and delusions are among the most commonly observed psychotic symptoms. Symptoms of schizophrenia are divided into two broad classes: positive symptoms and negative symptoms. Positive symptoms generally involve the experience of something in consciousness that should not normally be present. Specifically, psychotic thought processes are characteristically loose, disorganized, illogical, or bizarre. These disturbances in thought process frequently produce observable patterns of behavior that are also disorganized and bizarre. The severe disturbances of thought content and process that comprise the positive symptoms often are the most recognizable and striking features of psychotic disorders such as schizophrenia or manic depressive illness.
Common manifestations of schizophrenia
- Disorganized thoughts and behaviors
- Loose or illogical thoughts
- Flat or blunted affect
- Concrete thoughts
- Anhedonia (inability to experience pleasure)
- Poor motivation, spontaneity, and initiative
Patients with schizophrenia and other psychoses have been noted to exhibit major deficits in motivation and spontaneity that are referred to as negative symptoms. While positive symptoms represent the presence of something not normally experienced, negative symptoms reflect the absence of thoughts and behaviors that would otherwise be expected.
The psychotic symptoms represent manifestations of disturbances in the flow, processing, and interpretation of information in the central nervous system. They seem to share an underlying commonality of mechanism, insofar as they tend to respond as a group to specific pharmacological interventions. However, much remains to be learned about the brain mechanisms that lead to psychosis.
Disturbances of Mood
Most of us have an immediate and intuitive understanding of the notion of mood. We readily comprehend what it means to feel sad or happy. These concepts are nonetheless very difficult to formulate in a scientifically precise and quantifiable way; the challenge is greater given the cultural differences that are associated with the expression of mood.
Disturbances of mood characteristically manifest themselves as a sustained feeling of sadness or sustained elevation of mood. As with anxiety and psychosis, disturbances of mood may occur in a variety of patterns associated with different mental disorders. The disorder most closely associated with persistent sadness is major depression, while that associated with sustained elevation or fluctuation of mood is bipolar disorder.
Common signs of mood disorders
Symptoms commonly associated with depression
- Persistent sadness or despair
- Insomnia (sometimes hypersomnia)
- Decreased appetite
- Psychomotor retardation
- Anhedonia (inability to experience pleasure)
- Apathy, poor motivation, social withdrawal
- Poor self-esteem, feelings of helplessness
- Suicidal ideation
Symptoms commonly associated with mania
- Persistently elevated or euphoric mood
- Grandiosity (inappropriately high self-esteem)
- Psychomotor agitation
- Decreased sleep
- Racing thoughts and distractibility
- Poor judgment and impaired impulse control
- Rapid or pressured speech
Depression and mania are typically associated with characteristic changes in these basic functions. Mood appears to represent a complex group of behaviors and responses that undergo precise and tightly controlled regulation. Higher organisms that must adapt to changing environments depend on optimal control of basic functions such as sleep, appetite, sex, and physical activity. In humans, these complex behaviors and their regulation are believed to be associated with the expression of mood. A depressed mood appears to reflect a kind of global damping of these functions, while a manic state may result from an excessive activation of these same functions.
Disturbances of Cognition
Cognitive function refers to the general ability to organize, process, and recall information. Cognitive tasks may be subdivided into a large number of more specific functions depending on the nature of the information remembered and the circumstances of its recall.
Disturbances of cognitive function may occur in a variety of disorders. Progressive deterioration of cognitive function is referred to as dementia. Dementia may be caused by a number of specific conditions including Alzheimer’s disease. Impairment of cognitive function may also occur in other mental disorders such as depression. It is not uncommon to find profound disturbances of cognition in patients suffering from severe mood disturbances.
The manifestations of cognitive impairment can vary across an extremely wide range, depending on severity. Short-term memory is one of the earliest functions to be affected and, as severity increases, retrieval of more remote memories becomes more difficult. Attention, concentration, and higher intellectual functions can be impaired as the underlying disease process progresses. Language difficulties range from mild word-finding problems to complete inability to comprehend or use language. Functional impairments associated with cognitive deficits can markedly interfere with the ability to perform activities of daily living such as dressing and bathing.
