Resilience in mental health: linking psychological and neurobiological perspectives.

OBJECTIVE: To review the literature on psychological and biological findings on resilience (i.e. the successful adaptation and swift recovery after experiencing life adversities) at the level of the individual, and to integrate findings from animal and human studies. METHOD: Electronic and manual literature search of MEDLINE, EMBASE and PSYCHINFO, using a range of search terms around biological and psychological factors influencing resilience as observed in human and experimental animal studies, complemented by review articles and cross-references. RESULTS: The term resilience is used in the literature for different phenomena ranging from prevention of mental health disturbance to successful adaptation and swift recovery after experiencing life adversities, and may also include post-traumatic psychological growth. Secure attachment, experiencing positive emotions and having a purpose in life are three important psychological building blocks of resilience. Overlap between psychological and biological findings on resilience in the literature is most apparent for the topic of stress sensitivity, although recent results suggest a crucial role for reward experience in resilience. CONCLUSION: Improving the understanding of the links between genetic endowment, environmental impact and gene-environment interactions with developmental psychology and biology is crucial for elucidating the neurobiological and psychological underpinnings of resilience.

Scars in depression: is a conceptual shift necessary to solve the puzzle?

Although clinical findings suggest that in the aftermath of depression a process of 'scarring' may ensue, research examining the issue of 'scars' (including biological, psychological and cognitive changes) has remained largely inconclusive. This paper proposes a new approach to the concept of 'scars' that is (i) based on a dimensional view of depression, (ii) uses methods that take into account the dynamic interplay between the person and his context, (iii) differentiates between scars following depression and scars following the factor that actually caused the depression such as stress and (iv) introduces a dynamic view of the concept of 'scars' in that it hypothesizes that scars can wax and wane. This approach may stimulate the discovery of new entries in the puzzle underlying the ontogenesis of vulnerability and resilience. Furthermore, it may provide insights that help to develop new therapies for depression.

Meeting risk with resilience: high daily life reward experience preserves mental health.

OBJECTIVE: To examine prospectively whether high reward experience (the ability to generate positive affect boosts from pleasurable daily events) protects against affective symptoms and whether environmental or genetic risk factors moderate protective effects. METHOD: At baseline, 498 female twins participated in an experience sampling study measuring reward experience in daily life. They also completed questionnaires on childhood adversity and recent stressful life events (SLE). Affective symptoms were measured at baseline and at four follow-ups using SCL-90 anxiety and depression subscales. Co-twin affective symptoms were used as indicators of genetic risk. RESULTS: Baseline reward experience did not predict follow-up affective symptoms, regardless of level of genetic risk. However, high reward experience was associated with reduced future affective symptoms after previous exposure to childhood adversity or recent SLE. CONCLUSION: High daily life reward experience increases resilience after environmental adversity; modification of reward experience may constitute a novel area of therapeutic intervention.

Mechanisms of gene-environment interactions in depression: evidence that genes potentiate multiple sources of adversity.

BACKGROUND: Previous work suggests that daily life stress-sensitivity may be an intermediary phenotype associated with both genetic risk for depression and developmental stress exposures. In the current analysis we hypothesized that genetic risk for depression and three environmental exposures over the course of development [prenatal stress, childhood adversity and adult negative life events (NLEs)] combine synergistically to produce the phenotype of stress-sensitivity. METHOD: Twin pairs (n=279) participated in a momentary assessment study using the Experience Sampling Method (ESM), collecting appraisals of stress and negative affect (NA) in the flow of daily life. Prospective data on birthweight and gestational age, questionnaire data on childhood adversity and recent NLEs, and interview data on depression were used in the analyses. Daily life stress-sensitivity was modelled as the effect of ESM daily life stress appraisals on ESM NA. RESULTS: All three developmental stress exposures were moderated by genetic vulnerability, modelled as dizygotic (DZ) or monozygotic (MZ) co-twin depression status, in their effect on daily life stress-sensitivity. Effects were much stronger in participants with MZ co-twin depression and a little stronger in participants with DZ co-twin depression status, compared to those without co-twin depression. NLE main effects and NLE genetic moderation were reducible to birthweight and childhood adversity. CONCLUSIONS: The findings are consistent with the hypothesis that adult daily life stress-sensitivity is the result of sensitization processes initiated by developmental stress exposures. Genes associated with depression may act by accelerating the process of stress-induced sensitization.

