Bilateral electrodermal activity in depressive patients

Galvanic Skin Response Features in Psychiatry and Mental Disorders: A Narrative Review

This narrative review is aimed at presenting the galvanic skin response (GSR) Biofeedback method and possibilities for its application in persons with mental disorders as a modern form of neurorehabilitation. In the treatment of mental disorders of various backgrounds and courses, attention is focused on methods that would combine pharmacological treatment with therapies improving functioning. Currently, the focus is on neuronal mechanisms which, being physiological markers, offer opportunities for correction of existing deficits. One such indicator is electrodermal activity (EDA), providing information about emotions, cognitive processes, and behavior, and thus, about the function of various brain regions. Measurement of the galvanic skin response (GSR), both skin conductance level (SCL) and skin conductance responses (SCR), is used in diagnostics and treatment of mental disorders, and the training method itself, based on GSR Biofeedback, allows for modulation of the emotional state depending on needs occurring. Summary: It is relatively probable that neurorehabilitation based on GSR-BF is a method worth noticing, which-in the future-can represent an interesting area of rehabilitation supplementing a comprehensive treatment for people with mental disorders.

Skin conductance responses in Major Depressive Disorder (MDD) under mental arithmetic stress

Depressive symptoms are related to abnormalities in the autonomic nervous system (ANS), and physiological signals that can be used to measure and evaluate such abnormalities have previously been used as indicators for diagnosing mental disorder, such as major depressive disorder (MDD). In this study, we investigate the feasibility of developing an objective measure of depressive symptoms that is based on examining physiological abnormalities in individuals when they are experiencing mental stress. To perform this, we recruited 30 patients with MDD and 31 healthy controls. Then, skin conductance (SC) was measured during five 5-min experimental phases, comprising baseline, mental stress, recovery from the stress, relaxation, and recovery from the relaxation, respectively. For each phase, the mean amplitude of the skin conductance level (MSCL), standard deviations of the SCL (SDSCL), slope of the SCL (SSCL), mean amplitude of the non-specific skin conductance responses (MSCR), number of non-specific skin conductance responses (NSCR), and power spectral density (PSD) were evaluated from the SC signals, producing 30 parameters overall (six features for each phase). These features were used as input data for a support vector machine (SVM) algorithm designed to distinguish MDD patients from healthy controls based on their physiological responses. Statistical tests showed that the main effect of task was significant in all SC features, and the main effect of group was significant in MSCL, SDSCL, SSCL, and PSD. In addition, the proposed algorithm achieved 70% accuracy, 70% sensitivity, 71% specificity, 70% positive predictive value, 71% negative predictive value in classifying MDD patients and healthy controls. These results demonstrated that it is possible to extract meaningful features that reflect changes in ANS responses to various stimuli. Using these features, detection of MDD was feasible, suggesting that SC analysis has great potential for future diagnostics and prediction of depression based on objective interpretation of depressive states.

The association between electrodermal activity (EDA), depression and suicidal behaviour: A systematic review and narrative synthesis

BACKGROUND

Electrodermal activity (EDA) and other peripheral autonomic electrical parameters have been used as indicators of emotional states, including depressive states and suicidal state. We aimed to review EDA research systematically, focusing on EDA's usefulness as a biomarker for depression and suicidal behaviour.

METHODS

We searched MEDLINE, Scopus, Cochrane Library, and Web of Science databases, following PRISMA guidelines. The initial screening of articles was based on titles and abstracts; then the full text was reviewed. A preliminary synthesis of findings was developed using tables, thematic analysis and quality ratings.

RESULTS

1287 articles were screened and 77 relevant studies were identified and included in the systematic review. The studies were fairly consistent in maintaining that hypoactive electrodermal response is an established feature of patients affected by depression. There is also preliminary evidence that monitoring EDA may help to differentiate the phases of mood disorders. A few studies provided evidence that EDA can be used to differentiate acutely suicidal subjects from depressed patients who are not severely suicidal. Although EDA has been shown to be a valid, sensitive marker of suicidal ideation, suicide attempts and violent suicidal behaviour, it also seems to be influenced to some extent by antidepressant treatment.

CONCLUSIONS

Most of the studies summarised in this review are quite outdated and employed a variety of designs and methods to evaluate EDA. This limits the generalisability of the results and makes it difficult to draw clear conclusions about the role of EDA in real-world settings. Electrodermal hypoactivity seems to be a reliable feature of depression and a valid marker of suicidal risk. Nevertheless, the potential utility of EDA in diagnosis, prevention, and treatment planning for depression and suicidal behaviour, should be thoroughly studied.

