The hypothalamic-pituitary-adrenal axis is a key mediator of the stress response in humans. The corticotropin-releasing factor (CRF) type 1 receptor (CRFR-1) in the pituitary gland is a gatekeeper for that response, and the CRFR-1 receptor is also present in many other mood- and cognition-related neural structures. Behaviorally, a number of relationships between stress and psychiatric disorders can be observed: chronic or repeated stress is associated with onset of depression; stressors can cause a recovering alcoholic to relapse; overactive stress responses mark many anxiety disorders; and insomnia can arise from an overactive stress response. Thus, a CRFR-1 antagonist could be useful for treating or preventing the consequences of CRF-mediated stress in depression, anxiety, insomnia, and substance abuse.

Despite relevant evidence of physical illness promoting fibromyalgia syndrome (FMS), some authors claim that it is a psychological illness, or due to “psychological amplification.” Good evi-dence for such views is lacking. Selection processes lead to increased rates of psychological illness in general practice and in specialist practice. The phys-ical distress of FMS can increase both anxiety and depression. Questionable research supported by the insurance industry has tended to provide nega-tive and disparaging views of pain. Current imag-ing studies support the view that central effects connected with FMS relate to the processing of noxious stimulation more than affective disorder.

The anterior cingulate cortex (ACC) ventral to the genu of the corpus callosum has been implicated in the modulation of emotional behavior on the basis of neuroimaging studies in humans and lesion analyses in experimental animals. In a combined positron emission tomography/magnetic resonance imaging study of mood disorders, we demonstrated that the mean gray matter volume of this “subgenual” ACC (sgACC) cortex is abnormally reduced in subjects with major depressive disorder (MDD) and bipolar disorder, irrespective of mood state. Neuropathological assessments of sgACC tissue acquired postmortem from subjects with MDD or bipolar disorder confirmed the decrement in gray matter volume, and revealed that this abnormality was associated with a reduction in glia, with no equivalent loss of neurons. In positron emission tomography studies, the metabolic activity was elevated in this region in the depressed relative to the remitted phases of the same MDD subjects, and effective antidepressant treatment was associated with a reduction in sgACC activity. Other laboratories replicated and extended these findings, and the clinical importance of this treatment effect was underscored by a study showing that deep brain stimulation of the sgACC ameliorates depressive symptoms in treatment-resistant MDD. This article discusses the functional significance of these findings within the context of the preclinical literature that implicates the putative homologue of this region in the regulation of emotional behavior and stress response. In experimental animals, this region participates in an extended “visceromotor network” of structures that modulates autonomic/neuroendocrine responses and neurotransmitter transmission during the neural processing of reward, fear, and stress. These data thus hold important implications for the development of neural models of depression that can account for the abnormal motivational, neuroendocrine, autonomic, and emotional manifestations evident in human mood disorders.

Attention-deficit/hyperactivity disorder (ADHD) is highly co-morbid across the life span. However, co-morbidity is not uniform across time; individual co-morbid conditions tend to occur at different times developmentally, with rates often reflecting lifetime occurrence (Slide 1). In addition to changes in the rates of co-morbidity, the nature of co-morbidity may also differ in late adolescence/adulthood, when co-morbid conditions can be especially impairing (eg, antisocial disorder, substance use disorder [SUD], more severe mood disorders).

There is controversy about whether mindfulness-based approaches to psychotherapy represent a new wave of cognitive-behavioral therapy or a core process in all psychotherapies. One way of conceptualizing mindfulness is in terms of emotion regulation; mindfulness is a strategy aimed at opposing suppression and avoidance. Dispositional mindfulness has been associated with greater activation in prefrontal cortex and greater deactivation of amygdala during affect labeling. A number of rigorous studies of mindfulness-based cognitive therapy for depression have been positive. However, much remains to be discovered about the underlying mechanisms of and clinical indications for mindfulness-based approaches.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder in the United States and the number of AD patients is increasing at an alarming rate. There is no cure for AD and the currently available treatments are symptomatic, providing only limited effects on disease pathophysiology and progression. An overwhelming need exists for therapies that can slow or halt this debilitating disease process. Disease modification in AD has been defined from patient-focused, regulatory, and neurobiological perspectives. The latter two of these perspectives rely largely on an interruption of the disease process and a clear demonstration of this interruption. As defined by Cummings, a disease-modifying treatment is a “pharmacologic treatment that retards the underlying process of AD by intervening in the neurobiological processes that constitute the pathology and pathophysiology of the disease and lead to cell death or dysfunction.” By this definition, the burden of confirmatory study is placed on any new treatment for which the claim of “disease modification” is to be made (Slide 1).

