Substance Use Disorders

Substance use disorder, such as alcohol dependence or drug abuse, can either be a differential diagnosis to schizophrenia or a comorbid disorder (i.e., the individual can have both schizophrenia and a substance use disorder). With respect to differential diagnosis, substance use disorders can interfere with a clinician’s ability to diagnosis schizophrenia and can lead to misdiagnosis if the substance abuse is covert, denied, or not reported accurately (Corty, Lehman, & Myers, 1993; Kranzler et al., 1995). Psychoactive substances, such as alcohol, marijuana, cocaine, and amphetamines, can produce symptoms that mimic those found in schizophrenia, such as hallucinations, delusions, and social withdrawal (Schuckit, 1995). In those cases in which the substance is involved in the etiology of psychosis, a diagnosis of substance-induced psychotic disorder would be appropriate. Further complicating matters, the use of these substances can exacerbate psychotic symptoms and in many cases lead to a return of acute psychosis.

Because the diagnosis of schizophrenia requires the presence of specific symptoms in the absence of identifiable organic factors, schizophrenia can only be diagnosed in persons with a history of substance use disorder by examining the individual’s functioning during sustained periods of abstinence from drugs or alcohol. When such periods of abstinence can be identified, a reliable diagnosis of schizophrenia can be made. However, persons with schizophrenia who have a long history of substance abuse, with few or no periods of abstinence, are more difficult to assess. For example, in a sample of 461 individuals admitted to a psychiatric hospital, a psychiatric diagnosis could be neither confirmed nor ruled out because of history of substance abuse in 71 persons (15%; Lehman, Myers, Dixon, & Johnson, 1994).

Substance use disorder is the most common comorbid diagnosis for persons with schizophrenia. Because substance abuse can worsen the course and outcome of schizophrenia, recognition and treatment of substance abuse in schizophrenia is a critical goal of treatment. The diagnosis of substance abuse in schizophrenia is complicated by several factors. Substance abuse, as in the general population, is often denied because of social and legal sanctions (Galletly, Field, & Prior, 1993; Stone, Greenstein, Gamble, & McLellan, 1993), a problem that may be worsened in this population because of a fear of losing benefits. Denial of problems associated with substance abuse, a core feature of primary substance use disorders, may be further heightened by psychotic distortions and cognitive impairments present in schizophrenia. Furthermore, the criteria used to establish a substance use disorder in the general population are less useful for diagnosis in schizophrenia (Corse, Hirschinger, & Zanis, 1995). For example, the common consequences of substance abuse in the general population of loss of employment, driving under the influence of alcohol, and relationship problems are less often experienced by people with schizophrenia, who are often unemployed, do not own cars, and have limited interpersonal relationships. Rather, persons with schizophrenia more often experience increased symptoms and rehospitalizations, legal problems, and housing instability because of substance abuse (Drake & Brunette, 1998).

Individuals with schizophrenia tend to use smaller quantities of drugs and alcohol (Cohen & Klein, 1970; Crowley, Chesluk, Dilts, & Hart, 1974; Lehman et al., 1994) and rarely develop the full physical dependence syndrome that is often present in persons with a primary substance use disorder (Corse et al., 1995; Drake et al., 1990; Test, Wallisch, Allness, & Ripp, 1989) or show other physical consequences of alcohol such as stigmata (Mueser et al., 1999). Even very low scores on instruments developed for the primary substance use disorder population, such as the Addiction Severity Inventory, may be indicative of substance use disorder in persons with schizophrenia (Appleby, Dyson, Altman, & Luchins, 1997; Corse et al., 1995; Lehman, Myers, Dixon, & Johnson, 1996). Because of the difficulties in using existing measures of substance abuse for people with schizophrenia and other severe mental illnesses, a screening tool was developed specifically for these populations: the Dartmouth Assessment of Lifestyle Instrument (DALI; Rosenberg et al., 1998). The DALI is an 18-item questionnaire that has high classification accuracy for current substance use disorders of alcohol, cannabis, and cocaine for people with severe mental illness.