Human brain: left-right asymmetries in temporal speech region.

We have found marked anatomical asymmetries between tile upper surfaces of the human right and left temporal lobes. The planum temporale (the area behind Hesch's gyrus) is larger on the left in 65 percent of brains; on the right it is larger in only 11 percent. The left planum is on the average one-third longer than the planum. This area makes up part of the temporal speech cortex, whose importance is well established on the basis of both anatomical findings in aphasic patients ans cortical stimulation at operation.

Right-left asymmetrics in the brain.

Structural asymmetries between the hemispheres are found in the human brain. Asymmetries in the auditory regions and in the Sylvian fissures are present even in the fetus. The Sylvian asymmetries may have existed in Neanderthal man and are found consistently in some apes. They may relate to right-left differences infunction. Thus, the striking auditory asymmetries could underlie language lateralization. The asymmetries in the frontal and occipital lobes and the lateral ventricles are correlated with hand preference. Anatomical asymmetries may help to explain the range of human talents, recovery from acquired disorders of language function, certain childhood learning disabilities, some dementing illnesses of middle life, and the evidence for behavioral lateralization in nonhuman primates.

The interictal behavior syndrome of temporal lobe epilepsy.

A distinct syndrome of interictal behavior changes occurs in many patients with temporal lobe epilepsy. These changes include alterations in sexual behavior, religiosity, and a tendency toward extensive, and in some cases compulsive, writing and drawing. The concomitants of abnormal limbic acitivity therefore include behavior alterations as well as manifest seizures. The demonstration of interictal spike activity in temporal structures provides a pathophysiologic basis for this syndrome. The constellation of behavioral changes may be of great diagnostic value. In addition, it provides an example of a human behavioral syndrome assocaited with dysfunction at specific anatomic loci. The behavior syndrome of temporal lobe epilepsy may prove to be a useful model in studies on the neural substrates for behavior.

Small-diameter nonmyelinated axons in the primate corpus callosum.

The splenium of the corpus callosum of a primate (Macaca mulatta), examined with the electron microscope, was found to contain both myelinated and nonmyelinated axons. The majority of nonmyelinated axons had diameters of less tha 0.25 micron. On the basis of this diameter distribution, it is expected that many callosal axons conduct impulses at velocities of less than 1 m/s and that interhemispheric conduction times for some callosal axons are at least 30 ms and possibly much longer.

Human brain. Cytoarchitectonic left-right asymmetries in the temporal speech region.

The auditory regions in four normal brains were mapped and the full extent of the cytoarchitectonic subdivisions was measured for the presence of right-left asymmetries. It was found that asymmetries similar to those found in the planum temporale (left commonly larger than right) are also seen in auditory cytoarchitectonic area Tpt, and area of probable importance for language function. There is a strong positive correlation between the planum asymmetry and the asymmetry of Tpt. It is concluded that the previously described planum asymmetries probably reflect asymmetries in an auditory cytoarchitectonic area and therefore may represent, at least in part, the anatomic substrate for language lateralization.

Seizures induced by singing and recitation. A unique form of reflex epilepsy in childhood.

A 2-year-old boy of above-average intelligence experienced seizures, manifested by ticlike turning movements of the head, which were induced consistently by his own singing--not by listening to or imagining music. His seizures were also induced by his recitation and by his use of silly or witty language such as punning. The neurologic examination showed only a right-sided Babinski's sign. Seizure activity on an EEG was present in both temporocentral regions, especially on the right side, and was correlated with clinical attacks. A computed tomographic scan was normal. Phenobarbital therapy did not reduce seizure frequency.

