Mood: diagnosis, impairment and aetiology

Clinical diagnoses have traditionally been derived from careful observation and grouping of clinical characteristics, which has offered some prognostic benefit over time. However, given considerable variation in clinical presentation, it is not clear whether, and when, diagnostic criteria should be challenged. In this issue of the BJPsych, a proposal is put forward that the diagnostic focus on the different poles within affective disorder has not been helpful in progressing our understanding of the mechanisms underlying affective disorders. This view, highlighted in an editorial by Malhi & Geddes (pp. ), proposes a reverse translational approach to classification, predicated on the patient’s treatment response to lithium. Having reviewed the evidence for the efficacy of lithium in certain subtypes of affective disorder, they advocate for a diagnostic approach based on the treatment response to lithium over time, rather than the current focus on polarity. Affective disorders exert a heavy personal cost in terms of distress, and severely affect social and functional outcomes. Younger people with affective disorder may be anticipated to have lower levels of disability, and perhaps these may be more modifiable. Scott and colleagues (pp. ) demonstrate that there is marked functional impairment in younger people with affective disorders, with widespread comorbidity and substance misuse. Furthermore, they suggest that functional measures may be more efficient as a means of assessing outcomes than mood symptoms alone, highlighting that while functional recovery is usually associated with symptomatic recovery, clinical improvement is less robustly associated with functional recovery. Data support the hypothesis that adversity in early life, such as low birth weight and prematurity, can lead to adult depressive illness, but the literature remains mixed. A systematic review and meta-analysis of this area by Loret de Mola et al (pp. ) reports a positive association between low birth weight and depression in adulthood but did not find this relationship with prematurity. The authors suggest that children with low birth weight should be considered an at-risk population for depressive illness. The mechanism underlying this remains unclear, although poor nutrition leading to an overproduction of stress hormones having an effect via the hypothalamic-pituitary-adrenal axis has been a favoured model.

Brain changes in schizophrenia and obsessive-compulsive disorder

Changes in the hippocampus have been observed in patients with schizophrenia. However, the relationship between hippocampal change and ageing has not been clarified. Pujol and colleagues (pp. ) report a steeper age-related reduction in hippocampal volume in individuals with schizophrenia compared with healthy volunteers; this had a stronger impact on cognitive and socio-occupational outcomes than on the symptoms of psychosis or memory performance. The authors speculate that early neurodevelopmental injury may be followed by a neurodegenerative process in a subset of patients with schizophrenia, predisposing them to higher rates of dementia. Obsessive-compulsive disorder (OCD) has been conventionally associated with changes in the cortico-striatal connections of the brain. However, more recent data have suggested that other brain networks may also be affected in OCD. The ability to examine brain networks in the resting state offers a route to explore connectivity using a broader data-driven approach. Beucke et al (pp. ) report reduced network connectivity in OCD, particularly within regions of prefrontal cortex normally associated with self-referential processing, and increased connectivity with insula and parietal cortex, normally associated with salience and attentional processing. The latter hyperconnectivity has been observed in affective disorders and linked with excessive introspection, such as during rumination. The authors conclude that multiple brain networks contribute to the clinical phenotype of OCD - and there may need to be a greater focus on the role of self-referential processing in this disorder.

Drugs and suicide

Hypnotic drugs to aid sleep are generally recommended for short-term use. These include benzodiazepines acting on the GABA neurotransmitter system, and the more recently introduced ‘Z-drugs’ including zopiclone, zolpidem and zaleplone, which act on the same system but via a different mode of action from benzodiazepines. There has been concern about the misuse of these drugs for some time, but the levels of their misuse remain unknown. A web-based survey suggests that 7% of respondents had misused one or more of these medications - primarily to aid sleep (66%), cope with stress (37%) and get high (31%). Comparable figures for MDMA, cocaine and cannabis were 8%, 8% and 28%, which were very similar rates to the rates observed in other independent surveys. The majority of the drugs were prescribed by health professionals; the authors suggest that future initiatives to reduce misuse of these drugs will need to consider these access routes very carefully. One of the most adverse outcomes in psychiatric care is the suicide of a patient; this is arguably more devastating when the patient is a hospital in-patient, where there is an expectation of optimal risk management. Lukaschek and colleagues (pp. ) examined the determinants of 101 railway suicides and found that the strongest association was with a recent change of therapist, and where the therapeutic course had been noted as negative or unchanged. Less surprisingly, other strong associations were with suicidal ideation and polypharmacy treatment. The authors suggest that these factors could usefully be integrated into the risk management of patients with severe mental illness.

The Kaleidoscope section in the journal (pp. ) brings scientific colour relating to morality, aggression, gender differences and biomarkers into our view.