Despite the difficulties involved in assessing comorbid substance abuse in persons with schizophrenia, recent developments in this area indicate that if appropriate steps are taken, reliable diagnoses can be made (Drake, Rosenberg, & Mueser, 1996; Maisto, Carey, Carey, Gordon, & Gleason, 2000). The most critical recommendations for diagnosing substance abuse in schizophrenia include (a) maintain a high index of suspicion of current substance abuse, especially if a person has a past history of substance abuse; (b) use multiple assessment techniques, including self-report instruments, interviews, clinician reports, reports of significant others, and biological assays for the presence of substances, which are routinely collected on admission to inpatient treatment; and (c) be alert to signs that may be subtle indicators of the presence of a substance use disorder, such as unexplained symptom relapses, familial conflict, money management problems, and sudden depression or suicidality. Once a substance use disorder has been diagnosed, integrated treatment that addresses both the schizophrenia and the substance use disorder (co-occurring disorders) is necessary to achieve a favorable clinical outcome (Drake, Mercer-McFadden, Mueser, McHugo, & Bond, 1998).

Mood Disorders

Schizophrenia overlaps more prominently with the major mood disorders than any other psychiatric disorder. The differential diagnosis of schizophrenia from mood disorders is critical, because the disorders respond to different treatments, particularly pharmacological interventions. Two different mood disorders can be especially difficult to distinguish from schizophrenia: bipolar disorder with psychotic features and major depression. The differential diagnosis of these disorders from schizophrenia is complicated by the fact that mood symptoms are frequently present in all phases of schizophrenia (prodrome, acute, and remission), and psychotic symptoms (e.g., hallucinations, delusions) may be present in persons with severe mood disorders (APA, 2013; Pope & Lipinski, 1978).

The crux of making a differential diagnosis between schizophrenia and a major mood disorder is determining whether psychotic symptoms are present in the absence of mood symptoms. If there is strong evidence that psychotic symptoms persist even when the person is not experiencing symptoms of mania or depression, then the diagnosis is either schizophrenia or the closely related disorder of schizoaffective disorder (discussed in the following section). If, on the other hand, symptoms of psychosis are present only during a mood episode, but disappear when the person’s mood is stable, then the appropriate diagnosis is either major depression or bipolar disorder. For example, it is common for people with bipolar disorder to have hallucinations and delusions during the height of a manic episode, but for these psychotic symptoms to remit when the person’s mood becomes stable again. Similarly, persons with major depression often experience hallucinations or delusions during a severe depressive episode, which subside as their mood improves. If the patient experiences chronic mood problems, meeting criteria for manic, depressive, or mixed episodes, it may be difficult or impossible to establish a diagnosis of schizophrenia, because there are no sustained periods of stable mood.

Schizoaffective Disorder

Schizoaffective disorder is a diagnostic entity that overlaps with both the mood disorders and schizophrenia (APA, 2013). Three conditions must be met for a person to be diagnosed with schizoaffective disorder: (1) the person must meet criteria for a major mood episode (depressive or manic mood episodes) along with symptoms from criterion A from schizophrenia; (2) the person has delusions or hallucinations for 2 or more weeks in the absence of a major mood episode; and (3) the mood symptoms have to be present for a majority of the illness’s duration (i.e., a person who experiences brief, transient mood states and who is chronically psychotic and has other long-standing impairments would be diagnosed with schizophrenia, rather than schizoaffective disorder).

Schizoaffective disorder and major mood disorder are frequently mistaken for one another because it is incorrectly assumed that schizoaffective disorder simply requires the presence of both psychotic and mood symptoms at the same time. Rather, as described in the preceding section, if psychotic symptoms always coincide with mood symptoms, the person has a mood disorder, whereas if psychotic symptoms are present in the absence of a mood episode, the person meets criteria for either schizoaffective disorder or schizophrenia. Thus, schizoaffective disorder requires longitudinal information about the relationship between mood and psychosis to make a diagnosis. This information is often obtained from the individual but is subject to memory and self-reporting biases (poor insight, or lack of awareness of mood states). The distinction between schizophrenia and schizoaffective disorder can be more difficult to make, because judgment must be made as to whether the affective symptoms have been present for a substantial part of the person’s illness. Decision rules for determining the extent to which mood symptoms must be present to diagnose a schizoaffective disorder have not been clearly established.

