Patients with schizophrenia are unable to link the separate aspects of events into a cohesive, memorable, and distinctive whole. The corollary of this defective relational binding is a quantitative and qualitative impairment of autonoetic awareness.

Ketamine decreases episodic memory performance by impairing encoding, but not retrieval processes. It does not selectively impair subjective states of awareness associated with recognition memory as it has been seen in patients with schizophrenia. Ketamine might mimic the memory impairment associated with acute, but not chronic, forms of schizophrenia.

Meta-analyses and reviews on cognitive disorders in schizophrenia have shown that the most robust and common cognitive deficits are found in episodic memory and executive functions. More complex memory domains, such as autobiographical memory (AM), are also impaired in schizophrenia, but such impairments are reported less often despite their negative impact on patients' outcome. In contrast to episodic memory, assessed in laboratory tasks, memories of past personal events are much more complex and directly relate to the self. The meta-analysis included 20 studies, 571 patients with schizophrenia spectrum disorder, and 503 comparison subjects. It found moderate-to-large effect sizes with regard to the 3 parameters commonly used to assess AM: memory specificity (g = −0.97), richness of detail (g = −1.40), and conscious recollection (g = −0.62). These effect sizes were in the same range as those found in other memory domains in schizophrenia; for this reason, we propose that defective memories of personal past events should be regarded as a major cognitive impairment in this illness.

The efficacy of antidepressants is measured primarily by their ability to treat the acute symptoms of depression yet the underlying process may take longer to resolve. A period of emotional frailty follows resolution of the acute stage, during which the patient, although apparently symptom-free, is prone to suffer relapse of the original symptoms. Antidepressants should not be stopped immediately a response is observed, but should be given for a longer period to prevent early relapse. In those suffering from recurrent depression, long-term treatment may prevent later recurrences of new episodes of depression.The distinction between relapse of old symptoms and recurrence of new episodes is of particular importance, both in assessing efficacy of antidepressants during the continuation phase of acute treatment and in the separate assessment of their prophylactic efficacy. Unfortunately, though, many investigations have failed to distinguish between these two distinct phenomena. Klerman & Paykel (1970) emphasised the need to distinguish between early return of depressive symptoms, which they label ‘relapses’, from the later new episodes which they term ‘recurrence’. However, there has been a general lack of systematic investigation of this question, as well as a failure to use sufficiently precise methodology to distinguish between relapse and recurrence. Some studies which purported to be of prophylaxis were in effect only examining the continuation phase of acute treatment.

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Self-narratives of patients have received increasing interest in schizophrenia since they offer unique material to study patients’ subjective experience related to their illness, in particular the alteration of self that accompanies schizophrenia. In this study, we investigated the life narratives and the ability to integrate and bind memories of personal events into a coherent narrative in 27 patients with schizophrenia and 26 controls. Four aspects of life narratives were analyzed: coherence with cultural concept of biography, temporal coherence, causal-motivational coherence and thematic coherence. Results showed that in patients cultural biographical knowledge is preserved, whereas temporal coherence is partially impaired. Furthermore, causal-motivational and thematic coherence are significantly impaired: patients have difficulties explaining how events have modeled their identity, and integrating different events along thematic lines. Impairment of global causal-motivational and thematic coherence was significantly correlated with patients’ executive dysfunction, suggesting that cognitive impairment observed in patients could affect their ability to construct a coherent narrative of their life by binding important events to their self. This study provides new understanding of the cognitive deficits underlying self-disorders in patients with schizophrenia. Our findings suggest the potential usefulness of developing new therapeutic interventions to improve autobiographical reasoning skills.

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Unlike diazepam, lorazepam has repeatedly been shown to impair perceptual priming as well as explicit memory. To determine whether this deleterious effect was due to an impairment in acquisition of information, 60 healthy volunteers were randomly assigned to five treatment groups (placebo, lorazepam 0.026 or 0.038 mg/kg, diazepam 0.2 or 0.3 mg/kg) and successively performed perceptual priming tasks and a free-recall task. Priming performance on information learned before or 2 h after drug administration, i.e. at the peak concentration of lorazepam, was assessed under the influence of the drugs, using a picture-fragment and a word-stem completion task. Free-recall performance was altered by both drugs. Lorazepam decreased priming performance when information was acquired after, but not before, drug administration, indicating that the drug alters the acquisition of information. Lorazepam also impaired the ability to identify fragmented pictures, but there was no evidence that this perceptual effect accounts for the priming impairment. Surprisingly, diazepam also decreased priming when information was acquired after drug administration, suggesting that, at least in certain circumstances, the two benzodiazepines may exert similar effects on priming measures.