Given the frequency with which patients with substance use disorders (SUDs) and those with psychiatric disorders, such as major depressive disorder (MDD) and generalized anxiety disorder (GAD), suffer relapses and recurrences, the issue of long-term treatment for SUDs warrants special attention. Faced with recommending long-term treatment, the clinician must discern the primacy of disorder, which may have been only obliquely addressed at the time of the patient's presentation and then solved by concurrent treatment. Establishing primacy relies on determining whether the psychiatric symptoms were induced by SUD or the psychiatric disorder emerged first and substance use was a means of coping with it. A third possibility exists—that the two disorders developed independently of each other, albeit becoming intermingled over time and serving to exacerbate each other. Clues to the temporal relationship of the disorders can be deduced from a meticulous history obtained from multiple sources, the effects that acute treatment has had on either condition, and the patient's willingness to remain abstinent from the addictive substance. Hasin and colleagues demonstrated the importance that a history of depression has on long-term remission and relapse outcomes in substance dependence (Slide 1).

Psychosis in Parkinson's disease refers to a combination of hallucinations and delusions occurring with a clear sensorium and a chronic course. Hallucinations may involve several sensory modalities. Complex visual hallucinations are the most common type. “Minor” hallucinatory phenomena are frequently present and include visual illusions, passage hallucinations, and sense of presence. Insight may be lost in patients with cognitive impairment. Delusions of a paranoid type are more rare than hallucinations. Both hallucinations and delusions are more frequent in Parkinson's disease patients with dementia. Pathogenesis involves complex and probably multifactorial mechanisms, including pharmacologic (dopaminergic treatment and others) and disease-related factors.

Sometimes patients with organic brain lesions in neurologically silent brain areas might present only with psychiatric symptoms, such as depression, anxiety disorders, schizophrenia, anorexia nervosa, or cognitive dysfunction. This study presents eight cases of patients with brain lesions (four cases of meningiomas, one case of intracerebral cysts, one case of anaplastic oligodendroglioma, one case of multiform glioblastoma, and one case of occlusive hydrocephalus) who, for a significant period of time, were diagnosed and treated for psychiatric disorders (three cases of Alzheimer's disease, two cases of schizoaffective disorder, one case of schizophrenia, one case of depression, and one case of organic emotional lability disorder). When neurologic symptoms developed, they underwent neuroimaging studies and organic brain lesions were diagnosed. Further treatment required neurosurgical interventions. These cases show that brain tumors can be neurologically silent for a sufficient period of time and manifest as psychiatric disorders.

Obsessive-compulsive disorder is currently classified as an anxiety disorder. However, there is growing interest in the concept of an obsessive-compulsive spectrum of disorders (OCSDs). The relationship between anxiety disorders and OCSDs has been questioned. The psychobiology of anxiety disorders and OCSDs is briefly reviewed in this article. While there appear to be several distinct contrasts in the underlying psychobiology of these conditions, there is also evidence of overlapping mechanisms. In addition, there are crucial gaps in our current database, confounding nosological decision-making. Conceptualizing various anxiety disorders and putative OCSDs as lying within a broader spectrum of emotional disorders may be useful. However, clinicians must also recognize that individual anxiety and obsessive-compulsive spectrum conditions, including disorders characterized by body-focused repetitive behaviors, have distinct psychobiological underpinnings and require different treatment approaches.

Because a multitude of factors contribute to insomnia, the context of treatment can greatly impact treatment efficacy. Major depression or congestive heart failure, for example, can contribute to insomnia, and treatment of those conditions should exert a positive effect on insomnia symptoms. On the other hand, the treatment of other conditions, such as the use of selective serotonin reuptake inhibitors antidepressants, may have a negative effect on the quality of sleep. Clinicians, therefore, need to take a versatile, multifaceted approach for each patient when treating insomnia.