Although the differential diagnosis between schizophrenia and schizoaffective disorder is difficult to make, the clinical implications of this distinction are less important than between the mood disorders and either schizophrenia or schizoaffective disorder. Research on family history and treatment response suggest that schizophrenia and schizoaffective disorder are similar disorders and respond to the same interventions (Kramer et al., 1989; Levinson & Levitt, 1987; Levinson & Mowry, 1991; Mattes & Nayak, 1984). In fact, many studies of schizophrenia routinely include persons with schizoaffective disorder and find few differences. Therefore, the information provided in this chapter on schizophrenia also pertains to schizoaffective disorder, and the differential diagnosis between the two disorders is not of major importance from a clinical perspective.

Delusional Disorder

Delusions can be found in schizophrenia, schizoaffective disorder, severe mood disorders, organic conditions, and delusional disorder and are a nonspecific symptom in many cases. Persons with delusional disorder develop fixed delusions and do not show the other symptoms of schizophrenia (prominent auditory hallucinations, disorganization, odd or bizarre behaviors, negative symptoms). The delusion may lead to problems with others, but in general the person has good social, educational, and occupational functioning. Tactile and olfactory hallucinations can be present and will usually be incorporated into the delusional belief. Delusional disorder is more common in females (3:1 female-to-male ratio) and has a later age of onset (mean age of 40; Evans, Paulsen, Harris, Heaton, & Jeste, 1996; Manschreck, 1996; Yamada, Nakajima, & Noguchi, 1998). Delusional disorder accounts for 1% to 4% of all inpatient admissions and is relatively rare in clinical practice (Kendler, 1982).

In previous editions of the DSM, the differential diagnosis between delusional disorder and schizophrenia is based on the presence of nonbizarre delusions and absence of other symptoms of schizophrenia. Nonbizarre delusions are based on events or situations that could occur in real life but are highly improbable and lack supporting evidence (Sedler, 1995). Examples of nonbizarre delusions include being watched, followed, spied upon, harassed, loved, or poisoned. In contrast, bizarre delusions involve mechanisms not believed to exist in an individual’s culture, such as beliefs of thought insertion, control, and broadcasting. In reality, the distinction between nonbizarre and bizarre beliefs is highly subjective and difficult (Junginger, Barker, & Coe, 1992; Sammons, 2005). However, in the DSM-5 the issue of nonbizarre versus bizarre delusions has been removed and it emphasizes the presence of fixed delusions of any type that are present for 1 month. Many persons with delusions will provide convincing arguments that their beliefs are true, and a decision on whether the belief is plausible must often be made with very little corroborating evidence (Flaum, Arndt, & Andreasen, 1991; Jones, 1999). An examination of the person’s history, premorbid and current functioning, and symptom profile can be useful in distinguishing delusional disorder from schizophrenia. A structured interview, such as the SCID, can be useful in assessing delusional beliefs along with the other symptoms of schizophrenia.

Psychological Assessment

A wide range of different psychological formulations have been proposed for understanding schizophrenia. For example, there are extensive writings about psychodynamic and psychoanalytic interpretations of schizophrenia. Although this work has made contributions to the further development of these theories, these formulations do not appear to have improved the ability of clinicians to understand persons with this disorder or led to more effective interventions (Mueser & Berenbaum, 1990). Therefore, the use of projective assessment techniques based on psychodynamic concepts of personality, such as the Rorschach and Thematic Apperception Test, is not considered here.