Mental health problems after stroke

We investigated the mental health of 47 subjects (30 men, mean age 63.8+/-7.7; 17 women, mean age 68.9+/-8.7) with the 60-item General Health Questionnaire (GHQ). All the subjects lived at home in a Japanese rural community and were examined from 2 to 3 years after suffering a stroke. Among the subjects, 18 (38.3%) had GHQ scores of 17 or more, which indicated a mental health problem (MHP). The following variables were included in multiple logistic regression analysis: age, sex (men/women), grade of motor paralysis (no/slight/moderate/severe), side of motor paralysis (no/left side/right side/both sides: in analysis, we used dummy variables), paresthesia (no/yes), rehabilitation (need no rehabilitation or participate in rehabilitation/fail to participate in rehabilitation), social support (not needed or sufficient/insufficient) and overall physical recovery (1/2/3: 1 = 67-100, 2 = 34-66, and 3 = 0-33 on a visual analog scale 100 mm long, 100 meaning full recovery). In univariate analysis all variables except age and sex showed statistically significant associations with MHP. In multivariate analysis, only one variable, overall physical recovery', had a statistically independent association with the status of MHP (Odds ratio 4.39, 95% confidence interval 1.46-13.19). The results of logistic regression analysis indicate that the presence of an MHP is more strongly dependent upon subjective assessment about overall physical recovery after stroke than upon physical impairments and the other psychosocial variables. Therefore, in the community setting, the visual analog scale of overall physical recovery is considered to be a simple, valid method for assessing MHP following stroke.

The neuropsychology of depression and its implications for cognitive therapy

The past few years have witnessed a growing interest in the specialty of neuropsychology as well as continued support for cognitive therapy of depression. The purpose of this paper is the examination of the neuropsychology of depression and its implications for A. T. Beck's cognitive theory and therapy of depression ([1963] "Thinking and Depression: Idiosyncratic Content and Cognitive Distortions," Archives of General Psychiatry, Vol. 9, pp. 324-333; [1964] "Thinking and Depression," Archives of General Psychiatry, Vol. 10, pp. 561-571; [1967] Depression: Clinical, Experimental, and Theoretical Aspects, New York: Harper & Row). Specifically, the neuropsychological and cognitive theory and therapy literatures related to depression are reviewed followed by an integration of these areas. Neuropsychological evidence is presented that both supports cognitive theory and therapy of depression and helps explain why such therapy may prove ineffective in treating depression. Implications for clinical practice, including neuropsychological assessment of depressives, and potential future research directions are also provided.

Social and physical anhedonia in relation to cerebral laterality and electrodermal habituation in unmedicated psychotic patients

The neglect of psychophysiological investigation of social anhedonia, in contrast to physical anhedonia, was addressed by examining relations between electrodermal orienting responses and their lateral asymmetry in unmedicated schizophrenic, bipolar/schizoaffective, and unipolar depressive patients and normal control subjects. In support of relations between social withdrawal and right-hemispheric reactivity, social anhedonia was associated with a predominance of right-hemispheric influences in schizophrenic and bipolar/schizoaffective patients but not in depressive patients. Anhedonia in all but the depressive group was also related to responsiveness, particularly when fast habituators were pooled with nonresponders and compared with moderate and slow habituators. Anhedonia was higher in the more responsive group. This was particularly true of physical anhedonia. The results support associations between both types of anhedonia--social and physical--and psychophysiology, and they also suggest that anhedonia is not a unitary concept.

Bilateral electrodermal activity and cerebral mechanisms in syndromes of schizophrenia and the schizotypal personality

