Our share tips made light of growing worries over the health of the global economy last week with all four of our investment portfolios sporting further gains when we carried out our mid-week review of progress.

The stand out performance came from the 2015 selections which sported a rise of 2.4 per cent to reach its highest overall valuation of the year, thanks largely to fresh support for Borders-based companies Produce Investments and Aberdeen's FirstGroup.

But we were almost as pleased to see the long-standing 2012 list also move towards fresh peaks with a more modest 1.2 per cent increase even though a majority of its constituents suffered from mark-downs as a result of profit taking.

Much of the credit was down to speciality chemical group Croda International which ended its first week in the portfolio with a remarkable 6.6 per cent gain after directors confirmed our expectations with news of strong growth in its business with skin care and health food specialists.

The performance of this débutante persuaded us to add another newcomer to the list on Wednesday morning when we made a notional purchase of shares in mental health group Cambian ahead of a results presentation towards the end of next month.

We have been a little slow off the mark with this recommendation with no fewer than six brokers already tipping the shares but followers say recent profit taking has now dried up and the share price could rise 10 per cent or more in short order.

A major attraction is government promises of increased investment in mental health while the group's current share prices is more than matched by the value of its freehold property portfolio of hospitals, schools and clinics.

We have set out usual stop loss level at which nervous investors should consider selling on any share price reversal.

Meantime, the disappointing 2014 portfolio perked up 1.5 per cent following support for engineering consultant Ricardo while the 2013 list gained 0.5 per cent in line with the overall stock market performance.