One of the primary areas to assess is severity of psychotic symptoms, because treatment progression is mainly judged by a reduction of symptoms (Andreasen et al., 2005). This includes an assessment of positive and negative symptoms and general psychopathology due to the high co-morbidity with anxiety and mood disorders. Measures such as the Positive and Negative Syndrome Scale (PANN S; Kay, Fiszbein, & Opler, 1987), the Brief Psychiatric Rating Scale (BPR S; Overall & Gorham, 1962), and the Psychotic Rating Scale (PSYRATS; Haddock, McCarron, Tarrier, & Faragher, 1999) have been frequently used in schizophrenia research and have good psychometric properties. Scales specific to positive (Scale for the Assessment of Positive Symptoms; Andreasen & Olsen, 1982) and negative symptoms (Scale for the Assessment of Negative Symptoms; Andreasen, 1982) can be used for a more in-depth and detailed assessment of these areas. There are also self-report and interview-based measures of insight available as well (see Amador & David, 2004). Commonly, these symptom measures are used in conjunction with a structured diagnostic interview in the assessment of schizophrenia.

As noted earlier, schizophrenia is often associated with a variety of neuropsychological impairments. Core areas to assess in terms of cognitive functioning are verbal and visual learning and memory, working memory, attention/vigilance, abstract reasoning/executive functioning, speed of information processing, and social cognition. These areas are part of the National Institute of Mental Health—Measurement and Treatment Research to Improve Cognition in Schizophrenia cognitive battery (NIMH-MATRICS; Green et al., 2004). Having information on cognitive functioning in these areas will aid in examining the beneficial effects of antipsychotic medication on cognition. It also is important to consider the generalization of these impairments to different situations (i.e., transfer of training problems). Thus, assessment needs to be conducted in the environments in which the skills are to be used in order to provide a more ecologically valid assessment. For example, successful employment interventions incorporate assessment on the job on an ongoing basis rather than extensive prevocational testing batteries that do not generalize to real-world settings (Bond, 1998; Drake & Becker, 1996). Similarly, when assessing independent living skills, it is important that these be measured directly in the living environment of the patient or in simulated tests (Wallace, Liberman, Tauber, & Wallace, 2000).

A great deal of research has been done on the functional assessment of social skills in people with schizophrenia. Social skills refer to the individual behavioral components, such as eye contact, voice loudness, and the specific choice of words, which in combination are necessary for effective communication with others (Mueser & Bellack, 1998). As previously described, poor social competence is a hallmark of schizophrenia. Although not all problems in social functioning are the consequence of poor social skills, many social impairments appear to be related to skill deficits (Bellack, Morrison, Wixted, & Mueser, 1990).

Several different strategies can be used to assess social competence. Clinical interviews can be a good starting place for identifying broad areas of social dysfunction. These interviews can focus on answering questions such as: Is the patient lonely? Would the patient like more or closer friends? Is the patient able to stand up for his or her rights? Is the patient able to get others to respond positively to him or her? Patient interviews are most informative when combined with interviews with significant others, such as family members and clinicians who are familiar with the nature and quality of the patient’s social interactions, as well as naturalistic observations of the patient’s social interactions. The combination of these sources of information is useful for identifying specific areas in need of social skills training.

One strategy for assessing social skills that yields the most specific type of information is role-play assessments. Role-plays usually involve brief simulated social interactions between the person and a confederate taking the role of an interactive partner. During role-plays, individuals are instructed to act as though the situation were actually happening in real life. Role-plays can be as brief as 15 to 30 seconds to assess skill areas such as initiating conversations, or they can be as long as several minutes to assess skills such as problem-solving ability. Role-plays can be audiotaped or videotaped and later rated on specific dimensions of social skill. Alternatively, role-playing can be embedded into the procedures of social skills training, in which persons with schizophrenia practice targeted social skills in role-plays, followed by positive and corrective feedback and additional role-play rehearsal. In the latter instance, the assessment of social skills is integrated into the training of new skills, rather than preceding skills training.

A commonly used assessment measure for social skill is the Maryland Assessment of Social Competence (MASC; Bellack & Thomas-Lohrman, 2003). The MASC is a structured role-play assessment that consists of four 3-minute interactions. Following each role-play, ratings on verbal and nonverbal skill and effectiveness are made, thus allowing the clinician to examine social skill across different situations and contexts.