Anxiety, psychosis, mood disturbances, and cognitive impairments are among the most common and disabling manifestations of mental disorders. It is important, however, to appreciate that mental disorders leave no aspect of human experience untouched. Other common manifestations include, for example, somatic or other physical symptoms and impairment of impulse control. Many of these issues will be touched upon in subsequent chapters with reference to specific disorders.
Diagnosis of Mental Illness
The manifestations of mental disorders fall into a number of distinct categories such as anxiety, psychosis, mood disturbance, and cognitive deficits. These categories are broad, heterogeneous, and somewhat overlapping. Any particular patient may manifest symptoms from more than one of these categories. This is not unexpected, given the highly complex interactions that take place among the neurobiological and behavioral substrates that produce these symptoms. Despite these confounding difficulties, a systematic approach to the classification and diagnosis of mental illness has been developed. Diagnosis is essential in all areas of health for shaping treatment and supportive care, establishing a prognosis, and preventing related disability. Diagnosis also serves as shorthand to enhance communication, research, surveillance, and reimbursement.
The diagnosis of mental disorders is often believed to be more difficult than diagnosis of somatic, or general medical, disorders, since there is no definitive lesion, laboratory test, or abnormality in brain tissue that can identify the illness. The diagnosis of mental disorders must rest with the patients’ reports of the intensity and duration of symptoms, signs from their mental status examination, and clinician observation of their behavior including functional impairment. These clues are grouped together by the clinician into recognizable patterns known as syndromes. When the syndrome meets all the criteria for a diagnosis, it constitutes a mental disorder. Most mental health conditions are referred to as disorders, rather than as diseases, because diagnosis rests on clinical criteria. The term “disease” generally is reserved for conditions with known pathology (detectable physical change). The term “disorder,” on the other hand, is reserved for clusters of symptoms and signs associated with distress and disability (i.e., impairment of functioning), yet whose pathology and etiology are unknown.
Major Diagnostic Classes of Mental Disorders
Disorders usually first diagnosed in infancy, childhood, or adolescence
Delerium, dementia, and amnestic and other cognitive disorders
Mental disorders due to a general medical condition
Schizophrenia and other psychotic disorders
Sexual and gender identity disorders
Risk Factors and Protective Factors
The concepts of risk and protective factors, risk reduction, and enhancement of protective factors (also sometimes referred to as fostering resilience) are central to most empirically based prevention programs. Risk factors are those characteristics, variables, or hazards that, if present for a given individual, make it more likely that this individual, rather than someone selected at random from the general population, will develop a disorder. To qualify as a risk factor the variable must antedate the onset of the disorder. Yet risk factors are not static. They can change in relation to a developmental phase or a new stressor in one’s life, and they can reside within the individual, family, community, or institutions. Some risks such as gender and family history are fixed; that is, they are not malleable to change. Other risk factors such as lack of social support, inability to read, and exposure to bullying can be altered by strategic and potent interventions. Current research is focusing on the interplay between biological risk factors and psychosocial risk factors and how they can be modified.
Prevention not only focuses on the risks associated with a particular illness or problem but also on protective factors. Protective factors improve a person’s response to some environmental hazard resulting in an adaptive outcome. Such factors, which can reside with the individual or within the family or community, do not necessarily foster normal development in the absence of risk factors, but they may make an appreciable difference on the influence exerted by risk factors.
Preventive researchers use risk status to identify populations for intervention, and then they target risk factors that are thought to be causal and malleable and target protective factors that are to be enhanced. If the interventions are successful, the amount of risk decreases, protective factors increase, and the likelihood of onset of the potential problem also decreases. The risks for onset of a disorder are likely to be somewhat different from the risks involved in relapse of a previously diagnosed condition.
Many mental health problems, especially in childhood, share some of the same risk factors for initial onset, so targeting those factors can result in positive outcomes in multiple areas. Risk factors that are common to many disorders include individual factors such as neurophysiological deficits, difficult temperament, chronic physical illness, and below-average intelligence; family factors such as severe marital discord, social disadvantage, overcrowding or large family size, paternal criminality, maternal mental disorder, and admission into foster care; and community factors such as living in an area with a high rate of disorganization and inadequate schools.