Posttraumatic cerebral hemispheric disconnection syndrome.

Gross and microscopic lesions of the corpus callosum and neighboring structures are common in severe closed head injury. This report is the first, to our knowledge, to confirm neuropathologically the occurrence of extensive traumatic destruction of the corpus callosum in a patient with left-sided apraxia and agraphia. It also demonstrates that large traumatic lesions of the corpus callosum may occur without prolonged posttraumatic coma, vegetative state, or death. In our patient, coexisting extracallosal hemispheric lesions may have modified the effects of callosal pathology. Cases of this type may be more common than generally appreciated, but since symptoms of hemispheric disconnection are not apparent in ordinary behavior, specific tests of callosal function must be employed if disconnection phenomena are to be detected in the posttraumatic period.

The neurology of depression. Cognitive and behavioral deficits with focal findings in depression and resolution after electroconvulsive therapy.

Deficits in cognition and behavior have frequently been described in severely depressed patients. Recent reports have drawn attention to focal left-sided neurologic findings occurring in depression. We describe a depressed patient with marked cognitive and behavioral impairment and focal left-sided signs. The depression, mental status deficits, and physical findings all resolved after electroconvulsive therapy.

Neuroendocrine dysfunction in temporal lobe epilepsy.

Since medial temporal lobe structures are involved in the modulation of endocrine function and temporal lobe epileptics commonly show personality changes that resemble endocrine disorders, the existence of neuroendocrine dysfunction in temporal lobe epileptics was investigated by comparing the response of serum luteinizing hormone levels with intravenous luteinizing hormone-releasing hormone infusion in patients and normal controls. Five of seven consecutive patients had response curves that fell almost entirely outside of the normal control range, and all seven had either baseline or peak values that were outside of the normal range. These findings suggest that hypothalamic-pituitary control of gonadotropin secretion may be altered among patients with temporal lobe epilepsy.

Reproductive endocrine disorders in women with partial seizures of temporal lobe origin.

Of 50 consecutive women with partial seizures of temporal lobe origin (temporal lobe epilepsy [TLE]) evaluated for reproductive dysfunction, 28 had menstrual problems. Of those, 19 had reproductive endocrine disorders. Polycystic ovarian syndrome and hypogonadotropic hypogonadism occurred significantly more often in women with TLE than in the general female population. Polycystic ovarian syndrome was associated with predominantly left-sided lateralization of interictal epileptic discharges; hypogonadotropic hypogonadism was more commonly found with right-sided discharges. Hyposexuality occurred more often in women with predominantly right-sided interictal epileptic discharges and was associated with low serum luteinizing hormone levels. There are several possible interpretations: epileptic discharges in medial temporal limbic structures may disrupt hypothalamic regulation of pituitary gonadotropin secretion; anovulatory cycles of reproductive endocrine disorders may promote the development of epileptic discharges; and TLE and some associated reproductive endocrine disorders may represent the parallel effects of prenatal factors common to the development of the brain and the reproductive system.

Reproductive endocrine disorders in men with partial seizures of temporal lobe origin.

Twenty consecutive men with partial seizures of temporal lobe origin were evaluated for sexual or reproductive dysfunction. Eleven (55%) had diminished sexual interest or reduced potency. Nine of them had reproductive endocrine disorders, with features of hypogonadotropic hypogonadism in five, hyperprolactinemia in two, and hypergonadotropic hypogonadism in two. Among these nine were cases in which the reproductive endocrine abnormalities could not readily be attributed to antiseizure medication use. Other possible interpretations are as follows: epileptic discharges in medial temporal lobe structures may disrupt hypothalamic regulation of pituitary secretion, hypogonadism may promote the development of epileptic discharges, and temporal lobe epilepsy and associated reproductive endocrine disorders may represent the parallel effects of prenatal factors common to the development of both the brain and the reproductive system.