Bilateral electrodermal measurement was among the first to investigate abnormalities of lateralization in schizophrenia, and recent classification of non-institutionalized patients by lateral asymmetry has delineated positive and negative syndromes associated with opposite states of hemispheric balance. The neuropsychology of the symptoms is consistent with higher left- than right-hemispheric activity in the positive syndrome, and higher right- than left-hemispheric activity in the negative syndrome, evidence which in turn is consistent with current theory about hemispheric influences on electrodermal responses. As all patients had Schneiderian symptoms in common this provided a three-syndrome model, a model having affinities with contemporary reports of three-factor solutions in factor analyses of clinical ratings. All approaches describe two positive syndromes and one negative syndrome. The same model applied to the schizotypal personality has produced a three-factor solution having a strong bearing on the three schizophrenia syndromes, together with evidence of imbalances in functional lateralization that are consistent with the schizophrenia model. It is proposed that the controversy surrounding the orienting and habituation anomalies in schizotypal personality, which include reduced activity, augmented activity, and irregular habituation, may be elucidated by examining relationships with the three-syndrome model and through bilateral measurement. However, provision must be made for distinctions between processes of fixed structure and dynamic function, a critical requirement in view of the relations between electrodermal reactivity and orienting to the dynamic processes of arousal, attention and anxiety. The central nervous system underpinnings of electrodermal responsiveness in schizophrenia, notably the responder-non-responder distinction, is beginning to be elucidated through neuropsychological testing and brain imaging techniques. Research is warranted to explore an integration between the syndromes which evolved from bilateral measurement, and the responder-non-responder classification which arose from considerations of limbic dysfunction.

Regional cerebral blood flow in affective disorder

The results of two-dimensional cerebral blood flow (CBF) studies in depression and the results of measurements of regional CBF (rCBF) using single photon emission computerized tomography (SPECT) are briefly reviewed. A technical outline of both types of method is described. The majority of SPECT studies point to a decreased CBF in untreated patients with a tendency towards normalization, but other studies suggest that, following treatment, there is an increase above normal either from a decreased or an abnormally high initial level. One study has pointed to unipolar patients having lower flow in the right temporal and parietal lobes relative to normals, whereas non-endogenous patients did not differ significantly from normal controls. Bipolar depressives have been found to have higher flow values than normals in the parietal and temporal lobes in the left hemispheres. This relevant aspect or a possible relationship between type of depression and hemispheric asymmetry needs further study for full classification. Thus, most investigations designed to determine which brain structures might be involved in regulating affect have not been very successful, which may be a consequence of the biological heterogeneity of these disorders or of the limited spatial resolution of the techniques used for investigation. Even if some of these technical difficulties can be overcome with measurements of receptor kinetics supplemented, other biological variables that have proved valuable in psychiatry (such as rapid eye movement latency and biogenic amines) should be studied to find more precise biological markers for depressive illness.

Is anorexia nervosa a neuropsychological disease?

Evidence for central nervous system, and more particularly cortical, etiology of anorexia nervosa is reviewed. Topics covered are neuropsychiatric comorbidity, inheritance patterns, the neurobiology of body-image disturbance and of the eating function, perinatal and alcoholic insult to the brain, neurochemical and neuroelectric disturbance, anatomic and metabolic brain imaging, and neuropsychological impairment. It is concluded that there is indeed an important neuropsychological etiological dimension to anorexia nervosa. The profile most frequently associated with anorexia nervosa is right posterior hypometabolism, followed by right anterior hypermetabolism, both associated with right-sided abnormal electroencephalogram spiking. It is also proposed that bulimia consists of a "positive" neurological subtype and that restricting anorexia represents a "negative" neurological subtype. Priorities for further research into anorexia nervosa are specified to include twin adoption studies, brain electrical topography studies, postmortem histological studies, and experimentally inspired neuropsychological studies.

Asymmetry of recall in depression

We compared the verbal (auditory/semantic) and nonverbal (visual/configurational) recall of carefully defined depressed patients with a demographically matched control group of normal volunteers. Whereas controls were split as to whether their nonverbal recall exceeded or was inferior to their verbal recall, 89% of depressed patients demonstrated an asymmetry characterized by poorer nonverbal than verbal recall. Depressive subgroups (determined by clinical and psychoendocrine criteria) differed from controls, but not from each other, in demonstrating this asymmetry of recall. In contrast, depressed patients did not individually demonstrate an asymmetry between verbal and nonverbal recognition that differed from controls.