Because mental health is so intrinsically related to all other aspects of health, it is imperative when providing preventive interventions to consider the interactions of risk and protective factors, etiological links across domains, and multiple outcomes. For example, chronic illness, unemployment, substance abuse, and being the victim of violence can be risk factors or mediating variables for the onset of mental health problems. Yet some of the same factors also can be related to the consequences of mental health problems (e.g., depression may lead to substance abuse, which in turn may lead to lung or liver cancer).
Range of Treatments
Mental disorders are treatable, contrary to what many think. An armamentarium of efficacious treatments is available to ameliorate symptoms. In fact, for most mental disorders, there is generally not just one but a range of treatments of proven efficacy. Most treatments fall under two general categories, psychosocial and pharmacological. Moreover, the combination of the two—known as multimodal therapy—can sometimes be even more effective than each individually.
The degree of effectiveness tends to vary, depending on the disorder and the target population (e.g., older adults with depression). What is optimal for one disorder and/or age group may not be optimal for another. Further, treatments generally need to be tailored to the client and to client preferences.
The inescapable point is that studies demonstrate conclusively that treatment is more effective than placebo. Placebo is more effective than no treatment. Therefore, to capitalize on the placebo response, people are encouraged to seek treatment, even if the treatment is not as optimal as that described in this report.
Studies reveal that less than one-third of adults with a diagnosable mental disorder, and even a smaller proportion of children, receive any mental health services in a given year.
Psychotherapy is a learning process in which mental health professionals seek to help individuals who have mental disorders and mental health problems. It is a process that is accomplished largely by the exchange of verbal communication, hence it often is referred to as “talk therapy.”
Participants in psychotherapy can vary in age from the very young to the very old, and problems can vary from mental health problems to disabling and catastrophic mental disorders. Although people often are seen individually, psychotherapy also can be done with couples, families, and groups. In each case, participants present their problems and then work with the psychotherapist to develop a more effective means of understanding and handling their problems. This report focuses on individual psychotherapy and also mentions couples therapy and various forms of family interventions, particularly psycho-educational approaches. Although not discussed in the report, group psychotherapy is effective for selected individuals with some mood disorders, anxiety disorders, schizophrenia, personality disorders, and for mental health problems seen in somatic illness.
The first major approach to psychotherapy is called psychoanalysis. Since its origin more than a century ago, psychoanalysis has undergone many changes. But other variations have been developed—ego psychology, object relations theory, interpersonal psychology, and self-psychology, each of which can be grouped under the general term “psychodynamic”. Thus, an important part of psychodynamic psychotherapy is to make the unconscious conscious or to help the patient understand the origin of actions that are troubling so that they can be corrected.
For some psychodynamic approaches, the focus is on the individual and the experiences the person had in the early years that give shape to current behavior, even beyond the awareness of the patient. For other, more contemporary approaches, such as interpersonal therapy, the focus is on the relationship between the person and others. The goal of interpersonal therapy is to improve current interpersonal skills. The therapist takes an active role in teaching patients to evaluate their interactions with others and to become aware of self-isolation and interpersonal difficulties. The therapist also offers advice and helps the patient to make decisions.
It focuses on current behavior rather than on early patterns of the patient. In its earlier form, behavior therapy dealt exclusively with what people did rather than what they thought or felt. The general principles of learning were applied to the learning of maladaptive as well as adaptive behaviors. The role of the environment was very important for behavior therapists, because it provided the positive and negative reinforcements that sustained or eliminated various behaviors. Therefore, ways of shaping that environment to make it more responsive to the needs of the individual were important in behavior therapy.
