Chapter 11 Psychological Disorders 413to suffer from major depression, but depression in men may be
underdiagnosed.• Vulnerability-stress models of depression (and other mental
disorders) look at interactions between individual vulnerabilities
and stressful experiences. The theory that depleted serotonin
causes depression has not been supported, but because depres-
sion is moderately heritable, the search for specific genes
continues. For some vulnerable individuals, repeated losses of
important relationships can set off episodes of major depres-
sion. Experiences with parental neglect and violence, especially
in childhood, increase the risk of developing major depression
in adulthood. Cognitive habits also play an important role:
believing that the origin of one’s unhappiness is permanent and
uncontrollable; feeling hopeless and pessimistic; and brooding
or ruminating about one’s problems.
• In bipolar disorder, a person typically experiences episodes of
both depression and mania (excessive euphoria). It is equally
common in both sexes, and may share symptoms and origins
with major depression and schizophrenia, and other disorders
as well.
Personality Disorders
• Personality disorders are characterized by maladaptive traits that
cause distress or an inability to get along with others. One is
borderline personality disorder, characterized by extreme nega-
tive emotionality and an inability to regulate emotions, often
resulting in intense but unstable relationships, self-mutilating
behavior, feelings of emptiness, and a fear of abandonment by
others.
• The term psychopath describes people who lack conscience
and empathy; who do not feel remorse, shame, guilt, or anxiety
over wrongdoing; and who can con others with ease. In anti-
social personality disorder (APD), symptoms may include the
remorselessness of psychopathy but the major criteria involve
a lifelong pattern of aggressive, reckless, impulsive, and often
criminal behavior (although not necessarily a lack of empathy
and other social emotions). Abnormalities in the central nervous
system and prefrontal cortex are associated with a lack of emo-
tional responsiveness and with impulsivity in many people with
psychopathy and APD. A genetic predisposition also plays a role
in these disorders, but it usually must interact with stressful or
violent environments to be expressed.
Substance-Related and Addictive Disorders
• The DSM-5 uses the term substance use disorder rather than
addiction to reflect the fact that people’s misuse of any drug
can range in severity from mild impairment to compulsive drug
taking that impairs a person’s ability to function. Symptoms
of alcohol-use disorder include at least two of these symp-
toms: uncontrollable craving for alcohol; drinking in situations
where it is physically hazardous; drinking despite persistent
social or personal consequences; inability to cut back or
stop; or drinking larger amounts or in greater frequency than
intended.
• According to the biological (disease) model of addiction, some
people have a genetic vulnerability to the kind of alcoholism that
begins in early adolescence and is linked to impulsivity, antisocial
behavior, and criminality. Genes also affect sensitivity to alcohol,
which varies across ethnic groups as well as among individuals.
But cause and effect also runs in the other direction: Heavy drug
abuse changes the brain in ways that make addiction more likely.
• Advocates of the learning model of addiction point out that
addiction patterns vary according to cultural practices and val-
ues; policies of total abstinence tend to increase addiction rates
and abuse because people who want to drink fail to learn how to
drink in moderation; many people can stop taking drugs without
experiencing withdrawal symptoms; and drug abuse depends on
the reasons for taking a drug.
• The biological and learning models are polarized on many
issues, notably that of abstinence versus moderation. People
who are most likely to abuse alcohol and other drugs may have
a genetic vulnerability; may have damaged brains as a result of
prolonged drug abuse; believe that they have no control over the
drug; live in a culture or peer group that promotes drug abuse;
and rely on the drug to cope with problems.Dissociative identity Disorder
• In dissociative identity disorder (DID), formerly called multiple
personality disorder (MPD), two or more distinct personalities
and identities appear to split off (dissociate) within one per-
son. Some psychiatrists and other clinicians think the disorder
is legitimate and originates in childhood trauma. But most
psychological scientists hold a sociocognitive explanation,
namely that DID is an extreme form of the ability to present
different aspects of our personalities to others. In this view,
the disorder is a cultural syndrome that emerges from pressure
and suggestion by clinicians who believe in its prevalence,
interacting with vulnerable patients who find the diagnosis a
plausible explanation for their problems. Media coverage of
sensational alleged cases of multiple personality, including
the fraudulent case of “Sybil,” greatly contributed to the rise
in cases after 1980.Schizophrenia
• Schizophrenia is a psychotic disorder involving delusions, hal-
lucinations, disorganized speech (called word salads), inappro-
priate behavior (including in some cases catatonic stupor), and
negative symptoms such as loss of motivation and emotional
flatness. Contrary to stereotype, many people with schizophrenia
recover.
• Schizophrenia involves brain abnormalities such as reduced
gray matter, abnormalities in the hippocampus, and enlarged
ventricles, as well as abnormalities in neurotransmitters and