Skin conductance orienting response in unmedicated RDC schizophrenic, schizoaffective, depressed, and control subjects

In an evaluation of the skin conductance orienting response (SCOR) as a marker for schizophrenia, skin conductance (SC) activity was studied in 36 Research Diagnostic Criteria (RDC) schizophrenic (SCZ), 17 schizoaffective--mainly schizophrenic (SA), 24 depressed (DEP), and 25 psychiatrically well control (CONT) subjects. All subjects were unmedicated. Data are presented from four paradigms: a series of 1 s 70 dB tones in a no-task habituation paradigm; a similar series of 103 dB tones; a series of tones with a button-press (reaction time) task; and a loud white noise stimulus (without task). The proportion of SCOR nonresponse to the first 70 dB tone was 39% for SCZ, 82% for SA, 46% for DEP, and 36% for CONT subjects; the response rate for SA subjects was significantly lower than for all other groups. The CONT group was less responsive than in most previous studies. SCZ subjects did not show increased responsivity to more intense and to task-relevant stimuli, although SA subjects did show such increases. DEP subjects showed some evidence of autonomic hyperarousal (higher tonic SC level, trend toward more spontaneous SC responses). The overall pattern of results does not support SCOR to neutral, moderate-intensity tones as a specific marker for schizophrenia, although there was some evidence for a generalized decrease in autonomic responsivity to stimuli.

A role for hemispheric asymmetry in human behavioral variability

A model is presented in which functional lateral specialization and selective hemisphere priming combine to provide a mechanism for behavioral variability. The model is tested and supported by two experiments in which lateral attentional priming produces significant reductions in between-subject and within-subject variability. These findings help us to understand the source of behavioral variability, broaden our knowledge of the gross structures and functions of the brain, provide information about the manipulation of perceived control, and offer a technique for increasing statistical power in a wide variety of research settings.

Bilateral electrodermal asymmetry: past hopes and future prospects

In the present paper, I have reviewed data and evidence concerning bilateral electrodermal (EDA) recordings and hemispheric asymmetry. Nine papers published between 1982 and 1986 are evaluated together with the 51 papers reviewed in the prior Hugdahl (1984) paper. The overall impression of the data is skepticism concerning what bilateral differences imply. This does, however, not imply that EDA is a less relevant index of hemispheric asymmetry compared to other psychophysiological measures. The important aspect of psychophysiological laterality research is not the use of different dependent measures, but the design and manipulation of the independent variables. Thus, increased responding to a verbal stimulus initially projected only to the left as compared to the right hemisphere may be as instructive concerning conclusions about asymmetry as bilateral differences to a stimulus presented to both hemispheres simultaneously.

Cognitive dysfunction in melancholia

Sixty-seven patients with melancholia and 42 normal controls were tested with a battery of neuropsychological tasks selected to assess regional cortical functioning in both hemispheres. Compared with controls, melancholics exhibited a pattern of bifrontal and right parietal impairment, which was independent of age, sex, handedness and drug administration. These findings confirm and extend prior studies and contrast with those we and others have reported in patients with schizophrenia.

Sex differences in latencies of bilateral electrodermal responses

The present study examined sex differences in the latencies of bilateral electrodermal responses to stimuli presented in monocular vision. The stimuli were spatial-emotional, verbal-emotional, spatial-neutral and verbal-neutral slides, presented for either 35 ms or 1 s. Subjects were 15 males and 15 females. Bilateral latencies were not influenced by type of stimulus or by right/left hemisphere stimulation, which is in keeping with the most recent findings of bilateral electrodermal activity studies. However, females gave a faster right hand than left hand response and appeared to be more lateralized than males. Males showed shorter latencies on the left hand than on the right. These results confirm the importance of gender in experiments using the bilateral recordings of electrodermal activity.

Hemispheric lateralization of functions related to emotion

We have reviewed the evidence that processes and functions related to perception and expression of emotions are represented asymmetrically in the cerebral hemispheres. The literature describes three possible aspects of emotional lateralization: that emotions are better recognized by the right hemisphere; that control of emotional expression and related behaviors takes place principally in the right hemisphere; and that the right hemisphere is specialized for dealing with negative emotions, while the left is specialized for dealing with positive emotions. Evidence for the three hypotheses derives from methodologically diverse studies in unimpaired, brain-lesioned, and mood-disordered populations. Relatively little of the work has been precisely replicated, and conclusions rest on parallel lines of evidence from diverse sources. The present level of knowledge suggests a model of emotional control based on interactive inhibition between a right negatively biased and left positively biased hemisphere. However, the details of such a model, including the precise conditions under which emotion-related functions are lateralized, and the mechanisms of such lateralization have yet to be elucidated.