Cognitive-behavioral therapy draws on behaviorism as well as cognitive psychology, a field devoted to the scientific study of mental processes, such as perceiving, remembering, reasoning, decision making, and problem solving. The use of cognition in cognitive-behavioral therapy varies from attending to the role of the environment in providing a model for behavior, to the close study of irrational beliefs, to the importance of individual thought processes in constructing a vision of the surrounding world. Cognitive-behavioral therapy strives to alter faulty cognitions and replace them with thoughts and self-statements that promote adaptive behavior. For instance, cognitive-behavioral therapy tries to replace self-defeatist expectations (“I can’t do anything right”) with positive expectations (“I can do this right”). Cognitive-behavioral therapy has gained such ascendancy as a means of integrating cognitive and behavioral views of human functioning that the field is more frequently referred to as cognitive-behavioral therapy rather than behavior therapy.
The third wave of psychotherapy is referred to variously as humanistic, existential, experiential, or Gestalt therapy. The central focus of humanistic therapy is the immediate experience of the client. The emphasis is on the present and the potential for future development rather than on the past, and on immediate feelings rather than on thoughts or behaviors. It is rooted in the everyday subjective experience of the person seeking assistance and is much less concerned with mental illness than it is with human growth.
One critical aspect of humanistic treatment is the relationship that is forged between the therapist, who in some ways serves as a guide in an exploration of self-discovery, and the client, who is seeking greater knowledge of the self and an expansion of inherent human potential. The focus on the self and the search for self-awareness is akin to psychodynamic psychotherapy, while the emphasis on the present is more similar to behavior therapy.
Although it is possible to describe distinctive orientations to psychotherapy, as has been done above, most psychotherapists describe themselves as eclectic in their practice, rather than as adherents to any single approach to treatment. Psychotherapy integration includes various attempts to look beyond the confines of any single orientation but rather to see what can be learned from other perspectives.
The past decade has seen an outpouring of new drugs introduced for the treatment of mental disorders. New medications for the treatment of depression and schizophrenia are among the achievements stoked by research advances in both neuroscience and molecular biology. Through the process known as rational drug design, researchers have become increasingly sophisticated at designing drugs by manipulating their chemical structures. Their goal is to create more effective therapeutic agents, with fewer side effects, exquisitely targeted to correct the biochemical alterations that accompany mental disorders.
Mechanisms of Action
The mechanism of action refers to how a pharmacotherapy interacts with its target in the body to produce therapeutic effects. Pharmacotherapies that act in similar ways are grouped together into broad categories (e.g., stimulants, antidepressants). Within each category are several chemical classes. The individual pharmacotherapies within a chemical class share similar chemical structures.
Many pharmacotherapies for mental disorders have as their initial action the alteration—either increase or decrease—in the amount of a neurotransmitter. Neurotransmitter levels can be altered by pharmacotherapies in myriad ways: pharmacotherapies can mimic the action of the neurotransmitter in cell-to-cell signaling; they can block the action of the neurotransmitter; or they can alter its synthesis, breakdown (degradation), release, or reuptake, among other possibilities.
Neurotransmitters generally are concentrated in separate brain regions and circuits. At the time of neurotransmission, when a traveling signal reaches the tip (terminal) of the presynaptic cell, the neurotransmitter is released from the cell into the synaptic cleft. It migrates across the synaptic cleft in less than a millisecond and then binds to receptors situated on the membrane of the postsynaptic cell. The neurotransmitter’s binding to the receptor alters the shape of the receptor in such a way that the neurotransmitter can either excite the postsynaptic cell, and thereby transmit the signal to this next cell, or inhibit the receptor, and thereby block signal transmission. The neurotransmitter’s action is terminated either by enzymes that degrade it right there, in the synaptic cleft, or by transporter proteins that return unused neurotransmitter back to the presynaptic neuron for reuse, a “recycling” process known as reuptake.
Receptors for each transmitter come in numerous varieties. Not only are there several types of receptor for each neurotransmitter, but there may be many subtypes. A pharmacotherapy typically interacts with a receptor in either one of two ways—as an agonist or as an antagonist. When a pharmacotherapy acts as an agonist, it mimics the action of the natural neurotransmitter. When a pharmacotherapy acts as an antagonist, it inhibits, or blocks, the neuro-transmitter’s action, often by binding to the receptor and preventing the natural transmitter from binding there. An antagonist disrupts the action of the neurotransmitter.