Recent research on the reliability and validity of social skill assessments, and the benefits of social skills training for persons with schizophrenia, has demonstrated the utility of the social skills construct. Persons with schizophrenia have consistently been found to have worse social skills than persons with other psychiatric disorders (Bellack, Morrison, Wixted, et al., 1990; Bellack, Mueser, Wade, Sayers, & Morrison, 1992; Mueser, Bellack, Douglas, & Wade, 1991), and approximately half of the persons with schizophrenia demonstrate stable deficits in basic social skills compared to the nonpsychiatric population (Mueser, Bellack, Douglas, & Morrison, 1991). In the absence of skills training, social skills tend to be stable over periods of time as long as 6 months to 1 year (Mueser, Bellack, Douglas, & Morrison, 1991). Social skill in persons with schizophrenia is moderately correlated with level of premorbid social functioning, current role functioning, and quality of life (Mueser, Bellack, Morrison, & Wixted, 1990). Social skills tend to be associated with negative symptoms (Appelo et al., 1992; Bellack, Morrison, Wixted, et al., 1990; Lysaker, Bell, Zito, & Bioty, 1995; Penn, Mueser, Spaulding, Hope, & Reed, 1995), but not with positive symptoms (Mueser, Douglas, Bellack, & Morrison, 1991; Penn et al., 1995). Furthermore, role-play assessments of social skill are also strongly related with social skill in more natural contexts, such as interactions with significant others (Bellack, Morrison, Mueser, et al., 1990).

Persons with schizophrenia show a wide range of impairments in social skills, including areas such as conversational skill, conflict resolution, assertiveness, and problem solving (Bellack, Sayers, Mueser, & Bennett, 1994; Douglas & Mueser, 1990). Thus, ample research demonstrates that social skills are impaired with persons with schizophrenia, tend to be stable over time in the absence of intervention, and are strongly related to other measures of social functioning. Furthermore, there is growing evidence supporting the efficacy of social skills training for schizophrenia (Bellack, 2004; Heinssen, Liberman, & Kopelowicz, 2000).

The broadest area of psychological assessment is community functioning, and improvement in this area is linked to the concept of recovery (see “Course and Prognosis”). Persons with schizophrenia show not only poor social skills but also poor adaptive functioning in the community. Ideally, treatment programs should aim to improve the person’s quality of life and satisfaction. Independent living skills, quality of life, and social functioning may need to be assessed in order to examine the person’s current functional capacity level. The Social Functioning Scale (Birchwood, Smith, Cochrane, Wetton, & Copstake, 1990) and UCSD Performance-Based Skills Assessment (UPSA; Patterson, Goldman, McKibbin, Hughs, & Jeste, 2001) are widely used measures of adaptive and community functioning.

Family Assessment

The assessment of family functioning has high relevance in schizophrenia for two reasons. First, Expressed Emotion (EE), which refers to the presence of hostile, critical, or emotionally overinvolved attitudes and behaviors on the part of close relatives of persons with schizophrenia, is an important stressor that can increase the chance of relapse and rehospitalization (Butzlaff & Hooley, 1998). Second, caring for an individual with a psychiatric illness can lead to a significant burden on relatives (Webb et al., 1998), which ultimately can threaten their ability to continue to provide emotional and material support to the individual. Family burden has its own negative consequences and can be related to EE and the ability of the family to care for the person with schizophrenia. Thus, a thorough assessment of these family factors is important in order to identify targets for family intervention.

Several specific methods can be used to assess a negative emotional climate in the family and the burden of the illness. Interviews with individual family members, including the person with schizophrenia, as well as with the entire family, coupled with observation of more naturalistic family interactions, can provide invaluable information about the quality of family functioning. The vast majority of research on family EE has employed a semistructured interview with individual family members, the Camberwell Family Interview (Leff & Vaughn, 1985). This instrument is primarily a research instrument, and it is too time-consuming to be used in clinical practice. Alternatives to the Camberwell Family Interview have been proposed (e.g., Magaña et al., 1986), although none has gained widespread acceptance yet. Several studies have successfully employed the Family Environment Scale (Moos & Moos, 1981), a self-report instrument completed by family members, which has been found to be related to symptoms and outcome in patients with schizophrenia (Halford, Schweitzer, & Varghese, 1991).