Hemispheric asymmetry in the expression of positive and negative emotions. Neurologic evidence.

Three retrospective studies were conducted to examine functional brain asymmetry in the regulation of emotion. In the first study, reports of 119 cases were collected of pathological laughing and crying associated with destructive lesions. Pathological laughing was associated with predominantly right-sided damage, whereas pathological crying was associated with predominantly left-sided lesions. In the second study, 19 reports detailing mood following hemispherectomy were collected; right hemispherectomy was associated with euphoric mood change. In the third study, lateralization of epileptic foci was assessed in reports of 91 patients with ictal outbursts of laughing (gelastic epilepsy). Foci were most likely to be predominantly left-sided. The findings are congruent with studies of the effects of unilateral brain insult on mood, and a general model of hemispheric asymmetry in the regulation of emotion is presented.

Aphasia with predominantly subcortical lesion sites: description of three capsular/putaminal aphasia syndromes.

Nine cases of subcortical aphasia with capsular/putaminal (C/P) lesion sites demonstrated on computed tomographic (CT) scans were studied. Eight cases were occlusive-vascular in etiology and one was hemorrhagic. Three subcortical aphasia syndromes and three C/P lesion site patterns were observed. Patients with C/P lesion sites with anterior-superior white-matter lesion extension had good comprehension, grammatical, but slow, dysarthric speech, and lasting right hemiplegia. Patients with C/P lesion sites with posterior white-matter lesion extension across the auditory radiations in the temporal isthmus had poor comprehension, fluent Wernicke-type speech, and lasting right hemiplegia. Patients with C/P lesion sites with both anterior-superior and posterior extension were globally aphasic and had lasting right hemiplegia. Although these cases of C/P subcortical aphasia shared certain well-known features of Broca's and Wernicke's cortical aphasia syndromes, they did not completely resemble cases of either Broca's, Wernicke's, global, or thalamic aphasia in neurologic findings, CT scan lesion sites, or language behavior. Further study of the subcortical aphasias associated with these C/P lesion sites seems to be warranted.

Defective motor learning in ideomotor apraxia.

Liepmann suggested that the left hemisphere contained the engrams for motor sequences. Other investigators have suggested that ideomotor apraxia may be caused by either a destruction of these engrams or a disconnection of these engrams from motor systems in the nondominant hemisphere. If these hypotheses are correct, then ideomotor apraxics should not only show a defect on previously learned motor tasks but also a defect in new motor learning. Nine right-handed, hemiparetic, aphasic apraxics were given six trials on a rotary pursuit meter. Eight right-handed hemiparetic, aphasic, nonaprixic patients served as controls. All subjects were instructed to use their left (nonparetic) hand. The performance of the control group on the sixth trial was significantly better than that on the first trial, showing a distinct learning effect. In the apraxic group, however, there was no significant difference between the first and sixth trial, suggesting a defect in motor learning. This defect appeared to be caused by a combined defect of both acquisition and retention.

Stuttering: disappearance and reappearance with acquired brain lesions.

Despite 60 years of study, the brain mechanisms for stuttering are unknown. In an effort to shed light on these mechanisms, we studied two cases in which the fluency of speech changed after brain damage in adulthood. The first, an ambidextrous man, ceased to stutter after a head injury. The second, a converted left-handed man, experienced recurrence of childhood stuttering after a stroke.

Temporal lobe epilepsy: an extrahypothalamic pathogenesis for polycystic ovarian syndrome?

In a random sample of 20 women with temporal lobe epilepsy (complex partial seizures, CPS), we found 5 women with the polycystic ovarian syndrome. This finding in a small sample suggests a fivefold overrepresentation of polycystic ovarian syndrome among women with CPS. Clinical and experimental data support the notion that CPS and polycystic ovarian syndrome either favor a mutual development or are parallel effects of a common pathogenesis.