Complementary and Alternative Treatment
Recent interest in the health benefits of a plethora of natural products has engendered claims related to putative effects on mental health.
There are major challenges to evaluating the role of complementary and alternative treatments in maintaining mental health or treating mental disorders. In many cases, preparations are not standardized and consist of a variable mixture of substances, any of which may be the active ingredient(s). Purity, bioavailability, amount and timing of doses, and other factors that are standardized for traditional pharmaceutical agents prior to testing cannot be taken for granted with natural products.
Recognized since antiquity, the placebo effect refers to the powerful role of patients’ attitudes and perceptions that help them improve and recover from health problems. Hippocrates established the therapeutic principle of physicians laying their hands in a reassuring manner to draw on the inner resources of the patient to fight disease. Technically speaking, the placebo effect refers to treatment responses in the placebo group, responses that cannot be explained on the basis of active treatment. A placebo is an inactive treatment, either in the form of an inert pill for studying a new drug treatment or an inactive procedure for studying a psychological therapy. The effects of active treatment are often compared with a control group that receives a pharmacological or psychological placebo.
Psychological studies can employ a “psychological” placebo in the form of a treatment known to be ineffectual. Or they can employ a comparison group, which receives an alternative psychological therapy. Some treatment studies employ both a “psychological” placebo, as well as a comparison group.
The basis of the placebo response is not fully known, but there are thought to be many possible reasons. These reasons, which relate to attributes of the disorder or the disease, the patient, and the treatment setting, include spontaneous remission, personality variables (e.g., social acquiescence), patient expectations, attitudes of and compassion by clinicians, and receiving treatment in a specialized setting. In studies of postoperative pain, the placebo response is mediated by patients’ production of endogenous pain-killing substances known as endorphins.
Benefits and Risks
Most studies of efficacy of specific treatments for mental disorders have been highly structured clinical trials, performed on individuals with a single disorder, in good physical health. While necessary and important, these trials do not always generalize easily to the wider population, which includes many individuals whose mental disorder is accompanied by another mental or somatic disorder and/or alcohol or substance abuse, and who may be taking other medications. Moreover, children, adolescents, and the elderly are excluded from many clinical trials, as are those in certain settings, such as nursing homes. Newer, more generalizable studies are being undertaken to address these shortcomings of the scientific literature.
Pending the results of these newer studies, it is important for clinical decision makers to review the current best evidence for the efficacy of treatments. People with mental disorders and their health providers should consider all possible options and carefully weigh the pros and cons of each, as well as the possibility of no treatment at all, before deciding upon a course of action. Such an informed consent process entails the calculation of a benefit-to-risk ratio" for each available treatment option.
Gap Between Efficacy and Effectiveness
Mental health professionals have long observed that treatments work better in the clinical research trial setting as opposed to typical clinical practice settings. The diminished level of treatment effectiveness in real-world settings is so perceptible that it even has a name, the “efficacy-effectiveness gap.” Efficacy is the term for what works in the clinical trial setting, and effectiveness is the term for what works in typical clinical practice settings. The efficacy-effectiveness gap applies to both pharmacological therapies and to psychotherapies. The gap is not unique to mental health, for it is found with somatic disorders too.
The magnitude of the gap can be surprisingly high. With schizophrenia medications, one review article found that, in clinical trials, the use of traditional antipsychotic medications for schizophrenia was associated with an average annual relapse rate of about 23 percent, whereas the same medications used in clinical practice carried a relapse rate of about 50 percent. The magnitude of the gap found in this study may not apply to other medications and other disorders, much less to psychological therapies. Studies of real-world effectiveness are scarce. Yet some degree of gap is widely recognized.
Efficacy studies test whether treatment works under ideal circumstances. They typically exclude patients with other mental or somatic disorders. In the past, they typically have examined relatively homogeneous populations, usually white males. Furthermore, efficacy studies are carried out by highly trained specialists following strict protocols that require frequent patient monitoring. Finally, participation in efficacy studies is often free of charge to patients.