Many instruments have been developed for the assessment of family burden. The most comprehensive instrument, with well-established psychometric properties, is the Family Experiences Interview Schedule (Tessler & Gamache, 1995). This measure provides information regarding both dimensions of subjective burden (e.g., emotional strain) and objective burden (e.g., economic impact), as well as specific areas in which the burden is most severe (e.g., household tasks). The importance of evaluating family functioning is supported by research demonstrating clinical benefits of family intervention for schizophrenia. Numerous controlled studies of family treatment for schizophrenia have shown that family intervention has a significant impact on reducing relapse rates and rehospitalizations (Dixon et al., 2001; Pitschel-Walz, Leucht, Bäuml, Kissling, & Engel, 2001). The critical elements shared across different models of family intervention are education about schizophrenia, the provision of ongoing support, improved communication skills, and a focus on helping all family members improve the quality of their lives (Dixon & Lehman, 1995; Glynn, 1992; Lam, 1991).

Biological Assessment

Biological assessments are becoming more common in the clinical management of schizophrenia. For diagnosis, biological assessments may be used to rule out possible organic factors such as a tumor, stroke, or covert substance abuse. Urine and blood specimens are sometimes obtained in order to evaluate the presence of substance abuse. Similarly, blood samples may be obtained in order to determine whether the person is compliant with the prescribed antipsychotic medication, although the specific level of medication in the blood has not been conclusively linked to clinical response. Blood levels may also be monitored to ensure appropriate levels of mood stabilizers (e.g., lithium). Some newer medications (e.g., Clozaril) also require ongoing blood tests to detect very rare, but potentially lethal, blood disorders (Alvir, Lieberman, & Safferman, 1995; Young, Bowers, & Mazure, 1998). Client participation in this type of medical monitoring is crucial when using these medications.

Biological measures are sometimes used to characterize impairments in brain functioning associated with schizophrenia, although these assessments do not have clear implications for treatment of the illness at this time and are expensive. In addition, many clinicians do not have access to imaging technology, and its use has been specific to research settings. In terms of brain function and structure, computerized axial tomography (CAT) scans indicate that between one-half and two-thirds of all persons with schizophrenia display enlarged cerebral ventricles, particularly the lateral and third ventricles, which is indicative of cortical atrophy (Liddle, 1995).

Magnetic resonance imaging (MRI) studies have found structural changes and a reduction in gray matter volumes in the prefrontal, superior temporal, amygdala, hippocampus, and thalamus (Lawrie & Abukmeil, 1998; Wright et al., 2000). These findings have also been found in first-episode and nonill relatives as well and may be a pathophysiological marker for the disorder (Fannon et al., 2000; McDonald et al., 2002). These gross structural impairments in brain functioning, such as enlarged ventricles, tend to be associated with a wide range of neuropsychological impairments and negative symptoms often present in schizophrenia (Andreasen, Flaum, Swayze, Tyrrell, & Arndt, 1990; Buchanan et al., 1993; Merriam, Kay, Opler, Kushner, & van Praag, 1990). In addition, positron emission tomography (PET) and single photon emission computerized tomography (SPECT) have shown reduced metabolism and blood flow in several of the prefrontal and temporal cortexes, and abnormal activation of the thalamus (Kindermann, Karimi, Symonds, Brown, & Jeste, 1997; Liddle, 1997; McClure, Keshavan, & Pettegrew, 1998; Miyamoto et al., 2003). Functional MRI (fMRI) studies have found less activation in the prefrontal cortex and anterior cingulate cortex during working memory tasks (Carter, MacDonald, Ross, & Stenger, 2001; Perlstein, Carter, Noll, & Cohen, 2001). Finally, diffuse tensor imaging methods, which assess the integrity of white matter pathways in the brain, have found problems in myelinated neurons in the prefrontal lobes specifically and in the connections between the frontal, temporal, and parietal lobes (Burns et al., 2003; Lim, Hedehus, deCrespigny, Menon, & Moseley, 1998).

To date, most of the advances in the treatment of schizophrenia have been in psychopharmacology. Biological assessments are still not useful for diagnosing the illness or for guiding treatment. However, the clinical utility of biological assessment is likely to increase in the years to come as advances continue to be made in the understanding of the biological roots of schizophrenia.