Auditory laterality in depression: relation to circadian patterns and EEG sleep

Unmedicated endogenous (ED) and nonendogenous depressed (ND) patients were tested in the morning and evening on a dichotic click detection task and a dichotic consonant-vowel (CV) discrimination task. The ED and ND groups showed a morning to evening shift in lateral asymmetry for detecting dichotic clicks, which was opposite in direction to that previously seen for normal subjects. In contrast, there was no morning to evening shift in asymmetry for dichotic CV discrimination. Lateral asymmetry for dichotic click detection was significantly correlated with EEG sleep characteristics (sleep latency, REM period latency, REM time) and ratings of diurnal variation on the Hamilton Depression Scale. A reversal of the normal lateral asymmetry in the morning was associated with lengthened sleep latencies and with clinical ratings of diurnal variation.

Methodological problems in bilateral electrodermal research

Since the beginning of the 1970's, bilaterally recorded electrodermal activity (EDA) has generated a significant amount of research. It has been used in studies of hemispheric asymmetry, as well as in psychiatry as an indicator of left and right hemisphere activity. However an examination of the various studies which have utilized this technique does not show an overall consensus, and the results, as well as their interpretations, are often contradictory. These difficulties can partially be explained in terms of problems of methodology and interpretation. The aim of this paper is to review the methodological considerations, which have been grouped into 3 categories: stimulus specificity; the selection of subjects; and the measurement and interpretation of EDA.

Asymmetry of electrodermal activity: a review

Before the seventies, with a few exceptions, electrodermal activity had been studied only unilaterally, presuming symmetry. Only in the seventies do a growing number of authors take an interest in electrodermal asymmetry, due in part to the enthusiasm evoked by theories of hemispheric specialization. The purpose of this paper is to clarify and summarize the data - often contradictory - collected on this subject and to point out some remaining problems.

Hemispheric imbalances in schizophrenia

Evidence is presented of two syndromes in schizophrenia distinguished by opposite asymmetries in hemispheric activation. A florid syndrome is coincidental with left hemisphere overactivation and a non-florid syndrome with right hemispheric overactivation. In each case underactivation characterizes the opposite hemisphere. While this was first revealed by electrodermal lateral asymmetries, a review of the literature provides support from other measures of dynamic process asymmetries such as arousal and attention, and includes electrocortical activity in the form of EEG activity and evoked potentials (EP), the Hoffman reflex, lateral eye movements, auditory thresholds, dichotic listening, somatosensory extinction and handedness. A preliminary empirical test of the model involving a spectral analysis of EPs recorded from occipital and temporal placements was also confirmatory. While hemispheric imbalance may result from asymmetries in fixed structural processes the imbalance itself determines the form the psychosis follows which, due to the dynamic nature of the neuropsychological process, is presumably modifiable.

Multiple measures of hemispheric dysfunction in schizophrenia and depression

Electrodermal, electroencephalographic and perceptual measures of lateral hemispheric function were obtained from groups of chronic schizophrenics, depressives and normals on 2 occasions, separated by 4 weeks. The measures of hemispheric function were derived from previous research. About half of the schizophrenics were medicated on both occasions; the other schizophrenics underwent drug 'washout' before the first session. Results revealed that the measures of laterality were not strongly intercorrelated. In the perceptual task, the schizophrenics and normals displayed different laterality effects. Unlike the normals, the schizophrenics' left hemisphere function appeared to be inferior to the right hemisphere function in the perceptual task. The laterality effects of the depressives and normals differed on two electrodermal measures: skin conductance level and skin conductance response amplitude. The depressives' electrodermal activity from the right hand was diminished as compared with the left hand; the normals did not show this effect. Medication decreased electrodermal activity in the schizophrenics, but had no significant effect on laterality. These results suggest that the various measures of laterality used singly in previous research in psychopathology may not all assess the same phenomenon.

Lateralized cortical/cognitive processing and bilateral electrodermal activity: effects of sensory mode and sex

Forty-eight subjects were assigned to four equal-size cells defined by sex and familial handedness (presence versus absence of an immediate family member who is left-handed or ambidextrous). Subjects were presented a series of 40 stimuli, each of which was designed to represent the intersection of a sensory mode (visual versus auditory) and hemisphere mode (verbal versus spatial). The dependent measures were the number of stimulus-specific and nonspecific responses with magnitude larger on the lefthand. On the whole, results are supportive of the contralateral inhibitory process hypothesized by LaCroix and Comper (1979). Nonspecific response data appear to be sensitive to hemispheric manipulation as observed previously in this laboratory. Sensory mode appears to be an important determinant of lateralized phasic magnitude differences, with males showing the most striking verbal-spatial distinctions during visual mode presentation.