Personalizing medicine by understanding the unique properties of each patient's genome has the potential of predicting what drug to prescribe for that individual. This approach has already proven useful for several drugs in medicine and promises to become a strategy for selection of therapeutics in psychiatry soon. Understanding some of the key concepts, strategies, and advances in the field of pharmacogenomics can set the stage for adapting emerging findings to the practice of psychopharmacology.

Numerous “antihistamines” as well as various psychotropic medications with antihistamine properties are widely utilized to treat insomnia. Over-the-counter sleep aids usually contain an antihistamine and various antidepressants and antipsychotics with antihistamine properties have sedative-hypnotic actions. Although widely used for the treatment of insomnia, many agents that block the histamine H1 receptor are also widely considered to have therapeutic limitations, including the development of next-day carryover sedation, as well as problems with chronic use, such as the development of tolerance to sedative-hypnotic actions and weight gain. Although these clinical actions are classically attributed to blockade of the H1 receptor, recent findings with H1 selective agents and H1 selective dosing of older agents are challenging these notions and suggest that some of the clinical limitations of current H1-blocking agents at their currently utilized doses could be attributable to other properties of these drugs, especially to their simultaneous actions on muscarinic, cholinergic, and adrenergic receptors. Selective H1 antagonism is emerging as a novel approach to the treatment of insomnia, without tolerance, weight gain, or the need for the restrictive prescription scheduling required of other hypnotics.

A range of studies have contributed to understanding the psychobiology of emotional regulation. Functional imaging studies have demonstrated that cortico-limbic circuitry plays an important role in mediating processes such as reappraisal and suppression. Dorsolateral prefrontal cortex may be important in conscious reframing, while ventromedial prefrontal cortex and orbitofrontal cortex may be particularly important in emotion evaluation. Gene variants and early environments impact underlying emotional regulation and its neurobiology. It may be hypothesized that during interventions such as psychotherapy there are improvements in emotional regulation, together with the normalization of related psycho-biological mechanisms.

The heterogeneity of major depression suggests that multiple neurocircuits and neurochemicals are involved in its pathogenesis. Anhedonia and psychomotor symptoms are, however, particularly characteristic features of major depression and may provide insights into its underlying psychobiology. Importantly, these symptoms appear to be mediated by dopaminergic mesolimbic and mesostriatal projections, the function of which is, in turn, influenced by key gene variants and environment stressors. Indeed, there is growing evidence of the way in which the dopaminergic system is associated with cognitive-affective disturbances in depression, and provides a useful target for therapeutic interventions. At the same time, a range of other systems are likely to contribute to the psychobiology of this condition.

Dr. Janicak is professor of Psychiatry at Rush University in Chicago, Illinois, medical director of the Rush Psychiatric Clinical Research Center, and distinguished fellow at the American Psychiatric Association. He has been listed in Best Doctors of America since 1996, and Who's Who in America since 2002. In 2003, the Illinois chapter of the National Alliance for the Mentally III named Dr. Janicak “Psychiatrist of the Year.” With a strong interest in the assessment and treatment of mood and psychotic disorders, he has been a National Institute of Mental Health grant awardee as principal and co-investigator. Dr. Janicak is editor of the Psychopharm Review and has authored more than 250 publications in psychiatric literature, including Principles and Practice of Psychopharmacotherapy.

It is essential to recognize and treat psychosis in Parkinson's disease for several reasons. Studies have shown that psychosis in Parkinson's disease patients is a strong risk factor for nursing home placement. Psychosis may be the greatest source of stress for caretakers of Parkinson's patients; it is often persistent, and its presence markedly increases mortality. Treatment of psychotic symptoms should occur only after potential medical and environmental causes of delirium have been eliminated or addressed. Initial pharmacologic changes should include limiting the patient's antiparkinsonian medications to those that are necessary to preserve motor function. Should that fail, an atypical antipsychotic is presently the treatment of choice. An emerging treatment option is acetylcholinesterase inhibitors. This article reviews what is currently known about the course, prognosis, and treatment strategies in Parkinson's disease psychosis.