The syndrome of schizophrenia: relations between electrodermal response, lateral asymmetries and clinical ratings

Forty-eight undrugged hospital admissions with a present state examination (PSE) diagnosis of schizophrenia were subdivided by the direction of lateral differences in electrodermal response amplitudes to tones. The 29 with larger right-hand responses and the 19 with larger left-hand responses were compared on CATEGO syndromes and brief psychiatric rating scale (BPRS). The larger group had symptoms like those of classical Bleulerian schizophrenia--blunted affect, emotional withdrawal, impaired social functioning, disorganized thought and retarded motility. The other group manifested florid symptoms including hypomanic affect, pressure of speech, ideas of reference, depressive hallucinations and delusions, hypochondriasis, grandiosity and situational anxiety. The psychophysiological measures may provide an objective aid to diagnosis and implications for altered cerebral organization in psychotic patients.

Lateralized auditory processing in depression: dichotic click detection

The intensity needed to detect dichotic click stimuli was measured in 14 bipolar depressed patients, 19 unipolar depressed patients, and 15 normal controls. The results replicated, in unmedicated bipolar depressed patients, an earlier finding of reversed lateral asymmetry in medicated affective psychotic patients. Two new findings concern the relation of lateral asymmetry patterns to diagnostic subtypes of the Research Diagnostic Criteria and symptom ratings on the Schedule for Affective Disorders and Schizophrenia. First, patients with bipolar disorders (history of mania or hypomania) were more likely than patients with unipolar disorders to display reversed lateral asymmetry. Second, greater severity of depressive or endogenous symptoms was associated with less lateral asymmetry.

Bilateral electrodermal activity as a function of hemisphere-specific stimulation, hand preference, sex and familial handedness

The effects of unilateral stimulation on bilaterally recorded electrodermal activity are not well understood. Factors that may contribute to bilateral response differentiation under conditions of unilateral stimulation include preferred hand, sex and familial handedness. To assess the effects of these factors, 64 subjects were each assigned to one of four cells defined by sex and preferred hand. Each subject received a counterbalanced series of 31 slides depicting objects spatially and intended to activate the right hemisphere and 31 slides depicting objects spatially and intended to activate the left hemisphere. Each condition was followed by a blank slide. Results showed smaller mean nonspecific responses on the hand contralateral to the hemisphere for which stimulation was intended. This supports the hypothesis that a contralateral inhibitory process underlies electrodermal responsiveness. Further results showed that the effects of unilateral stimulation on bilaterally differentiated electrodermal activity are mediated by familial handedness and sex.

DESCRIPTORS

hemispheric processes, bilateral EDA, sex, familial handedness, preferred hand.

Reactive gaze laterality in schizophrenic patients

Reflective lateral eye movements (LEMs) in response to questions of different categories are indicative of differential hemispheric reactivity. These LEMs were studied in schizophrenic patients and normal subjects, in response to 24 questions (12 visual-emotional and 12 verbal-neutral). Two categories of saccades were observed: short-latency LEMs (S-LEMs) and long-latency LEMs (L-LEMs). S-LEMs are believed to be associated with orienting response mechanism. L-LEMs are considered to be related to decision-making or formulating hemispheric-activity-dependent response strategy. In the present study, a general trend of leftward LEMs was found among normals regardless of the question's category, whereas schizophrenics tended to show predominantly rightward LEMs. This suggests that individual cognitive style, rather than task variables, affects LEM direction. The two types of LEM's and their different involvement in hemispheric activity are discussed.

Clinical psychology in the chemical environment

Recent observations suggest that psychotherapy can influence biochemical and physiologic parameters which determine drug disposition and response to drugs. Consequently, clinical psychologists can participate in and share responsibility for the outcome of pharmacotherapy. Current interpretations of psychiatric concepts in biochemical and neurologic terms, and in particular, data on the asymmetry of hemispheric function in normal individuals and the mentally ill, now offer fresh opportunities to identify structural and neurochemical brain targets for psychotherapy which can be coupled with the sciences of drug distribution and neurochemical mechanisms of drug action. Several examples are presented to illustrate opportunities to achieve more desirable drug disposition and action by psychotherapeutic techniques. The objective of this report is to alert clinical psychologists, psychiatrists and drug therapists to the potential of this coordinated approach to treatment.